Objective To investigate the effect of histone deacetylase 2(HDAC2) expression by aminophylline on glucocorticoid sensitivity of guinea pigs with lipopolysaccharide -induced sudden hearing loss .Methods Fifty guinea pigs were randomly divided into five groups :control/artificial perilymph(AP) group (n=10) in which both the ears were administrated 5μl sterile artificial perilymph fluid by means of drilling the scala tympani of the cochle‐ar basal turn ;whereas 5 μl of 5 mg/ml LPS was transferred into the cochlea of both the ears of other groups in the same way ,which were model(LPS) group(n=10) ,lipopolysaccharide+ dexamethasone(LPS+ DEX) group(n=10) ,lipopolysaccharide+ aminophylline(LPS+ AMI) group(n= 10) ,and lipopolysaccharide+ dexamethasone+aminophylline(LPS+DEX+AMI) group(n=10) .Guinea pigs with normal hearing tested by auditory brain stem response (ABR) before treatment were included in this study .ABRs were recorded in all guinea pigs 48 hours after surgery .The immunofluorescence staining was used to detect for the HDAC2 in the inner ear .The HDAC2 levels in the cochlea of guinea pigs were detected by ELISA test .Results ABR results showsed that hearing loss in AP group was mild ,the threshold shifts were less than 10 dB at 4 kHz ,8 kHz ,16 kHz frequencies ,at 32 kHz the threshold shift was 11 .50 dB ,respectively .However ,the hearing loss was obvious in LPS group ,especially at the high frequency (the threshold shift was 60 .75 ± 6 .02 dB SPL) .Compared to AP group ,hearing loss in LPS group was statistically significant at all frequencies (P<0 .01) .The hearing improvement was obvious at frequeniies of 16 kHz and 32 kHz in group of LPS+DEX and LPS+AMI (P<0 .05) .The LPS+DEX+ AMI treatment for LPS -induced acute hearing loss was the most remarkable at all frequencies compared with glucocorticoid or aminophylline treatment alone ,especially at 16 kHz (P<0 .05) .The immunofluorescence staining showed positive expression of HDAC2 in the cochlea in the inner and outer hair cells ,stria vascularis ,spiral ganglion and spiral ligament .The correlation analysis showed negative correlations between the expression of HDAC2 and threshold shift of ABR at 8 kHz ,16 kHz ,and 32 kHz (P<0 .05) .Conclusion It is effective for dexamethasone and aminophylline treatment in induced hearing loss in guinea pigs .Aminophylline can elevate HDAC2 expression and improve the effect of glu‐cocorticoid .In conclusion ,HDAC2 plays a critical role in restoring glucocorticoid sensitivity in the inner ear .

Objective To find an optimum fixed position on the wire linked to floating mass transducer(FMT)by measuring FMT vibration with laser doppler vibrometer(LDV).Methods Fixing three points on the wire linked with FMT:10 mm,5 mm away from the FMT and the end of the wire.The vibration intensity of the FMT was measured with LDV when the FMT received continuous pure-tone stimuli at 100 and 80 dB SPL,respectively.Results The vibration amplitude of FMT was the highest at 1.5 and 2 kHz,and the lowest at 0.25 and 8 kHz when the FMT received pure-tone stimuli from 0.25 to 8 kHz.When the wire was fixed at/above different points,the FMT produced similar positive vibration amplitude.Conclusion The wire is fixed linked with FMT at/above three different points,FMT produces similar vibration amplitude when receiving pure tone stimuli.

Objective To establish an otitis media with effusion model in rat,and provide a pure physical approach of animal model for researching the otitis media with effusion.Methods Twenty-four clean grade male SD rats were selected.Only the right ears were used for the model group,the contralateral ears were used as the control group.The animal model of otitis media with effusion was established by blocking eustachian tube with cork stopper through the right side mandible,the hearing was evaluated by ABR and tympanogram configurations,the pathologic changes of middle ear and eustachian tube mucous membrane were examined by light microscopy.Results Twenty out of 24 ears of rats' of hearing threshold increased from 34.25?5.45 dB to 57.63?5.46 dB (P

Objective To evaluate expression of HDAC2 in peripheral blood mononuclear cells(PBMCs)from glucocorticoid-resistant versus glucocorticoid-sensitive patients with sudden sensorineural hearing loss and identi-ty the relationship between the level of HDAC2 and glucocorticoid insensitivity.Methods PBMCs were collected from10 patients with deviation of nasal septum (control group)and 20 sudden sensorineural hearing loss patients be-fore and after intratympanic methylprednisolone for 10 days.We divided the SSNHL patients into 2 groups (GC sensitive group and GC insensitive group)according to their hearing recovery.Real time PCR and HDAC2 Assay Kit were used to detect the expression level of HDAC2 mRNA and HDAC2 activity in PBMCs.The data were analyzed with SPSS 17.0 software.ResuIts Before intratympanic methylprednisolone,the level of HDAC2 activity were sig-nificantly depressed in SSNHL patients,while the HDAC2 mRNA expressing much higher than the control group. The expression level of HDAC2 mRNA increased significantly after intratympanic methylprednisolone.The HDAC2 activity in GC sensitive group increased significantly.ConcIusion Knockdown of HDAC2 expression induces corti-costeroid in-sensitivity.Glucocorticoids can increase the expression of HDAC2 mRNA.HDAC2 activity can be down-regulated by post-translational modifications.

Objective The goal of the present study was to determine the effects of different location perfora-tions on the middle ear transfer functions by measuring the velocity and pattern of the tympanic membrane vibration in guinea pigs with intact and perforated TM .Methods A laser Doppler vibrometer was used to measure the sound transmission properties on the movement of the tympanic membrane on 6 fresh temporal bones of guinea pigs in the frequency range of 0 .5~8 kHz at 90 dB SPL .The velocity was measured at three points on the manubrium before and after a different location perforation was made with a 20-gauge needle(1 .1 mm diameter) .The locations of the perforations were in anterior -inferior quadrants of left ears and in posterior -inferior quadrants of right ears .And the velocity was measured from 6 poins with the intact tympanic membrane .Results The highest velocities were re-corded at the site of inferior umbo throughout the frequency range .The manubrium vibration velocity losses were noted in the perforated ears below 1 .5 kHz ,the velocity losses were smaller above 1 .5 kHz ,and the maximum ve-locity loss was about 7 dB at 500 Hz with the posterior -inferior quadrant perforation .Although there was a trend for anterior-inferior perforations to show a slighter loss than posterior -inferior perforations in velocity below 1 .5 kHz ,no statistical differences in velocity loss were found between different perforations .The average ratio of short process velocity to umbo velocity at all frequencies was approximately 0 .5 ,and the ratios were found no systematic differences before and after perforation at almost all frequencies from different perforations .Conclusion The manu-brium vibration velocity losses from TM perforation are frequency -dependent and the largest losses occur at the lowest sound frequencies .Different sites of small perforation have not any important effects on middle ear sound transmission .

Objective To investigate the efficacy of intratympanic methylprednisolone perfusion (IMP) for the treatment of sudden sensorineural hearing loss (SSNHL ) which failed to be fully responsive to conventional treatment .Methods The hearing outcomes of 87 patients with unilateral SSNHL were retrospectively analyzed .All of the patients received IMP after not fully responsive to conventional treatment of varying periods of time .They were hospitalized in our department between January 2008 and December 2012 and were followed up for at least one year to exclude recurrent hearing loss .Results The effective rate was 66 .67% and the mean PTA improvement was (18 .53 ± 13 .54)dB of the patients with the time interval between onset of symptoms and IMP within 15 days , 21 .21% and (5 .92 ± 15 .18)dB of the patients with the interval between 16 and 30 days ,4 .76% and (3 .69 ± 7 .00) dB of the patients with the interval more than 30 days respectively .The significant difference in the effective rates were compared among the three groups(χ2 =25 .91 ,P<0 .01) .Regarding to the PTA improvement ,the group with interval within 15 days was better than the other two groups(F=11 .182 ,P<0 .01) .A total of 30 cases acquired more than 15 dB hearing gain after IMP .One of them was hearing loss in low frequencies and the other 29 cases were hearing loss at all frequencies .The mean hearing gains of the 29 cases in 0 .25 kHz ,0 .5 kHz ,1 kHz ,2 kHz , 4 kHz and 8 kHz were 35 .17 ± 18 .15 dB ,35 .38 ± 15 .90 dB ,31 .28 ± 19 .74 dB ,21 .31 ± 17 .34 dB ,14 .97 ± 16 .00 dB and 13 .80 ± 16 .35 dB ,respectively .The mean hearing gains at lower three frequencies (0 .25~1 kHz)were better than those at higher three frequencies (2 k~8 kHz)(F=9 .494 ,P<0 .01) .Conclusion Receiving IMP earlier might help to acquire better hearing gain for the patients with SSNHL after not fully responsive to conventional treat‐ments .The hearing gains at the lower frequencies were better than those at the higher frequencies after IMP .

OBJECTIVE: To study the relative factors of the changes of preoperative and postoperative bone conduction thresholds in chronic suppurative otitis media. METHOD: The preoperative and postoperative bone conduction thresholds were prospectively investigated in 45 patients with unilateral chronic suppurative otitis media after tympanoplasty. Preoperatively (within 3 days before operation), 10 dB or more depression of bone conduction threshold at least in consecutive 2 frequencies between 0.25 kHz and 8.00 kHz was considered to be significant. Similarly in the postoperative period (3 months after operation), 10 dB or more improvement or impairment of bone conduction threshold at least in consecutive 2 frequencies between 0.25 kHz and 8.00 kHz was regarded as significant. RESULT: Thirty-five of 45 cases (77.8%) were found to have depressed bone conduction threshold before operation, 6 of 35 cases (17.1%) had improved bone conduction thresholds and 5 of 45 cases (11.1%) had depressed bone conduction thresholds after tympanoplasty. CONCLUSION In cases with chronic suppurative otitis media, successful results could be achieved after tympanoplasty disregarding air conduction threshold, the air-bone gap and deteriorated bone conduction threshold. Impairment of bone conduction thresholds could be induced by chronic suppurative otitis media itself and could also be induced by touching the ossicle chain crudely and by the noise of drilling during the operation.
Adolescent ; Adult ; Auditory Threshold ; Bone Conduction ; Chronic Disease ; Female ; Humans ; Male ; Middle Aged ; Otitis Media, Suppurative ; physiopathology ; surgery ; Postoperative Period ; Tympanoplasty ; Young Adult

OBJECTIVE: To evaluate the effect of over-under myringoplasty technique on repairing tympanic membrane perforation regarding with the rate of perforation closure, the frequency of postoperative complications occurrence and the level of hearing improvement. METHOD: In this retrospective study, a total of 74 patients (77 ears) underwent myringoplasty and had been followed up for over 6 months, which was performed by means of the underlay technique in 44 patients (45 ears) and over-under technique in 30 patients (32 ears) from Jan 2002 to Jan 2007. In the underlay group, the grafted membrane was placed medial to the remaining drum and the manubrium of the malleus. In the over-under group, the grafted membrane was placed under the remaining drum and over the malleus. Comparatively evaluate the effect of the underlay technique and that of the over-underlay technique on repairing tympanic membrane perforation. RESULT: The rate of perforation closure and hearing improvement in the underlay group of 45 ears was 89.0% and 57.5% respectively, while that in the over-under group of 32 ears were 87.5% and 71.9% respectively. The air-bone gap decreased by 4.9 dB in the underlay group, while it decreased by 9.7 dB in over-under group. After more than 6 months of following-up, the frequency of postoperative atelectasis of the underlay group and the over-under group was 17.8% and 6.25% respectively. Meanwhile, the frequency of postoperative reperforation of these two groups was 5.9% and 6.25% respectively. Blunting of the anterior angle of the tympanic membrane occurred in 3 ears in the over-under group. Lateralization of the graft was not observed in either group. CONCLUSION Over-under technique could reduce the occurrence of the adhesions between the grafted membrane and promontorium tympani by placing the grafted membrane between the remaining drum and the malleus. Furthermore, the level of hearing improvement in over-under group was higher than that in underlay group. Over-under myringoplasty is a more effective technique as comparison to underlay myringoplasty for repairing middle to large tympanic membrane perforations.
Adolescent ; Adult ; Hearing ; Humans ; Middle Aged ; Myringoplasty ; methods ; Retrospective Studies ; Treatment Outcome ; Tympanic Membrane ; surgery ; Young Adult

OBJECTIVE: To study the efficacies of intratympanic prednisolone and dexamethasone injection for the subjective tinnitus. METHOD: A prospective study was designed to compare the efficacies of intratympanic prednisolone injection, intratympanic dexamethasone injection and carbamazepine by oral administration for subjective tinnitus. Seventy-three cases (78 ears) with subjective tinnitus for more than one month and treated by conservative therapy (such as vasodilator agent, Vitamin B, etc. by oral intake. ) were involved. The patients were randomized into 3 groups. Thirty-four cases (35 ears) were included in prednisolone group, 18 cases (18 ears) in dexamethasone group with intratympanic injection of prednisolone or dexamethasone, and 21 cases (25 ears) in carbamazepine group as a control group with oral administration of carbamazepine. All of the cases in intratympanic perfusion group were injected twice in the first week, then once a week consecutively. The patients were acupunctured 4-5 times in the whole course of treatment. All of the cases accepted Betahistine Mesylate, Mecobalamin and Vitamin B1 by oral intake at the same time. Pure tone audiogram and tinnitus matching were tested before the treatment immediately after the course of treatment, and were tested again after half a year's following up. RESULT: All of the cases accepted the whole treatment and were followed up for half a year successfully. The effective rate of the prednisolone group, dexamethasone group and the carbamazepine group was 48.6%, 33.3%, 44.0%, respectively; the control rate half a year after the treatment was 45.7%, 27.8%, 36.0%, respectively. There was no statistically significant difference in the effective rate and control rate between intratympanic perfusion group and carbamazepine group. There is a statistically significant difference both in the effective rate and the control rate between the prednisolone group and the dexamethasone group. Prednisolone may be better than dexamethasone in intratympanic perfusion for subjective tinnitus. CONCLUSION Intratympanic steroid injection has a positive effect on subjective tinnitus and may be considered to be an alternative treatment to subjective tinnitus.
Adolescent ; Adult ; Aged ; Carbamazepine ; administration & dosage ; therapeutic use ; Dexamethasone ; administration & dosage ; therapeutic use ; Drug Administration Routes ; Female ; Humans ; Male ; Middle Aged ; Prednisolone ; administration & dosage ; therapeutic use ; Prospective Studies ; Tinnitus ; drug therapy ; Treatment Outcome ; Young Adult

OBJECTIVES: To investigate glucocorticoid receptor (GR) and histone deacetylase 2 (HDAC2) gene expression and protein levels in peripheral blood mononuclear cells (PBMCs) of patients with severe or profound sudden sensorineural hearing loss (SSNHL) and to explore the roles of GRs and HDAC2 in glucocorticoid (GC) insensitivity. METHODS: Fifty-five severe or profound SSNHL patients were enrolled in the study. According to hearing improvement after GC treatment, patients were assigned into two groups: GC-sensitive and GC-resistant. A normal reference group included 20 healthy volunteers without hearing loss. Quantitative real-time polymerase chain reaction and Western blot analyses were used to detect the relative expression of GRα, GRβ, and HDAC2 in PBMCs at the mRNA and protein levels. RESULTS: The protein levels of GRs and HDAC2 in PBMCs of SSNHL patients were lower than the normal reference values before GC treatment. Compared with the GC-resistant group, both the mRNA and protein levels of GRα and HDAC2 were significantly increased in the GC-sensitive group after GC treatment. CONCLUSION: A lack of GRα and HDAC2 induction following steroid treatment in GC-resistant SSNHL patients may play a fundamental mechanistic role in GC insensitivity. Response of GRα and HDAC2 to steroid treatment may, thus, predict the prognosis of hearing improvement in SSNHL patients.
Blotting, Western ; Gene Expression ; Healthy Volunteers ; Hearing ; Hearing Loss ; Hearing Loss, Sensorineural ; Histone Deacetylase 2 ; Histone Deacetylases ; Histones ; Humans ; Prognosis ; Real-Time Polymerase Chain Reaction ; Receptors, Glucocorticoid ; Reference Values ; RNA, Messenger