线粒体毒素诱导伴有眩晕的突发性耳聋模型的建立

目的建立一个突发性感音神经性耳聋(SSNHL)的动物模型,以研究其发病机制和治疗方法。方法49只雄性豚鼠根据给药浓度和听性脑干反应(ABR)测试时间分为7组,用浸有0.3、0.5 mol/L3-硝基丙酸(3-NP)或磷酸盐缓冲液(PBS)的明胶海绵分别放置于豚鼠左耳圆窗龛,作用30 min后取出。4%多聚甲醛加1%戊二醛行活体心脏灌注固定,耳蜗JB4包埋、切片后做光镜观察。结果所有暴露于3-NP的动物均表现中、重度听力减退至ABR反应消失。高剂量(0.5 mol/L 3-NP)组动物均出现快相指向健侧的自发性眼震和不同程度的姿势失衡等单侧前庭功能损伤的典型症状;低剂量(0.3 mol/L3-NP)组仅1只动物出现自发性眼震,2只动物出现姿势失衡。前庭症状在暴露后2 d内消失。所有实验组动物柯蒂氏器和支持细胞出现一过性水肿。暴露后12 h,螺旋神经节细胞胞浆和胞核内有空泡形成,第7天螺旋神经节细胞变性。结论经圆窗膜投放3-NP至内耳可以复制出SSNHL的临床症状,螺旋神经节细胞损伤是其最明显的病理改变。

Clinically relevant human temporal bone measurements using novel high-resolution cone-beam CT

Objective: To test the feasibility of measuring fine temporal bone structures using a newly established cone-beam computed tomography(CBCT)system.Materials and methods: Six formalin-fixed human cadaver temporal bones were imaged using a high-resolution CBCT system that has 900 frames and copper t aluminum filtration. Fine temporal bone structures, including those of the facial nerve canal and vestibular structures, were identified and measured.Results: The fine structures of the middle ear, including the tympanic membrane, tendon of the tensor tympani, cochleariform process of the semicanal of the tensor tympani, pyramidal eminence, footplate of the stapes, full path of the facial nerve within the temporal bone, supralabyrinthine space, semicircular canals, pathway of the subarcuate canal, and full path of the vestibular aqueduct, were clearly demonstrated. The vestibular aqueduct has a midpoint width of 0.4 ± 0.0 mm and opercular width of 0.5 ± 0.1 mm(mean ± SD). The length of the internal acoustic meatus was 10.6 ± 1.2 mm(mean ± SD), and the diameter of the internal acoustic meatus was 3.7 ± 0.3 mm(mean ± SD).Conclusion: This novel high-resolution CBCT system has potentially broad applications in the diagnosis of inner ear disease and in monitoring associated pathological changes, surgical planning, navigation for the ear surgery, and temporal bone training.

Dexamethasone does not affect endolymphatic hydrops(EH)in patients with Meniere's disease within 24 h,and intratympanic administration of gadolinium plus dexamethasone simplifies high-quality imaging of EH using a novel protocol of 7 min

Background:Intratympanic administration of gadolinium chelate allows for a better visualization of endolymphatic hydrops(EH)using MRI than intravenous injection and was recently further improved to facilitate high-quality imaging of EH in 7 min.The aim of the present study was to simplify the intratympanic administration protocol by mixing gadolinium chelate with therapeutic dexamethasone and to evaluate the effects of this mixture on the visualization of EH in MRI.Materials and methods:In an in vitro study,the potential impact of gadolinium-diethylenetriamine pentaacetic acid(Gd-DTPA)on the stability of dexamethasone was evaluated by analyzing dynamic changes in dexamethasone with high-performance liquid chromatography(HPLC)after mixing with GdDTPA.Ten patients with definite Meniere's disease(MD)were recruited to study the potential interference of dexamethasone on MRI visualization of EH,and 49 patients with MD were recruited to evaluate the effect of intratympanic injection of Gd-DTPA mixed with dexamethasone on MRI of EH using a 3T MR machine and a novel heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery reconstructed using a magnitude plus zero-filled interpolation(hT2FLAIR-MZFI)sequence.Results:The retention times and peak area of dexamethasone in HPLC were not modified by the addition of Gd-DTPA.EH grading in the cochlea and vestibule was not influenced in any ear by intratympanic injection of dexamethasone.Excellent inner ear images were obtained from all patients,and EHs with various grades were displayed.There were significant correlations between diagnosis and cochlear EH(p<0.01,Spearman's Rho),between diagnosis and vestibular EH(p<0.01,Spearman's Rho),and between cochlear and vestibular EH(p<0.01,Spearman's Rho).The distribution of Gd-DTPA plus dexamethasone negatively correlated with the grade of vestibular EH.Injury of the endolymph-perilymph barrier was detected in one cochlea and three vestibules of 59 inner ears with MD.Conclusions:Intratympanic administration of Gd-DTPA plus dexamethasone yielded high-quality MRI images of EH in patients with MD using a novel 7-min protocol and simplified the clinical application.Intratympanic administration of Gd-DTPA plus dexamethasone might be used to test its therapeutic effect in future work.

Label-free visualization of cholesteatoma in the mastoid and tympanic membrane using CARS microscopy

Objective:The present study aimed to evaluate the possibility of using coherent anti-Stokes Raman spectroscopy（CARS） microscopy to determine the specific molecular morphology of cholesteatoma by detecting the natural vibrational contrast of the chemical bonds without any staining.Materials and methods:Specimens from the mastoid and tympanic membrane with and without cholesteatoma were analyzed using CARS microscopy,two-photon excited fluorescence（TPEF） microscopy,and the second harmonic generation（SHG） microscopy.Results:In cholesteatoma tissues from the mastoid,a strong resonant signal at 2845 cm;was observed by CARS,which indicated the detection of the CH;hydro-carbon lipid bonds that do not generate visible signals at 2940 cm;suggestive of CH;bonds in amino acids.A strong resonant signal at 2940 cm;appeared in an area of the same specimen,which also generated abundant signals by TPEF and SHG microscopy at 817 nm,which was suggestive of collagen.In the tympanic membrane specimen with cholesteatoma,a strong resonant signal with corrugated morphology was detected,which indicated the presence of lipids.A strong signal was detected in the tympanic membrane with chronic otitis media using TPEF/SHG at 817 nm,which indicated collagen enrichment.The CARS and TPEF/SHG images were in accordance with the histology results.Conclusion:These results suggest the need to develop a novel CARS microendoscope that can be used in combination with TPEF/SHG to distinguish cholesteatoma from inflammatory tissues.

Is Meniere Disease Caused by a Pathological Immune Response?

The etiology of Meniere disease (MD) is unknown. Among the several factors which can provoke the disease is a pathological immune response. Objective: To investigate whether MD is due to a pathological immune reaction. Materials and methods: Immunological assay (IA) was evaluated in a consecutive study on 159 patients with MD (mean age 47.8. years) and the results compared with those from 26 patients operated on because of vestibular schwannoma (VS, mean age 54.1 years), who served as a control group. In cases of MD, transtympanic electrocochleography (ECoG) and hearing threshold were measured. Results: The average hearing level (HL) in the affected ears of patients with MD was 30 dB. Evidence of abnormal plasma protein pattern was found in 127 MD patients (80%). Elevations were found in β1-globulin (54.5%), β2-globulin (26.5%), a2-globulin (34.3%), g-globulin (17.3%), complement (CH100, 36.4%) and antinuclear antibodies (ANA, 43.4%). The onset of the disease did not correlate with the level of the plasma protein neither with the level of IgG titers. Conclusion: Elevated certain plasma proteins in patients with Meniere’s disease could be a sign that Meniere’s disease is a consequence of pathological immune reaction.

Cochlear and Vestibular Functional Study in Patients with Sudden Deafness and Lyme Disease

Lyme disease (LD) and idiopathic sudden deafness (ISD) are supposed to be different diseases with different aetiologies. In an attempt to confirm this assumption, 10 patients with confirmed LD and 12 patients with ISD were consecutively included into the study. Further to the laboratory and audio logical investigation, a low frequency sound (LFS) stimulation on posturography was performed and evaluated. Patients with ISD had higher pure tone average (PTA) than patients with LD (PTA ISD/LD was 72 decibel (dB)/23 dB). There was no difference of vertigo between LD and ISD patients. Patients with ISD have more body sway velocity during the first stimulation than patients with LD. We conclude that the cochlear organ is more affected in ISD patients than in patients with LD. However, the vestibular organ seems to be affected in both diseases. ISD and LD are two different disease entities with different aetiologies but with common otological clinical signs.

MEFV,IRF8,ADA,PEPD,and NBAS gene variants and elevated serum cytokines in a patient with unilateral sporadic Meniere's disease and vascular congestion over the endolymphatic sac

The etiology and underlying mechanism of Meniere's disease(MD)development are still unknown,although inflammation and autoimmunity have been implicated as underlying mechanisms.The human endolymphatic sac(ES)has been reported to have innate and adaptive immune capacity in local immune reactions.In vivo demonstration of inflammation of the ES in patients with MD is missing in the literature.We report the case of a 47-year-old female patient diagnosed with unilateral MD with genetic variants and cytokine markers indicating inflammation and vascular congestion of the ES.Endolymphatic hydrops in the right cochlea(grade 2)and vestibulum(grade 3)were detected using MRI.She carried heterozygous variants in MEFV(c.442G>C),IRF8(c.1157G>T),ADA(c.445C>T),PEPD(c.151G>A),NBAS(c.4049T>C),CSF2RB(c.2222C>T),HPS6(c.277G>T),IL2RB(c.1109C>T),IL12RB1(c.1384G>T),IL17RC(c.260_271del GCAAGAGC TGGG),LIG1(c.746G>A),RAG1(c.650C>A),and SLX4(c.1258G>C,c.5072A>G).In the serum,the levels of granulocyte colony-stimulating factor(G-CSF),macrophage inflammatory protein 1a,and IL7 were significantly elevated,and the level of IL2Ra was reduced.Intratympanic administration of dexamethasone temporarily alleviated her hearing loss.Her vertigo was significantly relieved but remained slight after ES administration of corticosteroids.