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1.
Clin Exp Otorhinolaryngol ; 15(1): 69-76, 2022 Feb.
Article En | MEDLINE | ID: mdl-33848418

OBJECTIVES: This study was conducted to evaluate the user satisfaction, efficacy, and safety of round window (RW) vibroplasty using the Vibrant Soundbridge (VSB) in patients with persistent mixed hearing loss after mastoidectomy. METHODS: The study included 27 patients (mean age, 58.7 years; age range, 28-76 years; 11 men and 16 women) with mixed hearing loss after mastoidectomy from 15 tertiary referral centers in Korea. The VSB was implanted at the RW. The Korean translation of the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire and the Korean version of the International Outcome Inventory for Hearing Aids (K-IOI-HA) questionnaire were used to evaluate user satisfaction as the primary outcome. The secondary outcome measures were audiological test results and complication rates. RESULTS: The mean scores for ease of communication (61.3% to 29.7% to 30.2%), reverberation (62.1% to 43.1% to 37.4%), and background noise (63.3% to 37.7% to 34.3%) subscales of the APHAB questionnaire significantly decreased after VSB surgery. The mean K-IOI-HA scores at 3 and 6 months after surgery were significantly higher than the mean preoperative score (18.6 to 27.2 to 28.1). The postoperative VSB-aided thresholds were significantly lower than the preoperative unaided and hearing aid (HA)-aided thresholds. There was no significant difference between preoperative unaided, preoperative HA-aided, and postoperative VSB-aided maximum phonetically balanced word-recognition scores. None of the 27 patients experienced a change in postoperative bone conduction pure tone average. One patient developed temporary facial palsy and two developed surgical wound infections. CONCLUSION: RW vibroplasty resulted in improved satisfaction and audiological test results in patients with mixed hearing loss after mastoidectomy, and the complication rate was tolerable.

2.
Otol Neurotol ; 41(7): e783-e789, 2020 08.
Article En | MEDLINE | ID: mdl-32558748

OBJECTIVE: To evaluate the treatment outcomes of nimodipine and steroid combination therapy for idiopathic sudden sensorineural hearing loss (ISSNHL). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Seventy-eight patients who were diagnosed with ISSNHL were divided into two group based on the treatment strategies used: steroid+nimodipine (SN, n = 36) and steroid only (SO, n = 42) groups. Based on the level of hearing loss before treatment, subgroup analysis (<90 dB HL, SN-S versus SO-S groups; ≥90 dB HL, SN-P versus SO-P groups) was performed. INTERVENTIONS: Nimodipine+dexamethasone versus dexamethasone alone. MAIN OUTCOME MEASURES: Hearing thresholds and complete/partial recovery rate after treatment. RESULTS: Hearing thresholds after treatment were not significantly different between the SN and SO groups (46.8 ±â€Š29.4 versus 54.8 ±â€Š27.6 dB HL, p = 0.218). However, the complete recovery rate was significantly higher in the SN group than in the SO group (41.7% versus 16.8%, p = 0.014). In subgroup analysis, the complete recovery rate was significantly higher in the SN-S group than in the SO-S group (60.9% versus 19.2%, p = 0.003), whereas the difference between the SN-P and SO-P groups was not significant (7.7% versus 12.5%, p = 0.672). The cumulative incidence of complete recovery was significantly higher in SN-S group than in the SO-S group (p = 0.005); the mean recovery time was 4.4 weeks (95% confidence interval [CI], 2.8-6.1) in the SN-S group and 8.8 weeks (95% CI, 7.0-10.5) in the SO-S group. CONCLUSIONS: The results of this study suggest that nimodipine and steroid combination therapy for ISSNHL results in a higher complete recovery rate than steroid alone in patients with moderate to severe hearing loss.


Hearing Loss, Sensorineural , Hearing Loss, Sudden , Audiometry, Pure-Tone , Dexamethasone/therapeutic use , Glucocorticoids/therapeutic use , Hearing Loss, Sensorineural/drug therapy , Hearing Loss, Sudden/drug therapy , Humans , Nimodipine/therapeutic use , Retrospective Studies , Steroids/therapeutic use , Treatment Outcome
3.
Bioresour Technol ; 309: 123297, 2020 Aug.
Article En | MEDLINE | ID: mdl-32283483

The present study targeted towards the feasibility of various agricultural residues for bio-hythane production by anaerobic digestion (AD) process without pre-treatment. Biochemical methane potential (BMP) analysis was carried out for mixed fruit waste (MFW), mixed vegetable waste (MVW), sugarcane bagasse (SB), rice husk (RH), and wheat straw (WS). The analysis of gas was carried out in gas chromatography with a thermal conductivity detector (GC-TCD). The BMP test results in the study for SB, MFW, and MVW reveal that the average percentage value of bio-hythane production was 53.64%, 43.54%, and 40.92% and that of RH and WS was 16.74% and 29.75%, respectively. The result also shows that agricultural biomass, such as WS and RH produces less % of bio-hythane due to the presence of lignocellulosic components. The main contribution of this study is to highlight the bio-hythane potential with reference to the bio-methane and bio-hydrogen productions from the agricultural residues.


Methane , Saccharum , Anaerobiosis , Biofuels , Biomass , Hydrogen , Triticum
4.
Bioresour Technol ; 302: 122920, 2020 Apr.
Article En | MEDLINE | ID: mdl-32029301

The present fossil fuel-based energy sector has led to significant industrial growth. On the other hand, the dependence on fossil fuels leads to adverse impact on the environment through releases of greenhouse gases. In this scenario, one possible substitute is biohydrogen, an eco-friendly energy carrier as high-energy produces. The substrates rich in organic compounds like organic waste/wastewater are very useful for improved hydrogen generation through the dark fermentation. Thus, this review article, initially, the status of biohydrogen production from organic waste and various strategies to enhance the process efficiency are concisely discussed. Then, the practical confines of biohydrogen processes are thoroughly discussed. Also, alternate routes such as multiple process integration approach by adopting biorefinery concept to increase overall process efficacy are considered to address industrial-level applications. To conclude, future perspectives besides with possible ways of transforming dark fermentation effluent to biofuels and biochemicals, which leads to circular bioeconomy, are discussed.


Biofuels , Hydrogen , Fermentation , Fossil Fuels , Wastewater
5.
Bioresour Technol ; 294: 122220, 2019 Dec.
Article En | MEDLINE | ID: mdl-31606597

The present study was aimed to examine the Bio-Hythane production in a single and two-stage anaerobic digestion (AD) systems from the organic fraction of municipal solid waste (OFMSW) along with its quantification by gas chromatography (GC). The Bio-Hythane produced in a single-stage is a blend of 6% H2, 20% CH4 and 30% CO2 in the first run and 5% H2, 25% CH4 and 34% CO2 in the second run whereas 6% H2, 15% CH4 and 56% CO2 in the two-stage AD. Statistical analysis concluded that there is a significant difference between both the methods.


Refuse Disposal , Solid Waste , Anaerobiosis , Bioreactors , Methane
6.
J Audiol Otol ; 23(2): 112-117, 2019 Apr.
Article En | MEDLINE | ID: mdl-30857382

BACKGROUND AND OBJECTIVES: The purpose of this study was to evaluate the efficacy of revision cochlear implant (CI) surgery for better speech comprehension targeting patients with low satisfaction after first CI surgery. SUBJECT AND METHODS: Eight patients who could not upgrade speech processors because of an too early CI model and who wanted to change the whole system were included. After revision CI surgery, we compared speech comprehension before and after revision CI surgery. Categoies of Auditory Performance (CAP) score, vowel and consonant confusion test, Ling 6 sounds, word and sentence identification test were done. RESULTS: The interval between surgeries ranged from eight years to 19 years. Same manufacturer's latest product was used for revision surgery in six cases of eight cases. Full insertion of electrode was possible in most of cases (seven of eight). CAP score (p-value=0.01), vowel confusion test (p-value=0.041), one syllable word identification test (p-value=0.026), two syllable identification test (p-value=0.028), sentence identification test (pvalue=0.028) had significant improvement. Consonant confusion test (p-value=0.063), Ling 6 sound test (p-value=0.066) had improvement but it is not significant. CONCLUSIONS: Although there are some limitations of our study design, we could identify the effect of revision (upgrade) CI surgery indirectly. So we concluded that if patient complain low functional gain or low satisfaction after first CI surgery, revision (device upgrade) CI surgery is meaningful even if there is no device failure.

7.
Otol Neurotol ; 39(2): 206-211, 2018 02.
Article En | MEDLINE | ID: mdl-29227441

OBJECTIVE: To define the risk factors and adverse effects associated with repeated canalith repositioning procedures (CRPs). STUDY DESIGN: A case series featuring chart review. SETTING: An academic university hospital. PATIENTS: We retrospectively reviewed 1900 patients (average age, 54.9 years; range, 11-88 years) diagnosed with benign paroxysmal positional vertigo (BPPV). All underwent repeated CRPs. We recorded clinical features including age, gender, BPPV cause (idiopathic or secondary), symptom duration, the canal involved, the number of sessions of CRP, recurrence, follow-up duration, and complications. We compared these factors using Pearson's chi-squared test and multiple linear regression analysis with dummy variables. INTERVENTIONS: BPPV was diagnosed based on the results of the head roll and Dix-Hallpike tests. RESULTS: The overall BPPV resolution rate for patients treated with repeated CRPs was 96.4%. The risk factors for the need for multiple CRPs in BPPV were the duration of vertigo before treatment (ß = 0.326, p < 0.001), the type of canal involved (ß = 0.130, p < 0.001), and age (ß = 0.040, p = 0.040). The explanatory power of the regression model attained 46.0% (F = 172.510, p < 0.001). The failure rate of repeated CRPs was 3.6% and complications included canal conversion (3.1%), nausea (46.4%), vomiting (4.9%), head heaviness (50.8%), imbalance (31.9%), and hypotension or palpitations (8.6%). However, almost all patients recovered. CONCLUSION: The risk factors associated with the need for Multiple CRPs were as follows: longer duration of vertigo before treatment, bilateral or multiple canal involved, and age >50 years.


Benign Paroxysmal Positional Vertigo/therapy , Patient Positioning/methods , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Male , Middle Aged , Recurrence , Retrospective Studies , Risk Factors , Time Factors , Young Adult
8.
Ear Nose Throat J ; 95(10-11): 446-451, 2016.
Article En | MEDLINE | ID: mdl-27792822

This study investigated the changes in antibiotic resistance in recurrent Pseudomonas aeruginosa infections in chronic suppurative otitis media (CSOM). Its aim was to provide a treatment strategy for P aeruginosa infections in CSOM for the prevention of multidrug resistance. A case-control study was conducted in tertiary teaching hospitals in Korea. The experimental group included patients with recurrent P aeruginosa infection who had relapsed within 2 months after the successful control of a previous P aeruginosa infection. The control group consisted of patients with a P aeruginosa infection who had no history of such an infection. An antibiotic sensitivity test was performed for each culture. The proportion of recurrent P aeruginosa infection was 22.69% (98 of 432 cases). Drug resistance to amikacin, tobramycin, netilmicin, ciprofloxacin, and levofloxacin was significantly changed after recurrent infection. The fluoroquinolone strains seen in recurrent P aeruginosa showed high cross-resistance to other drugs. Antibiotic resistance of P aeruginosa in CSOM changed with recurrent infection.


Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Otitis Media, Suppurative/drug therapy , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/drug effects , Adolescent , Adult , Aged , Aged, 80 and over , Amikacin/pharmacology , Case-Control Studies , Child , Child, Preschool , Chronic Disease , Ciprofloxacin/pharmacology , Female , Humans , Infant , Levofloxacin/pharmacology , Male , Microbial Sensitivity Tests , Middle Aged , Netilmicin/pharmacology , Otitis Media, Suppurative/microbiology , Pseudomonas Infections/microbiology , Recurrence , Republic of Korea , Retrospective Studies , Tobramycin/pharmacology , Young Adult
9.
Int J Pediatr Otorhinolaryngol ; 78(12): 2198-204, 2014 12.
Article En | MEDLINE | ID: mdl-25458160

INTRODUCTION: Cisplatin is a widely used anticancer chemotherapeutic agent. However, it is notorious for its ototoxicity and nephrotoxicity due to induction of reactive oxygen species (ROS). Caffeic acid is a naturally occurring polyphenol present in honey that is known to reduce the generation of oxygen-derived free radicals. The objective of the present study was to evaluate the protective effects and mechanism underlying the effect of caffeic acid on cisplatin-induced ototoxicity in HEI-OC1 auditory cell lines. METHODS: Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was determined by Hoechst 33258 staining and Annexin V-fluorescein isothiocyanate/propidium iodide double staining. Cell cycle stages were analyzed by flow cytometry. The radical-scavenging activity of caffeic acid was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The expression levels of caspase-3, -8, and -9, as well as the activity of caspase-3, were evaluated. RESULTS: Caffeic acid showed a protective effect against cisplatin-induced HEI-OC1 cell damage as demonstrated by the MTT assay. Caffeic acid decreased cell death by apoptosis and necrosis. Caffeic acid showed strong scavenging activity against the radical DPPH and decreased intracellular ROS production. Caffeic acid decreased the expression of caspase-3 and -8 and increased the activity of caspase-3. CONCLUSIONS: Caffeic acid attenuated cisplatin-induced hair cell loss in HEI-OC1 cell lines; these effects were mediated by its radical scavenging activity and inhibition of apoptosis.


Antineoplastic Agents/adverse effects , Apoptosis/drug effects , Caffeic Acids/pharmacology , Cisplatin/adverse effects , Hair Cells, Auditory/drug effects , Antioxidants/pharmacology , Caspase 3/metabolism , Caspase 8/metabolism , Cell Line , Cell Survival/drug effects , Humans , Reactive Oxygen Species/metabolism
10.
Korean J Audiol ; 18(2): 69-75, 2014 Sep.
Article En | MEDLINE | ID: mdl-25279228

BACKGROUND AND OBJECTIVES: High-dose systemic steroid therapy is the mainstay treatment for sudden sensorineural hearing loss (SSNHL). Recovery rates from SSNHL range are about 47-63% and are influenced by various prognostic factors. To evaluate the prognostic value of specific clinical parameters, we reviewed 289 cases by clinical and statistical analysis. SUBJECTS AND METHODS: This study included 289 patients with SSNHL who visited the Department of Otolaryngology at Soonchunhyang University Hospital from January 2005 to December 2012. The cases were reviewed retrospectively based on clinical charts. Hearing improvement was evaluated in relation to pure-tone audiogram results, duration between SSNHL onset and time of initial treatment, seasonal incidence, dizziness, patient age, degree of hearing loss, patterns of initial pure-tone audiogram and presence of underlying disease. RESULTS: Hearing improvement was observed in 196 of 289 (67.8%) patients; such improvement began within 7 days in most patients, followed by rapid hearing recovery. Cases that failed to show improvement within 14 days were unlikely to achieve hearing recovery. The more severe the hearing loss during the early stage, the lower the hearing recovery rates. Patients aged less than 60 years appear to have better prognosis of hearing improvement compared to those who are over 60 years. CONCLUSIONS: Important prognostic factors for recovery in patients with SSNHL include the time of initiating treatment after symptom onset, the degree of early-stage hearing loss, and the age of the affected patient.

11.
Int J Pediatr Otorhinolaryngol ; 77(10): 1659-64, 2013 Oct.
Article En | MEDLINE | ID: mdl-23953484

OBJECTIVE: Acrolein is a hazardous air pollutant. Tobacco smoke and indoor air pollution are the main causes of human exposure. Acrolein has been shown to cause cytotoxicity in the airways and induce inflammation and mucin production in pulmonary cells. We investigated whether acrolein caused cytotoxicity, induced inflammation or increased expression of mucin in immortalized human middle ear epithelial cell lines (HMEECs). METHODS: Cytotoxicity following acrolein treatment was investigated using the MTT assay, flow cytometry, and Hoechst 33342 staining of HMEECs. We measured expression of inflammatory cytokines tumor necrosis factor (TNF)-α and cyclo-oxygenase (COX)-2 and the mucin gene MUC5AC using semi-quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. RESULTS: Exposure to >50 µg/mL acrolein caused a decrease in cell viability. Acrolein induced apoptosis and necrosis at 50 µg/mL. Acrolein at 5-50 µg/mL increased expression of TNF-α and COX-2, as shown by RT-PCR and Western blotting. Acrolein exposure at 5-50 µg/mL for 2-24h increased MUC5AC expression, as determined by RT-PCR. CONCLUSION: Acrolein decreased cell viability, induced an inflammatory response, and increased mucin gene expression in HMEECs. These findings support the hypothesis that acrolein, a hazardous air pollutant in tobacco smoke and ambient air, is a risk factor for otitis media.


Acrolein/pharmacology , Cell Survival/drug effects , Cyclooxygenase 2/metabolism , Cytokines/metabolism , Mucin 5AC/genetics , Acrolein/toxicity , Air Pollutants/toxicity , Analysis of Variance , Blotting, Western , Cells, Cultured , Cyclooxygenase 2/genetics , Cytokines/genetics , Ear, Middle/cytology , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Flow Cytometry , Gene Expression Regulation , Hazardous Substances/pharmacology , Humans , Inflammation Mediators/metabolism , Mucin 5AC/metabolism , Real-Time Polymerase Chain Reaction/methods , Sensitivity and Specificity , Smoke , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
12.
Allergy Asthma Immunol Res ; 5(4): 224-31, 2013 Jul.
Article En | MEDLINE | ID: mdl-23814676

PURPOSE: Angiogenesis is involved in the pathogenesis of chronic rhinosinusitis with nasal polyps. We aimed to investigate the effects of prostaglandin E2 (PGE2) on vascular endothelial growth factor (VEGF) production, the role of E-prostanoid (EP) 4 receptors, and the signal transduction pathway mediating VEGF production in nasal polyp-derived fibroblasts (NPDFs). METHODS: Eight primary NPDF cultures were established from nasal polyps, which were incubated with or without PGE2. Reverse transcription-polymerase chain reaction amplification of EP receptors (EP1, EP2, EP3, and EP4) and immunofluorescence staining for VEGF production were performed. VEGF production via the cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) and phosphatidylinositol 3-kinase (PI3K) pathways was evaluated by enzyme-linked immunosorbent assay. RESULTS: All EP receptors were expressed in NPDFs. PGE2 significantly increased VEGF production concentration- and time dependently, and VEGF production was regulated by an EP4 receptor. Activation of intracellular cAMP regulated VEGF production. VEGF production was decreased by PKA and PI3K inhibitors via intracellular cAMP. CONCLUSIONS: PGE2 stimulates VEGF production via the EP4 receptor in NPDFs. These results indicate that PGE2-induced VEGF production is mediated, at least partially, through cAMP-dependent signaling pathways. Therapies targeting the EP4 receptor may be effective in inhibiting the development of nasal polyps.

13.
Acta Otolaryngol ; 133(2): 150-3, 2013 Feb.
Article En | MEDLINE | ID: mdl-22953719

CONCLUSION: Our results show that cervical vestibular-evoked myogenic potential (cVEMP) or ocular VEMP (oVEMP) abnormalities in the recurrent benign paroxysmal positional vertigo (BPPV) group were significantly higher than those in the non-recurrent BPPV group. Therefore, we can infer that VEMP abnormality is one of risk factors for BPPV recurrence. OBJECTIVE: This prospective study aimed to test the hypothesis that otolith dysfunction using the VEMP test is a cause of recurrence of BPPV. METHODS: cVEMP and oVEMP tests using 500 Hz tone-burst stimuli were performed on 16 patients with recurrent BPPV between March 2010 and December 2011. Both VEMP tests were performed in 20 patients with non-recurrent BPPV. RESULTS: The differences in age, sex, and involved canal between the recurrent and non-recurrent BPPV groups were not significant. Abnormal cVEMP responses were detected in 5 of 16 (31.3%) subjects in the recurrent BPPV group and abnormal oVMEP responses were detected in 4 of 16 (25%) subjects in the recurrent BPPV group. When we defined VEMP abnormality as an abnormal cVEMP or abnormal oVEMP, VEMP abnormalities were detected in eight (50%) subjects in the recurrent BPPV group and in three (15%) subjects in the non-recurrent BPPV group; the difference between groups was significant.


Saccule and Utricle/physiopathology , Vertigo/diagnosis , Vestibular Evoked Myogenic Potentials/physiology , Benign Paroxysmal Positional Vertigo , Diagnosis, Differential , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Recurrence , Severity of Illness Index , Time Factors , Vertigo/physiopathology , Vestibular Function Tests/methods
14.
Korean J Audiol ; 17(1): 9-12, 2013 Apr.
Article En | MEDLINE | ID: mdl-24653896

Otitis media is defined as inflammation of the middle ear, including the auditory ossicles and the Eustachian tube. Otitis media is a major health problem in many societies. The causes of otitis media includes infection and anatomic/physiologic, host, and environmental factors. In general, otitis media is a childhood disease, and anatomic and physiologic changes have great effects on its development. Thus, in vitro or human experimental studies of otitis media are difficult. Several experimental animal models have been introduced to investigate the pathogenesis and treatment of otitis media. However, none are ideal. The aim of this review is to provide a brief overview of the current status of animal models of otitis media with effusion, acute otitis media, and cholesteatoma. This review will assist determination of the most appropriate animal models of otitis media.

15.
Ann Otol Rhinol Laryngol ; 121(11): 761-9, 2012 Nov.
Article En | MEDLINE | ID: mdl-23193910

OBJECTIVES: The aims of this study were to determine changes in gene expression in the chronic state of vestibular compensation by microarray analysis and to validate the asymmetrical levels of gene expression in the ipsilateral and contralateral vestibular nucleus complexes (VNCs). METHODS: Microarray analysis was used to examine the expression of genes up-regulated or down-regulated in the ipsilateral VNC at 1 and 7 days after unilateral labyrinthectomy. Up-regulated or down-regulated gene expression in the ipsilateral and contralateral VNCs was then validated by reverse transcriptase polymerase chain reaction at 1, 7, 14, and 28 days after labyrinthectomy. RESULTS: The genes down-regulated at 1 day after labyrinthectomy and up-regulated at 7 days after labyrinthectomy as determined by microarray analysis and reverse transcriptase polymerase chain reaction were zinc finger protein 307, zinc metallopeptidase, P34, calcitonin receptor, insulin-like growth factor binding protein 5, GATA binding protein 3, and CD151. Expression of zinc finger protein 307, zinc metallopeptidase, P34, and calcitonin receptor was up-regulated even after 7 days in the contralateral VNC of rats that had labyrinthectomy. CONCLUSIONS: This study demonstrated changes in gene expression in rats during the chronic phase of vestibular compensation after unilateral labyrinthectomy and provided profiles of these changes in gene expression.


Down-Regulation/physiology , Up-Regulation/physiology , Vestibular Nuclei/metabolism , Vestibule, Labyrinth/surgery , Animals , Male , Microarray Analysis , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Time Factors , Vestibular Diseases/etiology , Vestibular Nuclei/physiopathology , Vestibule, Labyrinth/physiopathology
16.
Int J Pediatr Otorhinolaryngol ; 76(9): 1265-9, 2012 Sep.
Article En | MEDLINE | ID: mdl-22704672

INTRODUCTION: NecroX is a novel necrosis and necroptosis inhibitor that shows scavenger activity against mitochondrial reactive oxygen species (ROS) and cytoprotective activity against various insults. These findings raise the possibility of its protective effect in ototoxicity. This study was performed to investigate the protective effect of NecroX on gentamicin (GM)-induced hair cell loss in neonatal mouse cochlea cultures. MATERIALS AND METHODS: The protective effects of NecroX were measured by phalloidin staining of cultures from postnatal day 2-3 mice with GM-induced hair cell loss. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was used to detect apoptosis. The radical-scavenging activity of NecroX was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. RESULTS: NecroX showed a significant and concentration-dependent protective effect against GM-induced hair cell loss, and hair cells retained their stereocilia well. NecroX decreased GM-induced apoptosis of hair cells as assessed by TUNEL staining. Additionally, NecroX showed direct radical scavenging activity in the DPPH assay. CONCLUSIONS: In this study, we demonstrated the protective effect of NecroX on GM-induced hair cell loss in neonatal cochlea cultures, and suggest that it may be of therapeutic use in the treatment of drug-induced ototoxicity.


Antioxidants/pharmacology , Apoptosis/drug effects , Cochlea/drug effects , Gentamicins/adverse effects , Hair Cells, Auditory/drug effects , Heterocyclic Compounds, 4 or More Rings/pharmacology , Reactive Oxygen Species/metabolism , Sulfones/pharmacology , Animals , Cells, Cultured , Cochlea/cytology , Cytoprotection , Hair Cells, Auditory/pathology , Mice
17.
Int J Pediatr Otorhinolaryngol ; 76(3): 334-8, 2012 Mar.
Article En | MEDLINE | ID: mdl-22209256

OBJECTIVE: In the present study, we investigate whether diesel exhaust particles (DEPs) cause cytotoxicity and induce inflammation or increase the expression of mucin in immortalized human middle ear epithelial cell lines (HMEECs). Several publications have shown an association between traffic-related air pollutants and otitis media. Additionally, DEP have been shown to cause inflammation and an allergic response in the airways. METHODS: Cell viability following DEP treatment was investigated in HMEECs using the MTT assay. We measured the expression of the inflammatory cytokines TNF-α and COX-2 and the mucin genes MUC5AC and MUC5B using semiquantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. RESULTS: Cell viability tests showed that exposure to more than 80 µg/mL of DEP caused a decrease in cell viability. DEP exposure also increased the expression of MUC5AC, but did not induce the expression of MUC5B in HMEECs. CONCLUSION: DEP decreased cell viability, induced an inflammatory response, and increased mucin gene expression in HMEECs. These findings support the hypothesis that environmental diesel exposure is a risk factor for otitis media.


Air Pollutants/pharmacology , Ear, Middle/drug effects , Ear, Middle/pathology , Epithelial Cells/drug effects , Vehicle Emissions/toxicity , Cell Culture Techniques , Cell Line , Cell Survival/drug effects , Cyclooxygenase 2/metabolism , Ear, Middle/metabolism , Epithelial Cells/metabolism , Epithelial Cells/pathology , Humans , Mucin 5AC/metabolism , Mucin-5B/metabolism , Tumor Necrosis Factor-alpha/metabolism
18.
Laryngoscope ; 122(1): 162-6, 2012 Jan.
Article En | MEDLINE | ID: mdl-22057812

OBJECTIVES/HYPOTHESIS: As the molecular biology of vestibular schwannoma (VS) is better understood, new means of targeting the pathways involved for intervention in schwannoma cells are being developed. Honokiol, a bioactive constituent of Magnolia officinalis, has attracted attention due to its diverse biological effects. This study was conducted to determine the inhibitory effect of honokiol on schwannoma cell proliferation. METHODS: HEI 193 cells were used to investigate the growth-inhibitory effects of honokiol. Cell proliferation was assessed by MTT assays. Apoptosis was measured by flow cytometry analysis and immunofluorescence staining including Hoechst 33342 and TUNEL. Western blot analysis was used to assess the potential inhibition of extracellular signal-regulated kinase (ERK) and AKT signaling by honokiol. RESULTS: Honokiol exhibited significant antiproliferative activity in a dose-dependent manner on HEI 193 cells. Significant apoptosis was detected on schwannoma cells with 7 mg/mL(IC50) honokiol. Western blot analysis showed significant inhibition of ERK phosphorylation. CONCLUSIONS: Honokiol, a low molecular weight natural product, inhibits cell proliferation and promotes apoptosis in schwannoma cells by targeting the ERK pathway. Our data suggest that honokiol can be evaluated as a chemotherapeutic agent for VS.


Antineoplastic Agents, Phytogenic/therapeutic use , Biphenyl Compounds/therapeutic use , Lignans/therapeutic use , Neuroma, Acoustic/drug therapy , Apoptosis/drug effects , Cell Proliferation/drug effects , Humans , Neuroma, Acoustic/pathology , Tumor Cells, Cultured
19.
Korean J Audiol ; 16(2): 43-6, 2012 Sep.
Article En | MEDLINE | ID: mdl-24653870

Otologists and audiologists care for patients and conduct clinical research to find more effective treatments that benefit patients. Institutional Review Board (IRB) permission is necessary for conducting clinical trials on humans. Furthermore, many bioethical conflicts are encountered while conducting research. However, few otologists and audiologists in Korea know bioethics and the principles and regulations of IRBs in detail. This paper reviews the history of ethics in clinical research and current bioethical principles and IRB regulations. We outline what you need as otologists or audiologists to get IRB approval while considering the principles of bioethics.

20.
Korean J Audiol ; 16(2): 71-4, 2012 Sep.
Article En | MEDLINE | ID: mdl-24653874

BACKGROUND AND OBJECTIVES: Sudden sensorineural hearing loss (SSNHL) is commonly defined as a loss of at least 30 dB in three contiguous frequencies occurring within 3 days. Systemic steroid administration has become the most widely accepted treatment option for SSNHL. Since viral infection and vascular compromise are considered specific causes of SSNHL, antiviral agents, anticoagulants, and stellate ganglion block have been used for its treatment, although the evidence of their effectiveness is weak. The present study evaluated the hearing recovery rate in the combination therapy group (systemic steroids, antiviral agent, anticoagulants, and stellate ganglion block) in comparison with patients treated with systemic steroids alone. SUBJECTS AND METHODS: A total of 85 patients diagnosed with SSNHL were treated with combination therapy (group A, 46 patients) or systemic steroids only (group B, 39 patients). Hearing improvement was defined as a hearing gain of more than slight improvement using Siegel's criteria. All patients were treated with a 10-day course of systemic steroids (10-mg dexamethasone for 5 days, followed by tapering for 5 days). Acyclovir, heparin, and stellate ganglion block were included in the group A treatment regimen. RESULTS: The overall rate of hearing improvement was 60.9% (28/46 patients) in group A, which was significantly higher than that (38.5%, 15/39 patients) in group B. The distribution of prognostic factors was not significantly different between the two groups with the exception of the degree of initial hearing loss, which was more severe in group A. Upon analysis according to prognostic factors, group A showed a better hearing improvement recovery rate than group B in patients with hearing loss >70 dB, age >41 years, dizziness, and early treatment (<1 week). CONCLUSIONS: Thus SSNHL patients treated with combination therapy have a higher likelihood of hearing improvement than those treated with systemic steroids alone.

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