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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.
711

A Look Into Alzheimer’s Disease—Interventions at The Molecular Level

Feliciano Nieves, Priscila 01 January 2022 (has links)
There are puzzle pieces to the cure for Alzheimer’s Disease (AD), and such can emerge by inspecting the biomolecular interactions and their effects on neuronal cells. The upcoming presented literature review will cover the molecular changes caused by AD pathological progression, explore the relationship between non-AD molecules and AD molecules in the body, and analyze potential contributing factors in AD. In addition, the information to be provided will highlight medicinal alternatives respective to a particular stage in AD.
712

ROLE OF GENOMIC COPY NUMBER VARIATION IN ALZHEIMER'S DISEASE AND MILD COGNITIVE IMPAIRMENT

Swaminathan, Shanker 14 February 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Alzheimer's disease (AD) is the most common form of dementia defined by loss in memory and cognitive abilities severe enough to interfere significantly with daily life activities. Amnestic mild cognitive impairment (MCI) is a clinical condition in which an individual has memory deficits not normal for the individual's age, but not severe enough to interfere significantly with daily functioning. Every year, approximately 10-15% of individuals with MCI will progress to dementia. Currently, there is no treatment to slow or halt AD progression, but research studies are being conducted to identify causes that can lead to its earlier diagnosis and treatment. Genetic variation plays a key role in the development of AD, but not all genetic factors associated with the disease have been identified. Copy number variants (CNVs), a form of genetic variation, are DNA regions that have added genetic material (duplications) or loss of genetic material (deletions). The regions may overlap one or more genes possibly affecting their function. CNVs have been shown to play a role in certain diseases. At the start of this work, only one published study had examined CNVs in late-onset AD and none had examined MCI. In order to determine the possible involvement of CNVs in AD and MCI susceptibility, genome-wide CNV analyses were performed in participants from three cohorts: the ADNI cohort, the NIA-LOAD/NCRAD Family Study cohort, and a unique cohort of clinically characterized and neuropathologically verified individuals. Only participants with DNA samples extracted from blood/brain tissue were included in the analyses. CNV calls were generated using genome-wide array data available on these samples. After detailed quality review, case (AD and/or MCI)/control association analyses including candidate gene and genome-wide approaches were performed. Although no excess CNV burden was observed in cases compared to controls in the three cohorts, gene-based association analyses identified a number of genes including the AD candidate genes CHRFAM7A, RELN and DOPEY2. Thus, the present work highlights the possible role of CNVs in AD and MCI susceptibility warranting further investigation. Future work will include replication of the findings in independent samples and confirmation by molecular validation experiments.
713

Mining brain imaging and genetics data via structured sparse learning

Yan, Jingwen 29 April 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Alzheimer's disease (AD) is a neurodegenerative disorder characterized by gradual loss of brain functions, usually preceded by memory impairments. It has been widely affecting aging Americans over 65 old and listed as 6th leading cause of death. More importantly, unlike other diseases, loss of brain function in AD progression usually leads to the significant decline in self-care abilities. And this will undoubtedly exert a lot of pressure on family members, friends, communities and the whole society due to the time-consuming daily care and high health care expenditures. In the past decade, while deaths attributed to the number one cause, heart disease, has decreased 16 percent, deaths attributed to AD has increased 68 percent. And all of these situations will continue to deteriorate as the population ages during the next several decades. To prevent such health care crisis, substantial efforts have been made to help cure, slow or stop the progression of the disease. The massive data generated through these efforts, like multimodal neuroimaging scans as well as next generation sequences, provides unprecedented opportunities for researchers to look into the deep side of the disease, with more confidence and precision. While plenty of efforts have been made to pull in those existing machine learning and statistical models, the correlated structure and high dimensionality of imaging and genetics data are generally ignored or avoided through targeted analysis. Therefore their performances on imaging genetics study are quite limited and still have plenty to be improved. The primary contribution of this work lies in the development of novel prior knowledge-guided regression and association models, and their applications in various neurobiological problems, such as identification of cognitive performance related imaging biomarkers and imaging genetics associations. In summary, this work has achieved the following research goals: (1) Explore the multimodal imaging biomarkers toward various cognitive functions using group-guided learning algorithms, (2) Development and application of novel network structure guided sparse regression model, (3) Development and application of novel network structure guided sparse multivariate association model, and (4) Promotion of the computation efficiency through parallelization strategies.
714

Consequences of the interaction of amyloid beta with amyloid binding alcohol dehydrogenase and the receptor for advanced glycation end products

Ren, Yimin January 2008 (has links)
Amyloid beta (Aβ) has been postulated to be the principle initiator of the pathogenesis of Alzheimer’s disease (AD). Therefore, understanding the underlying mechanisms of Aβ induced neurotoxicity in the early stages of AD would be essential for finding potential therapeutic targets of AD. Aβ-binding alcohol dehydrogenase (ABAD) has been shown to be a mitochondrial binding site for Aβ. Expression of ABAD has been found to be increased in brains of AD sufferers. Two dimensional electrophoresis studies have revealed that endophilin 1 was upregulated in Tg mAPP/ABAD mice brains as compared to Tg mAPP, Tg ABAD and non-Tg mice brains. Increased expression of endophilin 1 has also been found in brains of AD patients as compared to non-demented control brain tissues. Endophilin1 has been reported to regulate c-Jun N-terminal kinase (JNK) activation. In this study, expression of dominant negative forms of endophilin 1 (DN-endophilin 1) in mouse cortical neurons exhibited a significant reduction of Aβ induced JNK activation. Furthermore, using cell counting methods, it was shown that the transfection of DN-endophilin 1 increased neuron survival after Aβ treatment. Aβ has also been proposed to disrupt the interaction of ABAD and Cyclophilin D (CypD), which would trigger mitochondrial permeable transition, thereby leading to neurotoxicity. For fluorescence resonance energy transfer (FRET) analysis of the interaction of ABAD and CypD, a mitochondria targeted, EYFP tagged ABAD plasmid (pMito-ABAD-EYFP) and an ECFP tagged CypD (pCypD-ECFP) plasmid were developed. Positive FRET signals in SK-N-SH cells co-expressing pMito-ABAD-EYFP and pCypD-ECFP indicated that ABAD interacts with CypD in the mitochondria of mammalian cells. RAGE (receptor for advanced glycation end products) has been reported to bind to Aβ and mediate the toxic effects of Aβ peptides on neurons and microglia. It has been shown previously that Tg mAPP/DN-RAGE mice display preserved cognitive function as compared to Tg mAPP mice. To investigate possible mechanisms involved in rescuing cognitive function by RAGE blockage, two dimensional electrophoresis was used to analyze differential protein expression between Tg mAPP and Tg mAPP/DN-RAGE mice cortex. Altered expression of four proteins, including NADH dehydrogenase flavoprotein 2 (NDUFV2), glyoxalase 1 (GLO1), proteasome subunit beta type 4 (PSMB4, or β7 subunit of proteasome) and nitrilase family, member 2 (Nit2) have been observed between Tg mAPP/DN-RAGE mice cortex and Tg mAPP mice cortex. NDUFV2 is a 24kDa subunit of complex 1 which is involved in ATP synthesis. GLO1 is a cytosolic enzyme that plays a role the glutathione-dependent detoxification of α-oxoaldehydes, such as methylglyoxal. PSMB4 is a subunit of the 26s proteosome which is in the degradation of ubiquitinylated proteins. The function of Nit2 is still unclear.
715

Development and testing of a measure of Alzheimer’s disease knowledge in a rural Appalachian community

Unknown Date (has links)
Rural West Virginia has a very high percentage of older adults. The age-related disease of Alzheimer’s threatens the health of older Appalachians, yet research on Alzheimer’s disease (AD) in this population is scarce. In order to improve screening rates for cognitive impairment, Appalachians need to understand their vulnerability. The first step would be to assess their knowledge about AD but a suitable AD knowledge test has not been developed. The purpose of this study was to test the reliability and validity of a new measure of knowledge about AD that is culturally congruent, and to examine factors that may predict AD knowledge in this rural population. A correlational descriptive study was conducted with 240 participants from four samples of older adults in south central rural Appalachian West Virginia using surveys and face-to-face interviews. Results from tests for stability, reliability including Rasch modeling, discrimination and point biserial indices, and concurrent, divergent, and construct validity were favorable. Findings were that although more diversity in test item difficulty is needed, the test discriminated well between persons with higher and lower levels of education [F(2, 226) = 170.51, p = .001]. Using multiple regression, the predictors of AD knowledge included caregiver status, miles from a healthcare provider, gender, and education; (R2=.05, F(4,187) = 2.65, p =. 04). Only years of education accounted for a significant proportion of unique variance in predicting the total BKAD score (t = 2.14, p =. 03). Implications include the need for further tool refinement, testing for health literacy, coordination with recent statewide efforts to educate the public regarding AD, and community based participatory research in designing culturally effective education programs that will ultimately increase screening and detection of Alzheimer’s disease in rural populations. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2013.
716

Family resiliency, sense of coherence, social support and psychosocial interventions: reducing caregiver burden and determining the quality of life in persons with alzheimer’s disease

Unknown Date (has links)
Alzheimer's disease (AD) is a progressive, degenerative disorder that attacks the brain's nerve cells, or neurons, resulting in loss of memory, thinking and language skills, and results in behavioral changes and lack of communication. Family members and caregivers of persons with Alzheimer’s disease can assume added responsibilities and stress due to the progressive and degenerative component of this disability and places an added strain on the family system. This study was designed to examine predictors of quality of life of persons living with AD and to examine caregiver burden and predictors of quality of life of persons living with AD. This study hopes to empower the caregivers and test the resiliency model of family stress, sense of coherence and social support while incorporating individual patient and family needs by surveying caregivers involved with working with patients with AD. Specific aims of the study include validating relationships of the resiliency model while determining the importance of family resiliency, the sense of coherence, social support and the role of psychosocial interventions specifically Validation Communication Intervention (VCI), to reduce caregiver burden and to predict the quality of life in persons with Alzheimer’s disease. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
717

Neuroprotective mechanisms of Ginkgo biloba extract (EGb761) in Alzheimer's disease. / EGb761對Alzheimer氏病的神經保護機制 / CUHK electronic theses & dissertations collection / EGb761 dui Alzheimer shi bing de shen jing bao hu ji zhi

January 2010 (has links)
EGb761 consists of two major groups of substances, flavonoids and terpenoids. Using human neuroblastoma SH-SY5Y cells, the present study demonstrated that, EGb761 could block Abeta-42 (a 42-amino acid cytoxic form of beta amyloid protein)-induced cell apoptosis, reactive oxygen species (ROS) accumulation, mitochondrial dysfunction and activation of c-jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt signaling pathways, possibly via its antioxidant and platelet activating factor (PAF) antagonizing activities. Two active constituents of EGb761, quercetin (a flavonoid) and ginkgolide B (a terpenoid) might contribute to the protective effects of EGb761. Quercetin but not ginkgolide B might be responsible for the antioxidant action of EGb761. Both compounds might be involved in the PAF antagonist activity of EGb761. / EGb761, a Ginkgo biloba extract, is a medicinal product for the treatment and prevention of cardiovascular and neuronal diseases, including Alzheimer's disease (AD). While considerable researches have documented its neuroprotective effects, its clinical effect is inconclusive and the precise neuroprotective mechanisms are not clearly known. / In conclusion, EGb761 may have beneficial effects in treatment and prevention of neurodegenerative diseases like AD. Its neuroprotective effects may be associated with constituent multiplicity, the dosage and BBB permeability. / The ability of EGb761 to cross the blood brain barrier (BBB) is unclear. In this study, the ability of EGb761 to cross the BBB was speculated through comparison of the effects of EGb761 on mitochondrial function between platelets and central nervous system in two animal models, the senescence accelerated prone 8 (SAMP8) mouse strain and ovariectomized rats. Mitochondrial function was evaluated as cytochrome c oxidase (COX) activity, mitochondrial ATP content and mitochondrial glutathione (GSH) content. SAMP8 mice have been widely used as a model of age-related cognitive decline with relevance to biochemical and genetic alterations in AD. Using two age groups (3-week-old and 40-week-old) of SAMP8 mice, this study found that, EGb761 protected against mitochondrial dysfunction in both platelets and hippocampi of old mice, but only showed protective effects on platelet mitochondria of young mice. Estrogen withdrawal was suggested to play a primary role in the onset of post-menopausal AD. Using ovariectomized middle-aged rats to mimic the post-menopausal pathophysiological changes, this study also demonstrated that, EGb761 protected against mitochondrial dysfunction in both platelets and hippocampi of ovariectomized rats. In contrast, in sham-operated rats, EGb761 increased mitochondrial GSH content in platelets but failed to show similar effect on hippocampi. These results suggested that the effects of EGb761 on the brain might be interfered by the BBB permeability. / The effective dosage of EGb761 in the brain remains undetermined. Using SH-SY5Y cells, this study demonstrated that low doses of EGb761 (50--100 mug/ml) inhibited hydrogen peroxide (H2O2)-induced cell apoptosis via inactivation of Alet, JNK and caspase 3 while high doses of EGb761 (250--500 flg/ml) enhanced H2O2 toxicities via inactivation of Akt and enhancement of activation of JNK and caspase 3. Additional experiments suggested that the dosage effect of EGb761 on apoptotic signaling proteins might be correlated with regulation of the cell redox state. / Shi, Chun. / Adviser: Lee Ka Ho Kenneth. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 81-99). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
718

Genetische Polymorphismen und Progressionsgeschwindigkeit der Alzheimer-Demenz / Genetic Polymorphisms and Rate of Decline in Alzheimer's Disease

Wolff, Martin 22 October 2013 (has links)
Genetische Einflüsse stellen in der Ätiologie der Alzheimer-Demenz (AD) eine zentrale Rolle dar. In den letzten Jahren konnte eine Vielzahl neuer Kandidatengene entdeckt werden, die in sogenannten Genome-wide association studies (GWAS) eine signifikante Assoziation zur AD zeigten. Inwieweit diese neu entdeckten Polymorphismen auch die Progressionsgeschwindigkeit der AD beeinflussen, ist bislang jedoch nur unzureichend untersucht. Das Ziel dieser Arbeit war es daher, die 11 Polymorphismen mit der stärksten Assoziation zur AD in einem Kollektiv von 42 AD-Patienten hinsichtlich des Einflusses auf die Progressionsgeschwindigkeit zu untersuchen. Dazu wurde bei den Studienteilnehmern der Punktverlust im Mini-Mental-Status-Test (MMST) innerhalb eines Jahres gemessen. Unter den Polymorphismen wurde zusätzlich nach möglichen prädiktiven genetischen Markern für die „rapid-progressive AD“ (MMST-Verlust > 5 Punkte/Jahr) gesucht. Für den untersuchten rs541458-Polymorphismus des PICALM-Gens ließ sich bei C-Allel-Trägern eine signifikant höhere durchschnittliche MMST-Progression als bei Nicht-C-Trägern nachweisen (p = 0,039). Beim rs5930-Polymorphismus des LDLR-Gens konnte zudem für weibliche G-Allel-Träger eine signifikant erhöhte MMST-Progression gezeigt werden (p = 0,040). Prädiktive Marker für die rapid-progressive AD konnten nicht nachgewiesen werden. Der AG-Genotyp des untersuchten BIN1-Polymorphismus (rs744373) war jedoch signifikant häufiger in der langsamen Gruppe (≤ 5 Punkte Verlust im MMST/Jahr) anzutreffen (p = 0,026). Da bisher keine vergleichbaren Studien vorliegen, sind weitere Untersuchungen mit weitaus größeren Teilnehmerzahlen nötig, um die Ausprägung dieser möglichen Effekte genauer zu bestimmen. Die Möglichkeit, die gefundenen Polymorphismen als prognostische Marker zu verwenden und somit das Risiko des Krankheitsverlaufes zu bestimmen, hätte sowohl für Patienten und ihre Angehörigen als auch für die behandelnden Ärzte große Bedeutung.
719

A New Theory of Alzheimer's Disease

Meier-Stephenson, Felix 14 March 2014 (has links)
Alzheimer’s Disease (AD) is a chronic progressive neurological condition, clinically characterized by memory deficits, cognitive and physical impairment, and personality changes. Traditionally, AD was considered a type of protein folding disorder. Here, the concept of AD as an autoimmune disease of the innate immune system was developed. After exploring evolutionary connections between the AD peptide β-amyloid (Aβ) and known antimicrobial peptides (AMPs), and elucidating the structural similarities between Aβ and AMPs, a mechanism of action for Aβ’s antimicrobial activity is proposed that is based on the compromise of bacterial membranes. Following these theoretical considerations, experimental evidence is presented for the production of Aβ by cells in response to infection, and for Aβ’s antibacterial and antiviral activity. Rooted in similarities of the cell membranes of neuronal and bacterial cells in terms of lipid composition and transmembrane potential, it is hypothesised that Aβ’s neurotoxicity is caused by its misguided attack on neurons as an AMP. In reversing the concept of Aβ as an AMP, the similarity of AMPs to Aβ is demonstrated in experiments revealing the neurotoxicity of two AMPs, LL 37, and cecropin A. To determine a mechanism for the progressive nature of AD, it was shown that, although apoptosis may be involved in AD, it is actually necrosis that is responsible for the propagation of neuronal cell death so characteristic of AD. With the Vicious Cycle of AD, a scheme was devised, integrating the results obtained here with data and research from other groups, which explains the chronic and progressive nature of AD as a result of Aβ’s physiological role as an AMP and innate immune system effector. Borne from Aβ’s activity as an AMP and its central role in the Vicious Cycle of AD, a question was investigated: do antibiotics, such as penicillin, that cause release of bacterial endotoxins due to their mechanism of action, trigger the Vicious Cycle of AD and thus lead to the development of AD? Preliminary evidence supporting this notion was presented.
720

Perceptions of family caregivers of non-institutionalized Alzheimer's patients about support groups

Warner, Judy A. January 1999 (has links)
The purpose of this descriptive study was to document and analyze the perceptions of family caregivers of non-institutionalized Alzheimer's patients about the benefits and limitations of Alzheimer's support groups. Survey methodology was used to survey caregivers and support group leaders from eight Alzheimer's support groups in the central Indiana area. Several of the major findings challenge the literature. These findings are as follows: The majority of caregivers attended the support group to receive information. None of the caregivers attended the support group due to frustration, and only one caregiver responded that relieving frustration was a benefit of participating in the support group. A majority of caregivers and support group leaders were positive about mixed (spouses and adult children) support groups. A majority of caregivers responded that they did not have guilt, anger, fears about caregiving in the future, or stress concerning their caregiving responsibilities. The study generated several implications that can be used by planners to improve support groups. / Department of Educational Leadership

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