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  • 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

Aging in the mammalian olfactory system /

Clark, Stephen, January 2009 (has links) (PDF)
Thesis (M.S.)--Eastern Illinois University, 2009. / Includes bibliographical references (leaves 80-84).
2

Tissue-selective activation and toxicity of substituted dichlorobenzenes : studies on the mechanism of cell death in the olfactory mucosa /

Franzen, Anna, January 1900 (has links)
Diss. (sammanfattning) Uppsala : Univ., 2005. / Härtill 4 uppsatser.
3

Isoprenoids in Parkinson's disease

Ng, Khuen Yen, Prince of Wales Medical Research Institute, Faculty of Medicine, UNSW January 2009 (has links)
Parkinson???s disease (PD) is a progressive neurodegenerative disease characterised pathologically by the selective death of the dopaminergic neurons of the substantia nigra and the appearance of abnormal inclusions in some surviving neurons. A body of evidence from epidemiological, in vitro and in vivo studies suggest that isoprenoids, a lipid family which includes cholesterol, dolichol and ubiquinone, may play a role in PD, although to date the data has been conflicting with little consensus regarding the type or direction of change in isoprenoids in PD. The current study investigated isoprenoids in PD by quantifying a range of isoprenoids in blood sera, brain homogenates and olfactory mucosa derived from PD patients and controls. Further, isoprenoid synthesis pathways were investigated by comparing the activitites and amount of the rate-limiting enzyme for isoprenoid synthesis, HMG CoA reductase, in olfactory mucosal cultures from individuals with sporadic PD and leucine-rich repeat kinase 2 (LRRK2)-PD with those from healthy individuals. Serum levels of total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and dolichol were unchanged in patients with PD compared with controls. Similarly, total tissue cholesterol was unchanged in degenerating and non-degenerating regions of the PD brain, but tissue dolichol was significantly decreased in the substantia nigra in the PD brain, possibly reflecting a change in the neuron/glia ratio in this brain region. In olfactory mucosa, a significant decrease in cellular cholesterol content was identified in patients with LRRK2-PD compared with patients with sporadic PD or controls. The reduction in cholesterol was similar in two different LRRK2 mutations but was not associated with a change in either the amount or activity of HMG CoA reductase. This study suggests that decreased cholesterol is associated with LRRK2-PD but not with sporadic PD. As cholesterol levels in cells with different LRRK2 mutations were reduced to a similar extent, it is suggested that mutations in this gene result in a loss-of-function of LRRK2 protein. Further it suggests a role for LRRK2 in cholesterol homeostasis independent of HMG-CoA reductase-associated pathways. Recent data has suggested a functional role of LRRK2 in autophagy, a mechanism which may explain the reduction in cholesterol observed in LRRK2-PD.
4

The role of adenylyl cyclase type III in odorant perception /

Trinh, Kien Ai. January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 103-111).
5

Towards the development of an electronic nose.

Naidoo, Bashan. January 2003 (has links)
Electronic noses are targeted at determining odour character in a fashion that emulates conscious odour perception in mammals. The intention of this study was to develop an organisational framework for electronic noses and deploy a sample cheese odour discriminator within this framework. Biological olfactory systems are reviewed with the purpose of extracting the organisational principles that result in successful olfaction. Principles of gas handling, chemoreception, and neural processing are considered in the formulation of an organisational framework. An electronic nose is then developed in accordance with the biologically inspired framework. Gas sensing is implemented by an array of six commercially available (tin oxide) semiconductor sensors. These popular gas sensors are known to lack stability thus necessitating hardware and signal processing measures to limit or compensate for instability. An odorant auto-sampler was developed to deliver measured amounts of odorant to the sensors in a synthetic air medium. Each measurement event encodes a simulated sniff, and is captured across six sensor channels over a period of 256 seconds at a sampling rate of 1Hz. The simulated sniff captures sensor base references and responses to odorant introduction and removal. A technique is presented for representation and processing of sensor-array data as a two-dimensional (2D) image where one dimension encodes time, and the other encodes multi-channel sensory outputs. The near optimal, computationally efficient 2D Discrete Cosine Transform (DCT) is used to represent the 2D signal in a decorrelated frequency domain. Several coefficient selection strategies are proposed and tested. A heuristic technique is developed for the selection of transform domain coefficients as inputs to a non-linear neural network based classifier. The benefits of using the selection heuristic as compared to standard variance-based selection are evident in the results. Benefits include: significant dimensionality reduction with concomitant reduction in classifier size and training time, improved generalisation by the neural network and improved classification performance. The electronic nose produced a 99.1% classification rate across a set of seven different cheeses. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.
6

A potential role of the Squamate Harderian gland in vomerolfaction / by Susan Joyce Rehorek.

Rehorek, Susan Joyce January 1997 (has links)
Copies of author's previously published articles inserted. / Bibliography: leaves 89-123. / iv, 123, [21] leaves, [21] plates : col. ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The aims of this study are to morphologically examine the structure of the Hardorian gland within major squamate clades and to infer its potential role as a source of secretion for the squamate VNO. The thesis identifies some evolutionary trends in Harderian gland, olfactory mucosae and VNO structure across a range of taxa. Representative species exhibiting olfactory (Gekkota) or vomerolfactory (Serpentes) specialisation and generalised nasal chemosensory adaptation (Scincomorpha) are examined. / Thesis (Ph.D.)--University of Adelaide, Dept. of Anatomical Sciences, 1997
7

Acometimento do epitélio olfatório pela doença de Alzheimer: um estudo de correlação clínico-patológica / Olfactory epithelium involvement in Alzheimer\'s disease: a clinicalpathological study

Maria Dantas Costa Lima Godoy 22 July 2015 (has links)
A doença de Alzheimer (DA) é caracterizada por declínio cognitivo e funcional progressivo e constitui-se como a forma mais prevalente de demência. O diagnóstico da DA é realizado atualmente, exclusivamente por meio de critérios clínicos. No entanto, a manifestação clínica da DA é precedida por um longo período assintomático, com depósito silencioso das proteínas tau e -amiloide no tecido cerebral. Evidências recentes demonstram que a mucosa olfatória, estrutura periférica e facilmente acessível também está acometida na DA, podendo representar um bom método de diagnóstico preciso e precoce desta moléstia. Os objetivos desse estudo consistem em correlacionar a prevalência das proteínas tau e -amiloide no epitélio olfatório (EO) com os estágios clínicos e neuropatológicos da doença e determinar a sensibilidade e especificidade dos achados no EO para o diagnóstico da DA em seus diferentes estágios de evolução. Para tal fim, é proposto estudo post-mortem, com avaliação de 92 tecidos cerebrais de indivíduos com idade igual ou superior a 50 anos, provenientes do Banco de Encéfalos Humanos do Grupo de Estudos em Envelhecimento Cerebral da Universidade de São Paulo, com coleta dos blocos de mucosa olfatória no momento da autópsia. A avaliação cognitiva foi realizada por meio de entrevista com informante de convívio próximo com o falecido, aplicando as escalas CDR e IQCODE. A avaliação neuropatológica do encéfalo e do EO foi realizada por meio de técnicas de . Os casos foram classificados mediante critério neuropatológico do CERAD e do estadiamento de Braak e Braak para DA. A presença de proteína tau e -amiloide no EO foi correlacionada com os parâmetros clínicos e neuropatológicos obtidos. A análise do EO da concha superior permitiu identificar as proteínas tau e -amiloide com sensibilidade alta, quando comparada com o diagnóstico neuropatológico (>80%) e clínico ( > 90%). Desta forma, a análise para as proteínas tau e - amiloide do epitélio olfatório pode representar um possível biomarcador para diagnóstico da DA / Alzheimer\'s disease (AD) is characterized by a progressive functional and cognitive decline and is considered the most prevalent type of dementia. AD is diagnosed exclusively on the basis of clinical criteria. However, clinical symptoms of AD are preceded by a long asymptomatic period, with silent deposition of tau and amyloid proteins in brain tissue. Recent studies demonstrate the same findings in the olfactory epithelium, a ready accessible structure which could contribute to the precise and early diagnosis of AD. The objectives of the current study were to correlate the prevalence of tau and amyloid proteins distributed in several areas of the olfactory epithelium with clinical and neuropathological criteria used for the diagnosis of AD and to determine the sensitivity and specificity of the olfactory epithelium involvement for the diagnosis of AD. Ninety-two individuals, belonging to the Brazilian Brain Bank of the Aging Brain Study Group from University of São Paulo, whose blocks of olfactory mucosa were collected during autopsy, were tested. Cognitive data were gathered through an interview with a knowledgeable informant, using the CDR (Clinical Dementia Rating Scale) and the IQCODE (Informant Questionnaire on Cognitive Decline in the Elderly) scales. Neuropathological examination was carried out on the basis of accepted criteria, using immunohistochemistry. Neuropathological classification of AD was performed in accordance with the CERAD criteria and Braak & Braak staging. The presence of tau and amyloid protein deposits in the olfactory epithelium was compared with clinical and neuropathological parameters. Immunostaining of olfactory epithelium from the superior turbinate was able to identify tau protein and amyloid-? with high sensitivity when compared with neuropathological scales ( > 80%) and clinical classification of CDR ( > 90%). Thus, immunohistochemistry for tau and amyloid proteins of the olfactory epithelium may represent a potential biomarker for early diagnosis of AD
8

Acometimento do epitélio olfatório pela doença de Alzheimer: um estudo de correlação clínico-patológica / Olfactory epithelium involvement in Alzheimer\'s disease: a clinicalpathological study

Godoy, Maria Dantas Costa Lima 22 July 2015 (has links)
A doença de Alzheimer (DA) é caracterizada por declínio cognitivo e funcional progressivo e constitui-se como a forma mais prevalente de demência. O diagnóstico da DA é realizado atualmente, exclusivamente por meio de critérios clínicos. No entanto, a manifestação clínica da DA é precedida por um longo período assintomático, com depósito silencioso das proteínas tau e -amiloide no tecido cerebral. Evidências recentes demonstram que a mucosa olfatória, estrutura periférica e facilmente acessível também está acometida na DA, podendo representar um bom método de diagnóstico preciso e precoce desta moléstia. Os objetivos desse estudo consistem em correlacionar a prevalência das proteínas tau e -amiloide no epitélio olfatório (EO) com os estágios clínicos e neuropatológicos da doença e determinar a sensibilidade e especificidade dos achados no EO para o diagnóstico da DA em seus diferentes estágios de evolução. Para tal fim, é proposto estudo post-mortem, com avaliação de 92 tecidos cerebrais de indivíduos com idade igual ou superior a 50 anos, provenientes do Banco de Encéfalos Humanos do Grupo de Estudos em Envelhecimento Cerebral da Universidade de São Paulo, com coleta dos blocos de mucosa olfatória no momento da autópsia. A avaliação cognitiva foi realizada por meio de entrevista com informante de convívio próximo com o falecido, aplicando as escalas CDR e IQCODE. A avaliação neuropatológica do encéfalo e do EO foi realizada por meio de técnicas de . Os casos foram classificados mediante critério neuropatológico do CERAD e do estadiamento de Braak e Braak para DA. A presença de proteína tau e -amiloide no EO foi correlacionada com os parâmetros clínicos e neuropatológicos obtidos. A análise do EO da concha superior permitiu identificar as proteínas tau e -amiloide com sensibilidade alta, quando comparada com o diagnóstico neuropatológico (>80%) e clínico ( > 90%). Desta forma, a análise para as proteínas tau e - amiloide do epitélio olfatório pode representar um possível biomarcador para diagnóstico da DA / Alzheimer\'s disease (AD) is characterized by a progressive functional and cognitive decline and is considered the most prevalent type of dementia. AD is diagnosed exclusively on the basis of clinical criteria. However, clinical symptoms of AD are preceded by a long asymptomatic period, with silent deposition of tau and amyloid proteins in brain tissue. Recent studies demonstrate the same findings in the olfactory epithelium, a ready accessible structure which could contribute to the precise and early diagnosis of AD. The objectives of the current study were to correlate the prevalence of tau and amyloid proteins distributed in several areas of the olfactory epithelium with clinical and neuropathological criteria used for the diagnosis of AD and to determine the sensitivity and specificity of the olfactory epithelium involvement for the diagnosis of AD. Ninety-two individuals, belonging to the Brazilian Brain Bank of the Aging Brain Study Group from University of São Paulo, whose blocks of olfactory mucosa were collected during autopsy, were tested. Cognitive data were gathered through an interview with a knowledgeable informant, using the CDR (Clinical Dementia Rating Scale) and the IQCODE (Informant Questionnaire on Cognitive Decline in the Elderly) scales. Neuropathological examination was carried out on the basis of accepted criteria, using immunohistochemistry. Neuropathological classification of AD was performed in accordance with the CERAD criteria and Braak & Braak staging. The presence of tau and amyloid protein deposits in the olfactory epithelium was compared with clinical and neuropathological parameters. Immunostaining of olfactory epithelium from the superior turbinate was able to identify tau protein and amyloid-? with high sensitivity when compared with neuropathological scales ( > 80%) and clinical classification of CDR ( > 90%). Thus, immunohistochemistry for tau and amyloid proteins of the olfactory epithelium may represent a potential biomarker for early diagnosis of AD
9

Comprimento telomérico no sistema nervoso central de um modelo de doença de Alzheimer tratado com lí­tio / Telomere length in the central nervous system of a model for Alzheimer\'s disease treated with lithium

Cardillo, Giancarlo de Mattos 02 April 2018 (has links)
Telômeros são complexos DNA-proteína presentes nas extremidades dos cromossomos. Os telômeros se encurtam a cada divisão celular, sendo o comprimento telomérico, portanto, considerado um biomarcador do envelhecimento celular. Esse encurtamento é vinculado a diversas doenças relacionadas à idade avançada. Na doença de Alzheimer (DA), têm sido associados com diversas vias fisiopatológicas, como a neuroinflamação e o estresse oxidativo, porém seus mecanismos ainda são pouco conhecidos. A maioria dos estudos sobre comprimento telomérico na DA é realizada em DNA leucocitário, pouco se sabendo sobre seu estado no sistema nervoso central. O lítio é um importante estabilizador de humor, com efeitos neuroprotetores amplamente evidenciados, mas pouco se sabe sobre seu efeito na manutenção do comprimento telomérico. O objetivo do presente estudo foi avaliar o efeito do tratamento crônico com lítio no comprimento telomérico em diferentes regiões cerebrais (córtex parietal, hipocampo e epitélio olfatório) de camundongos triplo transgênicos para DA (3xTg-AD) e selvagens. Dezoito animais transgênicos e 22 selvagens foram tratados por oito meses com ração contendo 1,0 g (Li1) ou 2,0 g (Li2) de carbonato de lítio/kg, ou ração padrão (Li0). O comprimento telomérico do DNA extraído destes tecidos foi quantificado por PCR em tempo real. O tratamento crônico com lítio foi associado a telômeros mais longos no córtex parietal (Li1, p=0,04) e hipocampo (Li2, p=0,02) dos camundongos 3xTg-AD comparados com os respectivos selvagens. Nossos achados sugerem que o tratamento crônico com lítio afeta a manutenção do comprimento telomérico, mas que a magnitude desse efeito depende da concentração de lítio ministrada e das características do tecido envolvido. Esse efeito foi apenas observado quando comparando os animais triplo transgênicos com os selvagens, indicando que a presença da patologia, no caso a DA, se faz necessária para a modulação do comprimento telomérico promovida pelo lítio / Telomeres are DNA-protein complexes present in the extremities of chromosomes. Telomeres shorten at each cell division, being the telomere length, therefore, considered a cell aging biomarker. This telomere shortening is associated to several age-related diseases. In Alzheimer\'s disease (AD), telomere length has been linked to several pathophysiological pathways, such as neuroinflammation and oxidative stress, though its mechanism are still poorly understood. Majority of studies regarding telomere length in AD are based in leucocyte DNA, with little information about its status in the central nervous system. Lithium is an important mood stabilizer, with neuroprotective effects widely evidenced, but little is known about its effects in telomere length maintenance. The objective of this present study was to evaluate the effect of chronical lithium treatment on telomere length in different brain regions (parietal cortex, hippocampus and olfactory epithelium) of wild type and triple transgenic mice model for AD (3xTg-AD). Eighteen transgenic and 22 wild type male mice were treated for eight months with chow containing 1.0g (Li1) or 2.0g (Li2) of lithium carbonate/kg, or standard chow (Li0). Telomere length of extracted DNA from theses tissues was quantified by real-time PCR. Chronic lithium treatment was associated with longer telomeres in the parietal cortex (Li1, p=0.04) and in the hippocampus (Li2, p=0.02)of 3xTg-AD compared with the respective wild type.Our findings suggest that chronic lithium treatment does affect telomere maintenance, but the magnitude of this effect depends on the working concentrations of lithium and characteristics of the involved tissue. This effect was only observed when comparing triple transgenic with wild type mice, suggesting that the presence of AD pathology was required for the lithium modulation of telomere length
10

Distribuição do neuroepitélio olfatório em concha média e superior em cadáveres humanos / Distribution of olfactory neuroepithelium in the middle and superior turbinate of human cadavers

Pinna, Fabio de Rezende 03 September 2008 (has links)
INTRODUÇÃO: A biópsia do neuroepitélio olfatório (NeuO) oferece perspectivas para aplicações terapêuticas tanto em doenças do olfato como doenças neurodegenerativas. Uma coleta bem sucedida desse tecido in vivo ainda não é rotina, devido á carência de estudos sobre a distribuição do NeuO em conchas superior (CS) e média (CM). Neste trabalho, descrevemos a distribuição do NeuO na CS e CM em cadáveres a partir da retirada integral dessas estruturas e posterior análise histológica por coloração de hematoxilina e eosina (HE) e imunoistoquímica. Além disso, também analisamos a influência do sexo, idade e lateralidade no grau de presença do NeuO nas CS e CM. CASUÍSTICA E MÉTODOS: Estudo anatômico prospectivo realizado de março de 2006 a janeiro de 2008. A CS e a CM foram endoscopicamente retiradas de um total de 25 cadáveres frescos com menos de 12 horas de óbito. Cada concha foi seccionada na metade de seu comprimento ântero-posterior. Assim, cada um dos 25 cadáveres deu origem a oito fragmentos de mucosa de regiões anatômicas distintas, totalizando 200 lâminas para análise tanto por coloração de HE como por reação de imunoistoquímica. Nas lâminas coradas por HE, classificamos a distribuição do NeuO em graus 0, 1, 2, 3, 4, sendo que a análise foi realizada por 3 patologistas de forma cega. Para imunoistoquímica, só obtivemos positividade com a proteína S-100. A concordância entre os três patologistas foi avaliada aos pares utilizando-se o coeficiente de Kappa. A distribuição do NeuO foi analisada de acordo com a idade, sexo, tempo de óbito, simetria entre as fossas nasais e acurácia da imunoistoquímica. RESULTADOS: Pela HE na CS, o NeuO esteve presente em 82,9% das vezes e, na CM, em 17,1%. Na CS, o NeuO foi detectado em 82,9 % das lâminas, 4,9 vezes a prevalência na CM, que foi de 17,1 % das lâminas (p < 0,001). Pela imunoistoquímica, foi possível encontrar NeuO em um total de 15 fragmentos. Desses, 10 (20%) eram da metade posterior da CS e cinco (7,6%) da metade anterior da CS. Pelo cálculo da razão de prevalência, temos que a chance de encontrar NeuO é 4,9 vezes maior na CS do que na CM (IC95%: 3,3 7,4). Dos 15 fragmentos com marcação positiva para proteína S-100, sete corresponderam aos que tinham uma distribuição grau 3 (>50% e 75%) pela HE e outros sete aos que tinham uma distribuição grau 4 (acima de 75%). Somente um fragmento teve marcação positiva para imunoistoquímica no grupo 2 (entre 26 e 50%) na HE. A proteína S-100 apresentou uma sensibilidade de 13,5% e especificidade de 100% para detecção de NeuO. Não houve diferença estatisticamente significante na prevalência de NeuO quando os fragmentos foram divididos de acordo com o sexo, idade de óbito e lado da fossa nasal. No entanto, ao analisarmos a presença de NeuO de acordo com o grau de distribuição entre cada lado, não se percebe uma concordância. CONCLUSÕES: A quantidade total de NeuO foi simetricamente distribuída entre as fossas nasais, mas não houve uma concordância entre os lados quanto à maneira como o NeuO está distribuído. O NeuO apresenta maior probabilidade de ser encontrado na metade posterior de CS. A HE é um método eficaz para distinção entre NeuO e epitélio respiratório, devido a grande concordância entre três patologistas distintos. / INTRODUCTION: Olfactory neuroepithelium (ON) biopsy provides perspectives for several therapeutic applications, both in disorders of olfaction and in neurodegenerative diseases. Successful in vivo collection of ON is still not routine, due to a dearth of studies on ON distribution in the superior and middle turbinate (ST and MT respectively). This study describes the distribution of ON in cadaver ST and MT as determined by complete endoscopic removal of turbinates and histological analysis with hematoxylin and eosin (H&E) and immunohistochemical staining. We also analyzed the influence of gender, age, and naris side on the extent to which ON is present in the superior and middle turbinate. CASE SELECTION AND METHODS: We conducted a prospective anatomical study from March 2006 to January 2008. The superior and middle turbinates of 25 fresh cadavers (less than 12 hours post-mortem) were removed endoscopically. Each turbinate was halved into anterior and posterior fragments. Eight anatomically distinct fragments were therefore obtained from each of the 25 cadavers for a total of 200 specimens, which were analyzed through H&E staining and immunohistochemistry. Hematoxylin and eosin-stained slides were subjected to blind examination by three independent pathologists; ON distribution was graded on a fivepoint numeric scale (grade 0, 1, 2, 3, or 4). Immunohistochemistry was only positive through S-100 staining. Pairwise agreement between pathologists was assessed by means of the Kappa coefficient. The distribution of ON was analyzed regarding age, gender, time elapsed between death and specimen harvesting, symmetry between nares, and accuracy of immunohistochemistry results. RESULTS: In H&E-stained slides, olfactory neuroepithelium was present in 82.9% of ST and 17.1% of MT specimens; prevalence in the superior turbinate was therefore 4.9-fold greater (p < 0.001). Immunohistochemical analysis was able to identify ON in 15 fragments, 10 of which (20%) were from the posterior half of the superior turbinate; the remaining five specimens (7.6%) were from the anterior ST. According to prevalence ratio, the odds of finding ON are 4.9 times greater in superior turbinate than in the middle turbinate (CI, 95%; 3.37.4). Of the 15 immunohistochemistry-positive fragments, seven were assigned distribution grade 3 (>50% and 75% presence of ON) on H&E staining seven others were graded 4 (>75% presence of ON). A single immunohistochemistrypositive fragment was found to have grade 2 ON distribution (i.e., it contained 26% to 50% olfactory neuroepithelium) on H&E staining. S-100 staining showed a sensitivity of 13.5% and specificity of 100% for ON detection. There was no statistically significant difference in ON prevalence when fragments were compared according to gender, age at time of death, and naris side. However, when we analyzed ON presence according to the degree of ON distribution in each side, we found no concordance. CONCLUSIONS: Total ON was distributed symmetrically between nares, but we found no concordance between sides in the manner in which ON is distributed. ON is most likely to be found in the posterior half of the superior turbinate. Hematoxylin and eosin (H&E) staining is an effective method for distinguishing ON from respiratory epithelium, as shown by high inter-rater agreement among three independent pathologists

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