Evaluation of Sustained-Release Steroid Hydrogels in a Guinea Pig Model for Noise-Induced Hearing Loss

2018 ◽  
Vol 23 (2) ◽  
pp. 73-81 ◽  
Author(s):  
Chengjing Zhu ◽  
Julia Clara Gausterer ◽  
Hanna Schöpper ◽  
Michael Nieratschker ◽  
Nodir Saidov ◽  
...  

The otoprotective effects of thermoreversible poloxamer 407 hydrogels containing dexamethasone or triamcinolone acetonide were evaluated in an animal model of noise-induced hearing loss. Seven days after noise exposure, hearing threshold shifts at 16 kHz were significantly reduced in the 6% dexamethasone group (p < 0.05). Even though no significant differences in hair cell counts were found, histological analysis revealed a significantly higher spiral ganglion cell density in the first turn of the cochlea in this group (p < 0.05). No otoprotective effects were observed after the application of the triamcinolone acetonide hydrogels. As the findings of this study indicate potential otoprotective effects of sustained topical dexamethasone delivery in the setting of noise-induced hearing loss, this strategy merits further evaluation.

2014 ◽  
Vol 9 (1) ◽  
pp. 19-24
Author(s):  
MR Alam ◽  
MA Wahab ◽  
MM Rahman ◽  
AKM Asaduzzaman ◽  
MAS Al-Azad ◽  
...  

Introduction: Noise Induced Hearing Loss (NIHL) is an occupational health hazard linked with noise exposure of more than 85 dB. Aircraft noise and other occupational noise exposure cause military aviators more susceptible to NIHL than commercial jet pilots. Aim: To find out the prevalence of noise induced hearing loss among different military aircrew population with special emphasis on identifying the associated risk factors. Materials and Methods: This cross sectional study was conducted on Kuwait Air force pilots those who came for annual medical checkup from July 2010 to July 2012. Audiometry of all subjects was done by ENT specialist and necessary data were collected by structured questionnaires. All data were analyzed by SPSS (Statistical Package for the Social Sciences) version 17.0 Results: Out of 221 aircrew 32 (14.48%) developed NIHL. Hearing loss was mild to moderate and predominately at high frequencies. Most affected group was helicopter pilots. Pilots of more than 40 years of age and those who had more than 1000 flying hours had mean hearing threshold more than other groups. The right ear was affected in majority of cases than left ear. Conclusion: Noise exposure to aircrew is inevitable so hearing loss prevention strategies might play a pivotal role to save aircrew hearing. Active surveillance of hearing protection practices might have beneficiary effect. Steps can be taken for early detection of NIHL and hearing conservation program. DOI: http://dx.doi.org/10.3329/jafmc.v9i1.18721 Journal of Armed Forces Medical College Bangladesh Vol.9(1) 2013: 19-24


1989 ◽  
Vol 98 (6) ◽  
pp. 411-416 ◽  
Author(s):  
Joseph B. Nadol ◽  
Yi-Shyang Young ◽  
Robert J. Glynn

Ninety-three temporal bones from 66 patients who were profoundly deaf during life were reconstructed by analysis of serial light microscopic sections. The correlations of total and segmental spiral ganglion cell counts with age, duration of hearing loss and profound deafness, and cause of hearing loss were evaluated. Bivariate analysis demonstrated that total spiral ganglion cell count tended to be lower in older than in younger deaf individuals and lower with longer duration of hearing loss and total deafness. However, multiple regression analysis demonstrated that the cause of hearing loss was the single most significant determinant of total spiral ganglion cell count. Patients with deafness due to aminoglycoside toxicity or sudden idiopathic deafness had the highest residual spiral ganglion cell count and patients with deafness due to presumptive postnatal viral labyrinthitis, bacterial labyrinthitis, and congenital or genetic causes had the lowest numbers of residual spiral ganglion cells.


2020 ◽  
Vol 19 (2) ◽  
Author(s):  
Razali A ◽  
Othman MS ◽  
Rahman MS ◽  
Misaridin NFI

INTRODUCTION: Recreational noise exposure has become a major threat to the hearing system, and this includes exposure to loud noise during group exercises such as Zumba Fitness, where loud music plays an important role. This study aimed to assess the noise exposure and hearing threshold profile among Zumba Fitness regulars in Kuantan, Malaysia. MATERIALS AND METHODS: Noise exposure and hearing profile threshold were measured during Zumba Fitness sessions at a fitness studio in Kuantan, Malaysia from 24th June 2014 to 12th August 2014. Noise exposure was measured using a noise dosimeter for one hour of Zumba Fitness session with a total of nine sessions run by three different instructors while sound level pressure was taken using a sound level meter during ambient, peak session and during cooling down. Thirty participants answered questionnaires and underwent pure tone diagnostic audiometry test at a local clinic for hearing threshold documentation. RESULTS: Some areas of the hall posed higher risks of causing noise-induced hearing loss especially near the amplifiers. There were periods when the hearing level exceeded 115 dBA. Early abnormal pattern could be observed in the hearing profiles of some of the participants to suggest preliminary hearing problems. CONCLUSION: Zumba Fitness regulars have a risk of developing noise-induced hearing loss and preventive steps should be properly addressed as NIHL is permanent and irreversible.


2019 ◽  
Vol 24 (5) ◽  
pp. 237-244
Author(s):  
Clemens Honeder ◽  
Chengjing Zhu ◽  
Julia Clara Gausterer ◽  
Hanna Schöpper ◽  
Navid Ahmadi ◽  
...  

Introduction: In recent years, the preservation of residual hearing has become a major factor in patients undergoing cochlear implantation (CI). In studies attempting to pharmaceutically improve hearing preservation rates, glucocorticoids (GCs) applied perioperatively in many institutions have emerged as a promising treatment regimen. Although dexamethasone is most commonly used and has been applied successfully by various research groups, recently pharmacological properties have been reported to be relatively unsuitable for topical delivery to the inner ear. Consequently other glucocorticoids merit further evaluation. The aim of this study was therefore to evaluate the otoprotective effects of the topical application of a sustained-release triamcinolone acetonide (TAAC) hydrogel in CI with hearing preservation. Methods: Normal-hearing pigmented guinea pigs were randomized into a group receiving a single dose of a 6% TAAC poloxamer 407 hydrogel, a group receiving a 30% TAAC hydrogel and a control group. All hydrogel applications were performed 1 day prior to CI. After a cochleostomy was drilled, a specifically designed silicone electrode was inserted into the scala tympani for 5 mm. Frequency-specific compound action potentials of the auditory nerve (0.5–32 kHz) were measured pre- and directly postoperatively as well as on days 3, 7, 14, 21, and 28. Finally, temporal bones were harvested for histological evaluation. Results: Application of the TAAC hydrogels resulted in significantly reduced hearing threshold shifts in low, middle and high frequencies and improved spiral ganglion cell survival in the second turn of the cochlea. Outer hair cell numbers in the basal and second turn of the cochlea were slightly reduced after TAAC application. Conclusion: In summary, we were able to demonstrate functional benefits of a single preoperative application of a TAAC hydrogel in a guinea pig model for CI, which persisted until the end of the observational period, that is, 28 days after surgery.


2013 ◽  
Vol 38 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Małgorzata Pawlaczyk-Łuszczyńska ◽  
Małgorzata Zamojska ◽  
Adam Dudarewicz ◽  
Kamil Zaborowski

Abstract The overall purpose of this study was to assess hearing status in professional orchestral musicians. Standard pure-tone audiometry (PTA) and transient-evoked otoacoustic emissions (TEOAEs) were per- formed in 126 orchestral musicians. Occupational and non-occupational risk factors for noise-induced hearing loss (NIHL) were identified in questionnaire inquiry. Data on sound pressure levels produced by various groups of instruments were also collected and analyzed. Measured hearing threshold levels (HTLs) were compared with the theoretical predictions calculated according to ISO 1999 (1990). Musicians were exposed to excessive sound at weekly noise exposure levels of for 81-100 dB (mean: 86.6±4.0 dB) for 5-48 years (mean: 24.0±10.7 years). Most of them (95%) had hearing corresponds to grade 0 of hearing impairment (mean hearing threshold level at 500, 1000, 2000 and 4000 Hz lower than 25 dB). However, high frequency notched audiograms typical for noise-induced hearing loss were found in 35% of cases. Simultaneously, about 35% of audiograms showed typical for NIHL high frequency notches (mainly occurring at 6000 Hz). When analyzing the impact of age, gender and noise exposure on hearing test results both PTA and TEOAE consistently showed better hearing in females vs. males, younger vs. older musicians. But higher exposure to orchestral noise was not associated with poorer hearing tests results. The musician’s audiometric hearing threshold levels were poorer than equivalent non-noise-exposed population and better (at 3000 and 4000 Hz) than expected for noise-exposed population according to ISO 1999 (1990). Thus, music impairs hearing of orchestral musicians, but less than expected from noise exposure.


2012 ◽  
Vol 9 (4) ◽  
pp. 274-278 ◽  
Author(s):  
I Shrestha ◽  
B L Shrestha ◽  
M Pokharel ◽  
R C M Amatya ◽  
D R Karki

Background Noise induced hearing loss (NIHL) is a major preventable occupational health hazard. Objective To measure permanent threshold shift in traffic police personnel due to noise exposure and to examine whether it was associated with duration of noise exposure, years of work and risk factors. Methods Cross sectional, descriptive study conducted at Dhulikhel hospital, Kathmandu University Hospital in 110 responding traffic police personnel. Detailed history and clinical examination of ear, impedence audiometry and pure tone audiometry was performed. Results Mean age group was 29.82 years; 82(74.5%) were males and 28 (25.5%) were females. Mean duration of service is 11.86 years. Twenty six (23.6%) had tinnitus and 39(35.5%) had blocked sensation in ear. Sixty five (59.1%) worked between 10-19 years. Alcohol and smoking shows positive impact on NIHL (p value =0.00). Odds ratio with 95% confidence interval were 4.481 (1.925-10.432) and 6.578 (2.306-18.764) respectively. Among 73(66.4%) noise induced hearing loss positive cases, bilateral involvement was seen in 45 (40.9%) and unilateral in 28(25.4 %) cases. Among unilateral cases most were left sided. Hearing threshold at 4 kHz increased according to age and duration of service. Conclusion Traffic police personnel are in constant risk of noise induced hearing loss. Screening for hearing loss is recommended for people exposed to noise.DOI: http://dx.doi.org/10.3126/kumj.v9i4.6343 Kathmandu Univ Med J 2011;9(4):274-8


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mehrdad Mostaghaci ◽  
Seyyed Jalil Mirmohammadi ◽  
Amir Houshang Mehrparvar ◽  
Maryam Bahaloo ◽  
Abolfazl Mollasadeghi ◽  
...  

Introduction. Noise as a common physical hazard may lead to noise-induced hearing loss, an irreversible but preventable disorder. Annual audiometric evaluations help detect changes in hearing status before clinically significant hearing loss develops. This study was designed to track hearing threshold changes during 2-year follow-up among tile and ceramic workers.Methods. This follow-up study was conducted on 555 workers (totally 1110 ears). Subjects were divided into four groups according to the level of noise exposure. Hearing threshold in conventional audiometric frequencies was measured and standard threshold shift was calculated for each ear.Results. Hearing threshold was increased during 2 years of follow-up. Increased hearing threshold was most frequently observed at 4000, 6000, and 3000 Hz. Standard threshold shift was observed in 13 (2.34%), 49 (8.83%), 22 (3.96%), and 63 (11.35%) subjects in the first and second years of follow-up in the right and left ears, respectively.Conclusions. This study has documented a high incidence of noise-induced hearing loss in tile and ceramic workers that would put stress on the importance of using hearing protection devices.


2007 ◽  
Vol 137 (4) ◽  
pp. 607-611 ◽  
Author(s):  
Yen-Pin Wang ◽  
Yi-Ho Young

Objective To investigate the effect of chronic noise exposure on vestibular-evoked myogenic potentials. Study Design Prospective study. Subjects and Methods Twenty patients with chronic noise-induced hearing loss, presenting as bilateral notched audiogram at 4 kHz, underwent audiometry, caloric, and vestibular-evoked myogenic potential tests. Results Caloric and vestibular-evoked myogenic potential tests revealed abnormal responses in nine (45%) and 10 (50%) patients, respectively. However, when both results were considered together, the abnormal rate reached 70% (14 of 20). The hearing threshold of 4 kHz significantly associated with vestibular-evoked myogenic potential results (ie, vestibular-evoked myogenic potential was abnormal in patients with greater degrees of hearing loss), but not with caloric responses. Conclusion Patients with bilateral 4-kHz notched audiogram and hearing threshold of 4 kHz >40 dB may show abnormal (absent or delayed) vestibular-evoked myogenic potentials, indicating that the vestibular part, especially the sacculocollic reflex pathway, has also been damaged.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Chia-Hao Chang ◽  
Chia-Der Lin ◽  
Ching-Liang Hsieh

Acupuncture has long been used to relieve some inner ear diseases such as deafness and tinnitus. The present study examined the effect of electroacupuncture (EA) on noise-induced hearing loss (NIHL) in animals. A NIHL rat model was established. Electroacupuncture pretreatment at 2 Hz or posttreatment at the right Zhongzhu (TE3) acupoint was applied for 1 hour. Auditory thresholds were measured using auditory brainstem responses (ABRs), and histopathology of the cochlea was examined. The results indicated that the baseline auditory threshold of ABR was not significantly different between the control (no noise), EA-only (only EA without noise), noise (noise exposure only), pre-EA (pretreating EA then noise), and post-EA (noise exposure then posttreating with EA) groups. Significant auditory threshold shifts were found in the noise, pre-EA, and post-EA groups in the immediate period after noise exposure, whereas auditory recovery was better in the pre-EA and post-EA groups than that in the noise group at the three days, one week (W1), two weeks (W2), three weeks (W3), and four weeks(W4) after noise stimulation. Histopathological examination revealed greater loss of the density of spiral ganglion neurons in the noise group than in the control group at W1 and W2. Although significant loss of spiral ganglion loss happened in pre-EA and post-EA groups, such loss was less than the loss of the noise group, especially W1. These results indicate that either pretreatment or posttreatment with EA may facilitate auditory recovery after NIHL. The detailed mechanism through which EA alleviates NIHL requires further study.


Author(s):  
Nam-Jeong Kim ◽  
Hyoung-Ouk Park ◽  
Chang-Sun Sim ◽  
Choong-Ryeol Lee ◽  
Young-Joo Kwon ◽  
...  

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