scholarly journals Analysis of the Damage Mechanism Related to CO2 Laser Cochleostomy on Guinea Pig Cochlea

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xiang Liu ◽  
Xiao-qing Qian ◽  
Rui Ma ◽  
Fang-Lu Chi ◽  
Dong-Dong Ren
Keyword(s):  
Guinea Pig ◽  
Inner Ear ◽  
Round Window ◽  
Organ Of Corti ◽  
Damage Mechanism ◽  
Round Window Membrane ◽  
Control Group ◽  
Guinea Pig Cochlea ◽  
Brainstem Response ◽  
Laser Induced Damage

Different types of lasers have been used in inner ear surgery. Therefore, it is of the utmost importance to avoid damage to the inner ear (e.g., hyperthermia and acoustic effects) caused by the use of such lasers. The aim of this study was to use a high powered fibre-enabled CO2 laser (10 W, 606 J/cm2) to perform cochleostomies on guinea pig cochlea and to investigate the possible laser-induced damage mechanisms. The temperature changes in the round window membrane, auditory evoked brainstem response, and morphological of the hair cells were measured and recorded before and after laser application. All of the outcomes differed in comparison with the control group. A rise in temperature and subsequent increased hearing loss were observed in animals that underwent surgery with a 10 W CO2 laser. These findings correlated with increased injury to the cochlear ultrastructure and a higher positive expression of E-cadherin and β-catenin in the damaged organ of Corti. We assume that enhanced cell-cell adhesion and the activated β-catenin-related canonical Wnt-signalling pathway may play a role in the protection of the cochlea to prevent further damage.

Influence of carbon dioxide laser irradiation on the morphology and function of guinea pig cochlea

2005 ◽  
Vol 119 (9) ◽  
pp. 684-692 ◽  
Author(s):  
DongDong Ren ◽  
JingWU Sun ◽  
GuangLun Wan ◽  
Feng Yang ◽  
Fang Shen
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Guinea Pig ◽  
Inner Ear ◽  
Laser Irradiation ◽  
Carbon Dioxide Laser ◽  
Organ Of Corti ◽  
Spiral Ligament ◽  
Laser Application ◽  
Brainstem Response

Both experimental and clinical studies have demonstrated that carbon dioxide laser is suitable for stapedotomy. The aim of this study was to investigate morphological, electrophysiological and functional changes in the inner ear after irradiation with CO2 laser set with different energy parameters.A cochleostomy in the basal cochlear turn of guinea pig cochleae was performed with CO2 laser of 1, 2 and 3 w, respectively. The cochleae were removed three weeks after laser irradiation. The auditory evoked brainstem response (ABR) was measured before and after laser application and immediately before removal of the cochlea. Immunohistochemical methods were used to examine inducible nitric oxide synthase (iNOS/NOSII) and heat-shock protein 70(Hsp70) concentrations in the cochlea after laser application. The organ of Corti was studied by scanning electron microscopy.Worse hearing loss was observed in animals receiving higher-power CO2 laser. These findings correlated with more intense injury of the cochlear ultrastructure and with positiveexpression of iNOS and Hsp70 in spiral ganglion cells, nerve fibres, supporting cells of the organ of Corti and cells of the spiral ligament.The CO2 laser as a noncontact procedure is shown to be effective and safe if the total amount of energy is kept within the limits applied in this study. Nitric oxide and stressproteins play important roles in the traumatic mechanism of the inner ear, which are related tohearing loss and injury of the ultrastructure of the inner ear.

Distribution of PLGA nanoparticles in chinchilla cochleae

2007 ◽  
Vol 137 (4) ◽  
pp. 619-623 ◽  
Author(s):  
Xianxi Ge ◽  
Ronald L. Jackson ◽  
Jianzhong Liu ◽  
Elizabeth A. Harper ◽  
Michael E. Hoffer ◽  
...  
Keyword(s):  
Inner Ear ◽  
Round Window ◽  
Organ Of Corti ◽  
Plga Nanoparticles ◽  
Round Window Membrane ◽  
Scala Tympani ◽  
Magnetic Forces ◽  
Magnetic Exposure ◽  
Transmission Electron ◽  
Electron Energy Loss

Objectives To study the distribution of polylactic/glycolic acid–encapsulated iron oxide nanoparticles (PLGA-NPs) in chinchilla cochleae after application on the round window membrane (RWM). Study Design and Setting Six chinchillas (12 ears) were equally divided into controls (no treatments) and experimen-tals (PLGA-NP with or without magnetic exposure). After 40 minutes of PLGA-NP placement on the RWM, perilymph was withdrawn from the scala tympani. The RWM and cochleae were fixed with 2.5% glutaraldehyde and processed for transmission electron microscopy. Results Nanoparticles were found in cochleae with or without exposure to magnet forces appearing in the RWM, perilymph, endolymph, and multiple locations in the organ of Corti. Electron energy loss spectroscopy confirmed iron elements in nanoparticles. Conclusion The nanoparticles were distributed throughout the inner ear after application on the chinchilla RWM, with and without magnetic forces. Significance PLGA-NP applied to the RWM may have potential for sustained therapy to the inner ear.

Inner Ear Damage and Passage through the round Window Membrane of Pseudomonas Aeruginosa Exotoxin a in a Chinchilla Model

1992 ◽  
Vol 101 (5) ◽  
pp. 437-444 ◽  
Author(s):  
Lars Lundman ◽  
Teruhiko Harada ◽  
Peter A. Santi ◽  
Steven K. Juhn ◽  
Tetsuo Morizono ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inner Ear ◽  
Round Window ◽  
Organ Of Corti ◽  
Round Window Membrane ◽  
Enzyme Linked Immunosorbent Assay ◽  
Computer Assisted ◽  
Exotoxin A ◽  
Inner Ear Damage ◽  
Pseudomonas Aeruginosa Exotoxin

By the use of computer-assisted morphometric analysis of the organ of Corti and/or measurements of action potential threshold changes, inner ear changes in chinchillas were evaluated 4 weeks after application on the round window membrane of a Pseudomonas aeruginosa exotoxin A solution. Severe inner ear damage was detected after application of 50 ng (5 μL at a concentration of 10 μg/mL) exotoxin A, whereas application of 5 ng exotoxin did not cause measurable inner ear damage. Perilymph concentrations of exotoxin A were measured with an enzyme-linked immunosorbent assay 1.5 to 19 hours after 50 ng, 0.5 μg, or 5 μg of exotoxin A was applied on the round window membrane. Only the highest concentration produced measurable levels of exotoxin in the inner ear fluids. It is concluded that exotoxin A present on the round window membrane of the chinchilla has the ability to penetrate into the inner ear and cause irreversible inner ear changes.

scholarly journals Adenoviral–mediated Hath1–EGFP gene transfer into guinea pig cochlea through intact round window membrane

2008 ◽  
Vol 3 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Chen Wei ◽  
Hu Yin–yan ◽  
Yang Shi–ming ◽  
Guo Wei ◽  
Sun Jian–he ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Guinea Pig ◽  
Round Window ◽  
Round Window Membrane ◽  
Egfp Gene ◽  
Guinea Pig Cochlea

S228 – Direct Round Window Drug Application and Ototoxicity in Rats

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P151-P151
Author(s):  
Teresa Rivera ◽  
Fernando García Alcantara ◽  
Jon Alexander Sistiaga Suarez ◽  
Murillo-Cuesta Silvia ◽  
Vacas Elena ◽  
...  
Keyword(s):  
Round Window ◽  
Drug Application ◽  
Tone Burst ◽  
Auditory Brainstem ◽  
Round Window Membrane ◽  
Control Group ◽  
Cochlear Function ◽  
Before And After ◽  
Male Wistar Rats ◽  
Brainstem Response

Objectives 1) Manage to introduce ototoxic drugs, such as kanamycin and furosemide, directly on the round window in rats. 2) Use a purified gelatine sponge as a proper delivery vehicle. The purpose of the study is to assess the validity of this method to provoke local ototoxicity. Methods We carried out an experimental design with 3 groups of 6 male Wistar rats. The bulla and round window membrane were exposed using a ventral approach. In the first control group we only made a hole in the tympanic bulla. Second control group was treated with saline solution. The problem group was treated with 20 mg/kg of kanamycin and 5 mg/Kg of furosemide-soaked gelatine sponge directly upon the round window membrane. Cochlear function was assessed through tone burst auditory brainstem response (ABR) threshold (dB) and peak latency (ms) measurements. Anova with bonferroni correction was used (p level=0.05). Results All animals treated with kanamycin and furosemide exhibited significant increase in ABR threshold (x = 51.25 dB; SD = 6.29; p = 0,001) in contrast to the other groups, whose ABR thresholds did not show significant differences before and after treatment(x=31,50 dB; SD=5.53); and not significant increase in peak latencies I (x = 0.22 ms; SD = 0.12), II (x = 0.22 ms; SD = 0.20) and IV (x = 0.21 ms; SD = 0.18). Conclusions The ventral approach and placement of kanamycin and furosemide-soaked gelatine sponge directly upon the round window membrane represents a reliable method for ototoxicity in rats.

scholarly journals Ultrasound Microbubbles Enhance the Efficacy of Insulin-Like Growth Factor-1 Therapy for the Treatment of Noise-Induced Hearing Loss

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3626
Author(s):  
Yi-Chun Lin ◽  
Yuan-Yung Lin ◽  
Hsin-Chien Chen ◽  
Chao-Yin Kuo ◽  
Ai-Ho Liao ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Growth Factor ◽  
Inner Ear ◽  
Outer Hair Cells ◽  
Round Window Membrane ◽  
Insulin Like Growth Factor ◽  
Noise Induced Hearing Loss ◽  
Ear Diseases ◽  
Brainstem Response ◽  
Ultrasound Microbubbles

The application of insulin-like growth factor 1 (IGF-1) to the round window membrane (RWM) is an emerging treatment for inner ear diseases. RWM permeability is the key factor for efficient IGF-1 delivery. Ultrasound microbubbles (USMBs) can increase drug permeation through the RWM. In the present study, the enhancing effect of USMBs on the efficacy of IGF-1 application and the treatment effect of USMB-mediated IGF-1 delivery for noise-induced hearing loss (NIHL) were investigated. Forty-seven guinea pigs were assigned to three groups: the USM group, which received local application of recombinant human IGF-1 (rhIGF-1, 10 µg/µL) following application of USMBs to the RWM; the RWS group, which received IGF-1 application alone; and the saline-treated group. The perilymphatic concentration of rhIGF-1 in the USM group was 1.95- and 1.67- fold of that in the RWS group, 2 and 24 h after treatment, respectively. After 5 h of 118 dB SPL noise exposure, the USM group had the lowest threshold shift in auditory brainstem response, least loss of cochlear outer hair cells, and least reduction in the number of synaptic ribbons on postexposure day 28 among the three groups. The combination of USMB and IGF-1 led to a better therapeutic response to NIHL. Two hours after treatment, the USM group had significantly higher levels of Akt1 and Mapk3 gene expression than the other two groups. The most intense immunostaining for phosphor-AKT and phospho-ERK1/2 was detected in the cochlea in the USM group. These results suggested that USMB can be applied to enhance the efficacy of IGF-1 therapy in the treatment of inner ear diseases.

scholarly journals Cutaneous and Labyrinthine Tolerance of Bioactive Glass S53P4 in Mastoid and Epitympanic Obliteration Surgery: Prospective Clinical Study

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Daniele Bernardeschi ◽  
Yann Nguyen ◽  
Francesca Yoshie Russo ◽  
Isabelle Mosnier ◽  
Evelyne Ferrary ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Inner Ear ◽  
Round Window ◽  
Bone Conduction ◽  
Hearing Threshold ◽  
Round Window Membrane ◽  
Prospective Clinical Study ◽  
Local Skin ◽  
Local Skin Reaction ◽  
Bone Conduction Hearing

Objective. To evaluate the cutaneous and the inner ear tolerance of bioactive glass S53P4 when used in the mastoid and epitympanic obliteration for chronic otitis surgery.Material and Methods. Forty-one cases have been included in this prospective study. Cutaneous tolerance was clinically evaluated 1 week, 1 month, and 3 months after surgery with a physical examination of the retroauricular and external auditory canal (EAC) skin and the presence of otalgia; the inner ear tolerance was assessed by bone-conduction hearing threshold 1 day after surgery and by the presence of vertigo or imbalance.Results. All surgeries but 1 were uneventful: all patients maintained the preoperative bone-conduction hearing threshold except for one case in which the round window membrane was opened during the dissection of the cholesteatoma in the hypotympanum and this led to a dead ear. No dizziness or vertigo was reported. Three months after surgery, healing was achieved in all cases with a healthy painless skin. No cases of revision surgery for removal of the granules occurred in this study.Conclusion. The bioactive glass S53P4 is a well-tolerated biomaterial for primary or revision chronic otitis surgery, as shown by the local skin reaction which lasted less than 3 months and by the absence of labyrinthine complications.

Inner Ear Pathology and Otitis Media

1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 249-253 ◽  
Author(s):  
Michael M. Paparella ◽  
Marcos V. Goycoolea ◽  
William L. Meyerhoff
Keyword(s):  
Inner Ear ◽  
Otitis Media ◽  
Round Window ◽  
Round Window Membrane

Insidious inner ear complications of otitis media have been and are being studied in our laboratory. The purpose of this paper is to review these studies, coordinate, capsulize and highlight the results with emphasis on the transport role of the round window membrane.

Sign in / Sign up

Export Citation Format

Share Document