Intermittent overpressure of 20cmH 2 O was delivered to the external ear canal of guinea pigs. Histopathological changes in the middle and inner ear were examined under light microscope. Auditory evoked potential was recorded. The expression of atrial natriuretic peptide (ANP) was investigated by immunohistochemical SP method. We found that intermittent overpressure could minimize, but could not interrupt the development of endolymphatic hydrops,and could not improve hearing function. Expression of ANP decreased in the cochlear lateral wall after 2 week intermittent overpressure. The results suggested that intermittent overpressure of 20cmH 2 O was suitable in this experiment, and that ANP positive cells had an autocrine/paracrine function.

Objective To investigate the distribution and its significance of ? subunit isoforms of Na,K-ATPase in the inner ear of guinea pig.Methods The expression of ? subunit isoforms of Na,K-ATPase in labyrinth was studied immunocytochemically with the specific mouse antibodies against the ? 1?? 2 and ? 3 subunits of rat Na,K-ATPase.Results The expression of Na,K-ATPase ? subunit isoforms varied among different cell regions of the inner ear. The ? 1 subunit isoform was widely distributed in almost all regions, and was most abundant in the stria vascularis, sensory cells of the crista ampullaris and macula of the saccule, and the spiral ganglion cells, while the ? 2 and ? 3 subunit isoforms were present primarily in the spiral ganglion cells,the organ of Corti and stria vascularis.Conclusion The differential expression of Na,K-ATPase subunit isoforms presumably reflects different K + and Na + transport capacities among inner ear cells which, working in concert, serve to maintain homeostasis in inner ear.

Objective To investigate the cellular localization of aquaporins(AQPs) and its significance in various subregions of the cochlea and endolymphatic sac of guinea pig.Methods Adult guinea pigs were used and the expression patterns of AQP1,2,3 and 4 in the cochlea and endolymphatic sac were studied immunocytochemically. Paraffin- embedded sections were labeled with the specific polyclonal rabbit antibodies against the rat AQP1, 2, 3, and 4.Results In the cochlea, AQP1, 3, 4 were widely distributed in various subregions including the stria vascularis, spiral ligament, organ of Corti and spiral ganglion in the similar patterns except that AQP3 in the stria vascularis was weaker than AQP1 and AQP4. AQP2 was labeled only in the Reissner's membrane. In the endolymphatic sac, AQP1, AQP3 and AQP4 were strongly expressed in the epithelial cells and subepithelial cells with the exception that AQP3 was a little weaker than AQP1 and AQP4. No AQP2 immunoreactivity was detected in the endolymphatic sac.Conclusion Our immunohistochemical results suggest that different members of AQPs family in labyrinth may work in concert to regulate endolymph and to maintain homeostasis in the inner ear.

Objective To investigate the cellular localization of the neural precursor cell-expressed, developmentally downregulated isoforms(Nedd4), Nedd4- 1/2 and Nedd4- 2, and the serum glucocorticoid- inducible kinasel(SGK1) in various subregions of the rat cochlea. Methods The expression patterns of Nedd4-1/2, Nedd42 and SGK1 in the cochlea of rat were studied by immunohistochemistry with the specific polyclonal rabbit antibodies against the rat Nedd4-1/2, Nedd4-2 and SGK1. Results All three proteins were extensively expressed in various regions of the rat cochlea. They were found in the stria vascularis, spiral ligament, organ of Corti, spiral limbus, spiral ganglion and Reissner's membrane. Conclusion Our findings suggest that there exists a Na+ transport system in the cochlea consisting of SGK1, Nedd4 isoforms and ENaC, which may work in concert to transport Na+ and to maintain homeostasis in the inner ear as they do in other tight epithelia.

ObjectiveTo investigate the expression of asubunit isforms of Na,K-ATPase in stria vascularis of guinea pig, and the effect of gentamicin on it. MethodsThe expression of a subunit isoforms of Na, K-ATPase in stria vascualris of guinea pig and its change after gentamicin exposure were identified immunocytochemically using the specific mouse antibodies a gainst the α1 ,α2 and α3 subunits of rat Na,K-ATPase. ResultsAll marginal cells,intermediate cells and basal cells of stria vas cualris showed positive expression of α1 isoform and negative expression of α2 and α3 isoforms. The immunostaining of α1 isform was attenuated significantly after gentamicin esposture. ConclusionGentamicin significantly inhibits the expression of Na, K-ATPase α1 subunit isoform of the stria vascularis, sequentially inhibits the activity of Na,K-ATPase.

Objective To summarize the risk factors of head up tilt test (HUTT) in children with vasovagal syncope,and provide theoretical reference for the diagnosis of vasovagal syncope.Methods The total of 340 children with headache and syncope were included in the study,all the cases received HUTT,including basic tilt table test and sublingual nitroglycerin test.And they were divided into HUTT positive group and HUTT negative group according to the results.The clinical information of two groups was analyzed by multivariate Logistic regression to summarize risk factors.Results The frequency of syncope in HUTT positive group was 2.3 ± 1.1,significantly higher than that in HUTT negative group (0.7 ±0.2),chest tightness and blurred vision ratios were significandy higher than those in HUTT negative group (84/186,48/186 vs.34/154,23/154).Single factor analysis showed,older than 12 years old,female,blurred vision,with history and genetic history of syncope,numerous of syncope,chest tightness,fatigue were related factors as positive results for HUTT.Multivariate Logistic regression analysis showed,older than 12 years old,female,with history and genetic history of syncope were independent risk factors of positive HUTF.β was 0.744,1.126,1.312,0.514 respectively,95％ CI was 1.132-5.968,1.985-5.040,1.366-9.677,1.683-6.532 respectively.Conclusion Age,gender,family history,history of syncope have important significance to predict HUTT results.

Objective To study the effect of substance P (SP), calcitonin gene-related peptide (CGRP) on the blood flow and the function of endolymphatic sac (ES) in guinea pigs to clarify the pathogenesis of some inner ear diseases further.Methods The guinea pig model of superior cervical ganglion (SCG) resection was set up. The ESs of the model animals were stained by SP and CGRP immunocytochemically. The staining images were analysed by the computer. The ESBF was measured with the biologic microphere method.Results Compared with the control group, the staining of SP decreased sharply in the model group, however, the staining of CGRP remained unchanged. In the model animals, the ESBF was decreased either.Conclusion SP and CGRP could take part in the regulation of ESBF to affect the function of ES further.

Objective To investigate the effect of cisplatin ototoxicity on apoptosis of spiral ganglion cells(SGC), and relation between signal transportation of Caspase-3 and apoptosis of SGC.Methods Forty guinea pigs were randomly divided into 4 groups, and injected cisplatin (1, 2, 4 day group and control group). ABR and AERP (40 Hz Auditory Event Related Potentials) were tested every day after the injection, to find out the threshold changes of guinea pigs. Apoptosis was detected by terminal deoxynucleotidyl transferase(TdT)-mediated deoxyuridine triphosphate(d-UTP) nick end labeling method (TUNEL), and immunohistochemistry method was used to detect Caspase-3 p20 segment of SCGs.Results It was observed that the more cisplatin injected, the worse hearing guinea pigs got, and the damnification of threshold on 8KHz was significantly higher than that on 1 kHz. At the same time, TUNEL staining and the expression of Caspase-3p20 segment rose up gradually, and significant difference was observed compared with control group ( P

Objective To study the difference between the mRNA expressions of hyaluronan synthase in the epithelial cells of endolymphatic sac and renal tubules with the oligonucleotide probe. Methods The oligonucleotide probe of hyaluronan synthase was designed and synthesized, the mRNA expressions of hyaluronan synthase in the epithelial cells of endolymphatic sac and renal tubules were detected with hybridization in situ. Results mRNA of hyaluronan synthases were strongly expressed in some epithelial cells of endolymphatic sac and renal tubules. Conclusion It is confirmed that a dual regulatory system for hyaluronan /hyaluronidase exists in the epithelial cells of endolymphatic sac and renal tubules at the level of molecular biology.

Objective To evaluate which b value is the best to distinguish the glioma recurrence and radiation-induced brain injury using DWI when b value were at 1 000 s/mm2、3 000 s/mm2 and 5 000 s/mm2 respectively.Methods Retrospective analysis the DWI of 21 patients who suffered from glioma recurrence and radiation-induced brain injury obtained on a 3T MRI scanner.Results (1)All recurrent glioma (100%)showed hyper-intense signal,while most radiation-induced brain injury patients (80%)showed hypo-in-tense signal when b=5 000 s/mm2 .The sensitivity and specificity were high (100% and 80% respectively)when hyper-intense sig-nal was taken as a diagnostic point of glioma recurrence and radiation-induced brain injury.(2)The receiver operating characteristic (ROC)curve analysis suggested that the minimum ADC resulted in a highest sensitivity to differentiate glioma recurrence from radi-ation-induced brain injury when b=5 000 s/mm.Conclusion High b-value is more accurate to reflect cell density,and the minimum ADC is better to differentiate the glioma recurrence and radiation-induced brain injury when b=5 000 s/mm2 on DWI.