• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 295
  • 143
  • 27
  • 20
  • 12
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 2
  • Tagged with
  • 717
  • 164
  • 154
  • 153
  • 140
  • 99
  • 92
  • 80
  • 79
  • 66
  • 60
  • 58
  • 56
  • 53
  • 53
  • 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.
31

Achados da acuidade visual estática e dinâmica em pacientes com disfunção vestibular / Findings of static and dynamic visual acuity in patients with vestibular dysfunction

Renata Sales 03 May 2013 (has links)
SALES, R. Achados da acuidade visual estática e dinâmica em pacientes com disfunção vestibular. 106f. Tese (Doutorado) da Faculdade de Medicina de Ribeirão Preto-USP. Ribeirão Preto-SP, 2013. Para a obtenção da visão nítida é necessário que a imagem permaneça estável na retina, mesmo com a movimentação cefálica. As pessoas que sofrem de labirintopatias são mais sensíveis a efeitos visuais, podendo apresentar os sintomas de tontura, enjoo e oscilopsia durante a movimentação cefálica. Esse fato ocorre devido ao conflito sensorial entre o sistema vestibular e visual. O presente estudo objetivou verificar a variação da acuidade visual estática e dinâmica em pacientes com disfunção vestibular. Foram selecionados pacientes de ambos os sexos, com idade entre 14 e 88 anos de idade submetidos ao exame de vetoeletronistagmografia entre os anos de 2009 e 2011. Esses pacientes também foram submetidos ao exame de acuidade visual estática e dinâmica. Na acuidade visual dinâmica, foram pré-determinadas frequências de 0.5, 1.0, 1.5 e 2.0 Hertz para a movimentação cefálica. Os resultados mostraram maior decréscimo da acuidade visual estática e dinâmica entre os pacientes com labirintopatias bilaterais se comparadas com as unilaterais e o grupo controle. Além disso, o aumento da frequência produziu decréscimo da acuidade visual em todos os grupos e a posição da movimentação cefálica na vertical mostrou maior sensibilidade se comparada à horizontal. Pôde-se concluir que os pacientes com labirintopatias apresentaram decréscimo da acuidade visual estática e dinâmica, principalmente nas frequências mais altas e com a movimentação cefálica na posição vertical, sendo esses exames importantes para auxiliar no diagnóstico e monitoramento das labirintopatias. Palavras-chave: Acuidade visual; Sistema vestibular / For obtaining an accurate image is necessary that remains stable on the retina, even with head movement. People suffering from labyrinthopathy are more sensitive to visual effects, and may have symptoms of dizziness, nausea and oscillopsia during head movement. This fact occurs because the sensory conflict between visual and vestibular system. The present study aimed to determine the variation of static and dynamic visual acuity in patients with vestibular dysfunction. Selected patients were of both gender, aged between 14 and 88 years old who underwent examination vetoeletronistagmografia between the years 2009 and 2011 at the home Institution. The patients were subjected to tests of visual acuity static and dynamic. In dynamic visual acuity, were predetermined frequencies of 0.5, 1.0, 1.5 and 2.0 Hz for the patient\'s head movement. The results showed a greater decrease in static and dynamic visual acuity among patients with bilateral labyrinthopathy compared with the unilateral and control groups. In addition, the frequency increase produced decreased visual acuity in all groups and the position of head movement in the vertical showed a higher sensitivity compared to the horizontal. It was concluded that patients with labyrinthopathy showed a decrease of static and dynamic visual acuity, especially at higher frequencies and with head movement in a vertical position, and these important tests to assist in diagnosis and monitoring of the labyrinthopathy. Keywords: Visual acuity; Vestibular system
32

Cortisol sanguineo e salivar como indicadores de estresse / Serum and salivary cortisol as stress marker

Garcia, Marcia Carvalho 14 August 2008 (has links)
Orientador: Regina Celia Spadari / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-11T21:14:44Z (GMT). No. of bitstreams: 1 Garcia_MarciaCarvalho_D.pdf: 2444623 bytes, checksum: 19d8fc9818febb47b3d43f0f80c847d5 (MD5) Previous issue date: 2008 / Resumo: Hans Selye definiu stress como a " resposta não específica do organismo frente a agentes ameaçadores de sua integridade". O avanço de técnicas e métodos tanto de coleta de material biológico, quanto de análises destes tornaram esta definição polêmica. Apresentamos neste trabalho a evolução do conceito de estresse e os termos a ele associados, levando em conta que a resposta de estresse tem caráter adaptativo e visa proteger o organismo e garantir a sua sobrevivência, quando se refere a experiências de tempo limitado que o indivíduo pode superar. Por outro lado, o estresse torna-se perigoso para a saúde quando o senso de controle e o domínio são perdidos. O sistema de resposta de estresse envolve regiões cerebrais que se conectam entre si e desencadeiam estímulos por meio de dois eixos: um neural e outro hormonal aos sistemas periféricos. Os glicocorticóides participam em todas as etapas da resposta de estresse, e são, por isso, considerados como marcadores biológicos desta resposta. A determinação da concentração salivar de cortisol é, atualmente, a técnica de eleição para este fim. O objetivo deste trabalho foi avaliar se a determinação da concentração salivar de cortisol pode ser utilizada como indicador biológico de estresse relacionado a diversas atividades humanas. Determinamos a concentração sérica de cortisol em jogadores de futebol durante duas temporadas esportivas, e a concentração salivar de cortisol em atletas de basquetebol também durante duas temporadas esportivas, em estudantes durante o ano de preparo para o vestibular, além de utilizar esta técnica para investigar o índice de estresse associado ao baixo status socioeconômico. Nossos resultados mostraram que a concentração salivar de cortisol apresenta vantagens sobre a determinação da concentração sanguínea deste hormônio por ser não invasiva, ser indolor e de fácil manejo. Além disso, os dados permitiram avaliar o índice de estresse associado à prática esportiva, em duas modalidades diferentes, a uma atividade intelectual, representada pelo esforço realizado para entrar na universidade, e à condição socioeconômica adversa. Por outro lado, verificamos que cuidados devem ser tomados para garantir a adesão dos voluntários aos protocolos de coleta, uma vez que esta tende a ser baixa neste tipo de abordagem. Além disso, esta técnica é adequada para avaliar a concentração de cortisol como indicadora do índice de estresse relacionado à prática esportiva, à atividade intelectual, e o estresse associado ao baixo status socioeconômico. Nós também concluímos que no início da temporada esportiva os atletas ficam expostos a concentrações mais altas de cortisol, embora o ritmo circadiano do hormônio seja mantido. Nos jogos matinais, mas não nos vespertinos ou noturnos foi possível estabelecer correlação positiva entre concentração de cortisol e vitória. Concluímos que, estudantes brasileiros candidatos a ingressar na Universidade apresentaram stress, depressão e ansiedade. A concentração de cortisol salivar oscilou durante o ano, com altas concentrações nos meses que os estudantes tiveram que decidir sobre a carreira a seguir e a universidade. No mês novembro, concentrações moderadas de cortisol salivar foram significativamente correlacionadas com sucesso no exame. Em pessoas de baixo status socioeconômico verificamos que os altos índices de estresse percebido e da concentração salivar de cortisol impactam negativamente em sua saúde e se correlacionam com o estresse experimentado diariamente. Considerando que esta corresponde a 30% da população brasileira, isto pode representar um grande impacto nas políticas públicas de saúde. / Abstract: Hans Selye defined stress as 3the organism non specific response to any threat to its integrity3. During most of the past century, Selye's theory has been challenged by a number of scientists who discussed many of its aspects based on new data. In this work we present the evolution of stress theory and associated terms, considering that the stress response is adaptive and that it has been conserved to protect and to guarantee survival. This happens when the stressor is present for a short period, and when the subject can overcomes it. On the other hand, the stress response turns into harmful when the subject looses control over the situation. The stress system includes cerebral regions that are connected and that trigger stimuli through a neural and a hormonal axis towards the periphery, preparing the organism to the fight-or flight reaction or adaptation. Because glucocorticoids play a role in every phase of the stress response these hormones have been recognized as biological markers of the stress reaction. The aim of this work was to evaluate the salivary cortisol levels (SCL) related to several human activities and conditions. We determined the seric cortisol levels in soccer players and the salivary cortisol levels in basketball athletes during two competitive seasons, in Brazilian students during the year they prepare to enter the University, and in a group of people with low socioeconomic status. Results have shown that using salivary cortisol is better than blood levels because it is easier, painless and can be done by the subject anywhere. Moreover, this technique was suitable to evaluate the cortisol level as an indicator of the stress index related to sports practice, to intellectual activity, represented by the students fight to conquer a vacancy in the public university, and associated to low socioeconomic status (LSES). On the other hand, we also concluded that the volunteers' adhesion to the protocol of sample collection is poor and may represent a challenge to the researcher. By using this technique we concluded that in the beginning of the competitive season athletes are exposed to higher levels of cortisol. However, the cortisol circadian rhythm has been preserved during all the season. In the morning games the increase of cortisol levels are related to the game result, with higher increases correlated with victory. This does not happen for the afternoon and evening games. The Brazilian students, preparing for university entrance exams, were pronounced stressed, and have shown high levels of depression and anxiety. The salivary cortisol levels oscillate during the year, with higher values in the months when the students are choosing their courses and university. Although the levels of salivary cortisol diminished in November, SCL were not correlated with success in the exam. We have concluded that the LSES is associated with high index stress perceived (PSI) and salivary cortisol levels which could impact negatively in health and it is related to the daily life stress experienced by LSES group. Because the LSES corresponds to about 30% of the total Brazilian population, it might have a great impact on public health policies and costs. / Doutorado / Fisiologia / Doutor em Biologia Funcional e Molecular
33

Caracterização da tontura de origem metabólica em pacientes tratados com reabilitação vestibular / Dizziness characterization of metabolic origin in patients treated with vestibular rehabilitation

Bárbara Vieira Coró 04 July 2016 (has links)
A reabilitação vestibular sofre influências das doenças metabólicas na resposta final do tratamento. Os processos sistêmicos podem afetar negativamente na adaptação vestibular, levando a uma resposta parcial ou ainda ausência de resposta. Este estudo caracterizou a tontura de origem metabólica em pacientes tratados com reabilitação vestibular, identificando aspectos auditivos, otoneurológicos e aspectos da doença metabólica envolvida. O procedimento da pesquisa foi baseado em análise de questionários de pacientes com diagnóstico de tontura de origem metabólica, entre os anos de 2002 a 2014. Os resultados revelaram a ocorrência de doenças metabólicas em 55%(N=55) da população com a diabetes sendo a principal (N=28), seguida de hipotireoidismo (N=24) e colesterol (N=18), sendo que 15%(N=15) apresentaram essas doenças associadas. A queixa associada de zumbido e hipoacusia foi relatada por 46 pacientes. O padrão audiológico encontrado foi perda auditiva do tipo sensórioneural (42%N=42). A resposta de hiporreflexia unilateral foi a mais frequente (38% N=38). Os fármacos vasodilatadores foram os mais usados pelos pacientes deste estudo com destaque para o dicloridrato de betaistina (32% N=32). Não houve correlação entre tipo de tontura e resposta labiríntica. Houve correlação entre zumbido e hiporreflexia unilateral (r=0,9 p=0,02) e entre a associação de zumbido com hipoacusia e hiporreflexia unilateral (r=0,9 p=0,02). O grupo tratado com reabilitação vestibular isolada apresentou melhora significativa com nove meses (p=0,01). O grupo tratado com reabilitação vestibular e medicamentos apresentou melhora significativa com 45 dias (p=0,01). O grupo em uso de um fármaco não apresentou melhora significativa. O grupo em uso de vários fármacos apresentou melhora significativa com 45 dias (p=0,03). Conclui-se que a ocorrência de doenças metabólicas foi de 55% sendo a mais frequente a Diabetes. O zumbido e a hipoacusia foram relatados por 46% da população. Perda auditiva do tipo sensórioneural foi o padrão audiológico encontrado. Hiporreflexia unilateral foi à 9 resposta labiríntica mais frequente. Os fármacos vasodilatadores foram os mais utilizados pelos pacientes desse estudo. Houve correlação entre manifestações auditivas e hiporreflexia unilateral. Não houve correlação entre o tipo de tontura e resposta labiríntica. A reabilitação vestibular associada a uso de medicamentos no tratamento da tontura resultou em melhora dos sintomas de forma imediata, não colaborando para compensação em longo prazo. A reabilitação vestibular isolada no tratamento da tontura resultou em melhora dos sintomas com o efeito do tempo. As interações medicamentosas foram benéficas para alívio imediato da tontura, porém não contribuiu para compensação em longo prazo. / The vestibular rehabilitation is influenced metabolic diseases in response to therapy. Systemic processes may negatively affect the vestibular adaptation, leading to a partial response or lack of response. This study characterizes the labyrinthine metabolic in patients treated with vestibular rehabilitation, identifying aspects hearing, otoneurological and aspects of metabolic disease involved.The procedure of the research was based on analysis of patient questionnaires diagnosed with dizziness of metabolic origin between the years 2002-2014. The results revealed the occurrence of metabolic disorders in 55% (n = 55) of population with diabetes being the main (N = 28), followed by hypothyroidism (N = 24) and cholesterol (N = 18) and 15% (N = 15) had associated diseases. The complaint associated tinnitus and hearing loss was reported by 46 patients. The audiological pattern was sensorineural hearing loss type (42% N = 42). Unilateral hyporeflexia response was the most frequent (38% N = 38). Vasodilator drugs were the most commonly used by patients in this study highlighting the betahistine dihydrochloride (32% N = 32). There was no correlation between type of dizziness and labyrinthine response. There was a correlation between tinnitus and unilateral hyporeflexia (r = 0.9 p = 0.02) and between tinnitus associated with hearing loss and unilateral hyporeflexia (r = 0.9 p = 0.02). The group treated with isolated vestibular rehabilitation showed significant improvement with nine months (p = 0.01). The group treated with vestibular rehabilitation and medications showed significant improvement at 45 days (p = 0.01). The group using a drug did not show significant improvement. The group using several drugs showed significant improvement at 45 days (p = 0.03). It is concluded that the occurrence of metabolic disorders was 55% and the most frequent diabetes. Tinnitus and hearing loss were reported by 46% of the population. Sensorineural hearing loss type was the standard audiological found. Unilateral hyporeflexia was the most frequent response labyrinthine. Vasodilator drugs were the most commonly used by patients in this study. 11 There was a correlation between auditory events and unilateral hyporeflexia. There was no correlation between the type of dizziness and labyrinthine response. Vestibular rehabilitation associated with use of drugs in the treatment of dizziness resulted in improvement in symptoms immediately, not contributing to long-term compensation. Vestibular rehabilitation alone in the treatment of dizziness results in improvement of symptoms with the effect of time. Drug interactions were beneficial for immediate relief of dizziness, but did not contribute to long-term compensation.
34

The identification of vestibular processing dysfunction in disorders of sensory integration

Penberthy, Marie Louise 20 April 2017 (has links)
No description available.
35

Analysis of human vestibular responses to caloric stimulation

Demers, Robert. January 1975 (has links)
No description available.
36

CURRENT MEDICAL PRACTICES FOR TREATMENT OF VESTIBULAR DYSFUNCTION

Resavage, Allison Lynne 22 April 2004 (has links)
No description available.
37

Role of chondroitin sulfates in the projection of vestibular commissures during embryonic hindbrain development

Yuen, Ying-lai., 袁英麗. January 2008 (has links)
published_or_final_version / Physiology / Master / Master of Philosophy
38

A model for morphological change in the hominid vestibular system in association with the rise of bipedalism

Knox, Craig A. January 2007 (has links)
This study re-examines the morphological data and conclusions of Spoor, Wood, and Zonneveld concerning the morphology of the vestibular apparatus in relation to locomotor behavior in hominids (1994). The pedal and labyrinthine morphology of early hominid taxa are functionally analyzed for classification as either obligate bipeds or habitual bipeds with primarily arboreal locomotion. The bony labyrinth is investigated since the anatomy of the semicircular canals of the vestibular auditory system can be determined in fossil crania through computed tomographical analysis. It is thought that a relationship exists between semicircular canal size and locomotor behavior. Functionally modern pedal morphology precedes modern vestibular morphology in the fossil record. Complete modern pedal morphology, however, appears concurrently with modern vestibular morphology first at Homo erectus. A comparison of the genes involved in the development of both pedal and labyrinthine morphology was undertaken. It was found that only fibroblast growth factor 8 (FgfS) and sonic hedgehog (Shh) are shared between these systems in the determination of positional information. It is found that the function of Fgf8 in otic induction and in limb bud formation is very different. It is also found that the function of Shh in vestibular and pedal morphogenesis is different. Therefore, it is unlikely for alteration in the function or in the expression of either gene to result in the observed differences in pedal and vestibular morphology between early hominid taxa: Australopithecus afarensis, Australopithecus africanus, Homo habilis; and Homo erectus. My examination of the data on the timing of changes in pedal morphology rejects Spoor, Wood, and Zonneveld's conclusion. Moreover I find no gene mutation which could account for simultaneous change in the shape of the semicircular canals and the proportions of the metatarsals and pedal phalanges. Instead, it is postulated that the change to modern vestibular morphology at Homo erectus is in response to a concurrent enlargement in cranial capacity. It is also postulated that persistence of panid vestibular morphology in the semicircular canals of hominid taxa: Australopithecus afarensis, Australopithecus africanus, and Homo habilis is a functionally neutral trait in regard to bipedal locomotor capability. / Department of Anthropology
39

Dynamika vestibulární kompenzace u pacientů po resekci vestibulárního schwannomu / The dynamic of vestibular compensation in patients after vestibular schwannoma surgery

Kletenská, Markéta January 2016 (has links)
The thesis deals with the issue of vestibular compensation in patiens after vestibular schwannoma surgery. The aim of this thesis was to objectively evaluate the dynamics of vestibular compensation in the early postoperative period and to determine whether the application of gentamicin impacts the dynamics of equilibrium functions. 32 patients participated in the study (20 women and 12 men) ranging from 28 to 73 years of age. Patients underwent a rehabilitation program with visual feedback using the interactive rehabilitation system, Homebalance. This rehabilitation program was carried out daily from the 5th postoperative day until hospital discharge. Patients were examined preoperatively, postoperatively and after rehabilitation. To assess the vestibular compensation, static posturography, the Synapsys Posturography System, and the Activities-Specific Balance Confidence Scale were used. The statistical analysis showed a significant increase in mean values of measured COP parameters (the length of the COP trajectory and COP confidence elipse area) postoperatively. After completing the rehabilitation program no significant reduction of measured COP parameters was found. The total score from the Activities- Specific Balance Confidence Scale showed a statistically significant decrease in postoperative...
40

Cognitive and emotional effects of vestibular damage in rats and their medial temporal lobe substrates

Goddard, Matthew John, n/a January 2008 (has links)
Psychiatric disorders and cognitive impairment are increasingly being described in patients with vestibular pathology. Yet frameworks that describe the link between emotion, memory and the vestibular system have yet to reach maturity, partly because studies have not yet provided detailed accounts of behavioral changes in experimental animals, or in man. One of the goals of this thesis was to use experimental psychology to define changes in memory and emotional behaviour in rats given bilateral vestibular deafferentation (BVD, n=18) or sham surgery (Sham, n=17). In an elevated-plus maze task, BVD rats made up to 166% greater open arm entries and spent up to 42% more time in the open arms compared to Sham rats. In an elevated-T maze task, BVD rats failed to develop a normal learned inhibition response to open space. In an open field maze BVD rats consistently showed 50-60% greater movement velocity, spent on average 35% more time in the inner most aversive part of the arena, and failed to show the normal boundary-seeking behaviour (thigmotaxis) typical of untreated or Sham rats. In a social interaction test BVD rats spent up to 34% less time engaged in social contact compared to Sham rats. In a hyponeophagia test, BVD rats� latency to eat was 70% greater than Sham rats at 3-weeks post-op., however this difference disappeared at 3- and 5-months. These findings suggest that BVD treatment may in some cases disrupt normal behavioral inhibition. Memory performance was also affected. In a T-maze task BVD rats achieved 40-60% correct arm entries, compared to 90-100% for Sham controls. In a foraging task carried out in darkness, BVD rats� initial homing angle was random, homing paths were ~70% longer, and reference memory errors were ~56% greater compared to Sham rats. To elucidate possible neurochemical substrates for these behavioral changes, western blot assays on monoamine proteins were carried out on tissue from a naïve set of rats (BVD n=6; Sham n=6). In BVD rats, serotonin transporter protein expression was 39% lower in CA1 hippocampus and 27% lower in the forebrain region, despite forebrain tryptophan hydroxylase expression being 34% upregulated. Tyrosine hydroxylase expression in the forebrain region was 27% lower in BVD rats. Proteins related to synaptogenesis were also investigated. In the dentate gyrus SNAP-25 was 37% upregulated in BVD rats, while in area CA2/3 of the hippocampus neurofilament-L was 13% upregulated. Forebrain and entorhinal cortex drebrin expression was 28% and 38% downregulated in BVD rats. Neurofilament-L was also 31% downregulated in the forebrain region of BVD rats. To test whether any of these behavioral or biochemical changes may have been attributable to chronic physiological stress, a corticosterone assay was carried out at the conclusion of behavioral testing; however, the no significant between treatment differences were found. In conclusion, vestibular information appears to be needed for the acquisition of spatial and reference memory as well as the normal expression of emotional behaviour. The neurochemical changes described herein point toward possible substrates for these behaviors, however their full significance has yet to be determined.

Page generated in 0.0324 seconds