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‣ Saethre-Chotzen Syndrome, Pro136His TWIST Mutation, Hearing Loss, and External and Middle Ear Structural Anomalies: Report on a Brazilian Family

LAMONICA, Dionisia A. C.; MAXIMINO, Luciana P.; FENIMAN, Mariza Ribeiro; SILVA, Greyce K.; ZANCHETTA, Sthella; ABRAMIDES, Dagma V. M.; PASSOS-BUENO, Maria Rita; ROCHA, Katia; RICHIERI-COSTA, Antonio
Fonte: ALLIANCE COMMUNICATIONS GROUP DIVISION ALLEN PRESS Publicador: ALLIANCE COMMUNICATIONS GROUP DIVISION ALLEN PRESS
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
67.878223%
Objective: To describe the clinical, speech, hearing, and imaging findings in three members of a Brazilian family with Saethre-Chotzen syndrome (SCS) who presented some unusual characteristics within the spectrum of the syndrome. Design: Clinical evaluation was performed by a multidisciplinary team. Direct sequencing of the polymerase chain reaction amplified coding region of the TWIST1 gene, routine and electrophysiological hearing evaluation, speech evaluation, and imaging studies through computed tomography (CT) scan and magnetic resonance imaging (MRI) were performed. Results: TWIST1 gene analysis revealed a Pro136His mutation in all patients. Hearing evaluation showed peripherial and mixed hearing loss in two of the patients, one of them with severe unilateral microtia. Computed tomography scan showed structural middle ear anomalies, and MRI showed distortion of the skull contour as well as some of the brain structures. Conclusions: We report a previously undescribed TWIST1 gene mutation in patients with SCS. There is evidence that indicates hearing loss (conductive and mixed) can be related both with middle ear (microtia, high jugular bulb, and enlarged vestibules) as well as with brain stem anomalies. Here we discuss the relationship between the gene mutation and the clinical...

‣ Alteration of distortion product otoacoustic emission input/output functions in subjects with a previous history of middle ear dysfunction

Campos, Ualace De P.; Sanches, Seisse G.; Hatzopoulos, Stavros; Carvallo, Renata M. M.; Kochanek, Krzysztof; Skarzynski, Henryk
Fonte: INT SCIENTIFIC LITERATURE, INC; SMITHTOWN Publicador: INT SCIENTIFIC LITERATURE, INC; SMITHTOWN
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
68.194126%
Background: The aim of this study was to investigate the effects of sub-clinical alterations on the amplitudes and slopes of the DPOAE input-output responses from subjects with previous history of middle ear dysfunction. Material/Methods: The study included 15 subjects with and 15 subjects without a history of otitis media in the last 10 years. All participants were assessed with acoustic immittance, pure-tone audiometry, and DPOAEs. For the later, I/O functions and I/O slopes were estimated at 1501, 2002, 3174, 4004 and 6384Hz. Results: No statistically significant differences were found between the 2 groups in terms of behavioral thresholds. The group with a previous history of middle ear dysfunction presented significantly lower mean DPOAE amplitudes at 2002, 3174 and 4004 Hz. In terms of DPOAE slopes, no statistically significant differences were observed at the tested frequencies, except at 3174 Hz. Conclusions: Middle ear pathologies can produce subclinical alterations that are undetectable with traditional pure-tone audiometry. The data from the present study show that reduced amplitude DPOAEs are associated with a previous history of middle ear complications. The corresponding DPOAE slopes were affected at only 1 tested frequency...

‣ A new species of semiarboreal toad with a Salamander-Like Ear (Anura: Bufonidae: Rhinella)

Grant, Taran; Bolívar-G., Wilmar
Fonte: Herpetologists’ League, Inc.; Lawrence Publicador: Herpetologists’ League, Inc.; Lawrence
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
57.78852%
We describe a new species of the Rhinella acrolopha group (previously Rhamphophryne) from mid-elevations (1800–2500 m) of the Cordillera Occidental of Colombia. It is found exclusively in cloud forest habitats and is not associated with streams or other bodies of water. The species is characterized by possessing eight presacral vertebrae, fusion of the sacrum and urostyle, and nuptial excrescences in adult males, and in lacking conspicuous cranial ornamentation and vocal slits. The most striking characteristic of this species is its middle ear, which lacks a tympanic membrane and annulus but possesses a short stapes that articulates with the palatoquadrate and squamosal in a manner similar to the middle ear of many salamanders. A population of this species in the Serran´ıa de los Paraguas seems to be stable despite drastic declines in many sympatric species.; Fieldwork in the Serranía de los Paraguas in 1996 was made possible by H.D. Grant, who provided financial support, and G. Bolívar, who loaned his 434 vehicle, and in 2004 by a grant from the Declining Amphibian Task Force and logistical support from the Fundacion Serraniagua. This study was completed with support from Conselho Nacional de Desenvolvimento Científico e Tecnológico Proc. 307001/2011-3 and Fundação de Amparo a Pesquisa do Estado de São Paulo Proc. 2012/10000-5. Our fieldwork benefitted from the expertise of F. Castro...

‣ Função da orelha média e das curvas de crescimento nas respostas das emissões otoacústicas; Middle-ear and growth functions on the responses of the otoacoustic emissions

Campos, Ualace de Paula
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/06/2011 Português
Relevância na Pesquisa
58.32129%
INTRODUÇÃO: Dentre as medidas da função coclear, a curva de crescimento das Emissões Otoacústicas por produto de distorção (CCEOA PD) permite o registro da amplitude da emissão em função do crescimento sistemático nos níveis de tons primários. A CCEOA PD fornece parâmetros específicos sobre o limiar e o comportamento não-linear das EOA PD, porém a variabilidade das respostas inter e intrasujeitos reduz a confiabilidade dessa medida na avaliação da robustez das respostas cocleares e a relação dessa robustez com os limiares auditivos. OBJETIVOS: Esta pesquisa estudou as interações entre as medidas timpanométricas da orelha média e as medidas de função coclear em adultos jovens sem queixas auditivas, de acordo com as variáveis: antecedentes de alterações de orelha média, sexo e orelha direita / esquerda. MÉTODOS: Participaram 69 indivíduos com audição normal e idades entre 18 e 34 anos, sendo 21 homens e 48 mulheres. A caracterização das condições de orelha média foi obtida pela anamnese, com a informação dos antecedentes de alterações de orelha média e pela timpanometria com sondas de admitância de 226 e 1000 Hz. A audiometria foi realizada com resolução de 01 dB NA, o que possibilitou comparações mais refinadas entre o limiar psicoacústico da audiometria tonal...

‣ Jovem doutor: promoção da saúde auditiva e inclusão do deficiente auditivo com malformação de orelha externa e/ou média; Young doctor: promote hearing health and the inclusion of deaf malformation with external and/or middle ear

Oliveira, Valdéia Vieira de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/12/2012 Português
Relevância na Pesquisa
58.00013%
As malformações de orelha são anomalias que ocorrem no período de desenvolvimento embrionário e podem acometer a orelha externa, média e/ou interna, podendo ser uni ou bilaterais. Na fase escolar, crianças com malformação de orelha podem ser prejudicadas pela falta de estímulos adequados ao seu potencial cognitivo, socioafetivo, linguístico e politicocultural, acarretando prejuízo considerável ao desenvolvimento da aprendizagem. Nesse contexto, esta pesquisa teve como objetivo desenvolver um programa para alunos do ensino fundamental, utilizando a teleducação interativa do Projeto Jovem Doutor, visando a promoção da saúde auditiva e a inclusão do deficiente auditivo com malformação de orelha externa e/ou média, no âmbito escolar. O estudo foi dividido em duas fases. A primeira fase foi constituída pela construção de um conteúdo educacional (roteiro), avaliação por juízes da área de Fonoaudiologia, por meio de dois questionários e adequação de acordo com as sugestões dos juízes. A segunda fase constituiu da aplicação do conteúdo para 18 alunos sem malformações craniofaciais, deficiência auditiva, visual ou intelectual, utilizando a metodologia do Projeto Jovem Doutor e foi dividida em: atividade presencial informando a dinâmica do curso e introdução do tema; etapa não presencial...

‣ Reflectância de banda larga em indivíduos com artrite reumatoide; Middle ear wideband reflectance in rheumatoid arthritis individuals

Cibin, Bruna Carla
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 31/03/2015 Português
Relevância na Pesquisa
68.15126%
INTRODUÇÃO: Artrite reumatoide é uma doença autoimune que causa inflamação nas membranas sinoviais de articulações chamadas diartroses. As articulações da orelha média podem estar sujeitas às mesmas lesões reumáticas que as outras articulações do corpo. Perdas auditivas neurossensoriais e condutivas foram observadas na literatura, assim como o envolvimento da artrite reumatoide na orelha média, mas os resultados não estão em concordância. A imitância acústica de banda larga pode fornecer maior sensibilidade a mudanças sutis nas articulações dos ossículos. OBJETIVO: avaliar o efeito da artrite reumatoide no sistema auditivo com enfoque na avaliação da orelha média. MÉTODOS: O delineamento desta pesquisa é estudo de casos comparando três diferentes grupos: dois grupos de indivíduos com artrite reumatoide e um grupo controle pareado por gênero e idade. Foram incluídos 39 participantes com idades entre 26 e 51 anos, de ambos os gêneros. O grupo estudo foi separado em dois: AR1, com 15 participantes (artrite reumatoide há dez anos ou mais); e AR2, com 9 participantes (artrite reumatoide há cinco anos ou menos). Estes grupos foram recrutados do ambulatório de reumatologia do Hospital das Clínicas da FMUSP e o grupo controle com 15 participantes...

‣ Secretion of middle ear in infants - Occurrence, recurrence and related factors

Saes, Sandra de Oliveira; Goldberg, Tamara B. L.; Montovani, Jair C.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 133-138
Português
Relevância na Pesquisa
68.118076%
Objective: The present study aimed at evaluating the occurrence and recurrence of middle ear effusion and possible associated factors in the first two years of life of 190 newborns and infants, participants in the interdisciplinary prevention, detection, and intervention program at the Clínica de Educação para Saúde of Universidade do Sagrado Coração, Methods: Newborns and infants were monthly submitted to anamneses, otoscopy, behavioral hearing assessment using sound instruments and pure tones (pediatric audiometry) and tympanometry. Results: The results revealed that 68.4% of infants presented one or more episodes of middle ear effusion during their two first years, with more recurrence among males. Peak occurrence was between four and 12 months of age and, the earlier the first episode, the higher the probability of recurrence. Greatest incidence was during May and August. It was found that, of the variables investigated, the period of exclusive breastfeeding actuated as a protector factor. With respect of risk factors, it was observed that passive smoking, gastro-esophageal reflux and respiratory allergy were related with the recurrences of effusion. Conclusion: Findings revealed the importance of periodic auditory follow-up for infants during their first two years of life...

‣ The influence of muscles activation on the dynamical behaviour of the tympano-ossicular system of the middle ear

Gentil, F; Parente, M; Martins, P; Garbe, C; Paço, J; Ferreira, AJ; Tavares, JM; Jorge, RN
Fonte: Repositório Comum de Portugal Publicador: Repositório Comum de Portugal
Tipo: Artigo de Revista Científica
Publicado em //2013 Português
Relevância na Pesquisa
58.22146%
The human ear is a complex biomechanical system and is divided into three parts: outer, middle and inner ear. The middle ear is formed by ossicles (malleus, incus and stapes), ligaments, muscles and tendons, which transfers sound vibrations from the eardrum to the inner ear, linking with mastoid and Eustachian tube. In this work, a finite element modelling of the tympano-ossicular system of the middle ear was developed. A dynamic study based on a structural response to harmonic vibrations, for a sound pressure level (SPL) of 110, 120 and 130 dB SPL applied in the eardrum, is presented. The connection between the ossicles is made using a contact formulation. The model includes the different ligaments considering its hyperelastic behaviour. The activation of the muscles is based on the constitutive model proposed by previous work. The harmonic responses of displacement and pressure obtained on the stapes footplate, for a frequency range between 100 Hz and 10 kHz, are obtained simulating the muscle activation. The results are compared considering the passive and active states. The results are discussed and they are in accordance with audiological data published with reference to the effects of the middle ear muscles contraction.

‣ Imaging evaluation of middle ear cholesteatoma: iconographic essay

Ávila,Ana Flávia Assis de; Aburjeli,Bruna de Oliveira Melim; Moreira,Wanderval; Motta,Emília Guerra Pinto Coelho; Ribeiro,Marcelo Almeida; Diniz,Renata Lopes Furletti Caldeira
Fonte: Colégio Brasileiro de Radiologia e Diagnóstico por Imagem Publicador: Colégio Brasileiro de Radiologia e Diagnóstico por Imagem
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2013 Português
Relevância na Pesquisa
67.672637%
Middle ear cholesteatoma is a relevant and relatively common disease that may have severe consequences. In the present pictorial essay, the authors have selected illustrative examples of multislice computed tomography and magnetic resonance imaging depicting the main presentations of cholesteatomas, and describing their characteristics, locations, and major complications.

‣ Epidemiology of middle ear and mastoid cholesteatomas: study of 1146 cases

Aquino,Jose Evandro Andrade Prudente de; Cruz Filho,Nelson Alvares; Aquino,Julia Negro Prudente de
Fonte: Associação Brasileira de Otorrinolaringologia e Cirurgia Cervicofacial Publicador: Associação Brasileira de Otorrinolaringologia e Cirurgia Cervicofacial
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 Português
Relevância na Pesquisa
58.07419%
Middle ear cholesteatoma is an important and relatively common disorder which may have serious consequences. AIM: The purpose was to conduct a retrospective study of the statistics of 1,146 middle ear surgical procedures for middle ear cholesteatoma in adults and children of low income living in distant areas from our city. METHODS: From 1962 to 1988 there were 1,146 surgeries for unilateral or bilateral cholesteatomas in children and adults, which were reviewed for the following criteria: total number of surgeries, sex, onset of the first symptoms, duration of the disease, the site of perforation, the cholesteatoma site, changes in the ossicular chain, the contralateral ear, bilateral cholesteatomas, the site of residual cholesteatoma, and complications. RESULTS: Results are shown graphically on a pie chart. CONCLUSION: The etiology of cholesteatomas remains unknown. Epidemiological and statistical data, surgical reports, and conclusions of experimental studies are welcome, as they may provide support for clarifying the pathogenesis of cholesteatoma. Our results were compared with internationally published papers. We found no published papers on the epidemiology of cholesteatoma in the Brazilian literature.

‣ TNF-R2 expression in acquired middle ear cholesteatoma

Vitale,Rodrigo Faller; Pereira,Celina Siqueira Barbosa; Alves,Adriana Leal; Fregnani,Jose Humberto Tavares Guerreiro; Ribeiro,Fernando Quintanilha
Fonte: Associação Brasileira de Otorrinolaringologia e Cirurgia Cervicofacial Publicador: Associação Brasileira de Otorrinolaringologia e Cirurgia Cervicofacial
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2011 Português
Relevância na Pesquisa
67.878223%
Acquired middle ear cholesteatoma is a disease which promotes bone erosion resulting in potentially serious complications. The tumor necrosis factor alpha (TNF-α) is present in cholesteatoma and it is related to bone erosion, as shown by different authors. To understand the aggressiveness characteristics of cholesteatoma is necessary, however, to better address the presence and distribution of their receptors. OBJECTIVE: To evaluate the expression of type 2 TNF-α receptor (TNF-R2) in fragments of cholesteatoma and correlate it to the degree of inflammation present. MATERIAL AND METHODS: observational cross-sectional study, which analyzed 33 fragments of cholesteatomas through histological analysis and immunohistochemistry (using as primary antibody to TNF-R2 LabVision® brand). The evaluation was performed by means of a qualitative and semi-quantitative agreement with the observed intensity. For statistical analysis we used the Fisher exact test and Spearman´s correlation coefficient (considered statistically significant when p < 0. 05). RESULTS: The expression of TNF-R2 was present in all fragments, however a statistical analysis showed no correlation or association between inflammation and the expression of TNF-R2. CONCLUSIONS: TNF-R2 is present in cholesteatoma of the middle ear...

‣ Congenital defects of the middle ear - uncommon cause of pediatric hearing loss

Esteves,Sara Duarte Sena; Silva,Ana Pereira da; Coutinho,Miguel Bebiano; Abrunhosa,José Manuel; Sousa,Cecília Almeida e
Fonte: Associação Brasileira de Otorrinolaringologia e Cirurgia Cervicofacial Publicador: Associação Brasileira de Otorrinolaringologia e Cirurgia Cervicofacial
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 Português
Relevância na Pesquisa
58.253643%
INTRODUCTION: In children, hypoacusis, or conductive hearing loss, is usually acquired; otitis media with effusion is the most common etiology. However, in some cases this condition is congenital, ranging from deformities of the external and middle ear to isolated ossicular chain malformations. The non-ossicular anomalies of the middle ear, for instance, persistent stapedial artery and anomaly of the facial nerve, are uncommon but may accompany the ossicular defects. OBJECTIVE: This study aimed to describe the clinical presentation, diagnostic tests, and therapeutic options of congenital malformations of the middle ear. METHODS: This was a retrospective study of cases followed in otolaryngologic consultations since 2007 with the diagnosis of congenital malformation of the middle ear according to the Teunissen and Cremers classification. A review of the literature regarding the congenital malformation of the middle ear and its treatment is presented. CONCLUSION: Middle ear malformations are rarely responsible for conductive hearing loss in children. As a result, there is often a late diagnosis and treatment of these anomalies, which can lead to delays in the development of language and learning.

‣ Proliferating macrophages, dendritic cells, natural killer cells, T and B lymphocytes in the middle ear and Eustachian tube mucosa during experimental acute otitis media in the rat

Jecker, P; Pabst, R; Westermann, J
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
Publicado em /12/2001 Português
Relevância na Pesquisa
57.956724%
Although many studies focus on the increase of immunocompetent cells within the middle ear mucosa during acute otitis media it is poorly understood how this increase is mediated. The differentiation between two possible causes, i.e. immigration and local proliferation, would help to better understand the pathophysiology of this disease. Therefore, the number of proliferating macrophages, dendritic cells, natural killer cells and T and B lymphocytes was studied during acute otitis media in the rat middle ear mucosa (ME mucosa) and Eustachian tube mucosa (ET mucosa) by labelling proliferating leucocytes with the DNA precursor bromodeoxyuridine (BrdU). By removing the middle ear and Eustachian tube 24 h after BrdU injection, the contribution of immigrated newly formed cells was estimated. At this timepoint, many leucocytes in the ME and ET mucosa had incorporated BrdU (between 15 and 25% within the subsets). By analysing these tissues one hour after BrdU injection, the local proliferation rate was determined (between 2 and 9% within the subsets). Thus, the inflamed ME and ET mucosa are the destination of immunocompetent cells and, as our data show, the inflamed microenvironment supports local proliferation of immunocompetent cells.

‣ FGF23 Deficiency Leads to Mixed Hearing Loss and Middle Ear Malformation in Mice

Lysaght, Andrew C.; Yuan, Quan; Fan, Yi; Kalwani, Neil; Caruso, Paul; Cunnane, MaryBeth; Lanske, Beate; Stanković, Konstantina M.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
57.86702%
Fibroblast growth factor 23 (FGF23) is a circulating hormone important in phosphate homeostasis. Abnormal serum levels of FGF23 result in systemic pathologies in humans and mice, including renal phosphate wasting diseases and hyperphosphatemia. We sought to uncover the role FGF23 plays in the auditory system due to shared molecular mechanisms and genetic pathways between ear and kidney development, the critical roles multiple FGFs play in auditory development and the known hearing phenotype in mice deficient in klotho (KL), a critical co-factor for FGF23 signaling. Using functional assessments of hearing, we demonstrate that Fgf mice are profoundly deaf. Fgf mice have moderate hearing loss above 20 kHz, consistent with mixed conductive and sensorineural pathology of both middle and inner ear origin. Histology and high-voltage X-ray computed tomography of Fgf mice demonstrate dysplastic bulla and ossicles; Fgf mice have near-normal morphology. The cochleae of mutant mice appear nearly normal on gross and microscopic inspection. In wild type mice, FGF23 is ubiquitously expressed throughout the cochlea. Measurements from Fgf mice do not match the auditory phenotype of Kl−/− mice, suggesting that loss of FGF23 activity impacts the auditory system via mechanisms at least partially independent of KL. Given the extensive middle ear malformations and the overlap of initiation of FGF23 activity and Eustachian tube development...

‣ The effect of Nystatin on the inner ear : an experimental guinea pig study

Woods, Owen
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
Português
Relevância na Pesquisa
58.01342%
Objectifs: Le Nystatin est un antibiotique efficace pour le traitement d’otomycose. Bien que sa sécurité au niveau de l’oreille externe soit bien établie, son utilisation n’est pas recommandée lorsqu’il y a une perforation tympanique. L’objectif de cette étude est d’évaluer le potentiel ototoxique du Nystatin lorsque celui-ci est appliqué directement au niveau de l’oreille moyenne. Méthodes: Nous avons fait une étude expérimentale avec 18 cochons d’Indes de souche Hartley que nous avons divisés en deux groupes. En exposant l’oreille moyenne de chaque animal au Nystatin (groupe I) ou à la néomycine (groupe II) et chaque oreille controlatérale à une solution physiologique (NaCl), la fonction auditive a été évaluée avec un test de potentiels évoqués auditif du tronc cérébral avant et après les injections. Une étude par microscopie électronique a permis une comparaison histologique de l’état des cellules ciliées cochléaires entre les 2 groupes. Résultats: Les pertes auditives moyennes du groupe « Nystatin » étaient de 13.0 dB et comparables aux pertes moyennes observées dans les oreilles ayant été injectées avec du NaCl (4.0 dB dans le groupe I et 15.1 dB dans le groupe II). Le groupe de contrôle « néomycine » a subi une perte auditive moyenne de 39.3 dB...

‣ Congenital defects of the middle ear-uncommon cause of pediatric hearing loss

Esteves, S.; Silva, A.; Coutinho, M.; Abrunhosa, J.; Sousa, C.
Fonte: Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial Publicador: Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial
Tipo: Artigo de Revista Científica
Publicado em //2014 Português
Relevância na Pesquisa
58.253643%
INTRODUCTION: In children, hypoacusis, or conductive hearing loss, is usually acquired; otitis media with effusion is the most common etiology. However, in some cases this condition is congenital, ranging from deformities of the external and middle ear to isolated ossicular chain malformations. The non-ossicular anomalies of the middle ear, for instance, persistent stapedial artery and anomaly of the facial nerve, are uncommon but may accompany the ossicular defects. OBJECTIVE: This study aimed to describe the clinical presentation, diagnostic tests, and therapeutic options of congenital malformations of the middle ear. METHODS: This was a retrospective study of cases followed in otolaryngologic consultations since 2007 with the diagnosis of congenital malformation of the middle ear according to the Teunissen and Cremers classification. A review of the literature regarding the congenital malformation of the middle ear and its treatment is presented. CONCLUSION: Middle ear malformations are rarely responsible for conductive hearing loss in children. As a result, there is often a late diagnosis and treatment of these anomalies, which can lead to delays in the development of language and learning

‣ Structure and function of the mammalian middle ear. I: Large middle ears in small desert mammals

Mason, Matthew J.
Fonte: Wiley Publicador: Wiley
Tipo: Article; accepted version
Português
Relevância na Pesquisa
68.29167%
This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/joa.12313.; Many species of small desert mammals are known to have expanded auditory bullae. The ears of gerbils and heteromyids have been well-described, but much less is known about the middle ear anatomy of other desert mammals. In this study, the middle ears of three gerbils (Meriones, Desmodillus and Gerbillurus), two jerboas (Jaculus) and two sengis (elephant-shrews: Macroscelides and Elephantulus) were examined and compared, using micro-computed tomography and light microscopy. Middle ear cavity expansion has occurred in members of all three groups, apparently in association with an essentially ?freely mobile? ossicular morphology and the development of bony tubes for the middle ear arteries. Cavity expansion can occur in different ways, resulting in different subcavity patterns even between different species of gerbils. Having enlarged middle ear cavities aids low-frequency audition, and several adaptive advantages of low-frequency hearing to small desert mammals have been proposed. However, while Macroscelides was found here to have middle ear cavities so large that together they exceed brain volume, the bullae of Elephantulus are considerably smaller. Why middle ear cavities are enlarged in some desert species but not others remains unclear...

‣ Structure and function of the mammalian middle ear. II: Inferring function from structure

Mason, Matthew J.
Fonte: Wiley Publicador: Wiley
Tipo: Article; accepted version
Português
Relevância na Pesquisa
68.323647%
This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/joa.12316; Anatomists and zoologists who study middle ear morphology are often interested to know what the structure of an ear can reveal about the auditory acuity and hearing range of the animal in question. This paper represents an introduction to middle ear function targetted towards biological scientists with little experience in the field of auditory acoustics. Simple models of impedance matching are first described, based on the familiar concepts of the area and lever ratios of the middle ear. However, using the Mongolian gerbil Meriones unguiculatus as a test case, it is shown that the predictions made by such ?ideal transformer? models are generally not consistent with measurements derived from recent experimental studies. Electrical analogue models represent a better way to understand some of the complex, frequency-dependent responses of the middle ear: these have been used to model the effects of middle ear subcavities, and the possible function of the auditory ossicles as a transmission line. The concepts behind such models are explained here, again aimed at those with little background knowledge. Functional inferences based on middle ear anatomy are more likely to be valid at low frequencies. Acoustic impedance at low frequencies is dominated by compliance; expanded middle ear cavities...

‣ CIRURGIA DE RECONSTRUÇÃO DE ORELHA MÉDIA; MIDDLE EAR RECONSTRUCTION

Massuda, Eduardo T.
Fonte: Universidade de São Paulo. Faculdade de Medicina de Ribeirão Preto Publicador: Universidade de São Paulo. Faculdade de Medicina de Ribeirão Preto
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 30/12/2005 Português
Relevância na Pesquisa
57.78852%
Middle ear works as a sound amplifier. Three kinds of mechanism are used for this purpose: the hydraulic, the ossicular lever and the windows set. The most important of them is concentration of vibratory energy in the oval windows. (hydraulic mechanism). We can divide the disfunctions of the ossicular chain in two categories: with reduction of the chain vibration and with interruption of the ossicular chain. In this article we will report the problems that may occur in the surgery of the reconstruction of the ossicular chain.; A orelha média funciona como um amplificador sonoro. Utiliza para isso três mecanismos: o hidráulico, a alavanca dos ossículos e o jogo das janelas, sendo o mais importante o fato da energia mecânica captada pela membrana timpânica ser concentrada na área da janela oval, que é muitas vezes menor (mecanismo hidráulico). Podemos dividir o não funcionamento da cadeia ossicular em duas categorias: com diminuição da vibração da cadeia e com interrupção da cadeia. Neste artigo, o autor discorre sobre os problemas da cirurgia de reconstrução.

‣ Middle ear effusion: rate and risk factors in Australian children attending day care

Skull, Sue; Morris, Peter; Yonovitz, A; Attewell, R; Krause, Victoria; Leach, A J; Anand, A; Scott, J; Reid, S; Roberts, Leslee
Fonte: Cambridge University Press Publicador: Cambridge University Press
Tipo: Artigo de Revista Científica
Português
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There have been no previous longitudinal studies of otitis media conducted in non-Aboriginal Australian children. This paper describes the rate and risk factors for middle ear effusion (MEE) in children attending day care in Darwin, Australia. A prospective cohort study of 252 children under 4 years was conducted in 9 day care centres over 12 fortnights between 24 March and 15 September 1997. Tympanometry was conducted fortnightly and multivariate analysis used to determine risk factors predicting MEE. The outcome of interest was the rate of type B tympanograms per child detected in either ear at fortnightly examinations. After adjusting for clustering by child, MEE was detected on average 4.4 times in 12 fortnights (37% of all examinations conducted). Risk factors associated with presence of effusion were younger age, a family history of ear infection, previous grommets (tympanostomy tubes), ethnicity and the day care centre attended. A history of wheeze appeared protective. These effects were modest (RR 0.57-1.70). Middle ear effusion is very common in children attending day care in Darwin. This has clinical importance, since MEE during early childhood may affect optimal hearing, learning and speech development. There is little scope for modification for many of the risk factors for MEE predicted by this model. Further study of the day care environment is warranted.