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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.
791

Investigation of synaptic dysfunction in Alzheimer's disease

Jackson, Rosemary Joan January 2018 (has links)
Alzheimer's disease (AD) is characterized by the presence of aggregates of amyloid beta (Aβ) in senile plaques and tau in neurofibrillary tangles, as well as marked neuron and synapse loss. Of these pathological changes, synapse loss correlates most strongly with cognitive decline. Understanding the contributions of different risk factors, toxic proteins, and protein networks to synaptic dysfunction and loss is essential to understanding and one day curing this disease. Oligomeric species of both Aβ and tau are implicated in synapse, however the interaction between them requires further exploration. The first aim of this thesis was to investigate the interaction of Aβ and tau in a novel mouse model AD. In this model APP/PS1 mice were crossed with mice expressing full length wild type human tau (hTau). Expression of hTau in APP/PS1 mice increased plaque size by~50% and increased plaque-associated dystrophic neurites. However, no increase in neurite curvature, neuron loss, or synapse loss was observed in the hTau APP/PS1 animals compared with APP/PS1 alone. The underlying cause of most cases of AD is not known, however genetic risk factors have been identified, the strongest of which is the APOE e4 allele. APOE e4 is associated with increased risk of developing AD and increased rates of cognitive decline compared to the more common APOE e3 allele. The second aim of this thesis was to detect differences in the AD synaptic proteome compared with controls and to also investigate the effect of an APOE e4 allele on those changes. Unbiased label free LC-MS/ MS based proteomics of synapses isolated from human AD and control post-mortem brains of known APOE genotypes was used. Of the 1043 proteins detected in 20 synaptic preparations 17% (173) were found to differ significantly (p < 0.05, fold change >1.2) in AD compared with control. A significant sub-set of these proteins were affected by APOE e4 allele genotype. One of these was Clusterin which was not only increased in the AD synapse but further increased in cases with an APOE e4 allele. Clusterin is closely related to ApoE has also been genetically linked to AD in genome-wide association studies. Aim three was to further investigate the involvement of Clusterin at the synapse and the interaction of ApoE with Clusterin using array tomography. Array tomography confirmed an increase in Clusterin co-localization with presynapses and postsynapses in AD cases compared with controls and found a further increase in cases with an APOE e4 allele. Array tomography also found an increase in synapses which co-localized with Clusterin and Aβ together in cases with an APOE e4 allele. This implies that Clusterin is important in Aβ mediated synapse loss in AD. To further investigate the role of synapse loss in AD aim 4 of this thesis was to develop a novel human based model of Aβ mediated synapse loss. This model uses cortical neurons derived from induced pluripotent stem cells from a control individual that are challenged with Aβ extracted from brains from AD and control individuals. This model shows a significant and concentration dependent reduction in the number of synapses in response Aβ from AD brain but not to control brain extract or AD brain extract immunodepleted of Aβ. The work presented in this thesis has investigated two novel models of AD to assess the effect of known toxic proteins in AD related synapse degeneration. This work also shows that profound protein changes occur at the synapse in AD and that many of these are affected by APOE genotype. Many of these changes potentially cause or contribute to synaptic dysfunction in AD and therefore could be important for therapeutic interventions.
792

Developing oral curcumin-HP-ß-cyclodextrin complexes to enhance Aß removal and preserve memory in Tg2576 mice.

January 2012 (has links)
背景及研究目的:據報導薑黃素(curcumin)在阿爾茨海默癥(老年癡呆癥)的動物模型中表現出有效性。這可能與其能阻抑β 澱粉樣蛋白的聚集有關,而β 澱粉樣蛋白正是老年癡呆癥中達成共識的神經毒性物質。然而,薑黃素的水溶性很差,這一弱點直接限制其在作為口服藥物的生物利用度。羥丙基-β-環糊精是一種由七個單糖分子鍵合成的環狀分子,該環具有親水性的外部和疏水性的內部,這一特點使得疏水性藥物可以裝入環糊精分子內部從而提高該藥物的親水性,進而提高藥物的口服吸收率。 / 方法:包合物在50 攝氏度下,由摩爾比為1:2 的薑黃素和羥丙基-β-環糊精經過6 小時的攪拌而形成。其后对包合物的物化性質與相同摩爾比的薑黃素與羥丙基-β-環糊精的混合物的物化特性进行了对比以证实包合物的形成,诸如水溶性,掃描電鏡下的形態以及傅利葉紅外圖譜特性。接著用經包合物和普通薑黃素粉末喂食的SD 大鼠做藥代動力學研究,取出大鼠血樣然之後用高效液相色譜-質譜聯用法對薑黃素進行定量,計算出達峰時間(T{U+2098}{U+2090}{U+2093} ), 峰濃度(C{U+2098}{U+2090}{U+2093} )以及 0 到4 小時藥時曲綫下面積 (AUC₀→₄{U+2095} )從而比較包合物較普通薑黃素是否有優越之處。之後,用Tg2576 轉基因小鼠做短期研究,此种小鼠能過度表達β 澱粉樣蛋白,是一種被廣泛應用于老年癡呆癥相關科研的動物模型,經過連續7 日的喂食之後,對小鼠的β 樣澱粉蛋白進行觀察。進一步,將用能同時過度表達β 樣澱粉蛋白與神經纖維結(NTFs)的Tau/APP 轉基因小鼠做長達兩月的藥效學實驗,在實驗始末配以关联恐惧调件反应测试(CFC)和八臂迷宮(Radial Arm Maze)來對實驗小鼠的記憶失進行定量分析。處死小鼠之後,對β 樣澱粉蛋白與神經纖維結(NTFs)進行定量分析從而確定包合物在藥效學上的優勢。 / 結果:在包合的過程中,大部份的薑黃素被整合到包合物之中。通過傅利葉紅外圖譜和掃描電鏡照片都可以觀察到包合物與混合物的顯著不同。在藥代動力學研究中,普通薑黃素粉末的達峰時間為22 分鐘左右,而包合物是40 分鐘,同時,經過包合,峰濃度也提高了3 倍左右,藥時曲綫下面積提高了2 倍以上。在用Tg2576 進行的為期一周的短期實驗中,觀察不到包合物和普通薑黃素在β 樣澱粉蛋白清除方面有明顯差別,然後通過體內染色卻可以看到經包合物喂食的小鼠腦切片中可以觀察到更多的來自薑黃素的螢光信號。在2 個月的長期實驗中,就关联恐惧调件反应测试和八臂迷宮實驗的結果來看,可以觀察到包合物有更好延遲TAPP 小鼠記憶失過程的趨勢但無顯著性,除此之外,對處死后的小鼠腦部進行分析,其β 澱粉樣蛋白與神經纖維節的含量分析結果也和行為測試具有一致性。 / 結論:用羥丙基-β-環糊精對薑黃素進行包合確實可以通過增加薑黃素的水溶性從而提高其生物利用度,讓更多的薑黃素通過血腦屏障進入大腦進而與β 澱粉樣蛋白進行結合。然後短期實驗無法表明包合物具有β 澱粉樣蛋白清除效應。而長期實驗中行為實驗和處死後大腦分析顯示出較普通薑黃素而言包合物具有有限的優點,如果要證明這一優點確實存在,可能需要更長時間的喂食與另外劑量。 / Background: Curcumin is reported to be an effective treatment in animal models of Alzheimer’s disease (AD), possibly by inhibiting aggregation of amyloid-β peptides, which can be neurotoxic.However, curcumin is poorly soluble in water, limiting its oral bioavailability. Hydroxypropyl-β-cyclodextrin (HP-β-CD), a cyclic oligosaccharide made of seven sugar molecules bound togetherin a ring has a hydrophobic exterior and a hydrophobic interior, within which curcumin can reside, thus increasing the aqueous solubility of curcumin. This study aims to solve the problem of poor water-solubility of curcumin using HP-β-CD. / Method: The inclusion complexes were formed by stirring a suspension of curcumin and HP-β-CD at a molar ratio of 1:2 at 50°C for 6 hr. Physicochemical properties, including watersolubility,morphology under scanning electron microscopy (SEM) and the Fourier Transform Infrared (FTIR) spectrum, varied between the inclusion complex and a physical mixture of the two compounds. The inclusion complex and curcumin powder were fed to Sprague Dawley rats for pharmacokinetic studies, from which blood samples were analyzed using LC/MS/MS, and relevant parameters such as T{U+2098}{U+2090}{U+2093}, C{U+2098}{U+2090}{U+2093} and AUC₀→₄{U+2095} were calculated to study the effect of HP-β-CD on the bioavailability of curcumin. To evaluate the pharmacodynamic effects, Tg2576 mice, which over express amyloid-β, were treated for 7 consecutive days with curcumin powder or inclusion complexes. Further, to examine effects of long-term treatment, Tau/APP mice, a commonly used AD model producing both amyloid-β and mutant tau proteins, were treated for 2 months. Behavior tests were conducted at the beginning and end of the long-term treatment to quantify the memory loss of the mice, and post mortem analyses, including quantification of amyloid-β plaques and neurofibrillary tangles, were performed after sacrificing the mice. / Result: The majority of curcumin was integrated into complexes. FTIR profiles and SEM photographs of complexes displayed significant differences from the physical mixture. In the pharmacokinetic study, the concentration of curcumin in the control group peaked at around 22.5 min, while that of inclusion complexes peaked around 40 min. The maximum concentration of curcumin trebled and the area under the curve from 0 to 4 hours more than doubled. For shortterm treatment in Tg2576 mice, paraffin sections stained with Thioflavin T, a dye detecting amyloid-β plaques, showed no obvious difference between mice treated with curcumin powder or complexes; however brain sections from complex-treated mice had more fluorescence signal from curcumin than did mice treated with curcumin powder. For long-term treatment, in terms of the results of contextual fear conditioning and radial arm maze, there was a trend toward inclusion complexes delaying the memory loss of Tau/APP mice more effectively than curcumin powder. Compared to curcumin powder, complexes tended to reduce the number of plaques and neurofibrillary tangles. / Conclusion: Complexation with HP-β-CD can significantly enhance curcumin bioavailability by increasing its water-solubility, allowing more curcumin to penetrate the blood brain barrier to bind to amyloid-β plaques. However, short-term treatment showed no advantage of inclusion complexes in clearing amyloid-β plaques. The results of behavior tests and post-mortem studies from the 2-month long-term treatment indicated limited superiority of inclusion complexes over curcumin powder. A longer feeding period or altered dosage or both might be necessary to enhance the effect of curcumin inclusion complexes. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Liu, Hao. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 104-117). / Abstracts also in Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview of Alzheimer’s disease --- p.1 / Chapter 1.1.1 --- The pathological mechanisms of Alzheimer’s disease --- p.2 / Chapter 1.1.2 --- Anti-Alzheimer’s disease drugs --- p.3 / Chapter 1.2 --- Curcumin as a potential anti-AD agent --- p.5 / Chapter 1.2.1 --- Actions of curcumin on Aβ --- p.6 / Chapter 1.2.2 --- Anti-inflammatory and anti-oxidant activities of curcumin in AD --- p.8 / Chapter 1.2.3 --- Activities of curcumin to combat metal toxicity --- p.9 / Chapter 1.3 --- The physicochemical properties of curcumin and limitations of curcumin in clinical usage --- p.12 / Chapter 1.4 --- Cyclodextrin in pharmaceutical usage --- p.18 / Chapter 1.5 --- Aims of the study --- p.23 / Chapter Chapter 2 --- Preparation and characterization of curcumin-HP-β-CD complexes --- p.24 / Chapter 2.1 --- Introduction --- p.24 / Chapter 2.2 --- Phase solubility study --- p.24 / Chapter 2.1.2 --- Preparation of solid complexes --- p.28 / Chapter 2.1.3 --- Characterization of solid complexes --- p.29 / Chapter 2.1.4 --- Previous work on the curcumin HP-β-CD inclusion complex --- p.31 / Chapter 2.2 --- Methodology --- p.33 / Chapter 2.2.1 --- Phase solubility test --- p.33 / Chapter 2.2.2 --- Preparation of curcumin-CD complexes --- p.33 / Chapter 2.2.3 --- Recovery --- p.35 / Chapter 2.2.4 --- Differential solubility --- p.36 / Chapter 2.2.5 --- SEM Studies --- p.37 / Chapter 2.2.6 --- Infrared --- p.37 / Chapter 2.3 --- Results and discussion --- p.38 / Chapter 2.3.1 --- Phase solubility analysis --- p.38 / Chapter 2.3.2 --- Recovery test --- p.40 / Chapter 2.3.3 --- Differential solubility --- p.42 / Chapter 2.3.4 --- SEM study --- p.44 / Chapter 2.3.5 --- Infrared study --- p.45 / Chapter Chapter 3 --- Staining of amyloid plaques in Tg2576 mice after oral administration of curcumin-HP-β-cyclodextrin inclusion complex --- p.47 / Chapter 3.1 --- Introduction --- p.47 / Chapter 3.2 --- In vitro staining of amyloid plaques by thioflavin T and curcumin --- p.49 / Chapter 3.2.1 --- Thioflavin T and curcumin specifically binding to amyloid plaques --- p.49 / Chapter 3.2.2 --- Chemicals --- p.51 / Chapter 3.2.3 --- Method --- p.51 / Chapter 3.3 --- In vivo staining of amyloid plaques after oral administration of curcumin-HP-β-CD inclusion complex --- p.53 / Chapter 3.3.1 --- Animal treatment --- p.53 / Chapter 3.3.2 --- Method --- p.54 / Chapter 3.4 --- Results and discussion --- p.56 / Chapter 3.4.1 --- In vitro staining of amyloid plaques by thioflavin T and curcumin --- p.56 / Chapter 3.4.2 --- In vivo staining of amyloid plaques by curcumin --- p.57 / Chapter 3.4.3 --- Plaque removal effects after short-term feeding --- p.58 / Chapter Chapter 4 --- Pharmacokinetic study of curcumin in Sprague-Dawley (SD) rats after oral administration of curcumin-HP-β-cyclodextrin inclusion complex --- p.61 / Chapter 4.1 --- Introduction --- p.61 / Chapter 4.1.1 --- Previous pharmacokinetic study of curcumin-HP-β-CD inclusion complex --- p.61 / Chapter 4.1.2 --- Previously established LC/MS/MS methods for quantification of curcumin in SD rat plasma sample --- p.62 / Chapter 4.2 --- Development and validation of LC/MS/MS assay --- p.63 / Chapter 4.2.1 --- Chemicals --- p.63 / Chapter 4.2.2 --- Instrumentation and chromatographic conditions --- p.63 / Chapter 4.2.3 --- Preparation of standard solutions --- p.63 / Chapter 4.2.5 --- Validation of the assay method --- p.64 / Chapter 4.3 --- Pharmacokinetic profile of curcumin in SD rats --- p.65 / Chapter 4.3.1 --- Animals --- p.65 / Chapter 4.3.2 --- Animal treatment and blood sampling --- p.65 / Chapter 4.3.3 --- Plasma sample analysis --- p.65 / Chapter 4.3.4 --- Data analysis --- p.66 / Chapter 4.4 --- Result and discussion --- p.67 / Chapter 4.4.1 --- Mass spectrum --- p.67 / Chapter 4.4.2 --- Chromatography and specificity --- p.69 / Chapter 4.4.3 --- Linearity and sensitivity --- p.71 / Chapter 4.4.4 --- Method validation---Precision and accuracy --- p.71 / Chapter 4.4.5 --- Method validation---Liquid-liquid extraction recovery --- p.72 / Chapter 4.4.6 --- Pharmacokinetics parameters --- p.73 / Chapter Chapter 5 --- Long-term effects of curcumin-HP-β-CD inclusion complex on Alzheimer’s disease model mice --- p.79 / Chapter 5.1 --- Introduction --- p.79 / Chapter 5.1.1 --- Tau/APP trangenic mouse --- p.79 / Chapter 5.1.2 --- Memory --- p.80 / Chapter 5.1.3 --- The role of the hippocampus in memory --- p.81 / Chapter 5.1.4 --- Memory task contextual fear conditioning (CFC) --- p.82 / Chapter 5.1.5 --- Memory task radial arm maze (RAM) --- p.83 / Chapter 5.2 --- Methods --- p.85 / Chapter 5.2.1 --- Animal treatment --- p.85 / Chapter 5.2.2 --- Contextual fear conditioning test --- p.85 / Chapter 5.2.3 --- Radial arm maze test --- p.87 / Chapter 5.2.4 --- Post-mortem analysis amyloid plaque removal effects of the curcumin-HP-β-CD inclusion complex --- p.88 / Chapter 5.2.5 --- Post-mortem analysis neurofibrillary tangle removal effects of the curcumin-HP-β-CD inclusion complex --- p.90 / Chapter 5.3 --- Results and discussion --- p.92 / Chapter 5.3.1 --- Mortality of the mice --- p.92 / Chapter 5.3.2 --- Contextual fear conditioning test --- p.93 / Chapter 5.3.3 --- Radial arm maze (RAM) test --- p.95 / Chapter 5.3.4 --- Post-mortem analysis amyloid plaque removal effects of the curcumin-HP-β-CD inclusion complex --- p.97 / Chapter 5.3.5 --- Post-mortem analysis neurofibrillary tangle removal effects of the curcumin-HP-β-CD inclusion complex --- p.99 / Chapter Chapter 6 --- Conclusions and future perspective --- p.100 / Chapter 6.1 --- Conclusions --- p.101 / Chapter 6.2 --- Future perspective --- p.103 / References --- p.104
793

Comparação do efeito de diferentes tipos de dietas sobre o estado nutricional de pacientes com Doença de Alzheimer em cuidados paliativos

Lopes, Angélica dos Santos 10 October 2017 (has links)
Submitted by Suzana Dias (suzana.dias@famerp.br) on 2018-10-19T22:57:37Z No. of bitstreams: 1 AngélicadosSantosLopes_dissert.pdf: 674384 bytes, checksum: b2d42cc3b6f4dc90e7e4f03d2ae00560 (MD5) / Made available in DSpace on 2018-10-19T22:57:37Z (GMT). No. of bitstreams: 1 AngélicadosSantosLopes_dissert.pdf: 674384 bytes, checksum: b2d42cc3b6f4dc90e7e4f03d2ae00560 (MD5) Previous issue date: 2017-10-10 / With increasing years of life, there has been an increase in the prevalence of degenerative diseases, among them Alzheimer's disease, which causes progressive disability and incapacitation. The family and society are strongly impacted by this new reality, especially the caregiver, who has to adapt his routine to the needs of this patient. One of the areas affected by this pathology is food, causing difficulties in the preparation and carrying out of meals, limitations of chewing and / or swallowing, leading to changes in eating habits. To help feed these patients, we offer countless industrialized, nutritionally complete diets that are expensive and inaccessible to most of the population. Objective: to analyze differences in nutritional status, symptoms and difficulties between administering the home diet, partially industrialized or totally industrialized in patients with Alzheimer's disease in home palliative care. We also aim to assess the profile of the caregivers, identifying their feelings and point of view regarding the care, the patient and the nutritional intervention employed. Patients and methods: During five months, the following anthropometric measures were measured at home visits: weight, height, circumference of the arm and calf, triceps and subscapular skinfolds. Food recall, symptom survey, and Mini Nutrition Assessment - MAN were also collected. For the caregivers, a semi-structured questionnaire was applied and new complaints and symptoms were collected at each visit. Results: 19 patients were followed between 67 and 90 years of age, of whom 13 were women. Of these, 32% used homemade diet, 21% industrialized and 47% partially industrialized. 84% were malnourished, with a body mass index of 17.7 kg / m² at the first meeting and 17.4 kg / m² at the last, regardless of the type of diet. On the other hand, the caregivers presented an optimistic and loving view regarding care, few complainants and satisfied with the service provided, and in relation to nutritional intervention, they demonstrated a problem-free or insecure domain, indicating a balance between attending to the patient's wishes and following the Medical prescription / nutritionist. Conclusions: there is no difference in the use of different diets in relation to the evolution of the nutritional status of the patient with Alzheimer's disease in palliative care, which does not often justify the use of a more expensive diet, such as industrialized, for better patient care . The way this caregiver assimilates this situation and the support received are key factors in determining the weight that care will have on his or her life. An optimistic view relates to improved mental health and better coping. / Com o aumento dos anos de vida, houve crescimento na prevalência de doenças degenerativas, entre elas a Doença de Alzheimer, que causa deficiência progressiva e incapacitação. A família e a sociedade são fortemente impactadas com essa nova realidade, principalmente o cuidador, que tem de adaptar sua rotina as necessidades deste paciente. Uma das áreas afetadas por essa patologia é a alimentação, causando dificuldades para o preparo e realização das refeições, limitações de mastigação e/ou deglutição, gerando modificações dos hábitos alimentares. Para auxiliar a alimentação desses pacientes, disponibilizamos de inúmeras dietas industrializadas, nutricionalmente completas, porem cara e inacessível para a maior parte da população. Objetivo: analisar se há diferenças no estado nutricional, sintomas apresentados e dificuldades na administração da dieta caseira, parcialmente industrializada ou totalmente industrializada em pacientes portadores da doença de Alzheimer em cuidados paliativos domiciliares. E também avaliar o perfil dos cuidadores, identificando seus sentimentos e ponto de vista em relação ao cuidado, ao paciente e a intervenção nutricional empregada. Casuística e métodos: Durante cinco meses, foram aferidas, em visitas domiciliares, as seguintes medidas antropométricas: peso, altura, circunferência do braço e panturrilha, pregas cutâneas tricipital e subsescapular. Também foi coletado recordatório alimentar, levantamento de sintomas, e aplicada a Mini Avaliação Nutricional – MAN. Para os cuidadores, foi aplicado questionário semi-estruturado e levantamento de novas queixas e sintomas a cada visita. Resultados: 19 pacientes foram acompanhados, entre 67 e 90 anos de idade, sendo 13 mulheres. Destes, 32% faziam uso de dieta caseira, 21% industrializada e 47% parcialmente industrializada. 84% encontravam-se desnutridos, com Índice de massa corpórea de 17,7 Kg/m², no primeiro encontro e 17,4 Kg/m² no último, independentemente do tipo de dieta. Já os cuidadores, apresentaram uma visão otimista e amorosa em relação ao cuidado, pouca queixosa e satisfeita com o serviço prestado e, em relação à intervenção nutricional, eles demonstraram domínio sem dificuldades ou inseguras, indicando equilíbrio entre atender a vontade do paciente e seguir a prescrição médica/nutricionista. Conclusões: não há diferença no uso das diferentes dietas em relação à evolução do estado nutricional do paciente com Doença de Alzheimer em cuidados paliativos, o que não justifica muitas vezes o uso de uma dieta mais cara, como a industrializada, visando melhor cuidado do paciente. A forma que esse cuidador assimila essa situação e o apoio recebido são fatores fundamentais para definir o peso que o cuidado terá sobre sua vida. Uma visão otimista relaciona-se com uma melhoria na saúde mental e melhor enfrentamento.
794

Conjugalidade, funcionamento familiar e doença de Alzheimer: um estudo com esposas cuidadoras brasileiras e portuguesas / Conjugality, family functioning and Alzheimer\'s disease: a study with Brazilian and Portuguese caretaker wives

Garcia, Camila Rodrigues 04 May 2018 (has links)
A Doença de Alzheimer (DA) é uma doença progressiva e irreversível, que causa perda de memória, comprometimento nas atividades motoras e consequentemente comprometimento da autonomia, levando a pessoa doente a necessitar de auxílio. A dinâmica de cuidado, do casamento e da família se modificam de acordo com a progressão da doença, verificando-se a necessidade de maior apoio aos cônjuges cuidadores. Este estudo objetivou analisar a conjugalidade e o funcionamento familiar na perspectiva de esposas cuidadoras brasileiras e portuguesas de idosos com DA. Participaram da pesquisa 12 mulheres, sendo a amostra obtida por conveniência. Foram utilizados um questionário com questões fechadas e entrevista com roteiro semiestruturado sendo os dados analisados pela técnica de análise de conteúdo de Bardin e análise estatística descritiva. Os resultados destacaram que apesar das diferenças culturais, alguns significados atribuídos ao conceito casamento e cuidado, no contexto da doença de Alzheimer, foram semelhantes para as esposas brasileiras e portuguesas. Verificou-se também, que com relação as mudanças conjugais relacionadas à demência, a maioria das esposas sentia- se bem executando seu papel de cuidadora, e que o impacto causado pela doença nem sempre é visto de forma negativa no casamento. E, por fim, os resultados também identificaram tipos de suporte diferentes recebidos pelas esposas brasileiras e portuguesas, podendo este dado ser ocasionado devido as diferenças culturais / Alzheimer\'s Disease (AD) is a progressive and irreversible disease, which causes memory loss, impaired motor activity and consequently impairs autonomy, causing the sick person to need help. The dynamics of care, marriage and family change according to the progression of the disease, and there is a need for greater support to the caregiver spouses. This study aimed to analyze conjugality and family functioning in the perspective of Brazilian and Portuguese caregivers of elderly people with AD. Twelve women participated in the study, and the sample was obtained for convenience. We used a questionnaire with closed questions and interview with a semi-structured script, the data analyzed by the Bardin content analysis technique and descriptive statistical analysis. The results pointed out that despite the cultural differences, some meanings attributed to the concept of marriage and care in the context of Alzheimer\'s disease were similar for Brazilian and Portuguese wives. It was also found that in relation to marital changes related to dementia, most wives felt well performing their role of caregiver, and that the impact caused by the disease is not always seen negatively in marriage. And, finally, the results also identified different types of support received by the Brazilian and Portuguese wives, which may be due to cultural differences
795

De la cellule au primate, propagation physiopathologique de la protéine Tau / From cells to primates, pathophysiological propagation of Tau proteins

Dujardin, Simon 21 September 2015 (has links)
Tau est une protéine stabilisatrice des microtubules majoritairement exprimée au niveau neuronal qui existe en six isoformes différentes appelées isoformes 3R ou 4R en fonction de l’inclusion de 3 ou 4 séquences répétées dans leur domaine de liaison aux microtubules. Dans une vingtaine de pathologies neurodégénératives appelées tauopathies, des protéines Tau anormalement modifiées s’agrègent formant des lésions intracellulaires appelées dégénérescence neurofibrillaire (DNF). Selon les tauopathies, la morphologie des lésions, leur composition en isoformes ainsi que l’évolution spatio-temporelle de la pathologie diffèrent. Dans la plupart des cas, les tauopathies sont sporadiques mais quelques mutations du gène codant Tau (MAPT) causent des formes familiales de démences fronto-temporales. Dans certaines tauopathies sporadiques comme la maladie d’Alzheimer, la DNF est initiée dans des régions spécifiques et évolue ensuite de manière stéréotypée. Ces stades neuropathologiques sont bien définis, mais les mécanismes expliquant cette évolution restent méconnus. Récemment, certaines études ont proposé que des espèces pathologiques de la protéine Tau sont capables de se déplacer activement de région en région suivant des connections neuro-anatomiques propageant ainsi la pathologie Tau dans le cerveau.Dans ce contexte, nous avons démontré à la fois in vitro, en utilisant un système de chambre microfluidique mais également in vivo dans un nouveau modèle de rat, que la protéine Tau est activement et physiologiquement transférée de cellule en cellule. De manière intéressante, la pathologie Tau qui se développe dans l’hippocampe des rats se propage également de région en région. Ce modèle étant basé sur une technologie de vectorisation virale, nous avons pu tester différentes constructions pour montrer qu’étonnamment, la pathologie Tau induite par des espèces mutées ou des isoformes 3R est restreinte autour du site d’initiation et ne propage pas aussi loin que pour les espèces sauvages 4R. La protéine Tau ainsi que la DNF se propagent donc de cellules en cellules mais les mécanismes expliquant cette propagation restent inconnus. Pour aborder cette question, et connaissant l’importance des vésicules extracellulaires (EVs) dans les mécanismes de communication intercellulaire, nous avons analysé leur implication dans le transfert de la protéine Tau. Nous avons purifié des EVs in vitro depuis des surnageants de culture mais également in vivo depuis des échantillons de liquide céphalorachidien de primates ainsi que des échantillons de fluide interstitiel cérébral de rat. Nous avons ainsi démontré que la protéine Tau est sécrétée de manière physiologique sous forme libre mais également au sein de EVs issues du bourgeonnement de la membrane plasmique nommées ectosomes. Il apparaît aussi qu’en cas de surexpression ou de présence de DNF, la protéine Tau est retrouvée dans des exosomes, des EVs issues de la voie endosomes/lysosomes.Ces résultats nous montrent que la protéine Tau se propage de neurone en neurone physiologiquement mais aussi durant des processus pathologiques. Il semble aussi exister des espèces particulières de protéine Tau plus promptes à se propager que d’autres. Ces différences pourraient en partie expliquer les différents phénotypes observés au sein des tauopathies. Nous avons aussi démontré que la protéine Tau est sécrétée via plusieurs voies de sécrétions qui pourraient refléter différents stades physiopathologiques. Des études complémentaires sont nécessaires notamment pour 1-clairement identifier les mécanismes de sortie et d’entrée de Tau dans les neurones. 2-comprendre si certaines espèces vont spécifiquement induire la pathologie dans les neurones secondaires et s’il est possible de les bloquer grâce à des thérapies ciblées. Et 3-identifier les raisons qui expliquent les vulnérabilités de certaines populations cellulaires. / Tau is a microtubule-associated protein mainly expressed in neurons. There are six different isoforms of this protein bearing either 3 or 4 microtubule-binding domains and called 3R-Tau or 4R-Tau. During the course of tauopathies, Tau proteins are abnormally modified and aggregate in specific intracellular lesions called neurofibrillary degeneration (NFD). According to tauopathies, the morphology of lesions, their isoforms’ composition and the spatiotemporal evolution of the pathology are different. Moreover, tauopathies are mostly sporadic but some mutations on Tau gene (MAPT) induce rare forms of familial fronto-temporal dementia. In some sporadic tauopathies like Alzheimer’s disease, the NFD is initiated in specific brain areas and evolves stereotypically in well-defined neuropathological stages. The mechanisms underlying such evolutions are mainly unknown but recently, different studies had proposed that some pathological species of Tau protein are able to actively move from region-to-region following neuro-anatomical connections and to spread the Tau pathology intra-cerebrally by this way.Within this context, we have demonstrated either in vitro using a microfluidic chamber system or in vivo using a new rat model, that Tau proteins are actively and physiologically transferred from cell-to-cell. Interestingly, in this model we could also follow the development of the Tau pathology inside the rats’ hippocampus but also its propagation from region-to-region. This model is based on a viral vector technology; therefore, we were able to test different construct and to show that surprisingly, Tau pathology induced by mutated or 3R-Tau species is restricted to the vicinity of the initiation site and do not propagate as far as the wild-type 4R-Tau species.Tau proteins as well as NFD are cell-to-cell propagating but the mechanisms underlying this phenomenon are still unknown. In order to address this point and knowing the significance of extracellular vesicles (EVs) in the intercellular communication mechanisms, we analysed their implication in the transfer of Tau proteins. We purified EVs in vitro from culture supernatants but also in vivo from primates’ cerebrospinal fluid samples and rats’ cerebral interstitial fluid samples. We demonstrated that Tau proteins are secreted physiologically in a free form but also within specific EVs named ectosomes and coming from a budding of the plasma membrane. Also, it seems that when Tau is overexpressed and when NFD is present, Tau proteins are retrieved within EVs named exosomes and derived from the endosomes/lysosomes pathway.These results clearly show that Tau proteins are propagating from neuron to neuron physiologically but also during pathological processes. It seems also that some specific Tau species are more prone to propagate than others. These differences could partly contribute to the different phenotypes observed among tauopathies. We have also demonstrated that Tau proteins are secreted via several pathways of secretion that could reflect different pathophysiological stages. Some complementary studies are needed particularly to 1- clearly identify the cellular mechanisms of Tau exit and entry. 2- to understand if some Tau species will specifically induce Tau pathology in secondary neurons and if it is possible to block this phenomenon thanks to targeted therapy. And 3- to identify the reasons that explain the vulnerability of some specific cell populations to Tau pathology propagation.
796

Planejamento, ensaio e otimização in silico de novos protótipos inibidores da enzima acetilcolinesterase / Design, assay and in silico optimization of new prototypes inhibitors of acetylcholinesterase

Jonathan Resende de Almeida 26 January 2015 (has links)
A acetilcolinesterase (AChE) é uma enzima essencial que encerra a transmissão colinérgica através de uma rápida hidrólise do neurotransmissor, acetilcolina (ACh). Uma ampla série de evidências mostraram que os inibidores da AChE podem interferir com a progressão da doença de Alzheimer (DA). O desenvolvimento bem sucedido de compostos inibidores da AChE foi baseado na teoria de que o declínio nas funções cognitivas e mentais associadas a DA está relacionado com a perda da neurotransmissão cortical colinérgica, sendo assim, esses compostos podem ser usados para tratar as deficiências colinérgicas. Uma coleção de moléculas orgânicas foi escaneada para ser avaliada a capacidade dessas moléculas em inibir a atividade enzimática da AChE com o objetivo de se encontrar compostos líderes para posteriores otimizações, conduzindo a fármacos com aumento da eficácia e/ou menores efeitos adversos. As estratégias aplicadas incluem o screening ou triagem virtual baseado na estrutura e também no ligante, modelagem farmacofórica, docking molecular e buscas por similaridade (forma e eletrostática). Os estudos foram também concentrados na descoberta de novas classes de inibidores da AChE, tendo como molécula de referência o fármaco donepezil, o qual inaugurou uma nova classe de inibidores da AChE com a ação mais longa e mais seletiva com efeitos adversos manejáveis. Do total de compostos triados, 50 foram selecionados com adequadas propriedades físico-químicas e ADME/Tox. Em geral, esses compostos possuem substancial interação com o sítio periférico aniônico (PAS) da AChE e a maioria deles faz interações adicionais com o sítio catalítico (CAS) e com outros resíduos de aminoácidos importantes ao longo da enzima. Destes 50 compostos, oito foram comercialmente adquiridos e os ensaios enzimáticos revelaram que estes compostos exibem uma alta afinidade pela AChE. Os resultados apontam, ainda, que o composto entitulado ZINC30019441 exibiu a mais potente atividade inibitória para a AChE, com 1,8 micromolar de concentração, e os demais ficaram ainda situados em baixo micromolar, de 2 a 3 micromolar de concentração. Estes resultados, além das modificações químicas ora propostas in silico para estes inibidores protótipos, apontam para o desenvolvimento de uma nova e promissora série de potentes anticolinesterásicos, contendo propriedades de fármacos, as quais são ainda apropriadas para atuarem no Sistema Nervoso Central e interagirem com o peptídeo beta-amiloide, com vistas ao tratamento quimioterápico da doença de Alzheimer. A perspectiva imediata inclui os ensaios de anti-agregação do peptídeo com os oito inibidores já testados com a Acetilcolinesterase. / Acetylcholinesterase (AChE) is an essential enzyme that terminates cholinergic transmission by rapid hydrolysis of the neurotransmitter acetylcholine (ACh). A wide range of evidence shows that AChE inhibitors may interfere with the progression of Alzheimer\'s disease (AD). The successful development of AChE inhibitor compounds was based on the theory that the decline in cognitive and mental functions associated with AD is related to the loss of cortical cholinergic neurotransmission, thus, these compounds can be used for treating cholinergic deficiencies. A collection of organic molecules has been scanned to evaluate the ability of these molecules to inhibit the enzymatic activity of AChE in order to find lead compounds for further optimization, leading to drugs with increased efficacy and/or fewer adverse effects. The strategies applied include structure-based virtual screening and also in ligand-based virtual screening, pharmacophoric modeling, molecular docking and similarity searches (shape and electrostatic). Studies have also focused on the discovery of new classes of AChE inhibitors, having as a reference molecule the drug donepezil, which has opened a new class of AChE inhibitors with longer and more selective action with manageable side effects. 50 of the compounds screened, were selected with appropriate physical and chemical properties and ADME/Tox. In general, these compounds possess substantial interaction with the peripheral anionic site (PAS) of AChE and most of them make further interact with the catalytic site (CAS) and other key amino acid residues throughout the enzyme. Out of these 50 compounds, eight were commercially purchased and the enzyme assays have shown that these compounds exhibit a high affinity for AChE. The results show also that the compound titled ZINC30019441 exhibited the most potent inhibitory activity for AChE, with 1.8 micromolar concentration, and the rest were still located in low micromolar, 2-3 micromolar concentration. These results as well as chemical modifications herein proposed for these prototypes, indicate the development of a new and promising series of potent anticholinesterase containing drug properties, which are still suitable to act on the central nervous system and interact with the ?-amyloid peptide, for chemotherapy treatment of Alzheimer\'s disease. The immediate prospect includes the peptide anti-aggregation assays with the eight inhibitors already tested against acetylcholinesterase
797

Contribuições da metapsicologia freudiana para a compreensão dos sintomas da demência tipo Alzheimer / Contributions of Freudian metapsychology to the understanding of the symptoms of Alzheimer\'s dementia

Katia Cherix 04 August 2017 (has links)
Esta tese de doutorado busca fazer uma articulação entre conceitos da metapsicologia freudiana e sintomas da demência de tipo Alzheimer, como descritos pela neuropsicologia. A pesquisa levou a estudar a relação do idoso com seu corpo, durante o processo de envelhecimento, assim como o desenvolvimento do conceito de narcisismo por Freud e a implicação da estruturação deste para o surgimento das demências. Num segundo momento, seguindo os passos já trilhados por autores que levantaram a hipótese da relação entre o aparecimento do sintoma de perda de memória e a dificuldade na elaboração dos lutos, levantou-se a hipótese do sintoma de perda de memória como um mecanismo de defesa. A história subjetiva em relação ao complexo de castração define a maneira como o sujeito poderá lidar com a castração imposta pela aproximação do fim do Eu. Por fim, propôs-se uma leitura psicanalítica para as mudanças experimentadas pelo sujeito, desde o diagnóstico da doença de Alzheimer até o estágio avançado da doença. Nesse percurso, fica claro que, na fase inicial, o Supra Eu encontra-se abalado; na fase intermediária, são as funções do Eu que são atingidas até o ponto de nos encontrarmos diante de um sujeito sem um funcionamento egoico. É possível supor que, sem a possibilidade da sublimação ou da simbolização, as pulsões, sem representações que possam enlaçá-las, invadem o aparelho psíquico e o corpo do idoso, o qual já não se reconhece mais como um sujeito. Essa desintegração do Eu, à luz da metapsicologia, poderia ser compreendida como uma forma de mecanismo de defesa que protegeria o sujeito de entrar em contato com uma dor maior, ligada a uma história de lutos não elaborados e de traumas que seriam reatualizados no contato com os desafios do processo de envelhecimento / This doctoral thesis seeks to articulate concepts of Freudian metapsychology and the symptoms of Alzheimer\'s dementia as described by neuropsychology. The research led us to study the relationship that the elderly develop with their body during the aging process as well as the development of the concept of narcissism by Freud and the implication of the structure of this to the onset of dementia. In a second chapter, following the steps already taken by authors who raised the hypothesis of the relationship between the appearance of the symptom of memory loss and the difficulty in the elaboration of mourning, we hypothesized that the memory loss symptom can be understood as a defense mechanism. The subjective history of the castration complex defines the way in which the subject can deal with the castration imposed by the approximation of the end of life. Finally, we propose a psychoanalytic reading for the changes experienced by the subject from the diagnosis of Alzheimer\'s disease to the advanced stage of the disease. In this course, it is clear that in the initial phase, the Superego is shaken, in the intermediate phase, the functions of the ego are affected to the point of being faced with a subject without an egoic functioning. It is possible to suppose that without the possibility of sublimation or symbolization, the drives, without representations that can entail them, invade the psychic apparatus and the body of the elder who no longer recognizes himself as a subject. This disintegration of the ego, in the light of metapsychology, could be understood as a form of defense mechanism that would protect the subject from coming into contact with a greater pain, linked to a history of unprocessed mourning and traumas that would be awoken by the challenges of the aging process
798

Efeito protetor de nanocápsulas poliméricas contendo crisina em modelo de doença de Alzheimer induzida por injeção intracerebroventricular do peptídeo β-amilóide 1-42

Giacomeli, Renata 23 July 2015 (has links)
Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-13T19:44:23Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Renata Giacomeli.pdf: 1026894 bytes, checksum: b5f9c6a47c7fdc580b5b82dbafdcf4a8 (MD5) / Approved for entry into archive by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-13T19:44:45Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Renata Giacomeli.pdf: 1026894 bytes, checksum: b5f9c6a47c7fdc580b5b82dbafdcf4a8 (MD5) / Made available in DSpace on 2016-09-13T19:44:46Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Renata Giacomeli.pdf: 1026894 bytes, checksum: b5f9c6a47c7fdc580b5b82dbafdcf4a8 (MD5) Previous issue date: 2015-07-23 / A doença de Alzheimer (DA) é uma desordem neurodegenerativa crônica caracterizada clinicamente pela perda progressiva de função cognitiva, distúrbios neuropsiquiátricos e comportamentais. Patologicamente esta doença caracteriza-se pelo acúmulo anormal do peptídeo β-amilóide (Aβ) no córtex e no hipocampo, emaranhados neurofibrilares intracelulares formados por Tau hiperfosforilada, disfunção progressiva sináptica e, posteriormente perda neuronal. As opções terapêuticas disponíveis melhoram os sintomas, mas não impedem a progressão da doença, portanto, ainda está faltando uma estratégia terapêutica efetiva para DA. A Crisina (5, 7-dihidroxiflavona) é um flavonoide natural encontrada em extratos de plantas (tais como Passiflora caerulea e Populus tremula), própolis e mel que apresenta propriedades farmacológicas relevantes, incluindo efeito antioxidante, antiinflamatório, hipolipidêmico, anti-aterogênico, anticâncer e, de forma mais significativa, efeito neuroprotetor. Porém, existem algumas desvantagens que podem limitar a sua potencial aplicação na terapêutica tais como baixa solubilidade e má absorção intestinal. Somando-se a isso, um fato determinante na neuroterapia é o efeito restritivo da barreira hematoencefálica (BHE), a qual limita a eficácia de tratamentos. Muitos estudos têm-se centrado sobre este problema fundamental através da concepção de estratégias diferentes para 5 facilitar a passagem de ativos em todo a BHE. Entre estes, as abordagens baseadas em nanotecnologia ganharam impulso significativo, já que podem efetivamente transportar substâncias ativas através da BHE. Assim, o objetivo deste trabalho foi preparar um sistema baseado em nanopartículas, capaz de veicular a crisina, bem como investigar os efeitos biológicos em um modelo de DA induzida por injeção intracerebroventricular (icv) do peptídeo beta amiloide1-42 (Aβ1-42) em camundongos Swiss fêmeas com idade entre 18 e 22 meses. Para tanto, determinou-se parâmetros de estresse oxidativo, neuroinflamação e níveis do fator neurotrófico derivado do cérebro (BDNF) no córtex pré-frontal e hipocampo, também verificou-se os efeitos comportamentais cognitivos dos camundongos. Os animais foram divididos em 10 grupos: (1) veículo/tampão phosphate-buffered saline (PBS); (2) veículo/nanocápsula (NC)-branca; (3) veículo/crisina livre (5 mg/kg); (4) veículo/NC-crisina (1 mg/kg); (5) veículo/NC-crisina (5 mg/kg); (6) Aβ1-42/PBS; (7) Aβ1-42/NC-branca; (8) Aβ1-42/crisina livre (5 mg/kg); (9) Aβ1-42/NC-crisina (1 mg/kg) e; (10) Aβ1-42/NC-crisina (5 mg/kg). O peptídeo Aβ1-42 ou o veículo foram infundidos por injeção icv e, um dia depois, iniciou-se o tratamento, por via oral, durante 14 dias. Após o fim do tratamento, os animais foram submetidos aos testes comportamentais. Os resultados demonstraram que os efeitos neuroprotetores do crisina foram mais elevados quando administrada em nanopartículas. O nanossistema melhorou as concentrações de crisina nos tecidos cerebrais, bem como a eficácia farmacológica. O presente estudo demonstrou que o tratamento com crisina, principalmente na formulação de nanopartículas, foi eficaz em atenuar as seguintes alterações resultantes da exposição de camundongos à Aβ1-42: o comprometimento da memória em testes de comportamento, o aumento dos níveis de espécies reativas (RS), fator de necrose tumoral α (TNF-α) e interleucina-1β (IL-1β), a redução dos níveis de tióis não-proteicos (NPSH), BDNF e IL-10; o aumento da atividade de glutationa peroxidase (GPx) e glutationa redutase (GR) em córtex pré-frontal e hipocampo. Em conclusão, esses resultados demonstram que a atenuação da neuroinflamação e do estresse oxidativo está envolvido no efeito neuroprotetor da crisina neste modelo de DA, além disso, sugerem que a formulação de nanopartículas potencializa seus efeitos, o que pode fornecer uma nova abordagem terapêutica para o tratamento e prevenção de DA. / Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized clinically by progressive loss of cognitive function, neuropsychiatric and behavioral disorders. Pathologically the disease is characterized by abnormal accumulation of β-amyloid peptide (Aß) in cortex and hippocampus, intracellular neurofibrillary tangles consisting of hyperphosphorylated Tau, and synaptic dysfunction progressively later neuronal loss. The therapeutic options available improve symptoms but did not prevent disease progression, therefore, is still missing an effective therapeutic strategy for AD. Chrysin (5, 7-dihidroxiflavone) is a flavonoid found in natural plant extracts (such as Passiflora caerulea and Populus tremula), honey and propolis which has significant pharmacological properties including antioxidant, anti-inflammatory, hypolipidemic, anti-atherogenic, anti-cancer effects and, more significantly, neuroprotection. However, there are some disadvantages that may limit their potential application in therapeutics such as low solubility and intestinal malabsorption. Adding to this, a key fact in Neurotherapy is the restrictive effect of the blood-brain barrier (BBB), which limits the effectiveness of treatments. Many studies have focused on this fundamental problem by designing different strategies to facilitate the transition of assets across the BBB. Among these, nanotechnology-based approaches have gained significant momentum as they can effectively carry active substances through the BBB. The 7 objective of this work was to prepare a system based on nanoparticles, capable of relaying chrysin, as well as investigating the biological effects in a model of AD induced by intracerebroventricular injection (icv) of Beta amyloid1-42 peptide (Aβ1-42) in swiss mice females aged between 18 and 22 months. Therefore, it was determined parameters of oxidative stress, neuroinflammation and levels of brain-derived neurotrophic factor (BDNF) in the prefrontal cortex and hippocampus, it was also observed cognitive behavioral effects in mice. The animals were divided into 10 groups: (1) vehicle/phosphate-buffered saline (PBS); (2) Vehicle/blank-nanocapsule (NC); (3) vehicle/free chrysin (5 mg / kg); (4) Vehicle/NC-chrysin (1 mg / kg); (5) vehicle/NC-chrysin (5 mg / kg); (6) Aβ1-42/PBS; (7) Aβ1-42/blank-NC; (8) Aβ1-42/free chrysin (5 mg / kg); (9) Aβ1-42/NC-chrysin (1mg / kg) and; (10) Aβ1-42/NC-chrysin (5 mg / kg). The Aβ1-42 peptide or vehicle were infused icv injection and, one day later, treatment began, orally, for 14 days. After the end of treatment, animals were subjected to behavioral testing. The results showed that the neuroprotective effects of chrysin were higher when administered in nanoparticles. The nano system improved chrysin concentrations in the brain tissue as well as the pharmacological effectiveness. The present study demonstrated that treatment with chrysin, especially in nanoparticle formulation was effective in attenuating the following shortcomings arising from exposure of mice to Aβ1-42: the memory impairment in behavioral tests; the increased reactive oxygen species (RS), tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) levels, reduction non-thiol protein (NPSH), BDNF, and IL-10 levels; increasing the glutathione peroxidase (GPx) and glutathione reductase (GR) activity in the prefrontal cortex and hippocampus. In conclusion, these results demonstrate that blocking neuroinflammation and oxidative stress is involved in the neuroprotective effect of chrysin in this model, moreover, suggest that the nanoparticle formulation potentiates their effects, which may provide a new therapeutic approach for the treatment and prevention of AD.
799

Antibody-based Diagnostics and Therapeutics for Alzheimer's disease and Frontotemporal Dementia

January 2018 (has links)
abstract: Alzheimer’s Disease (AD) and Frontotemporal Dementia (FTD) are the leading causes of early onset dementia. There are currently no ways to slow down progression, to prevent or cure AD and FTD. Both AD and FTD share a lot of the symptoms and pathology. Initial symptoms such as confusion, memory loss, mood swings and behavioral changes are common in both these dementia subtypes. Neurofibrillary tau tangles and intraneuronal aggregates of TAR DNA Binding Protein 43 (TDP-43) are also observed in both AD and FTD. Hence, FTD cases are often misdiagnosed as AD due to a lack of accurate diagnostics. Prior to the formation of tau tangles and TDP-43 aggregates, tau and TDP-43 exist as intermediate protein variants which correlate with cognitive decline and progression of these neurodegenerative diseases. Effective diagnostic and therapeutic agents would selectively recognize these toxic, disease-specific variants. Antibodies or antibody fragments such as single chain antibody variable domain fragments (scFvs), with their diverse binding capabilities, can aid in developing reagents that can selectively bind these protein variants. A combination of phage display library and Atomic Force Microscopy (AFM)-based panning was employed to identify antibody fragments against immunoprecipitated tau and immunoprecipitated TDP-43 from human postmortem AD and FTD brain tissue respectively. Five anti-TDP scFvs and five anti-tau scFvs were selected for characterization by Enzyme Linked Immunosorbent Assays (ELISAs) and Immunohistochemistry (IHC). The panel of scFvs, together, were able to identify distinct protein variants present in AD but not in FTD, and vice versa. Generating protein variant profiles for individuals, using the panel of scFvs, aids in developing targeted diagnostic and therapeutic plans, gearing towards personalized medicine. / Dissertation/Thesis / Doctoral Dissertation Neuroscience 2018
800

Epigenetic Dysregulation in the Basocortical Cholinergic Projection System During the Progression of Alzheimer's Disease

January 2018 (has links)
abstract: Alzheimer’s disease (AD) is characterized by the degeneration of cholinergic basal forebrain (CBF) neurons in the nucleus basalis of Meynert (nbM), which provides the majority of cholinergic input to the cortical mantle and together form the basocortical cholinergic system. Histone deacetylase (HDAC) dysregulation in the temporal lobe has been associated with neuronal degeneration during AD progression. However, whether HDAC alterations play a role in cortical and cortically-projecting cholinergic nbM neuronal degeneration during AD onset is unknown. In an effort to characterize alterations in the basocortical epigenome semi-quantitative western blotting and immunohistochemistry were utilized to evaluate HDAC and sirtuin (SIRT) levels in individuals that died with a premortem clinical diagnosis of no cognitive impairment (NCI), mild cognitive impairment (MCI), mild/moderate AD (mAD), or severe AD (sAD). In the frontal cortex, immunoblots revealed significant increases in HDAC1 and HDAC3 in MCI and mAD, followed by a decrease in sAD. Cortical HDAC2 levels remained stable across clinical groups. HDAC4 was significantly increased in prodromal and mild AD compared to aged cognitively normal controls. HDAC6 significantly increased during disease progression, while SIRT1 decreased in MCI, mAD, and sAD compared to controls. Basal forebrain levels of HDAC1, 3, 4, 6 and SIRT1 were stable across disease progression, while HDAC2 levels were significantly decreased in sAD. Quantitative immunohistochemistry was used to identify HDAC2 protein levels in individual cholinergic nbM nuclei immunoreactive for the early phosphorylated tau marker AT8, the late-stage apoptotic tau marker TauC3, and Thioflavin-S, a marker of mature neurofibrillary tangles (NFTs). HDAC2 nuclear immunoreactivity was reduced in individual cholinergic nbM neurons across disease stages, and was exacerbated in tangle-bearing cholinergic nbM neurons. HDAC2 nuclear reactivity correlated with multiple cognitive domains and with NFT formation. These findings identify global HDAC and SIRT alterations in the cortex while HDAC2 dysregulation contributes to cholinergic nbM neuronal dysfunction and NFT pathology during the progression of AD. / Dissertation/Thesis / Doctoral Dissertation Neuroscience 2018

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