Objective To investigate whether cochlear hair cells occur apoptosis following kanamycin treatment in guinea pigs. Methods It was comprised of two groups of six animals each. Experiment group and control group were subjected to administration of kanamycin,im,400 mg?kg -1 ?d -1 ,and saline respectively for successive 10 days. One week later, animals were sacrificed. Left cochlea and right cochlea were taken for cochlea preparation and cochlea section respectively. Apoptosis was detected by terminal deoxynucleotidyl transferase(TdT)-mediated deoxyuridine triphosphate(d-UTP) nick end-labling(TUNEL) method.Results Apoptosis was present in cochlear hair cells, supporting cells as well as marginal cells of stria vascularis except for the spiral ganglion cells in kanamycin treatment guinea pigs. No apoptosis was detected in control animals. Conclusion Apoptosis of cochlear cells play important role in kanamycin ototoxicity.

BACKGROUND:Tetramethylpyrazine (TMP) can inhibit the expression of vascular endothelial growth factor (VEGF), but it is uncertain that TMP inhibit the growth and proliferation of HL-60 leukemic cells induced by VEGF.OBJECTIVE:To observe the effect of TMP on the proliferation of HL-60 leukemic cells induced by VEGF.DESIGN:Repetitive measurement and observation.SETTING:School of Medicine, Wuhan University of Science and Technology.MATERIALS:The experiment was carried out in the Molecular Biology Laboratory Center, School of Medicine, Wuhan University of Science and Technology from March to June in 2007. Human leukemic cell line HL-60 cells were purchased from Shanghai Institute of Cell Biology. TMP hydrochloride injection was produced by Wuxi Seventh Pharmaceutical Products Limited (Lot number:011014), protamine sulfate injection was produced by Shanghai First Biochemical Pharmaceuticals (Batch number:010302), and immunohistochemistry kit was purchased from Boster company.METHODS:①Human leukemic cell line HL-60 cells at log phase were used for the experiments. Cells were treated with 100 μg/L VEGF, and then TMP at final concentrations of 1.5, 15, 150 mg/L was added into culture medium. While the cells in medium without TMP were taken as blank control group, and the cells in medium with 20 mg/L protamine as positive control group. Meanwhile cells without treatment of VEGF were served as VEGF control group. After cells were incubated for 48 hours, the growth inhibiting rate of HL-60 cells was detected by MTT assay.②After HL-60 cells were treated with TMP at the final concentrations of 1.5, 15, 150 mg/L for 24 hours, the protein expression of VEGF in HL-60 cells was examined by SP immunohistochemistry.MAIN OUTCOME MEASURES:①Growth inhibiting rate of HL-60 cells.②Protein expression of VEGF.RESULTS:①Growth inhibiting rate of HL-60 cells:After HL-60 cells induced by VEGF were treated with 15 and 150 mg/L TMP, the absorbance value was significantly lower than that in VEGF control group (P < 0.05).②Protein expression of VEGF:After HL-60 cells were treated with TMP for 24 hours, the protein expression of VEGF was down-regulated with increasing TMP concentration in a dependent manner. Significant differences were observed in the protein expression of VEGF between cells treated by TMP and the controls (P < 0.01).CONCLUSION:shRNA, by targeting hTERT mRNA, has no noticeable influence on growth and proliferation of hMSCs, and might be safe for the somatic cells which are normal but do not express hTERT.

Objective: Surfactant protein A (SP-A) is protein that appears to play an important role in mammalian first-line host defense. The objective of this study was to immunolocalize SP-A in human sinonasal tissue. Method:Eleven cases of allergic rhinitis, fifteen cases of polyp and seven cases of normal middle turbinate were studied with immunohistochemistry and immunofluorescence method to detect the expression of SP-A. Result:The expression of SP-A in allergic rhinitis and polyp were dramatically higher than that in controls(P<0.05), and there was no remarkable difference in the expression of SP-A between allergic rhinitis and polyp(P>0.05). The result demonstrated that SP-A was positivly correlated with eosinophils within the basement membrane of epitheli-um(R=0.81,0.55). In the result of immunofluorescence, there was significantly higher expression SP-A in nasal mucosa of allergic rhinitis and nasal polyp than that in control group(P<0.05). Conclusion:SP-A is likely to play key roles in the inflammatory reaction process of allergic rhinitis and polyp. Its secretion in the upper airway indicates that future studies may allow manipulation of this protein and development of novel treatments for sinonasal pathology.

Objective To investigate telomerase reverse transcriptase (TERT ) and acticator protein 1(AP -1) expression and it's corroloation in laryngeal carcinoma tissue .Methods 24 human laryngeal carcinoma tissue were analised by RT -PCR and quantum -dot based immunofluorescence assay for the expression of TERT and AP -1 . Results The expression of TERT mRNA and the expression of c -Fos ,c-Jun in laryngeal carcinoma were postive‐ly related .Correlation coefficient was 0 .574 and 0 .809 ,respectivly(P<0 .01) .Conclusion TERT and AP -1 were expressed at high levels and positively correlated in human laryngeal carcinoma .

Objective To observe the effects of long term injection sodium salicylate on the auditory brain-stem response(ABR)and expression of glutamic acid decarboxylase -67(GAD67) in rat inferior colliculus .Methods Eighteen healthy Wistar rats were randomly divided into three groups :the sodium salicylate group (intramuscular injection of 10% sodium salicylate ,175 mg/kg ,twice daliy for 28 days) ,the saline group (intramuscular injection with saline on same does at the same time) ,the control group (without any treatment) .The rats received ABR after modeling ,then were decapitated and inferior colliculus tissues were stripped .Western blot was used to study the dif-ferent expression of GAD67 protein levels in the three groups .Results Compared with the saline group and control group ,ABR thresholds of the sodium salicylate group were significantly elevated and latency of wave Ⅲ was aslo sig-nificantly prolonged(P<0 .01) ,while there was no significant difference between the saline group and the control group(P>0 .05) .The inferior colliculus GAD67 protein expression level of sodium salicylate group was significantly higher than the saline group and control group(P<0 .01) ,while there was no significant difference between the saline group and the control group(P>0 .05) .Conclusion Long term injection of sodium salicylate can cause a change in the inferior colliculus of GAD67 protein expression and the up regulation of GAD67 expression may occur as a com-pensatory response to increase inhibiting effect .The change of GAD67 protein expression is likely as a compensatory and regulatory mechanisms for sodium salicylate ototoxicity .

OBJECTIVE To observe the changes of GABA and Glu in rat inferior colliculus following unilateral cochlear ablation and explore the function and significance of GABA and Glu in reorganization of auditory center after deafferentation. METHODS Twenty-five Sprangue Dawley (SD) rats were divided randomly into 5 groups. The content of GABA and Glu were measured by 835-50 type Amino Acid Automatism Analyzer and compared at 1 week, 2 week and 1 month after unilateral cochlear ablation respectively. RESULTS Compared with sham operated groups, the content levels of GABA decreased (from 78.00?7.50 to 51.65?10.36, about decreasing 33.6 %)1 week after unilateral cochlear ablation and there was a significant difference in GABA levels between 2 groups(P0.05). CONCLUSION The dynamic change of GABA and Glu in rat inferior colliculus reflected the neuronal activity, which implied both GABA and Glu may play an important role in reorganization of auditory center after unilateral cochlea ablation.

OBJECTIVE To investigate the influence of short hairpin RNA targeting human telomerase reverse transcriptase(hTERT)on inhibition of telomerase activity and on expression of protein c-myc in nasopharyngeal carcinoma cells. METHODS Plasmid shRNA1 containing fluorescein gene and hTERT cDNA sequences were synthesized. Cells were transfected with plasmid shRNA1. The cell viability was examined using the MTT assay. The activity of telomerase was tested by polymerase chain reaction telomeric repeat amplification protocol- enzyme-linked immunosorbent assay (PCR-TRAP- ELISA),protein c-myc expression was tested by western blot. RESULTS It was observed that treatment with pshRNA1 in the presence of a valid transfection reagent could significantly reduce telomerase activity and the expression of protein of c-myc. CONCLUSION Inhibition of telomerase activity or expression of hTERT mRNA in nasopharyngeal carcinoma cells could inhibit cells proliferation and reduce the expression of protein of c-myc.

OBJECTIVE To study the significance by analyzing the expression of human protection of telomeres1(POT1)and telomeric repeatbinding factor-2(TRF2)in the tissues of laryngneal squamous cell carcinoma(LSCC)and in polyp of vocal cord tissues. METHODS The expression of POT1 and TRF2 in 20 tumor samples and 19 polyp of vocal cord were determined by the indirect immunofluorescence method. The results were scored and analyzed statistically. RESULTS The positive expression rates of POT1 and TRF2 in tumor samples was 65.00% and 70.00% respectively. There were no positive expression of POT1 and TRF2 in polyp of vocal cord. The positive expression of POT1 was higher in poorly differentiated laryngeal carcinoma than that in well-differentiated and moderately differentiated laryngeal carcinoma(Chi-square test with contingency table, P0.05). CONCLUSION The expression of POT1 and TRF2 in laryngneal squamous cell carcinoma were remarkable, POT1 and TRF2 may play a critical role in tumorigenesis of laryngneal squamous cell carcinoma. There was statistical significant difference for degrees of POT1 expression in different tumor histological grades.

To study the effects of ouabain on the inner ear glial cells, and to lay the foundation for the study of stem cell transplantation in the treatment of sensorineural hearing loss.Methods Sixty adult female SPF grade CBA / J mice were randomly divided into experimental group and control group, with 30 mice in each group.Animals in the experimental group received 3mM ouabain via the round window membrane, while mice in control group received normal saline.The mice were sacrificed at 7 days, 14 days and 30 days after the administration,respectively.Immunofluorescence histochemical staining was used to detect the inner ear glial cells in spiral ganglion.Results Some inner ear glial cells survived in the spiral ganglion of the experimental group, while with decreased numbers and disorganized structure compared to those of in the control group.Comparing to those of in the control group, the number and density of inner ear glial cells in the experimental group were significantly decreased from 7 days afterouabain administration,further decreased at 14 days and reduced to the lowest at 30 days after ouabain administration, the differences between the 2 groups were statistically significant (P < 0.05).Among the experimental group, the number of inner ear glial cells at 30 days was significantly decreased when compared to those of at 7 days and 14 days, respectively.Conclusion Application of ouabain to mouse inner ear via the round window membrane leads to an acute and progressive direct damage to the inner ear glial cells in the spiral ganglion.

This study was designed to disclose the specific changes of distortion product otoacoustic emission (DPOAE), including DP-gram and I/O-gram in guinea pigs treated with GM for 10 and 17 days. Forty guinea pigs were divided into four groups:group I (treated with GM for 10 days), group II (treated with normal saline for 10 days), group III (treated with GM for 17 days), group IV (treated with normal saline for 17 days). DPOAE including DP-gram and DP-I/O was recorded by use of CELESTA 503 Cochlear Emission Analysis and the out hair cell loss was numerated. (1) The amplitude in group I showed significant reduction at frequencies of 4, 6, 8 kHz. There were significant differences, compared to group II (t=2.52, 1.92, 2.10, P<0.05). The amplitude in group III also decreased at frequencies of 3, 4, 6, 8 kHz. There were also significant differences compared to group IV (t=3.27, 2.81, 2.92, 3.13, P<0.01). The amplitude of DP-I/O in group I and group III at different frequencies and stimulus levels showed reduction. (2) At the level L1 <60 dB SPL, the stimulus levels to elicit a 0 dB response in group I and group III were higher than those in corresponding control groups, respectively. (3) The mean of threshold shift was 5.0+/-3.8 dB in group I and 25.0+/-6 dB in group III at 8 kHz frequency. (4) The out hair cell loss was 22.16% in group I and 48.36% in group III, both showed significant difference as compared to controls, respectively (P<0.01). The employment of DPOAE can be a useful tool in monitoring ototoxicity of GM for its sensitivity and specificity in guinea pigs treated with GM. The changes in DPOAE were consistent with those in histology.
Acoustic Stimulation ; methods ; Animals ; Cochlea ; drug effects ; physiopathology ; Female ; Gentamicins ; administration & dosage ; adverse effects ; Guinea Pigs ; Hair Cells, Auditory, Outer ; drug effects ; pathology ; Male ; Otoacoustic Emissions, Spontaneous ; physiology ; Perceptual Distortion ; drug effects ; physiology ; Random Allocation