• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 7
  • 1
  • Tagged with
  • 17
  • 17
  • 8
  • 8
  • 7
  • 7
  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Tmpanometric measures of eustachian-tube function

Riedel, Catherine Lynn. January 1984 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 134-139).
2

Experimental obstruction of the eustachian tube a contribution to knowledge of the pathogenesis of secretory otitis media /

Beek, Johan Marinus Herman van der, January 1981 (has links)
Thesis (doctoral)--Katholieke Universiteit te Nijmegen.
3

The efficacy of betahistine as treatment for eustachian tube dysfunction in an allergic rat model

Wilson, James David 08 April 2016 (has links)
Otitis media is a quite common disease, especially in children due largely to their underdeveloped Eustachian tubes. One potential factor, thought to be a large contributor to the disease, is an allergic reaction causing congestion and blockage of the Eustachian tube, leaving the middle ear prone to bacterial infection and effusions. The H3 receptor has recently been discovered in the nasal mucosa of humans and rodents and is linked to the immune response. Excess histamine released in an allergic response causes nasal vascular constriction and congestion. By blocking the H3 receptor, the local vasculature may be allowed to dilate, resulting in decongestion. This could play a large role in the treatment of otitis media with effusion. The effectiveness of betahistine dihydrochloride, an H3 receptor blocker, in providing possible relief from middle ear congestion was tested using a rat model. An allergic response was induced in rats followed by one of two betahistine dihydrochloride treatment regimens: drug delivery via transtympanic or intranasal route. Changes in Eustachian tube function were monitored during this process. Four measurements were used to measure the function of the Eustachian tube: passive opening pressure, passive closing pressure, active clearance of negative pressure, and Mucociliary transit time. Lower opening pressure and closing pressure, higher clearance of negative pressure, and shorter Mucociliary transit time were indications of better Eustachian tube function. Regardless of delivery method, no significant results were found among the experimental groups to suggest improved Eustachian tube function after drug treatment. Although the middle dose of betahistine dihydrochloride (50 mg/mL) delivered transtympanically followed the expected response outcome, the trend did not achieve statistical significance. Overall, the results of this study are inconclusive for measuring the beneficial effects of betahistine dihydrochloride on Eustachian tube function. Further investigations are being conducted to measure the magnitude and duration of the effects of allergic responses on Eustachian tube anatomy and physiology.
4

Estudo da função da tuba de eustáquio em pacientes com retrações da membrana timpânica e em indivíduos normais / Assessment of eustachian tube function in patients with tympanic membrane retraction and in normal subjects

Canali, Inesângela January 2013 (has links)
Introdução: O diagnóstico das disfunções da tuba auditiva é essencial para o melhor entendimento da patogênese da otite média crônica. Estão descritos, na literatura, uma série de testes que avaliam a função tubária, entretanto, entre eles, há uma diversidade metodológica que varia desde os protocolos de aplicação até a padronização dos testes e seus resultados. Objetivo: Avaliar a variação da pressão na orelha média em pacientes com retração da membrana timpânica e em indivíduos normais, durante a realização dos testes de função tubária, bem como avaliar a variação intraindividual desses testes. Este estudo também tem por objetivo avaliar o número de movimentações da membrana timpânica na orelha contralateral, durante a realização dos testes. Métodos: Estudo observacional do tipo transversal e contemporâneo, onde o fator em estudo foi a variação de pressão na orelha média, durante a realização dos testes de função tubária (Manobra de Valsalva, Sniff Test, Manobra de Toynbee) em indivíduos normais e em pacientes com retrações timpânicas leves e moderadas/severas. Foram incluídos 38 pacientes, totalizando 76 orelhas. Os pacientes foram submetidos, em dois momentos diferentes, aos testes de função tubária para determinar a medida da pressão após cada manobra. Durante a realização dos testes, videotoscopia era realizada concomitantemente na outra orelha, a fim de se observar a movimentação da membrana timpânica. A análise estatística foi realizada por meio do programa SPSS versão 18.0, em que foram considerados como estatisticamente significativos os valores de p< 0,05. Resultados: A média ± desvio-padrão da idade foi de 11 ± 2,72 anos; 55,3% dos pacientes foram do sexo masculino e 44,7% do sexo feminino. A prevalência de curva A foi maior nos grupos de orelhas normais e retrações leves, enquanto que de curva C foi maior no grupo de retrações moderadas/severas. Observamos aumento das pressões na orelha média durante a realização da Manobra de Valsalva no primeiro momento de avaliação nos três grupos de orelhas (p= 0,012). A variação da pressão não foi significativa nem para o Sniff Test, nem para o Toynbee nos dois momentos de avaliação (p≥0,05). A concordância das medidas nos dois diferentes momentos foi de fraca a moderada para os testes nos três grupos de orelhas, e as variâncias da discrepância entre as medidas foram maiores nas orelhas com retrações moderadas/severas. Apesar de não ter atingido significância estatística, o número de movimentações da membrana timpânica foi maior durante a manobra de Valsalva nos três grupos de orelhas. Conclusão: Na população estudada, a média das pressões na cavidade timpânica apresentou uma variação significativa somente durante a Manobra de Valsalva, no primeiro momento de avaliação, nos três grupos de orelhas. As orelhas normais e as com retração leve se comportaram de forma semelhante entre si em todos os testes. As manobras utilizadas apresentaram uma variação intraindividual de fraca a moderada, sendo que maior variação ocorreu em orelhas com retrações moderadas/severas. O número de movimentações da membrana timpânica foi maior durante a manobra de Valsalva nos três grupos de orelhas. / Introduction: The diagnosis of Eustachian tube dysfunctions is essential for better understanding the pathogenesis of chronic otitis media. The literature describes a series of tests to assess tube function; however, there is methodological diversity between them, which varies from application protocols to standardization of tests and their results. Objective: To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal subjects during tube function tests, as well as to evaluate intra-individual variation between these tests. This study also aimed to evaluate the number of tympanic membrane movements of the contralateral ear during the tests. Methods: An observational contemporary cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, Sniff Test, Toynbee maneuver) in normal subjects and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears) were included in the study. Patients underwent tube function tests at two different time points, in order to determine the measure of pressure after each maneuver. During the tests, videotoscopy was performed concomitantly in the contralateral ear, in order to observe tympanic membrane movement. Statistical analysis was performed using SPSS software, version 18.0, considering p values < 0.05 as statistically significant. Results: Mean ± standard deviation for age was 11 ± 2.72 years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher in the groups with normal ears and mild retraction, while type C tympanogram was higher in the group with moderate/severe retraction. An increase in middle ear pressure was observed during Valsalva maneuver at the first time point evaluated in the three groups of ears (p= 0.012). The variation in pressure was not significant either for the Sniff Test or for Toynbee maneuver at the two time points evaluated (p≥0.05). The agreement of the measures at the two different time points was from weak to moderate for the tests in the tree groups of ears, and the variations in discrepancy between measures were higher in ears with moderate/severe retraction. Although it had not reached statistical significance, the number of tympanic membrane movements was higher during the Valsalva maneuver in the tree groups of ears. Conclusion: In this study population, mean pressure in the middle ear showed a significant variation only during the Valsalva maneuver at the first time point evaluated in the three groups of ears. Normal ears and those with mild retraction behaved similarly in all tests. The maneuvers used showed intra-individual variation from weak to moderate, with the higher variation occurring in ears with moderate/severe retraction. The number of tympanic membrane movements was higher during the Valsalva maneuver in the three groups of ears.
5

Estudo da função da tuba de eustáquio em pacientes com retrações da membrana timpânica e em indivíduos normais / Assessment of eustachian tube function in patients with tympanic membrane retraction and in normal subjects

Canali, Inesângela January 2013 (has links)
Introdução: O diagnóstico das disfunções da tuba auditiva é essencial para o melhor entendimento da patogênese da otite média crônica. Estão descritos, na literatura, uma série de testes que avaliam a função tubária, entretanto, entre eles, há uma diversidade metodológica que varia desde os protocolos de aplicação até a padronização dos testes e seus resultados. Objetivo: Avaliar a variação da pressão na orelha média em pacientes com retração da membrana timpânica e em indivíduos normais, durante a realização dos testes de função tubária, bem como avaliar a variação intraindividual desses testes. Este estudo também tem por objetivo avaliar o número de movimentações da membrana timpânica na orelha contralateral, durante a realização dos testes. Métodos: Estudo observacional do tipo transversal e contemporâneo, onde o fator em estudo foi a variação de pressão na orelha média, durante a realização dos testes de função tubária (Manobra de Valsalva, Sniff Test, Manobra de Toynbee) em indivíduos normais e em pacientes com retrações timpânicas leves e moderadas/severas. Foram incluídos 38 pacientes, totalizando 76 orelhas. Os pacientes foram submetidos, em dois momentos diferentes, aos testes de função tubária para determinar a medida da pressão após cada manobra. Durante a realização dos testes, videotoscopia era realizada concomitantemente na outra orelha, a fim de se observar a movimentação da membrana timpânica. A análise estatística foi realizada por meio do programa SPSS versão 18.0, em que foram considerados como estatisticamente significativos os valores de p< 0,05. Resultados: A média ± desvio-padrão da idade foi de 11 ± 2,72 anos; 55,3% dos pacientes foram do sexo masculino e 44,7% do sexo feminino. A prevalência de curva A foi maior nos grupos de orelhas normais e retrações leves, enquanto que de curva C foi maior no grupo de retrações moderadas/severas. Observamos aumento das pressões na orelha média durante a realização da Manobra de Valsalva no primeiro momento de avaliação nos três grupos de orelhas (p= 0,012). A variação da pressão não foi significativa nem para o Sniff Test, nem para o Toynbee nos dois momentos de avaliação (p≥0,05). A concordância das medidas nos dois diferentes momentos foi de fraca a moderada para os testes nos três grupos de orelhas, e as variâncias da discrepância entre as medidas foram maiores nas orelhas com retrações moderadas/severas. Apesar de não ter atingido significância estatística, o número de movimentações da membrana timpânica foi maior durante a manobra de Valsalva nos três grupos de orelhas. Conclusão: Na população estudada, a média das pressões na cavidade timpânica apresentou uma variação significativa somente durante a Manobra de Valsalva, no primeiro momento de avaliação, nos três grupos de orelhas. As orelhas normais e as com retração leve se comportaram de forma semelhante entre si em todos os testes. As manobras utilizadas apresentaram uma variação intraindividual de fraca a moderada, sendo que maior variação ocorreu em orelhas com retrações moderadas/severas. O número de movimentações da membrana timpânica foi maior durante a manobra de Valsalva nos três grupos de orelhas. / Introduction: The diagnosis of Eustachian tube dysfunctions is essential for better understanding the pathogenesis of chronic otitis media. The literature describes a series of tests to assess tube function; however, there is methodological diversity between them, which varies from application protocols to standardization of tests and their results. Objective: To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal subjects during tube function tests, as well as to evaluate intra-individual variation between these tests. This study also aimed to evaluate the number of tympanic membrane movements of the contralateral ear during the tests. Methods: An observational contemporary cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, Sniff Test, Toynbee maneuver) in normal subjects and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears) were included in the study. Patients underwent tube function tests at two different time points, in order to determine the measure of pressure after each maneuver. During the tests, videotoscopy was performed concomitantly in the contralateral ear, in order to observe tympanic membrane movement. Statistical analysis was performed using SPSS software, version 18.0, considering p values < 0.05 as statistically significant. Results: Mean ± standard deviation for age was 11 ± 2.72 years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher in the groups with normal ears and mild retraction, while type C tympanogram was higher in the group with moderate/severe retraction. An increase in middle ear pressure was observed during Valsalva maneuver at the first time point evaluated in the three groups of ears (p= 0.012). The variation in pressure was not significant either for the Sniff Test or for Toynbee maneuver at the two time points evaluated (p≥0.05). The agreement of the measures at the two different time points was from weak to moderate for the tests in the tree groups of ears, and the variations in discrepancy between measures were higher in ears with moderate/severe retraction. Although it had not reached statistical significance, the number of tympanic membrane movements was higher during the Valsalva maneuver in the tree groups of ears. Conclusion: In this study population, mean pressure in the middle ear showed a significant variation only during the Valsalva maneuver at the first time point evaluated in the three groups of ears. Normal ears and those with mild retraction behaved similarly in all tests. The maneuvers used showed intra-individual variation from weak to moderate, with the higher variation occurring in ears with moderate/severe retraction. The number of tympanic membrane movements was higher during the Valsalva maneuver in the three groups of ears.
6

Estudo da função da tuba de eustáquio em pacientes com retrações da membrana timpânica e em indivíduos normais / Assessment of eustachian tube function in patients with tympanic membrane retraction and in normal subjects

Canali, Inesângela January 2013 (has links)
Introdução: O diagnóstico das disfunções da tuba auditiva é essencial para o melhor entendimento da patogênese da otite média crônica. Estão descritos, na literatura, uma série de testes que avaliam a função tubária, entretanto, entre eles, há uma diversidade metodológica que varia desde os protocolos de aplicação até a padronização dos testes e seus resultados. Objetivo: Avaliar a variação da pressão na orelha média em pacientes com retração da membrana timpânica e em indivíduos normais, durante a realização dos testes de função tubária, bem como avaliar a variação intraindividual desses testes. Este estudo também tem por objetivo avaliar o número de movimentações da membrana timpânica na orelha contralateral, durante a realização dos testes. Métodos: Estudo observacional do tipo transversal e contemporâneo, onde o fator em estudo foi a variação de pressão na orelha média, durante a realização dos testes de função tubária (Manobra de Valsalva, Sniff Test, Manobra de Toynbee) em indivíduos normais e em pacientes com retrações timpânicas leves e moderadas/severas. Foram incluídos 38 pacientes, totalizando 76 orelhas. Os pacientes foram submetidos, em dois momentos diferentes, aos testes de função tubária para determinar a medida da pressão após cada manobra. Durante a realização dos testes, videotoscopia era realizada concomitantemente na outra orelha, a fim de se observar a movimentação da membrana timpânica. A análise estatística foi realizada por meio do programa SPSS versão 18.0, em que foram considerados como estatisticamente significativos os valores de p< 0,05. Resultados: A média ± desvio-padrão da idade foi de 11 ± 2,72 anos; 55,3% dos pacientes foram do sexo masculino e 44,7% do sexo feminino. A prevalência de curva A foi maior nos grupos de orelhas normais e retrações leves, enquanto que de curva C foi maior no grupo de retrações moderadas/severas. Observamos aumento das pressões na orelha média durante a realização da Manobra de Valsalva no primeiro momento de avaliação nos três grupos de orelhas (p= 0,012). A variação da pressão não foi significativa nem para o Sniff Test, nem para o Toynbee nos dois momentos de avaliação (p≥0,05). A concordância das medidas nos dois diferentes momentos foi de fraca a moderada para os testes nos três grupos de orelhas, e as variâncias da discrepância entre as medidas foram maiores nas orelhas com retrações moderadas/severas. Apesar de não ter atingido significância estatística, o número de movimentações da membrana timpânica foi maior durante a manobra de Valsalva nos três grupos de orelhas. Conclusão: Na população estudada, a média das pressões na cavidade timpânica apresentou uma variação significativa somente durante a Manobra de Valsalva, no primeiro momento de avaliação, nos três grupos de orelhas. As orelhas normais e as com retração leve se comportaram de forma semelhante entre si em todos os testes. As manobras utilizadas apresentaram uma variação intraindividual de fraca a moderada, sendo que maior variação ocorreu em orelhas com retrações moderadas/severas. O número de movimentações da membrana timpânica foi maior durante a manobra de Valsalva nos três grupos de orelhas. / Introduction: The diagnosis of Eustachian tube dysfunctions is essential for better understanding the pathogenesis of chronic otitis media. The literature describes a series of tests to assess tube function; however, there is methodological diversity between them, which varies from application protocols to standardization of tests and their results. Objective: To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal subjects during tube function tests, as well as to evaluate intra-individual variation between these tests. This study also aimed to evaluate the number of tympanic membrane movements of the contralateral ear during the tests. Methods: An observational contemporary cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, Sniff Test, Toynbee maneuver) in normal subjects and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears) were included in the study. Patients underwent tube function tests at two different time points, in order to determine the measure of pressure after each maneuver. During the tests, videotoscopy was performed concomitantly in the contralateral ear, in order to observe tympanic membrane movement. Statistical analysis was performed using SPSS software, version 18.0, considering p values < 0.05 as statistically significant. Results: Mean ± standard deviation for age was 11 ± 2.72 years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher in the groups with normal ears and mild retraction, while type C tympanogram was higher in the group with moderate/severe retraction. An increase in middle ear pressure was observed during Valsalva maneuver at the first time point evaluated in the three groups of ears (p= 0.012). The variation in pressure was not significant either for the Sniff Test or for Toynbee maneuver at the two time points evaluated (p≥0.05). The agreement of the measures at the two different time points was from weak to moderate for the tests in the tree groups of ears, and the variations in discrepancy between measures were higher in ears with moderate/severe retraction. Although it had not reached statistical significance, the number of tympanic membrane movements was higher during the Valsalva maneuver in the tree groups of ears. Conclusion: In this study population, mean pressure in the middle ear showed a significant variation only during the Valsalva maneuver at the first time point evaluated in the three groups of ears. Normal ears and those with mild retraction behaved similarly in all tests. The maneuvers used showed intra-individual variation from weak to moderate, with the higher variation occurring in ears with moderate/severe retraction. The number of tympanic membrane movements was higher during the Valsalva maneuver in the three groups of ears.
7

Characterization of surfactant proteins in porcine Eustachian tube

Paananen, R. (Reija) 03 September 2001 (has links)
Abstract The Eustachian tube (ET) connects the upper respiratory tract and the middle ear. It equilibrates the pressure in the middle ear and prevents the harmful impact of the airways. Middle ear infection, or otitis media, is one of the most common illnesses in childhood and affects nearly all children at least once. ET dysfunction is considered to be a major pathogenic factor in the development of otitis media. Surfactant proteins A (SP-A) and D (SP-D) have an important role in the pulmonary host defence system, and interactions with bacteria that also cause middle ear infections raised a question about the expression of surfactant proteins in ET. The local defence system could be significant in preventing ear infections. The purpose of the study was to increase our basic knowledge of the putative ET surfactant system. ET and lung epithelia are both of endodermal origin, and ET epithelium with its mucociliary system resembles that of the lower airways. The aim was to determine whether SP-A, SP-B and SP-D are expressed in ET. The expressions were characterized with reverse transcriptase polymerase chain reaction (RT-PCR), Northern hybridizations and in situ hybridizations. The surfactant proteins were localized using immunohistochemistry and immunoelectron microscopy. The proteins were characterized with Western analyses, and the properties of the ET surfactant were evaluated using electrospray ionization mass spectrometry and a pulsating bubble surfactometer. SP-A, SP-B and SP-D were found to be expressed in porcine ET epithelium, and the cDNA sequences were homologous to those detected in lung tissue. The proteins were localized to specific ET epithelial cells, and their sizes were characteristic of lung SP-A, SP-B and SP-D. ET lavage fluid contained the surfactant proteins and phospholipid. However, the phospholipid molecular species and surface tension measurements showed the structure and function of the surfactant in ET to be different from lung surfactant, suggesting that a very low surface tension is not a critical determinant of ET surfactant function. As a conclusion, surfactant proteins in ET are likely to be involved in the local host defence system and may contribute to the mucociliary function of the tube.
8

Using Computational Modeling Techniques to Identify and Target Viable Drug Delivery Protocols to Treat Chronic Otitis Media

Malik, Jennifer E. January 2018 (has links)
No description available.
9

Numerical Assessment of the Impact and Relative Importance of the Underlying Biomechanics of the Eustachian Tube Phenotype to Overall Tubal Function and Diagnostics

Torres-Rodriguez, Justo Juvian 08 July 2019 (has links)
No description available.
10

Middle ear structure in relation to function : the rat in middle ear research

Albiin, Nils January 1985 (has links)
The present study was undertaken to evaluate the rat as a model for middle ear re­search. The rat was chosen primarily because the gross structure of its middle ear shows several similarities to that of man. It was considered of great importance to make a thorough structural study of the rat middle ear and to compare the results with those reported for the human middle ear. The thesis therefore includes indepen­dent studies on various aspects of rat middle ear structure and function as well as a review of the literature. The most pertinent findings in the experimental part of this study were the following. The rat Eustachian tube consists of a nasopharyngeal, and a cartilaginous and bony portion. The orifice of the nasopharyngeal portion is composed of two soft tissue lips, which appear to be opened mainly by the action of the salpingopharyngeal mus­cle, but also by the levator and tensor veli palatini muscles. The cartilaginous por­tion appears to be opened solely by the tensor veli palatini muscle. The tensor tympani muscle seems to have no effect on the tube. A ciliated and secretory epithelium lines the inferomedial walls of the tube throughout its length. In the tympanic cavity these thelial cell types extend as two tracts - one anterior and the other inferoposterior to  the promontory - which communicate with the epitympanic/attic compartments. The remaining parts of the tube and the tympanic cavity are covered by a squamous/cuboidal, non-ciliated epithelium. The subepithelial loose connective tissue contains vessels, nerves, and connective tissue cells, among these mast cells. The mast cells are confined to areas covered by the ciliated epithelium, and in the floor of the bulla, in the pars flaccida, and along the manubrial vessels. Glands are restricted to the Eustachian tube. In the clearance/transport of serum-like material, from the epitympanum towards the tube, hydrostatic forces appear to be important. The tympanic membrane is vascularized from meatal and tympanal vessels. Meatal ves­sels branch in the pars flaccida and along the handle of the malleus, where they are localized directly beneath the outer, keratinizing, stratified, squamous epithelium. Furthermore, meatal vessels form a vascular network at the junction between the fi­brocartilaginous annulus and the tympanic sulcus. Tympanal vessels send branches to the periphery of the pars tensa, where they run immediately beneath the tympanal, simple, squamous epithelium. In the major portion of the pars tensa, no blood vessels were found. The rat stapedial artery is a thin-walled vessel with a wide lumen. Without branch­ing, it runs through the tympanic cavity to the extratympanal regions it supplies. In contrast to the corresponding artery in man, the rat stapedial artery persists throughout life. The artery does not seem to be affected by the fluid produced during experimentally induced otitis media with effusion. The middle ear structure in the rat and in man show both similarities and differ­ences. If the differences are kept in mind and considered, it would seem that the rat is indeed a suitable model for experimental middle ear research. / digitalisering@umu

Page generated in 0.1011 seconds