RESUMEN
BACKGROUND: Vestibular schwannoma (VS) is a benign tumor of the vestibular nerve. Flair-attenuated inversion recovery (FLAIR) of magnetic resonance imaging (MRI) images are sensitive in detecting high protein contents of fluids. OBJECTIVES: To investigate the association between signal intensity (SI) on FLAIR images and audiovestibular findings in patients with VS. METHODS: Medical records of twenty-five patients with VS were retrospectively analyzed. RESULTS: Larger tumors were associated with increased FLAIR SI of the cochlea, vestibule, and semicircular canal (SCC) on the affected side compared to those of the unaffected side. Pure-tone audiometry (PTA), and speech audiometry were associated with the SI of the affected cochlea. There was no significant correlation between the SI of the vestibule and vestibular evoked myogenic potential, SI of the SCC, and caloric test or video head impulse test results. CONCLUSION: Our study suggests that tumor size was significantly associated with high SI on FLAIR imaging, and audiological findings were associated with the SI of the affected cochlea. Further studies with larger cohorts are required to confirm the association between vestibular function and FLAIR imaging in VS.
Asunto(s)
Imagen por Resonancia Magnética , Neuroma Acústico , Humanos , Neuroma Acústico/diagnóstico por imagen , Neuroma Acústico/complicaciones , Femenino , Persona de Mediana Edad , Masculino , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Estudios Retrospectivos , Audiometría de Tonos Puros , Potenciales Vestibulares Miogénicos Evocados/fisiología , Vestíbulo del Laberinto/diagnóstico por imagen , Vestíbulo del Laberinto/fisiopatología , Cóclea/diagnóstico por imagen , Adulto Joven , Canales Semicirculares/diagnóstico por imagen , Canales Semicirculares/fisiopatologíaRESUMEN
PURPOSE: Facial nerve schwannomas (FNSs) are rare intracranial tumors, and the optimal management of these tumors remains unclear. We investigated the long-term follow-up results of FNS with good facial nerve function. METHODS: At nine medical centers in the Korean Facial Nerve Study Group, 43 patients undergoing observation periods longer than 12 months for FNS with good facial nerve function (House-Brackmann grade ≤ II) were enrolled, and clinical and radiographic data were obtained for these cases. RESULTS: The mean follow-up period was 63 months. In the majority of cases, tumors involved multiple segments (81.4%) and only eight cases were confined to a single site. There were no cases where the tumor was confined to the extratemporal region. Tumor size increased slightly, with an average estimated change of 0.48 mm/year. Twenty (46.5%) of 43 patients showed no change in tumor size. Seven patients (16.3%) showed worsening House-Brackmann (H-B) grade, of which two patients deteriorated from H-B grade I to II, four worsened to grade III, and one deteriorated to grade IV. The remaining 36 patients (83.7%) showed no change in facial nerve function. There was no difference in H-B grade according to tumor size at the time of diagnosis or change in tumor size. CONCLUSION: We conducted a large-scale observational study of FNS with good facial nerve function. Our study showed that many patients maintained facial nerve function during long-term follow-up. Conservative management with regular examination and imaging can be an appropriate option for managing FNS with good facial nerve function.
RESUMEN
BACKGROUND: This article presents a comprehensive review of data on the impact of facial palsy during the coronavirus disease 2019 (COVID-19) pandemic. The possible causes and pathophysiological mechanisms of changes in the epidemiology of facial palsy during the COVID-19 pandemic are also discussed. METHODS: This multicenter retrospective cohort study included 943 patients diagnosed with Bell's palsy or Ramsay Hunt syndrome. This study compared patient demographics, comorbidities, symptoms, and treatments before the COVID-19 pandemic (from 2017 to 2019) and during the COVID-19 pandemic, from 2020 to 2022). RESULTS: Following the COVID-19 outbreak, there has been a significant increase in the number of cases of Bell's palsy, particularly among elderly individuals with diabetes. Bell's palsy increased after the COVID-19 outbreak, rising from 75.3% in the pre-COVID-19 era to 83.6% after the COVID-19 outbreak. The complete recovery rate decreased from 88.2% to 73.9%, and the rate of recurrence increased from 2.9% to 7.5% in patients with Bell's palsy. Ramsay Hunt syndrome showed fewer changes in clinical outcomes. CONCLUSION: This study highlights the impact of the COVID-19 pandemic on the presentation and management of facial palsy, and suggests potential associations with COVID-19. Notably, the observed increase in Bell's palsy cases among elderly individuals with diabetes emphasizes the impact of the pandemic. Identifying the epidemiological changes in facial palsy during the COVID-19 pandemic has important implications for assessing its etiology and pathological mechanisms of facial palsy disease.
Asunto(s)
Parálisis de Bell , COVID-19 , Herpes Zóster Ótico , SARS-CoV-2 , Humanos , Parálisis de Bell/epidemiología , COVID-19/epidemiología , Estudios Retrospectivos , Masculino , Persona de Mediana Edad , Femenino , Anciano , SARS-CoV-2/aislamiento & purificación , Adulto , Herpes Zóster Ótico/epidemiología , Herpes Zóster Ótico/tratamiento farmacológico , Herpes Zóster Ótico/diagnóstico , Pandemias , Comorbilidad , Anciano de 80 o más AñosRESUMEN
PURPOSE: To evaluate the predictive factors of tumor growth in patients with vestibular schwannoma (VS) managed with the wait-and-scan approach. METHODS: The data of 31 patients diagnosed with intracanalicular VS and followed for > 5 years were retrospectively analyzed. VS was diagnosed according to MRI findings and tumor growth was monitored. Tumor growth was defined as an increase of 2 mm or more in the maximal tumor diameter. The association between the initial tumor size and shape and tumor growth was assessed. RESULTS: Tumor growth was observed in 16 of 31 patients (51.6%) over a mean follow-up duration of 7.3 years. The initial tumor size was not statistically correlated with tumor growth. However, fusiform or cylindrical tumors exhibited higher growth rates than oval or round tumors. Additionally, a significant correlation was observed between cerebellopontine angle extension and tumor shape. CONCLUSION: In this study, 51.6% of the patients with intracanalicular VS who were managed with the wait-and-scan strategy over a follow-up period of > 5 years showed tumor growth. Tumor shape, especially fusiform or cylindrical shape, was found to be a significant predictor of tumor growth.
Asunto(s)
Imagen por Resonancia Magnética , Neuroma Acústico , Humanos , Neuroma Acústico/patología , Neuroma Acústico/diagnóstico por imagen , Masculino , Femenino , Persona de Mediana Edad , Estudios Retrospectivos , Imagen por Resonancia Magnética/métodos , Adulto , Pronóstico , Anciano , Estudios de Seguimiento , Carga Tumoral , Espera VigilanteRESUMEN
INTRODUCTION: Several studies have reported that the number of patients with Bell's palsy varied significantly by month and season. However, few studies have reported the monthly variation in Bell's palsy based on the whole population. We investigated the monthly variation in Bell's palsy in Korea during a long-term period based on whole population data. METHODS: This retrospective study used the data of the National Health Insurance Service of Korea, which included the entire Korean population from 2008 to 2020. The monthly incidence of Bell's palsy per 100,000 was evaluated in total and according to sex, age, and residence. RESULTS: The total average monthly incidence differed significantly by month, with the highest observed in January (9.1 per 100,000) and the lowest in June (7.7 per 100,000) (p < 0.001). The average monthly incidence according to sex, age, and residence also varied significantly by month, with most of the highest values noted in January and the lowest in June. CONCLUSION: There was significant monthly variation in the incidence of Bell's palsy, with the highest in January during the winter and the lowest in June during the summer, based on whole population data over a long-term period in Korea.
Asunto(s)
Parálisis de Bell , Estaciones del Año , Parálisis de Bell/epidemiología , Humanos , República de Corea/epidemiología , Masculino , Femenino , Persona de Mediana Edad , Adulto , Incidencia , Estudios Retrospectivos , Anciano , Adulto Joven , Adolescente , Niño , Preescolar , Lactante , Anciano de 80 o más Años , Recién NacidoRESUMEN
OBJECTIVES: Persistent postural-perceptual dizziness (PPPD) is a chronic functional vestibular disorder for which the Bárány Society has established diagnostic criteria. This nationwide multicenter study aims to investigate the clinical features of individuals with definite PPPD and clinical variant PPPD who do not fully meet the diagnostic criteria, with a particular focus on visual exaggeration. METHODS: Between September 2020 and September 2021, a total of 76 individuals with definite PPPD and 109 individuals with clinical variant PPPD who did not meet all three exacerbating factors outlined in Criterion B were recruited from 18 medical centers in South Korea. The study gathered information on demographic factors, clinical manifestations, balance scales, and personality assessments. RESULTS: Comparative analysis between groups with definite PPPD and clinical variant with visual exacerbation revealed no significant differences in sociodemographic characteristics, clinical course, dizziness impact, and specific precipitants. Only disease duration was significantly longer in definite PPPD compared with variant with visual exacerbation. However, the variant without visual exacerbation displayed significantly reduced rates of panic disorder, diminished space-motion discomfort, lesser impact of dizziness, and decreased prevalence of depression when compared with the definitive PPPD. CONCLUSION: This is the first comprehensive nationwide study examining clinical features of both definite PPPD patients and its clinical variants, considering visual exacerbating factors. Differences in dizziness and personality traits emerged between definite PPPD and its potential variant without visual issues. Our results highlight the possibility of a distinct clinical variant of PPPD influenced by visual dependency.
Asunto(s)
Mareo , Enfermedades Vestibulares , Humanos , Mareo/diagnóstico , Mareo/epidemiología , Estudios Transversales , Vértigo , Enfermedades Vestibulares/diagnóstico , Enfermedades Vestibulares/epidemiología , República de Corea/epidemiologíaRESUMEN
Auditory brainstem response (ABR) is the response of the brain stem through the auditory nerve. The ABR test is a method of testing for loss of hearing through electrical signals. Basically, the test is conducted on patients such as the elderly, the disabled, and infants who have difficulty in communication. This test has the advantage of being able to determine the presence or absence of objective hearing loss by brain stem reactions only, without any communication. This paper proposes the image preprocessing process required to construct an efficient graph image data set for deep learning models using auditory brainstem response data. To improve the performance of the deep learning model, we standardized the ABR image data measured on various devices with different forms. In addition, we applied the VGG16 model, a CNN-based deep learning network model developed by a research team at the University of Oxford, using preprocessed ABR data to classify the presence or absence of hearing loss and analyzed the accuracy of the proposed method. This experimental test was performed using 10,000 preprocessed data, and the model was tested with various weights to verify classification learning. Based on the learning results, we believe it is possible to help set the criteria for preprocessing and the learning process in medical graph data, including ABR graph data.
RESUMEN
The objective of this study is to design and synthesize substituted η6-chromium(0) tricarbonyl metal complexes carrying o-carborane units as potential boron neutron capture therapy (BNCT) agents. In this study, 1,2-diphenyl-o-carborane (1) units were used as starting materials to generate biologically active species. We investigated how the structural changes of 1 substituted with chromium(0) tricarbonyl affect the biological properties, and 1-(Phenyl-η6-chromium(0) tricarbonyl)-2-phenyl-o-carborane (2) and 1,2-bis(phenyl-η6-chromium(0) tricarbonyl)-o-carborane (3) species were produced in moderate yields. The molecular structures of compounds 1-3 were identified and established by infrared (IR); 1H, 11B, and 13C nuclear magnetic resonance (NMR) and X-ray crystallography analyses. Crystal structures of 1,2-diphenyl-o-carborane and the corresponding chromium complexes 1, 2, and 3 were obtained. In an in vitro study using B16 and CT26 cancer cells containing the triphenyl-o-carboranyl chromium(0) complexes Ph3C2BCr2 and Ph3C2BCr3, which we reported previously, compounds 2 and 3 accumulated at higher levels than compounds Ph3C2BCr2 and Ph3C2BCr3. However, the phenylated o-carboranyl chromium complexes have been found to be more cytotoxic than p-boronophenylalanine (BPA).
Asunto(s)
Boranos , Cromo , Rayos X , Compuestos de Boro/química , Estructura MolecularRESUMEN
BACKGROUND: The association between programed cell death-ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) in vestibular schwannoma (VS) has been investigated in a few studies. These published studies report a difference in the PD-L1 positivity rate in malignant peripheral nerve sheath tumors. We examined PD-L1 expression and lymphocyte infiltration in patients with VS who had undergone surgical resection and investigated the association between PD-L1 expression and clinicopathological features. METHODS: The expression of PD-L1, CD8, and Ki-67 in 40 VS tissue specimens was investigated using immunohistochemistry, and a clinical review of the patients was performed. RESULTS: Of the 40 VS samples, 23 (57.5%) were positive for PD-L1 and 22 (55%) were positive for CD8. No significant differences in age, tumor size, pure-tone audiometry, speech discrimination, or Ki-67 expression were observed between patients in the PD-L1-positive and PD-L1-negative groups. A higher level of CD8-positive cell infiltration was observed in PD-L1-positive tumors than in PD-L1-negative tumors. CONCLUSION: We demonstrated that PD-L1 was expressed in VS tissues. Although no correlation was identified between clinical characteristics and PD-L1 expression, the association between PD-L1 and CD8 was confirmed. Thus, additional research on targeting PD-L1 is necessary to improve immunotherapy for VS in the future.
Asunto(s)
Antígeno B7-H1 , Neuroma Acústico , Humanos , Antígeno B7-H1/metabolismo , Antígeno Ki-67 , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/patología , PronósticoRESUMEN
Importance: Hearing loss is the most important modifiable risk factor for cognitive impairment; however, the association of hearing loss with anatomical and functional connectivity is not fully understood. This association may be elucidated by evaluating the findings of newer imaging technologies. Objectives: To evaluate the association of hearing loss with anatomical and functional connectivity in patients with mild cognitive impairment (MCI) by using multimodal imaging technology. Design, Setting, and Participants: This was a prospective cross-sectional study of patients with MCI under the care of a neurology clinic at the Soonchunhyang University Bucheon Hospital (Republic of Korea) from April to September 2021. Data were analyzed from April 1 to June 30, 2022. Main Outcomes and Measures: Pure tone averages (PTA) and word recognition scores were used to measure hearing acuity. Magnetic resonance imaging (MRI) and positron emission tomography scans of the brain were used to assess functional and anatomical connectivity. Results of diffusion MRI, voxel- and surface-based morphometric imaging, and global brain amyloid standardized uptake ratio were analyzed. Neuroimaging parameters of patients with MCI plus hearing loss were compared with those of patients with MCI and no hearing loss. Correlation analyses among neuroimaging parameters, PTA, and word recognition scores were performed. Results: Of 48 patients with MCI, 30 (62.5%) had hearing loss (PTA >25 dB) and 18 (37.5%) did not (PTA ≤25 dB). Median (IQR) age was 73.5 (69.0-78.0) years in the group with hearing loss and 75.0 (65.0-78.0) years in the group with normal hearing; there were 20 (66.7%) and 14 (77.8%) women in each group, respectively. The group with MCI plus hearing loss demonstrated decreased functional connectivity between the bilateral insular and anterior divisions of the cingulate cortex, and decreased fractional anisotropy in the bilateral fornix, corpus callosum forceps major and tapetum, left parahippocampal cingulum, and left superior thalamic radiation. Fractional anisotropy in the corpus callosum forceps major and bilateral parahippocampal cingulum negatively correlated with the severity of hearing loss shown by PTA testing. The 2 groups were not significantly different in global ß-amyloid uptake, gray matter volume, and cortical thickness. Conclusion and Relevance: The findings of this prospective cross-sectional study suggest that alterations in the salience network may contribute to the neural basis of cognitive impairment associated with hearing loss in patients who are on the Alzheimer disease continuum.
Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Sordera , Pérdida Auditiva , Humanos , Femenino , Anciano , Masculino , Estudios Transversales , Estudios Prospectivos , Pruebas Neuropsicológicas , Encéfalo/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Enfermedad de Alzheimer/diagnóstico , Pérdida Auditiva/fisiopatología , Sordera/fisiopatologíaRESUMEN
OBJECTIVES: Endoscopic tympanoplasty (ET) provides minimally invasive transcanal access to the middle ear and improves middle ear visibility for the treatment of tympanic membrane (TM) perforations. However, the literature on surgical outcomes for large TM perforations is lacking and limited to small series. This study aimed to evaluate the clinical benefits of ET for large TM perforations. METHODS: This retrospective cohort study was conducted at nine tertiary referral hospitals in South Korea, where 252 patients who underwent ET as primary surgery from September 2019 to August 2021 were included. The outcome measures included the graft success rate and pre- and postoperative audiometric data. RESULTS: In 239 patients, the graft success rate of ET for large or subtotal perforations was 86.2% (206 patients), while the graft failure rate was 13.8% (33 patients). The graft failure rate was directly correlated with surgical techniques, including overlay and medial or lateral underlay tympanoplasty (P=0.027). Lateral underlay tympanoplasty showed the most favorable. RESULTS: Sex, laterality, etiology, site and size of perforation, operation time, and graft materials did not vary significantly between the graft success and failure groups (P>0.05). The mean air-bone gap (ABG) improved significantly in both groups (graft success group: 10.0±0.6 dB and graft failure group: 7.7±0.3 dB; P<0.001). However, the ABG improvement did not significantly differ between the groups. Analysis of covariance revealed that the postoperative 500-Hz bone conduction threshold improved after successful ET (adjusted coefficient, -11.351; 95% confidence interval, -21.491 to -1.212; P=0.028). CONCLUSION: This study involved the largest population to date of large TM perforations treated by ET. The study findings suggest that ET is feasible and effective in treating large TM perforations.
RESUMEN
Importance: Transcanal endoscopic ear surgery (TEES) provides minimally invasive transcanal access to the middle ear and improves middle ear visibility during cholesteatoma resection. However, the literature on outcomes following TEES alone for the removal of congenital cholesteatoma (CC) is lacking and limited to small series. Objective: To assess outcomes of TEES for CC limited to the middle ear and/or mastoid antrum and to explore the risk factors associated with recidivism (ie, recurrent and/or residual cholesteatoma). Design, Setting, and Participants: This cohort study evaluated retrospective, multicenter data for 271 children with CC who underwent TEES at 9 tertiary referral hospitals in South Korea between January 1, 2013, and December 31, 2021, and had a follow-up of at least 6 months after surgery. Main Outcomes and Measures: Outcomes included the incidence of residual cholesteatoma and audiometric data after TEES. A multivariable analysis using Cox proportional hazards regression models was used to assess associations between cholesteatoma characteristics and recidivism, with hazard ratios (HRs) and 95% CIs reported. Results: Of the 271 patients (mean [SD] age, 3.5 [2.9] years; 194 [71.6%] boys, 77 [28.4%] girls), 190 had Potsic stage I CC (70.1%), 21 (7.7%) had stage II, 57 (21.0%) had stage III, and 3 (1.1%) had stage IV. Thirty-six patients (13.3%) with residual cholesteatoma were found, including 15 (7.9%) with Potsic stage I, 3 (14.3%) with stage II, and 18 (31.6%) with stage III. In the multivariable analysis, invasion of the malleus (HR, 2.257; 95% CI, 1.074-4.743) and posterosuperior quadrant location (HR, 3.078; 95% CI, 1.540-6.151) were associated with the incidence of recidivism. Overall, hearing loss (>25 dB on auditory behavioral test or >30 dB of auditory evoked responses) decreased from 24.4% to 17.7% after TEES. Conclusions and Relevance: This cohort study involved the largest known population to date of CC removed by TEES. The findings suggest that TEES may be feasible and effective for the removal of CC limited to the middle ear and/or mastoid antrum in children.
Asunto(s)
Colesteatoma del Oído Medio , Masculino , Niño , Femenino , Humanos , Preescolar , Colesteatoma del Oído Medio/cirugía , Estudios Retrospectivos , Estudios de Cohortes , Endoscopía , Resultado del TratamientoRESUMEN
Owing to their unique properties and biological activities, ionic liquids (ILs) have attracted research interest in pharmaceutics and medicine. Hypoxia-inducible factor (HIF)- 1α is an attractive cancer drug target involved in cancer malignancy in the hypoxic tumor microenvironment. Herein, we report the inhibitory activity of ILs on the HIF-1α pathway and their mechanism of action. Substitution of a dimethylamino group on pyridinium reduced hypoxia-induced HIF-1α activation. It selectively inhibited the viability of the human colon cancer cell line HCT116, compared to that of the normal fibroblast cell line WI-38. These activities were enhanced by increasing the alkyl chain length in the pyridinium. Under hypoxic conditions, dimethylaminopyridinium reduced the accumulation of HIF-1α and its target genes without affecting the HIF1A mRNA level in cancer cells. It suppressed the oxygen consumption rate and ATP production by directly inhibiting electron transfer chain complex I, which led to enhanced intracellular oxygen content and oxygen-dependent degradation of HIF-1α under hypoxia. These results indicate that dimethylaminopyridinium suppresses the mitochondria and HIF-1α-dependent glucose metabolic pathway in hypoxic cancer cells. This study provides insights into the anticancer activity of pyridinium-based ILs through the regulation of cancer metabolism, making them promising candidates for cancer treatment.
Asunto(s)
Neoplasias del Colon , Líquidos Iónicos , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Líquidos Iónicos/toxicidad , Hipoxia , Oxígeno , Microambiente TumoralRESUMEN
BACKGROUND: Sporadic Creutzfeldt-Jakob disease (sCJD) is a prion disease characterized as a fatal transmissible neurodegenerative disorder. Dizziness is often the first presenting symptom of sCJD, but hearing loss as an early manifestation is very rare. CASE SUMMARY: A 76-year-old man presented with bilateral sudden hearing impairment and dizziness for 10 d. He was taking medications for hypertension and diabetes. He denied any difficulty with activities of daily living or hearing impairment before the onset of symptoms. Pure tone audiometry showed bilateral severe hearing impairment. Brain magnetic resonance imaging (MRI) and laboratory tests were within normal limits. Given his diagnosis of sudden sensory hearing loss, the patient received corticosteroid treatment but it was ineffective. Two weeks later, he complained of aggravated gait impairment, disorientation, and cognitive impairment. Repeat brain MRI showed diffuse cortical high signal intensities on diffusion-weighted imaging. In cerebrospinal fluid analysis, the real-time quaking-induced conversion assay was positive, and 14-3-3 protein was detected in the by western blotting. Considering all the data, we diagnosed probable sCJD, and the patient's symptoms rapidly progressed into akinetic mutism. CONCLUSION: For patients with abrupt bilateral hearing impairment, especially in the elderly, various differential diagnoses, including sCJD, should be considered.
RESUMEN
BACKGROUND: Sudden sensorineural hearing loss (SSNHL) has several aetiologies and may be a presenting symptom of vestibular schwannoma (VS). OBJECTIVES: The aim of this study was to investigate the recovery rate after steroid treatment and the prognostic factors of SSNHL with VS. MATERIALS AND METHODS: This was a retrospective observational study wherein 32 patients with VS who presented with SSNHL were analysed at a tertiary referral centre. Hearing gain and prognostic factors were the main outcome measures for steroid treatment intervention. RESULTS: Among the 1698 patients presenting with SSNHL, VS was found in 43 (2.5%) patients. Eleven cases (34.3%) showed good recovery, with significant improvements in the pure-tone audiometry values. Even though age was a significant factor, there were no associations between steroid response and initial hearing level, presence of vertigo, tumour size, and tumour extension. CONCLUSIONS AND SIGNIFICANCE: Our study showed that hearing recovery of SSNHL does not exclude a VS diagnosis. We suggest that steroid treatment be considered in patients with VS presenting SSNHL.
Asunto(s)
Pérdida Auditiva Sensorineural , Pérdida Auditiva Súbita , Neuroma Acústico , Audiometría de Tonos Puros , Pérdida Auditiva Sensorineural/diagnóstico , Pérdida Auditiva Sensorineural/tratamiento farmacológico , Pérdida Auditiva Sensorineural/etiología , Pérdida Auditiva Súbita/diagnóstico , Pérdida Auditiva Súbita/tratamiento farmacológico , Pérdida Auditiva Súbita/etiología , Humanos , Neuroma Acústico/complicaciones , Neuroma Acústico/diagnóstico , Neuroma Acústico/tratamiento farmacológico , Estudios Retrospectivos , EsteroidesRESUMEN
Vestibular schwannoma (VS), one of characteristic tumors of neurofibromatosis type 2 (NF2), is an intracranial tumor that arises from Schwann cells of the vestibular nerve. VS results in hearing loss, tinnitus, dizziness, and even death, but there are currently no FDA-approved drugs for treatment. In this study, we established a high-throughput screening to discover effective compounds that could inhibit the viability of VS cells. Among 1019 natural products from the Korea Chemical Bank screened, we found that celastrol, a pentacyclic triterpene derived from a Tripterygium Wilfordi plant, exerted potent inhibitory effect on the viability of VS cells with an IC50 value of 0.5 µM. Celastrol (0.5, 1 µM) dose-dependently inhibited the proliferation of primary VS cells derived from VS patients. Celastrol also inhibited the growth, and induced apoptosis of two other VS cell lines (HEI-193 and SC4). Aberrant activation of Wnt/ß-catenin signaling has been found in VS isolated from clinically defined NF2 patients. In HEI-193 and SC4 cells, we demonstrated that celastrol (0.1, 0.5 µM) dose-dependently inhibited TOPFlash reporter activity and protein expression of ß-catenin, but not mRNA level of ß-catenin. Furthermore, celastrol accelerated the degradation of ß-catenin by promoting the formation of the ß-catenin destruction complex. In nude mice bearing VS cell line SC4 allografts, administration of celastrol (1.25 mg · kg-1 · d-1, i.p. once every 3 days for 2 weeks) significantly suppressed the tumor growth without showing toxicity. Collectively, this study demonstrates that celastrol can inhibit Wnt/ß-catenin signaling by promoting the degradation of ß-catenin, consequently inhibiting the growth of VS.
Asunto(s)
Neuroma Acústico , beta Catenina , Ratones , Animales , beta Catenina/metabolismo , Neuroma Acústico/tratamiento farmacológico , Neuroma Acústico/metabolismo , Neuroma Acústico/patología , Ratones Desnudos , Proliferación Celular , Línea Celular Tumoral , Triterpenos Pentacíclicos/farmacología , Apoptosis , Vía de Señalización WntRESUMEN
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.
RESUMEN
OBJECTIVE: To describe a novel approach for intractable Ménière's disease exclusively through a transcanal endoscopic ear surgery (TEES) approach. PATIENT: A 56-year-old male with intractable Ménière's disease despite conservative treatment and chemical labyrinthectomy. INTERVENTIONS: Transcanal endoscopic labyrinthectomy. MAIN OUTCOME MEASURE: Subjective vertigo control, surgical morbidity. RESULTS: The TEES approach provided a wide exposure of the oval window. This facilitated removal of stapes crura and footplate. After widening of the oval window, the perilymph was suctioned, and gentamicin was injected through the oval window. The oval window was obliterated using the perichondrium of the tragal cartilage and fibrin glue. After 2 years of follow-up, there was no recurrence of vertigo. CONCLUSIONS: As a compelling alternative to the transmastoid approach, we propose endoscopic labyrinthectomy as an option for patients with intractable MD without functional hearing who have failed chemical labyrinthectomy. Additional studies are needed to determine the risk-benefit profile of this technique.