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The two aims of this study were (1) designing and developing an affordable visual reaction system for badminton training that monitors and provides instant feedback on agility; and (2) to measure and improve the footwork and movement of badminton players and output useful reference data. Ten junior high school badminton players were invited to serve as the subjects of this study. They participated in a three-week (nine sessions) training program. Training was primarily in the form of fixed or random footwork drills. Timed tests were performed before and after each session to measure the players' agility in performing six-point and four-point footwork drills. The results were compared to the training effects calculated using dependent-sample t-tests. In addition, the long-term durability and functionality of the training system were tested. The training system was able to maintain stable and reliable training and evaluation operations for extended periods. Results showed significant improvements in the visual reaction time (p = 0.003) and agility (p = 0.001) of players. The proposed training system is an affordable option for training and monitoring, evaluating, and recording training performance. It can accurately record movement and response times and simulate competitive environments.
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Rendimiento Atlético , Monitoreo Fisiológico , Deportes de Raqueta , Humanos , Movimiento , Tiempo de ReacciónRESUMEN
Non-alcoholic fatty liver disease (NAFLD) has become the most common liver disease in the recent decades in both developed and developing countries, and is predicted to be the major etiology for liver transplantation in the next decade. Thus, pharmacological strategies to treat NAFLD are urgently needed. Natural products are considered an excellent source for drug discovery. By utilizing an image-based high-throughput screening with a library containing 3000 Taiwanese indigenous plant extracts, we discovered that the extract of Syzygium simile leaves (SSLE) has an anti-lipid droplet (LD) accumulation effect in hepatic cell lines. Analyses of the expression profile of genes involved in lipid metabolism revealed that SSLE suppressed the mRNA expression of CD36, fatty acid translocase. In agreement with this observation, we showed that SSLE inhibited CD36 protein expression and fatty acid uptake and has only limited effects on pre-formed LDs. Moreover, SSLE reduced LD accumulation and CD36 expression in enterocyte and macrophage cell lines. In conclusion, our findings suggest that SSLE could serve as a potential source for the discovery of novel therapeutic modalities for NAFLD and that the suppression of CD36 expression and fatty acid uptake could contribute to the lipid-lowering effect of SSLE.
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Ácidos Grasos/metabolismo , Extractos Vegetales/farmacología , Hojas de la Planta/química , Syzygium/química , Línea Celular Tumoral , Células Hep G2 , Humanos , Metabolismo de los Lípidos/efectos de los fármacosRESUMEN
Acquired sensory hearing loss (SHL) is suggested to be associated with depression. However, some studies have reported conflicting results. Our study investigated the relationship between the prevalence of SHL and the incidence of depression over 12 years of follow-up by using data from the Taiwan National Health Insurance Research Database (NHIRD). We sought to determine the association between SHL and subsequent development of depression and discuss the pathophysiological mechanism underlying the association.Patients with SHL were identified from the NHIRD (SHL cohort). A non-SHL cohort, comprising patients without SHL frequency-matched with the SHL patients according to age group, sex, and the year of diagnosis of SHL at the ratio of 1:4, was constructed, and the incidence of depression was evaluated in both cohorts. A multivariable model was adjusted for age, sex, and comorbidity.The SHL cohort and non-SHL cohort comprised 5043 patients with SHL and 20,172 patients without SHL, respectively. The incidences density rates were 9.50 and 4.78 per 1000 person-years in the SHL cohort and non-SHL cohort, respectively. After adjustment for age, sex, and comorbidities, the risk of depression was higher in the SHL cohort than in the non-SHL cohort (hazard ratioâ=â1.73, 95% confidence intervalâ=â1.49-2.00).Acquired SHL may increase the risk of subsequent depression. The results demonstrated that SHL was an independent risk factor regardless of sex, age, and comorbidities. Moreover, a strong association between hearing loss and subsequent depression among Taiwanese adults of all ages, particularly those aged ≤49 and >65 years and without using steroids for the treatment of SHL was observed. Prospective clinical and biomedical studies on the relationship between hearing loss and depression are warranted for determining the etiopathology.
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Depresión/epidemiología , Depresión/etiología , Pérdida Auditiva Sensorineural/complicaciones , Adulto , Anciano , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Medición de Riesgo , Factores de TiempoRESUMEN
BACKGROUND: This study was undertaken to evaluate whether endoscopic sinus surgery (ESS) with a microdebrider had an impact on complication rates, and to facilitate the determination of factors associated with complications in patients who underwent ESS at a tertiary referral center in Taiwan. METHODS: This investigation was a retrospective study and literature review. We analyzed 997 consecutive patients who underwent ESS at Mackay Memorial Hospital in Taipei, Taiwan from January 2006 through February 2010. All data including those of patient medical information, and peri- and postoperative complications were provided by the surgeons involved in patient medical care. We analyzed the complication rates using the following 10 variables by univariate analysis and multivariate logistic regression: sex, age, Lund-Mackay score, polyp grading, previous sinonasal surgery, surgeon skill, adjunctive sinonasal surgery, mesenteric type of anterior ethmoid artery, Keros skull base type, and the use of a microdebrider. RESULTS: Of the 997 patients in our study, 78 (7.8%) had complications. Major complications occurred in five patients (0.5%): two with cerebrospinal fluid rhinorrhea, one with medial rectus muscle damage, and two with retrobulbar hematoma. Minor complications were found in 73 patients (7.3%), which included 32 patients with perioperative estimated blood loss > 15% of the total estimated blood volume, 26 with lamina papyracea damage, two with orbital cellulitis, and 13 with postoperative bleeding. Univariate analysis showed that risk factors related to complication rate were advanced Lund-Mackay scores (scores 19-24), advanced polyp grading (Grades 2 and 3), inexperienced surgeon (resident), and microdebrider usage. However, multivariate analysis revealed that complication rate was linked to advanced Lund-Mackay scores (Scores 19-24), mesenteric type of anterior ethmoid artery, and inexperienced surgeon. CONCLUSION: Overall, the results of our study showed that the ESS complication rate was 7.8%, with risk factors including advanced Lund-Mackay scores (19-24, odds ratio 10.4) and inexperienced surgeon. It was also noted that ESS with a microdebrider had no impact on complication rates, although the presence of a mesenteric type of anterior ethmoid artery proved to be a protective factor.
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Endoscopía/efectos adversos , Senos Paranasales/cirugía , Adolescente , Adulto , Anciano , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
CONCLUSIONS: ITSI as a first-line therapy in uremia patients with SSNHL offers a valid and safe treatment compared with intravenous systemic steroid treatment. A specific pathophysiology caused by possible sodium pump paralysis may be explained for uremia patients with SSNHL. OBJECTIVE: To compare the efficacy of intratympanic steroid injection (ITSI) with that of systemic intravenous steroids as a first-line therapy in uremia patients with sudden sensorineural hearing loss (SSNHL). MATERIALS AND METHODS: A total of 23 consecutive uremia patients with SSNHL were enrolled in this study. Patients were divided into two groups: the ITSI group (n = 15) and the non-ITSI group (n = 8), in which patients received intravenous systemic steroid treatment. The two groups were homogeneous in all respects. RESULTS: The hearing improvement and relative gain were statistically significant between the two groups. The value of hearing gain (ΔPTA = PTA pre - PTA post) in the ITSI group and the non-ITSI group was 24.6 ± 16.4dB and 8.4 ± 19.3dB. The value of relative gain (ΔPTA/PTApre) in the ITIS group and the non-ITSI group was 31.1 ± 22% and 9.4 ± 20.5%. In the ITSI group, 11 patients (73.3%) exhibited hearing recovery (ΔPTA > 10 dB).
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Pérdida Auditiva Sensorineural/tratamiento farmacológico , Pérdida Auditiva Súbita/tratamiento farmacológico , Audición/fisiología , Uremia/complicaciones , Anciano , Audiometría de Tonos Puros , Dexametasona , Relación Dosis-Respuesta a Droga , Femenino , Estudios de Seguimiento , Glucocorticoides/administración & dosificación , Pérdida Auditiva Sensorineural/etiología , Pérdida Auditiva Sensorineural/fisiopatología , Pérdida Auditiva Súbita/etiología , Pérdida Auditiva Súbita/fisiopatología , Humanos , Inyección Intratimpánica , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Uremia/tratamiento farmacológicoRESUMEN
Most studies on ultra-fast cryopreservation assume an immediate placement of the cryopreservation tube in the liquid nitrogen tank. However, in practice, before the tube is placed into the liquid nitrogen, it passes through a space containing gaseous nitrogen (pre-cooling zone) formed via the evaporation of the bulk liquid nitrogen. Comparing with ultra-fast cryopreservation, the cooling rate is insufficiently high during the falling transition to vitrify the liquid. As the tube passes through this region, its temperature may fall to the temperature required for the formation of ice crystals, and thus cell damage may occur. Consequently, in optimizing the cryopreservation process, the effects of this transition region should be properly understood. Accordingly, the present study utilizes a thermal model to investigate the temperature variation in the tube as it falls through the pre-cooling region. The simulation results show that the cooling rate within the tube increases with an increasing tube velocity. Furthermore, the results reveal that the cooling rate at the front end of the tube is higher than that at any other position of the tube. Thus, to prevent the formation of ice crystals, the material used to seal the front end of the tube should have a low thermal conductivity. In addition, a streamlined design of the front end of the tube is advised. Finally, the cooling rate within the tube depends on the tube material as well as the falling speed. The height of the pre-cooling zone needs to be carefully designed based on the tube material and falling speed, thus the ice crystal formation can be prevented.
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Frío , Criopreservación/métodos , Vitrificación , Calor , Modelos Teóricos , Nitrógeno/química , Conductividad TérmicaRESUMEN
PURPOSE: To detect the differences in the distribution of micromotion within implants and alveolar bone with different implant thread designs during immediate loading. MATERIALS AND METHODS: A three-dimensional finite element model with contact elements was used to simulate the contact behavior between the implant and alveolar bone. Implants with four different thread designs were created: Acme (trapezoidal) thread (AT), buttress thread (BT), square thread (ST), and a standard V-thread (VT). To simulate immediate loading, the model was designed without osseointegration between the implant and alveolar bone. A load of 300 N was applied axially to the model, and the micromovements were measured. RESULTS: The maximum micromotion values of the ST, AT, VT, and BT models were 8.53, 9.57, 11.00, and 15.00 µm, respectively. All micromotion was located near the interface of cortical and cancellous bone. Different thread designs showed different distribution of micromotion during loading. This indicates that initial stability in immediate loading may be affected by thread design. CONCLUSION: The ST profile showed the most favorable result in the study. An implant with an ST profile might provide the best primary stability in an immediate loading situation.
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Proceso Alveolar , Simulación por Computador , Implantes Dentales , Análisis de Elementos Finitos , Carga Inmediata del Implante Dental , Movimiento (Física) , Fuerza de la Mordida , Pins Dentales , Diseño de Prótesis Dental , Análisis del Estrés Dental/métodos , Humanos , OseointegraciónRESUMEN
The diesel engine is the main power source for most agricultural vehicles. The control of diesel engine emissions is an important global issue. Fuel injection control systems directly affect fuel efficiency and emissions of diesel engines. Deterioration faults, such as rack deformation, solenoid valve failure, and rack-travel sensor malfunction, are possibly in the fuel injection module of electronic diesel control (EDC) systems. Among these faults, solenoid valve failure is most likely to occur for in-use diesel engines. According to the previous studies, this failure is a result of the wear of the plunger and sleeve, based on a long period of usage, lubricant degradation, or engine overheating. Due to the difficulty in identifying solenoid valve deterioration, this study focuses on developing a sensor identification algorithm that can clearly classify the usability of the solenoid valve, without disassembling the fuel pump of an EDC system for in-use agricultural vehicles. A diagnostic algorithm is proposed, including a feedback controller, a parameter identifier, a linear variable differential transformer (LVDT) sensor, and a neural network classifier. Experimental results show that the proposed algorithm can accurately identify the usability of solenoid valves.
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Diseño de Equipo/métodos , Gasolina , Emisiones de Vehículos/análisis , Algoritmos , Electrónica , Modelos Teóricos , Redes Neurales de la Computación , Análisis de Componente Principal/métodos , Reproducibilidad de los ResultadosRESUMEN
CONCLUSIONS: Administration of high-dose gentamicin for intractable Meniere's disease appears to be effective in achieving long-term control of vertigo. However, the safety of this route of administration with respect to the patient's hearing has not yet been sufficiently established. OBJECTIVES: The study aimed to analyze the long-term results of patients receiving high-dose intratympanic gentamicin (ITG) instillation for refractory Meniere's disease. PATIENTS AND METHODS: Fourteen patients with Meniere's disease according to 1995 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guidelines who had failed medical (12 subjects) or surgical (2 subjects) treatment were included. Intratympanic injections of 27 mg/ml gentamicin were performed three times daily for 4 days. Vertigo control, the patients' functional level, and their hearing threshold were all analyzed. Criteria described in 1995 by AAO-HNS were used. RESULTS: The overall successful vertigo control rate was 92.9% over the 2-year follow-up and 85.7% at long-term follow-up (average 10 years). Hearing level as pure-tone average was worse in four patients (28.5%) after 2 years follow-up and in six patients (42.8%) after long-term follow-up, respectively. Profound sensorineural hearing loss occurred as a result of gentamicin injection in one patient (7%).
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Gentamicinas/efectos adversos , Pérdida Auditiva/inducido químicamente , Enfermedad de Meniere/tratamiento farmacológico , Inhibidores de la Síntesis de la Proteína/efectos adversos , Vértigo/tratamiento farmacológico , Adulto , Anciano , Femenino , Estudios de Seguimiento , Gentamicinas/administración & dosificación , Humanos , Masculino , Enfermedad de Meniere/complicaciones , Persona de Mediana Edad , Inhibidores de la Síntesis de la Proteína/administración & dosificación , Vértigo/etiologíaRESUMEN
AIMS: To differentiate hepatoblastoma (HB) from hepatocellular carcinoma (HCC) by computerized image analysis. This is critical for treatment modalities and prognostic stratification but is usually difficult in small biopsy specimens. METHODS AND RESULTS: Computerized image-processing technology was used to calculate the nuclear-cytoplasmic ratio (N/C), cellularity (CEL) and other cellular and nuclear parameters in HB (n = 18) and paediatric HCC (pHCC, n = 11). The proliferation index (PI) and apoptotic index (AI) were also measured. Fetal type HB (FHB) compared with pHCC had more uniform nuclei (P < or = 0.014), lower PI (P = 0.028) and AI (P = 0.009), whereas the embryonal type HB (EHB) had a higher N/C (P < 0.001), higher CEL (P = 0.043), smaller cells (P = 0.043) and higher PI (P = 0.020) than pHCC. Moreover, EHB had a higher N/C (P < 0.001), higher CEL (P = 0.021), smaller cells (P = 0.021), more nuclear pleomorphism (P < or = 0.036) and higher PI (P < 0.001) than FHB. Multivariate analysis showed that FHB, EHB and pHCC could be classified accurately by a regression model. This logistic model further correctly stratified four additional test cases from biopsy specimens. CONCLUSIONS: These results indicate that computerized morphometric analysis can yield useful criteria to distinguish HB from pHCC in small biopsy specimens, and, compared with FHB, the poorer prognosis of EHB may result from its more undifferentiated (immature) and proliferative phenotype.
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Carcinoma Hepatocelular/patología , Hepatoblastoma/patología , Neoplasias Hepáticas/patología , Modelos Logísticos , Apoptosis , Proliferación Celular , Preescolar , Simulación por Computador , Femenino , Humanos , Lactante , MasculinoRESUMEN
This paper adopts Taguchi's signal-to-noise ratio analysis to optimize the dynamic characteristics of a SAW gas sensor system whose output response is linearly related to the input signal. The goal of the present dynamic characteristics study is to increase the sensitivity of the measurement system while simultaneously reducing its variability. A time- and cost-efficient finite element analysis method is utilized to investigate the effects of the deposited mass upon the resonant frequency output of the SAW biosensor. The results show that the proposed methodology not only reduces the design cost but also promotes the performance of the sensors.
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We investigate the power losses in bent and elongated graded-index polymer optical fibers (GI POFs). The variations of power losses in deformed GI POFs for various radii of curvature and elongations are measured. A simple tensile test result is used to calculate the average plastic energy density (APED) in a deformed GI POF at various elongations. The results indicate that the APED accumulated in a deformed GI POF can be considered as a key index to study the power loss in POF. Based on the experimental results, a curve-fitted equation is proposed to estimate the power loss using the APED for various radii of curvature. The maximum difference between the proposed equation and the experimental results is less than 3% for the deformed GI POFs.
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Artefactos , Diseño Asistido por Computadora , Tecnología de Fibra Óptica/instrumentación , Modelos Teóricos , Polímeros/química , Refractometría/métodos , Simulación por Computador , Elasticidad , Transferencia de Energía , Diseño de Equipo , Análisis de Falla de Equipo , Luz , Ensayo de Materiales , Fibras Ópticas , Dispersión de Radiación , Estrés MecánicoRESUMEN
BACKGROUND: Wolfram syndrome gene 1 (WFS1) accounts for most of the familial nonsyndromic low-frequency sensorineural hearing loss (LFSNHL) which is characterized by sensorineural hearing losses equal to and below 2000 Hz. The current study aimed to contribute to our understanding of the molecular basis of LFSNHL in an affected Taiwanese family. METHODS: The Taiwanese family with LFSNHL was phenotypically characterized using audiologic examination and pedigree analysis. Genetic characterization was performed by direct sequencing of WFS1 and mutation analysis. RESULTS: Pure tone audiometry confirmed that the family members affected with LFSNHL had a bilateral sensorineural hearing loss equal to or below 2000 Hz. The hearing loss threshold of the affected members showed no progression, a characteristic that was consistent with a mutation in the WFS1 gene located in the DFNA6/14/38 locus. Pedigree analysis showed a hereditarily autosomal dominant pattern characterized by a full penetrance. Among several polymorphisms, a missense mutation Y669H (2005T>C) in exon 8 of WFS1 was identified in members of a Taiwanese family diagnosed with LFSNHL but not in any of the control subjects. CONCLUSION: We discovered a novel heterozygous missense mutation in exon 8 of WFS1 (i.e., Y669H) which is likely responsible for the LFSNHL phenotype in this particular Taiwanese family.
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Pérdida Auditiva Sensorineural/genética , Proteínas de la Membrana/genética , Mutación Missense , Síndrome de Wolfram/genética , Análisis Mutacional de ADN , Salud de la Familia , Heterocigoto , Humanos , Linaje , Fenotipo , TaiwánRESUMEN
This paper investigates the effect of electrical contact on the thermal contactstress of a microrelay switch. A three-dimensional elastic-plastic finite element model withcontact elements is used to simulate the contact behavior between the microcantilever beamand the electrode. A model with thermal-electrical coupling and thermal-stress coupling isused in the finite element analysis. The effects of contact gap, plating film thickness andnumber of switching cycles on the contact residual stress, contact force, plastic deformation,and temperature rise of the microrelay switch are explored. The numerical results indicatethat the residual stress increases with increasing contact gap or decreasing plating filmthickness. The results also show that the residual stress increases as the number of switchingcycles increases. A large residual stress inside the microcantilever beam can decrease thelifecycle of the microrelay.
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Otitis media (OM), inflammation of the middle ear, remains the most common cause of hearing impairment in children. It is also the most common cause of surgery in children in the developed world. There is evidence from studies of the human population and mouse models that there is a significant genetic component predisposing to OM, yet nothing is known about the underlying genetic pathways involved in humans. We identified an N-ethyl-N-nitrosourea-induced dominant mouse mutant Junbo with hearing loss due to chronic suppurative OM and otorrhea. This develops from acute OM that arises spontaneously in the postnatal period, with the age of onset and early severity dependent on the microbiological status of the mice and their air quality. We have identified the causal mutation, a missense change in the C-terminal zinc finger region of the transcription factor Evi1. This protein is expressed in middle ear basal epithelial cells, fibroblasts, and neutrophil leukocytes at postnatal day 13 and 21 when inflammatory changes are underway. The identification and characterization of the Junbo mutant elaborates a novel role for Evi1 in mammalian disease and implicates a new pathway in genetic predisposition to OM.
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Proteínas de Unión al ADN/genética , Predisposición Genética a la Enfermedad/genética , Mutación/genética , Otitis Media/genética , Proto-Oncogenes/genética , Factores de Transcripción/genética , Secuencia de Aminoácidos , Animales , Mapeo Cromosómico , Clonación Molecular , Análisis Mutacional de ADN , Proteínas de Unión al ADN/química , Oído Medio/citología , Oído Medio/patología , Citometría de Flujo , Granulocitos/inmunología , Pulmón/citología , Pulmón/patología , Proteína del Locus del Complejo MDS1 y EV11 , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Mutantes , Datos de Secuencia Molecular , Nariz/citología , Nariz/patología , Otitis Media/inmunología , Fenotipo , Organismos Libres de Patógenos Específicos , Factores de Transcripción/químicaRESUMEN
With the completion of the first draft of the human genome sequence, the next major challenge is assigning function to genes. One approach is genome-wide random chemical mutagenesis, followed by screening for mutant phenotypes of interest and subsequent mapping and identification of the mutated genes in question. We (a consortium made up of GlaxoSmithKline, the MRC Mammalian Genetics Unit and Mouse Genome Centre, Harwell, Imperial College, London, and the Royal London Hospital) have used ENU mutagenesis in the mouse for the rapid generation of novel mutant phenotypes for use as animal models of human disease and for gene function assignment (Nolan et al., 2000). As of 2003, 35,000 mice have been produced to date in a genome-wide screen for dominant mutations and screened using a variety of screening protocols. Nearly 200 mutants have been confirmed as heritable and added to the mouse mutant catalogue and, overall, we can extrapolate that we have recovered over 700 mutants from the screening programme. For further information on the project and details of the data, see http://www.mgu.har.mrc.ac.uk/mutabase.
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Mapeo Cromosómico , Modelos Animales de Enfermedad , Genoma , Ratones/genética , Animales , Mutación , FenotipoRESUMEN
OBJECTIVE: To study the effectiveness of intratympanic dexamethasone (IT-DEX) in patients with severe or profound sudden sensorineural hearing loss (SSNHL) after treatment failure with conventional therapy. STUDY DESIGN: Randomized, controlled study. METHODS: Patients who met the criteria for SSNHL, with a severity of severe to profound, underwent 10 days of standard treatment with oral steroid and other facilitating agents. Patients showing poor response to standard treatment were assigned randomly to a control group or to a group receiving IT-DEX. IT-DEX injections were performed once a week for 3 consecutive weeks. Pure-tone audiometry was obtained before each injection. Minimum follow-up time was 1 month. Successful treatment was defined as a hearing improvement of greater than 30 dB. RESULTS: Thirty-nine patients meeting the inclusion criteria were studied. After treatment with oral steroid, 10 of 39 (26%) patients demonstrated hearing improvement, whereas the remaining 29 (74%) patients showed a hearing improvement of less than 30 dB. For those without hearing improvement, 15 received IT-DEX, and 14 received further standard treatment (except oral steroid and carbogen inhalation). Hearing improved in 8 of 15 (53.3%) compared with 1 of 14 (7.1%), with an average decrease in threshold of 28.4 dB and 13.2 dB for the IT-DEX group and the control group, respectively (P <.05). Prognostic factors such as age, treatment delay time, and sex did not significantly affect the response to therapy. CONCLUSIONS: IT-DEX injection effectively improves hearing in patients with severe or profound SSNHL after treatment failure with standard therapy and is not associated with major side effects. It is therefore a reasonable alternative as salvage treatment.
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Antiinflamatorios/uso terapéutico , Dexametasona/uso terapéutico , Pérdida Auditiva Súbita/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antiinflamatorios/administración & dosificación , Audiometría de Tonos Puros , Distribución de Chi-Cuadrado , Niño , Dexametasona/administración & dosificación , Humanos , Inyecciones , Persona de Mediana Edad , Terapia Recuperativa , Resultado del Tratamiento , Membrana TimpánicaRESUMEN
The semi-dominantly inherited mouse mutation pardon (Pdo) was isolated due to the lack of a Preyer reflex (ear flick) in response to sound from a large-scale N -ethyl- N -nitrosourea (ENU) mutagenesis programme. Dissection of the middle ear revealed malformations in all three ossicles, rendering the ossicular chain incomplete. Hair cell counts in the apical turn of the organ of Corti revealed a significant 22.7% increase in the number of outer hair cells. Raised compound action potential thresholds in Pdo/+ mutants suggested a combined sensorineural/conductive hearing loss. We show that a missense mutation in the homeobox gene Emx2 is responsible for these defects, identifying a new function for this gene in the development of specific structures in the ear.