• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 159
  • 93
  • 52
  • 42
  • 32
  • 18
  • 16
  • 11
  • 8
  • 6
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 290
  • 157
  • 150
  • 137
  • 131
  • 129
  • 85
  • 84
  • 70
  • 61
  • 58
  • 54
  • 52
  • 52
  • 52
  • 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.
391

Estudo da prevalência e das características do zumbido em trabalhadores expostos ao ruído ocupacional

Possani, Lissi Nara Amaral January 2006 (has links)
Introdução: O zumbido é definido como uma sensação auditiva ilusória sem a presença de um som externo. Acomete homens e mulheres, mais comumente entre 40 e 70 anos de idade, às vezes podendo ocorrer em crianças. Análises de dados epidemiológicos indicam que a exposição ao ruído é uma das causas mais comuns de zumbido. Objetivos: Os objetivos gerais deste estudo foram verificar a prevalência do zumbido em trabalhadores expostos ao ruído ocupacional e avaliar a freqüência e a intensidade do zumbido. Os objetivos específicos foram avaliar a gravidade do zumbido; analisar a presença do zumbido por sexo, cor, idade e tempo de trabalho com exposição ao ruído e analisar a relação do zumbido com as freqüências mais acometidas na audiometria e com a presença e grau da perda auditiva, independente do nexo da perda. Materiais e Métodos: Trata-se de um estudo transversal para o qual foram selecionados 362 prontuários de trabalhadores expostos a ruído ocupacional ≥80dB(NA)/8h diárias. Estes trabalhadores haviam sido submetidos a meatoscopia, anamnese clínica e ocupacional, audiometria de via aérea, avaliação de freqüência e intensidade do zumbido e à escala de avaliação da gravidade do zumbido. Conclusão: A prevalência do zumbido foi de 9,9%. Nas análises de regressão conclui-se que trabalhadores com presença de perda auditiva em pelo menos um dos ouvidos têm 2,396 vezes mais chances de ter zumbido quando comparados com os que não tem perda auditiva. Os trabalhadores com faixa etária acima ou igual a 30 anos tem 5,353 vezes mais chances de ter perda auditiva em pelo menos um dos ouvidos quando comparados com os de faixa etária menor que 30 anos. Com relação ao tempo de trabalho em contato com o ruído, a analise estatística revela que trabalhadores com diferença de 1 ano no tempo de trabalho em contato com ruído tem um risco 5,3 % (OR=1,053) maior de apresentar perda auditiva. / Background: Tinnitus is an auditory phantom sensation experienced when no external sound is present. It occurs in both men and women, and is more prevalent between the age of 40 and 70; however, it may also occur in children. Analyses of epidemiologic data indicate that exposure to noise is its most common cause. Object: The aim of this study was to investigate the prevalence and characteristics of tinnitus in noise-exposed workers. Its specific objectives were to evaluate the severity of tinnitus, to compare the presence of tinnitus with the individual’s sex, race, age, and time of exposure to noise in the workplace, and to analyze the relation between tinnitus and the most affected frequencies in audiometric tests as well as the presence and level of hearing loss. Materials and Methods: The present was a cross-sectional study for which 362 files of workers exposed to noise (≥80dB(A)/8h per day) were selected. These workers had undergone otoscopy, clinical and occupational anamnesis, audiometric test of ear conduction, and an investigation of frequency, intensity, and severity of tinnitus. Conclusion: The prevalence of tinnitus found was 9.9%. After logistic regression analyses, it was concluded that workers with hearing loss in at least one ear have 2.396 times more chance of having tinnitus than those who do not have hearing loss. Workers aged 30 or older have 5.353 times more chance of having hearing loss in at least one ear than those younger than 30. As to time of exposure to noise in the workplace, statistical analysis showed that workers with a difference of 1 year in time of exposure to noise have a 5.3% (OR=1.053) higher risk of suffering hearing loss.
392

Prevalencia de sinais e sintomas otologicos em portadores de espondilose cervical / Prevalence of signs and symptoms in patients with cervical spondylosis

Santos, Elizângela dos, 1976- 28 August 2006 (has links)
Orientador: Ibsen Bellini Coimbra / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-08T15:22:56Z (GMT). No. of bitstreams: 1 Santos_Elizangelados_M.pdf: 1146638 bytes, checksum: 6c22665ed4ca26b8c6d58369b61b8268 (MD5) Previous issue date: 2006 / Resumo: A osteoartrite (OA), osteoartrose, ou ainda doença articular degenerativa é enfermidade que tem sido muito estudada em razão do grande número de pessoas acometidas por ela. A espondilose cervical é o tipo de osteoartrite que acomete a coluna cervical e é também conhecida pela sua grande incidência. Os trabalhos disponíveis na literatura e que estudaram a OA limitaram-se fundamentalmente à sua etiologia, métodos diagnósticos, marcadores bioquímicos e formas de tratamento, não considerando, no entanto, algumas queixas apresentadas por esses pacientes sobre alguns sinais e sintomas auditivos como as disacusias, os zumbidos e as tonturas, muitas vezes presentes e relatados pelos pacientes por ela acometidos. Este estudo analisou em uma amostra de 50 pacientes, a prevalência de sinais e sintomas auditivos em portadores de espondilose cervical através da anamnese e da avaliação audiométrica e da vectoeletronistagmografia. Verificou-se através das respostas obtidas na anamnese que 44% (22) dos enfermos consideravam sua audição boa, enquanto 56% (28 pacientes) não. Dentre esses pacientes, encontraram-se em 33% deles alterações na orelha direita, 48% na orelha esquerda e em 19% alterações nas duas orelhas. Na avaliação dos resultados dos exames audiométricos (audiometria tonal) encontrou-se ainda uma maior porcentagem de indivíduos com uma alteração auditiva nas freqüências altas (4,6,8Hz) (52%,66%,66%) na orelha esquerda e na orelha direita somente na freqüência de 6 Hz (56%). Em relação à presença de zumbidos, 36 (72%) pacientes relataram a sua presença. Quando verificada a ocorrência de vertigem, 37 (74%) dos 50 pacientes a apresentaram, no entanto, os exames de vectoeletronistagmografia foram normais. conclui-se, portanto, que há prevalência de sinais e sintomas otológicos em portadores de espondilose cervical, embora eles não apareçam, necessariamente, concomitantemente, sendo que a vertigem aparece com maior freqüência, seguida por zumbido e, logo após, pela hipoacusia / Abstract: The osteoarthiris (OA) is the most common rheumatologic disease and cervical spondylosis is the OA on the cervical spine. It has been well studied in the past few years, mainly due to its high prevalence, as well as the costs to the health systems all over the world. The great majority of those studies have been focusing on its pathophysiologic aspects, etiology, diagnosis and its treatment. However few studies considered some symptoms that cervical spondylosis carriers can present, such as tinnitus and vertigo, in a such way frequent in the practical clinic. The aim of this study was to analyze in a sample of 50 patients with cervical spondylosis the auditory prevalence of signs and symptoms. It was observed that 56% of them (28 patients) didn't consider their audition as ?Good?, whereas 44% (22 patients) didn?t have any complaint. Among those subjects that didn't consider audition good the right ear was reported with deficit by 33%, the left ear by 48% and by 19% patients, both ears had problems.All patients underwent to a tonal audiometric evaluation. Its was observed a greater percentage of individuals with an audition "No Good" in the high (4, 6, 8Hz) (52%, 66%, 66% respectively) frequencies in the left ear and in the frequency of 6 Hz (56%) in the right ear. The results showed that 36 (72%) patients presented tinnitus complaint. When it verified the complaint of vertigo, 37 (74%) patients presented complaint, whose examinations of vectography had been normal. We concluded that there is a connection between signs and hearing symptoms, such as hearing loss, tinnitus e vertigo, among the patients with cervical spondylosis, suggesting that more studies in this area are required / Mestrado / Clinica Medica / Mestre em Clinica Medica
393

"Audiometria de altas freqüências em indivíduos com audição normal entre 250 e 8.000 Hz com e sem queixa de zumbido" / High frequency audiometry in individuals with normal hearing between 250 and 8.000 Hz with and with no tinnitus complaint

Ana Paula de Souza Guedes 31 August 2005 (has links)
Indivíduos com audição normal entre 250 e 8.000 Hz podem apresentar zumbido. Além da avaliação audiológica convencional, a audiometria de altas freqüências tem sido aplicada nestes casos. O objetivo desta pesquisa foi avaliar os limiares de audibilidade nas altas freqüências em indivíduos com audição normal entre 250 e 8.000 Hz com e sem queixa de zumbido. A pesquisa foi realizada em 33 indivíduos com zumbido e 33 sem zumbido. Houve piora estatisticamente significante entre os limiares de audibilidade dos indivíduos com zumbido em relação aos indivíduos sem zumbido para as seguintes freqüências: 9.000, 10.000, 12.500, 14.000, 16.000, 18.000 e 20.000 Hz / Subjects with normal hearing between 250 and 8.000 Hz may show tinnitus. Beyond the conventional audiological evaluation, the high frequency audiometry has been applied in these cases. The research's goal was to evaluate the audibility thresholds in high frequencies in subjects with normal hearing between 250 and 8.000 Hz with and with no tinnitus complaint. The research was carried through in 33 individuals with tinnitus and 33 with no tinnitus. A significant statistical worsening occurred between hearing thresholds of subjects with tinnitus with relation to subjects with no tinnitus for the following frequencies: 9.000, 10.000, 12.500, 14.000, 16.000, 18.000 and 20.000 Hz
394

Influência do fluxo arterial vertebral nos sinais e sintomas auditivos em portadores de espondilose cervical / Influence of vertebral arterial flow in signs and symptoms in patients with impaired cervical spondylosis

Santos, Elizângela dos, 1976- 24 August 2018 (has links)
Orientador: Simone Appenzeller / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T16:23:29Z (GMT). No. of bitstreams: 1 Santos_Elizangelados_D.pdf: 1569830 bytes, checksum: 0312d7e3143dbf6847b4b3af7e90d245 (MD5) Previous issue date: 2013 / Resumo: Objetivo: Verificar se há uma associação entre a espondilose cervical, sinais e sintomas auditivos e alterações no fluxo da artéria vertebral. Material e método: Foram selecionados 150 indivíduos que freqüentavam a Universidade Aberta à Terceira Idade da Universidade Federal de Alfenas. Foram excluídos indivíduos com traumas, doenças sistêmicas ou locais que pudessem interferir com o sistema auditivo e vestibulococlear . No total, 102 indivíduos [91 (89,2%) do sexo feminino; média de idade de 59,4± 12,0 anos (variação de 30 a 91 anos)]. A presença de sinais e sintomas auditivos foi avaliada através de uma anamnese elaborada específicamente para esse fim. Radiografias nas posições anteroposterior, perfil e oblíquas foram realizadas em todos os indivíduos e analisadas por dois radiologistas, cegos em relação a sintomatologia. Ultrassonografia (US) Doppler foi realizada nas artérias vertebrais direita e esquerda em posição anatômica em todos os indivíduos, por um ultrassonografista cego quanto às manifestações clínicas ou radiográficas. A análise estatística foi realizada no programa SAS e Systat. Os testes estatísticos aplicados foram selecionados de acordo com a natureza das variáveis. Resultados: A prevalência de sintomas vestibulococleares foi observada em 83 (81,4%) dos indivíduos da amostra. Espondilose cervical foi observada em 71 (69,6%) dos indivíduos. A média de fluxo da artéria vertebral direita foi significativamente menor [85,3 ± 43,1 ml/min (variação 18,1 ¿ 208,9 ml/min)] quando comparados aos indivíduos sem espondilose cervical [101,2 ± 44,3 ml/min (variação 43,8 ¿ 282,3 ml/min; p=0,02). Não observamos alterações no fluxo arterial vertebral esquerda em pacientes com espondilose cervical, comparado aos indivíduos sem espondilose cervical. Não houve relação entre a alteração do fluxo arterial vertebral, a presença de espondilose cervical e sintomas vestibulococleares. Conclusão: Observamos uma elevada prevalência de sintomas vestibulococleares e espondilose em nossa amostra. O fluxo da artéria vertebral direita estava reduzido em indivíduos com espondilose, porém não houve associação com sintomas clínicos / Abstract: Objective: To determine the relationship between in signs and symptoms of hearing, espondylosis and vertebral artery flow. Methods: A total of 150 individuals from the Universidade aber ta a tercei ra idade da Universidade Federal de Al fenas were invi ted. Individuals wi th t rauma, systemic or local diseases that could inf luence vest ibulococlear symptoms were excluded. A total of 102 individuals[91 (89.2%) female; median age 59,4± 12,0 years (range 30 a 91 years)] were included. Vestibulocolcear symptoms were evaluated by clinical interview. X-ray of the cervical spine were done in anterior-posterior, lateral and oblique view and reviewed by two radiologist blind to the individuals' symptoms. Doppler ultrasound (US) of the vertebral artery was done in anatomic position in all individuals by an ultrasound expert blind to individuals characteristics. Statistics was performed using SAS and Systat according to the nature of the variable. Results: The prevalence of signs and symptoms of hearing was observed in 83 (81.4%) and spondylosis in 71 (69.6%) individuals. The mean right vertebral flow was significant smaller in individuals with spondylosis [85.3 ± 43.1 ml/min (range18.1 ¿ 208.9 ml/min)] when compared to individuals without spondylosis. We did not observe a difference regarding the left vertebral flow. No relation between arterial vertebral flow, spondylosis and vestibulocolear symptoms was observed. Conclusion: A high prevalence of vestibulococlear symptoms and spondylosis was observed in this cohort. The right vertebral artery had reduced flow in individuals with spondylosis, however no relation to symptoms was observed / Doutorado / Clinica Medica / Doutora em Clínica Médica
395

Cervicocephalic artery dissection:radiological study with clinical outcome

Pelkonen, O. (Outi) 30 January 2004 (has links)
Abstract The aim of this study was to analyze angiographic findings and the presence and topography of cerebral ischemic and/or hemorrhagic lesions in cerebral CT or MRI, and to assess the long-term clinical outcome of a series of 136 consecutive cervicocephalic artery dissection (CCAD) patients. Pulsatile tinnitus was evaluated as a symptom of CCAD. Medical records and films were reviewed retrospectively. Irregular stenosis was found in angiography in 50% and occlusion in 33% of the dissected cervicocephalic arteries. Irregular stenosis normalized in 81% and occlusion recanalized in 34%. Other findings, such as pseudoaneurysms, intimal flaps, double lumens, and irregular dilatations were rare and often remained unchanged in follow-up. Pulsatile tinnitus was a presenting symptom in 12% of the CCAD patients, but the majority of patients had concomitant head or neck pain, ischemic brain symptoms, Horner's syndrome, or cranial neuropathies. Of the 131 patients who underwent brain imaging, 73 (56%) had signs of infarction in cerebral CT or MRI. Occlusion of the dissected vessel was accompanied by infarction in 76%, irregular stenosis in 40%, and other findings only rarely. Of the anterior circulation infarctions, 95% (39/41) were territorial, subcortical, or territorial infarctions with fragmentation and could thus be considered embolic. Subarachnoid hemorrhage was found in CT in 5 of the 22 patients (23%) with intracranial dissection. The patient's long-term clinical outcome was assessed using two methods: a classification into categories based on neurological symptoms and defects and the modified Rankin Scale (mRS). Of the 136 CCAD patients, 60% recovered with no or mild disability and 79% scored 0–2 on mRS. In the case of dissection of one or more cervicocephalic arteries without occlusion, the figures were 75% and 89%. In the case of occlusive dissection of one or more arteries, only about 35% of the patients recovered well, having no or mild disability, and 61% scored 0–2 on mRS. No significant differences were seen in recovery after intra- and extracranial dissections. In conclusion: irregular stenosis, which is the most common angiographic finding in CCAD, is associated with brain infarction less frequently than occlusion, and the long-term clinical outcome is good in most cases. Occlusion of the dissected vessel causes more brain infarctions, and only about 35% of the patients recover well, having no or mild disability. More than 10% of CCAD patients have pulsatile tinnitus as a presenting, and sometimes the only symptom.
396

Aspectos fisiologicos e fisicos da orelha como emissora de sons / Physics and physiological aspects of the ear as a sound emitter system

Ferreira, Denise Rezende 29 August 2006 (has links)
Orientadores: Jorge Humberto Nicola, Ester Maria Danielli Nicola / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-07T13:57:05Z (GMT). No. of bitstreams: 1 Ferreira_DeniseRezende_M.pdf: 701948 bytes, checksum: fc978779bb5a79b92989795b47d5a788 (MD5) Previous issue date: 2006 / Resumo: A orelha é o receptor de sons em nosso organismo. O som é captado e conduzido pela orelha externa, amplificado e modulado na orelha média e transformado em sinal elétrico (conhecido como transdução) na orelha interna. Entretanto, as emissões otoacústicas e o zumbido objetivo são exemplos de um processo inverso, onde a orelha se comporta como um emissor de sons. Visando entender alguns destes eventos em que a emissão de sons ocorre, revisou-se a literatura da fisiologia da audição e das bases físicas do percurso do som através do sistema auditivo. Utilizou-se como ferramenta principal, os artigos contidos no Web of Science, dos últimos 25 anos. A partir deste ponto, desenvolveu-se um modelo teórico do percurso do som gerado na cóclea que se propaga em direção à membrana timpânica. Foram realizados cálculos para a atenuação do som decorrente da existência de uma inércia mecânica da estrutura janela oval ¿ ossículos ¿ tímpano. Para isso, considerou-se a razão entre as áreas da janela oval e tímpano e as dimensões dos dois braços de alavanca formada pelos ossículos. Como conclusão, verificou-se que som gerado na cóclea pela eletromotilidade das células ciliadas externas, sofre uma atenuação da ordem de 20 vezes ao passar pela cadeia tímpano-ossicular no sentido inverso. Além disto, demonstrou-se que na interface perilinfa ¿ janela oval, assim como aquela da cadeia ossicular para a membrana timpânica, a transmissão do som é considerável (70%), pois não há grandes diferenças entre as impedâncias acústicas dos meios envolvidos (líquidos labirínticos e sistema tímpano-ossicular). Assim, foi explicado, fisicamente, como as emissões de sons através da orelha podem ter origem a partir de movimentos de muito baixa energia, como aqueles gerados pela contração das células ciliadas externas / Abstract: Ear is the sound receptor in our body. Sound is captured and driven through external ear, amplified and modulated in middle ear and transduced to electrical sign in internal ear. However, otoacoustic emissions and objective tinnitus are examples of an inverse process, where ear can be a sound emitter. Trying to understand some of theses events, in which sound emission occurs, the physiology of hearing and the physical basis to the sound propagation through the ear was revised. It was used as main tool, articles of Web of Science, from the last 25 years. From this point, it was developed a theoretical model to the way of sound, generated inside cochlea that propagates in tympanic membrane direction. It was performed mathematical calculations to sound attenuation, caused by the mechanical inertia of oval window - ossicles - tympanic membrane structure. For that, it was considered the area ratio between oval window and tympanum and the lever action ossicular chain. We concluded that sound generation by electromotility of outer hair cells inside cochlea, is attenuated in 20 times when it passes through ossicular chain in the inverse way. Besides this lost in sound energy, it was also demonstrated that in perilymph-oval window interface sound transmission is considerable (70%), because there are not big differences between the acoustic impedances of involved structures. Then, in physical basis, it was shown how ear can emit sound from contraction of outer hair cells / Mestrado / Otorrinolaringologia / Mestre em Ciências Médicas
397

Avaliação da atenção seletiva em pacientes com misofonia / Evaluation of selective attention in patients with misophonia

Fúlvia Eduarda da Silva 02 October 2017 (has links)
INTRODUÇÃO: A misofonia é caracterizada pela aversão a sons bem seletivos, que provocam uma forte reação emocional. Foi proposto que a misofonia, assim como o zumbido, esteja associada à hiperconectividade entre os sistemas auditivo e límbico. Indivíduos com zumbido de incômodo significativo podem apresentar comprometimento da atenção seletiva, o que ainda não foi demonstrado no caso da misofonia. OBJETIVO: caracterizar uma amostra de indivíduos com misofonia e compará-la com dois grupos controle, um com zumbido (sem misofonia) e outro assintomático (sem zumbido e sem misofonia). METODOLOGIA: Foram avaliados 40 sujeitos normo-ouvintes, sendo 10 com misofonia (grupo misofonia - GM), 10 com zumbido (sem misofonia) (grupo controle zumbido - GCZ) e 20 sem zumbido e sem misofonia (grupo controle assintomático - GCA). Foi realizada anamnese geral em todos os grupos e anamnese específica apenas para o GM. Nos três grupos, foi aplicado o Teste de Identificação de Sentenças Dicóticas em três situações. Na primeira, foi realizado o exame padrão. Em seguida, foi aplicado incluindo mensagem competitiva, uma com som de mastigação (exame mastigação), e outra com white noise (exame white noise). RESULTADOS: A amostra do GM apontou que os primeiros sintomas da misofonia foram percebidos ainda na infância ou adolescência (média 11,5 anos). O grau de incômodo variou de 6 a 10 na escala visual analógica e, dentre os 10 participantes do GM, nove (90%) responderam que a misofonia atrapalha, sempre ou às vezes, a vida social e profissional. No teste de Identificação de Sentenças Dicóticas, foi observado que no exame mastigação, as médias da porcentagem de acertos diferem entre os grupos GM e GCA (valor-p = 0,027) e entre os grupos GM e GCZ (valor-p = 0,002), sendo menor em ambos os casos no GM. Para os exames padrão e white noise, não há diferença entre as médias da porcentagem de acertos nos três grupos (valores-p >= 0,452). CONCLUSÃO: os participantes do GM apresentaram menor porcentagem de acertos no Teste de Identificação de Sentenças Dicóticas na situação de apresentação de um ruído distraidor (exame mastigação) em relação ao mesmo teste aplicado em situação padrão ou white noise, sugerindo que indivíduos com misofonia podem apresentar alteração da atenção seletiva quando expostos a sons que desencadeiam esta condição / INTRODUCTION: Misophonia is characterized by the aversion to very selective sounds, which evoke a strong emotional reaction. It has been proposed that misophonia, as well as tinnitus, is associated with hyperconnectivity between the auditory and limbic systems. Individuals with bothersome tinnitus may have selective attention impairment, but it has not been demonstrated in case of misophonia yet. OBJECTIVE: to characterize a sample of misophonic subjects and compare it to two control groups, one with tinnitus individuals (without misophonia) and the other one with asymptomatic individuals (without misophonia and without tinnitus), regarding self-perception of the condition and selective attention. METHODOLOGY: we had evaluated 40 normal hearing participants: 10 with misophonia (GM), 10 with tinnitus (without misophonia) (GCZ) and 20 without tinnitus and without misophonia (GCA). General questionnare was applied in all of three groups and specific misophonia questionnaire was applied only in GM. In order to evaluate the selective attention, it was applied the Dichotic Sentence Identification (DSI) Test in three situations: In the first one, it was applied the original test. Then, the test was applied in two other situations including two competitive sounds, one with chewing sound (chewing test), and the other one with white noise sound (white noise test). RESULTS: The GM sample indicated that the onset of misophonia occurred in childhood or adolescence (mean 11.5 years). According to the visual analog scale, the discomfort with misophonia ranged from 5 to 10, and nine (90%) participants answered that misophonia always or sometimes limits their social and professional interactions. In the chewing test, it was observed that the average of correct responses differed between GM and GCA groups (pvalue = 0.027) and between GM and GCZ groups (p-value = 0.002), in both cases it was lower in GM. In the original and white noise tests, no difference was observed between the averages of correct responses in the three groups (p-values >= 0.452). CONCLUSION: The GM participants had a lower percentage of correct responses in the chewing test, suggesting that individuals with misophonia may have selective attention impairment when they are exposed to sounds that trigger the condition
398

Lokalizace GABAB receptoru v dorzálním kochleárním jádře a sluchové kůře myši za fyziologických a patologických podmínek / Localization of GABAB receptor in the mouse dorsal cochlear nucleus and auditory cortex under physiological and pathological conditions

Melichar, Adolf January 2018 (has links)
GABAB receptors play an important role in regulation of neuronal excitability and stability of neural microcircuits. It is well known that dysregulation of slow GABAergic signalisation can lead to many pathological conditions (epilepsy, anxiety etc.). Current research indicates that the imbalance in the inhibitory transfer, caused by changes in the expression of GABABR in the auditory system could play an important role in the progression of tinnitus. The goal of the present thesis was to determine the distribution of the GABAB receptor and its auxiliary subunit KCTD12 in the mouse auditory cortex and the dorsal cochlear nucleus (DCN). Furthermore, a change in GABAB receptor localization in the DCN was observed in mice exposed to an acoustic stress. The GABAB receptor was expressed across the entire auditory cortex, both on the body and on the neuronal fibres. On the contrary, KCTD12 was found only in a particular subgroup of neurons that includes VIP (vasoactive intestinal peptide) and cholecystokinin positive interneurons., GABABR and KCTD12 protein were found in all layers and in all studied cells types (fusiform, cartwheel and stellate) of the DCN. Acoustic trauma of the WT mice resulted in GABAB receptor internalization specifically in fusiform cells that are the main projection neurons of the...
399

Effekter av kognitiv beteendeterapi vid tinnitusrelaterade besvär

Ekelund, Viktoria, Yin, Janina January 2009 (has links)
En tiondel av Sveriges befolkning är drabbade av tinnitus så chansen är stor att svenska sjuksköterskor träffar på individer drabbade av detta fenomen i sitt dagliga arbete. Syftet med denna studie var att öka kunskapen om tinnitus hos allmänsjuksköterskor och sjuksköterskestudenter, med två specifika frågeställningar. Den första var vilket bevis det finns för ett samband mellan tinnitus och depression, ångest, kognitiva besvär och sömnbesvär. Den andra frågeställningen handlade om på vilket sätt som kognitiv beteendeterapi har effekt på tinnitusrelaterade besvär. Metoden för den systematiska litteraturöversikten var Goodmans sju steg modifierad av Willman et al (2006), och ett modifierat protokoll av Carlsson & Eiman (2003) användes för att kvalitetsbedöma de artiklar som hittats i litteratursökningen. Resultatet byggde på tio kvantitativa artiklar. Svaga bevis fanns för ett samband mellan tinnitus och ångest, depression och sömnbesvär. Vad beträffar kognitiva besvär så visade resultatet att det fanns belägg för att tinnitus påverkar uppmärksamheten när den riktas åt flera håll. Kognitiv beteendeterapi hade effekt på tinnitus på så sätt att behandlingen reducerade besvär relaterade till tinnitus. Effekten av behandlingen analyserades med Lazarus copingstrategi som teoretisk referensram. Förslag på rekommendationer till implementering i vården är att då sjuksköterskan möter en patient med tinnitus bör sjuksköterskan förhöra sig om eventuella besvär, och vid behov rekommendera kognitiv beteendeterapi. / One-tenth of the Swedish population is affected by tinnitus so chances are that Swedish nurses will meet individuals affected by this phenomenon in their daily work. The aim of this study was to increase understanding concerning tinnitus in general nurses and nursing students, with two specific questions. The first one was what evidence there is that a relation between tinnitus and depression, anxiety, cognitions disorders and sleep disorders exists. The second question concerned how cognitive behavioral therapy has an effect on tinnitus-related complaints. The method for the systematic literature review was the seven steps of Goodman modified by Willman et al (2006), and a modified protocol by Carlsson & Eiman (2003) was used to assess the quality of the articles found in the literature search. The result is based on ten quantitative articles. There was weak evidence for a relationship between tinnitus and anxiety, depression and sleep disorders. As for cognition disorders, the results showed that there was support for tinnitus affecting attention when it is directed in several directions. The way that cognitive behavioral therapy was effective on tinnitus was that the treatment reduced complaints related to tinnitus. The effect of the treatment was analyzed with the coping-strategy of Lazarus as a theoretic frame. Suggestions for recommendations to the implementation of care is that when the nurse meets a patient with tinnitus should the nurse inquire about any inconvenience, and if there is a need recommend cognitive behavioral therapy.
400

In Vitro Cortical Networks for Disease Modeling and Drug Evaluation

Wu, Calvin 12 1900 (has links)
In translational research, disease models in preclinical studies are used as media for discovery of drugs or novel therapeutics. Development of in vitro models for various neurological diseases that enable efficient pharmacological or toxicological screening has been ongoing but challenging. Recognizing the potential benefit of in vitro disease models, dysfunctions in the cortical neuronal networks were induced to mimic the functional pathology of neurological symptoms using microelectrode arrays. Two different disease states – tinnitusand excitotoxicity – were investigated and discussed. In this model, pentylenetetrazol-induced increase in spontaneous firing rate and synchrony in the auditory cortical networks was used as correlate of tinnitus. Potential tinnitus treatment drugs from several different classes – including the novel class of potassium channel openers – were screened and quantified. The potentialtherapeutic values of these drugs were also discussed as the basis for drug repurposing. Functional excitotoxicity was induced by cisplatin (a cancer drug that causes neurological sideeffects) and glutamate (the major excitatory neurotransmitter). As proof-of-principle that the model may contribute to expediting the development of therapeutics, cisplatin excitotoxicity wasprevented by the antioxidant D-methionine, while glutamate excitotoxicity was prevented by ceftriaxone (a modulator of a glutamate reuptake transporter). In the latter part of the study, with results linking two of the screened drugs L-carnitine and D-methionine to GABAA receptor activation, it was demonstrated that this model not only served as an efficient drug-screening platform, but can be utilized to functionally investigate the underlying mechanism of drugs. Inaddition, several practical or conceptual directions for future studies to improve on this in vitro disease model are suggested.

Page generated in 0.0406 seconds