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EXPLORATIONS IN HOMEOVISCOUS ADAPTATION AND MASS SPECTRAL ANALYSIS OF MEMBRANE LIPIDSTimmons, Michael Douglas 01 January 2010 (has links)
The focus of this dissertation is centered on the mass spectral analysis of lipids and changes occurring in keeping with the concept of homeoviscous adaptation [1]. Homeoviscous adaptation is the process of modification of membrane lipids in response to environmental stimuli [1]. Dissertation investigations applied this concept to prokaryotic and eukaryotic organisms, and expanded the perception of environmental factors from exogenous organic solvents to intracellular environment.
The field of lipidomics deals with the analysis of phospholipid and fatty acid components of membranes the changes that occur due to environmental stimuli and their biological significance [2-6]. The high sensitivity of mass spectrometry (MS) is an ideal tool for lipidomics allowing detection, quantification and structural elucidation [6]. Coupling of a mass spectrometer to a chromatographic system, such as gas chromatograph (GC), allows the separation of fatty acid methyl esters analytes prior to analysis [7].
The research investigations that comprise this dissertation are divided into three interrelated projects. The first project involved the analysis of composition and structure of Clostridium thermocellum membranes from wild-type and ethanol-adapted strains in response to adaptation of cultures to growth in ethanol. The hypothesis being that adaptation of cultures to growth in ethanol would result in compensatory change to the membrane composition.
Rat mitochondrial fatty acid profiles isolated from brain, liver, kidney and heart tissues were compared. The hypothesis being that differences in cellular environments found among various tissues would be reflected in the mitochondrial membrane composition. These data support the concept that variations to the lipid content of neurological mitochondria may increase susceptibility to the products of oxidative stress.
Lastly, changes in neurological mitochondria as a function of Alzheimer’s disease progression were studied. The hypothesis being that changes to the mitochondrial lipidome would be significantly reflected during advanced stages of AD, in addition to being more prevalent in regions displaying greater pathology.
The three interrelated projects increased our understanding of the boundaries established by the concept of homeoviscous adaptation. Project specific hypotheses were supported by data obtained from these investigations.
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OXIDATIVE DAMAGE TO DNA IN ALZHEIMER'S DISEASESoman, Sony 01 January 2013 (has links)
Previous studies from our laboratory and others show a significant increase in levels of both nuclear and mitochondrial DNA and RNA oxidation in vulnerable brain regions in the progression of Alzheimer’s disease (AD). Although total DNA oxidation is increased in AD it remains unclear whether oxidative damage is widespread throughout the genome or is concentrated to specific genes. To test the hypothesis that specific genes are more highly oxidized in the progression of AD, we propose to quantify the percent oxidative damage in genes coding for proteins shown to be altered in the progression of AD using quantitative/real-time polymerase chain reaction (qPCR/ RT-PCR). To further test the hypothesis that diminished DNA repair capacity in the progression of AD contributes to increased DNA oxidation we will use custom PCR arrays and qPCR, Western blot analysis and activity assays to quantify changes in enzymes involved in base excision repair (BER).
In order to carry out these studies tissue specimens from superior and middle temporal gyri (SMTG) and inferior parietal lobe (IP), as well as, a non-vulnerable region, the cerebellum (CER) will be analyzed from normal control (NC) subjects and subjects throughout the progression of AD including those with preclinical AD (PCAD), mild cognitive impairment (MCI), and late stage AD (LAD). We will also analyze specimens from diseased control subjects (DC; Frontotemporal dementia (FTD) and dementia with Lewy bodies (DLB)) to determine if the changes we observe in AD are specific.
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ROLE OF CALCIUM AND NITRIC OXIDE SYNTHASE (NOS) IN BRAIN MITOCHONDRIAL DYSFUNCTIONNukala, Vidya Nag 01 January 2007 (has links)
Mitochondria are essential for promoting cell survival and growth through aerobic metabolism and energy production. Mitochondrial function is typically analyzed using mitochondria freshly isolated from tissues and cells because they yield tightly coupled mitochondria, whereas those from frozen tissue can consist of broken mitochondria and membrane fragments. A method, utilizing a well-characterized cryoprotectant such as dimethyl sulfoxide (DMSO), is described. Such mitochondria show preserved structure and function that presents us with a possible strategy to considerably expand the time-frame and the range of biochemical, molecular and metabolic studies that can be performed without the constraints of mitochondrial longevity ex vivo.
Mitochondrial dysfunction is implicated in Alzheimer’s disease (AD) mainly through oxidative stress and altered metabolism. Mitochondria are isolated from post-mortem brain samples from selective regions of AD and control patients and, utilizing the cryopreservation strategy, analyzed for respiration and oxidative damage. While we did not observe increases in free radicals, we did observe decreased respiration and increases in oxidative damage markers in AD patients, suggesting a role for oxidative stress in mitochondrial dysfunction.
While in the mitochondria, calcium (Ca2+) increases free radical generation by processes not completely understood. A new isoform of nitric oxide synthase (mtNOS) has been isolated and localized to mitochondria; though its existence and physiological role is debated. Nitric oxide synthase (NOS), when activated by Ca2+, produces nitric oxide (NO•) that can interact with ROS producing various reactive nitrogen species (RNS). These highly reactive radical species can damage DNA, proteins and lipids, ultimately resulting in cell death via apoptosis or necrosis.
The current research is aimed at understanding the role of Ca2+ and NOS in oxidative stress leading to mitochondrial dysfunction. We observed a significant reduction in mitochondrial respiration with increasing doses of calcium. We also observed NOS enzyme activity and detected NOS protein in the purified mitochondrial fraction. Lastly, we were also able to show that Ca2+ increased the levels of free radicals and changes in oxidative damage markers. These results suggest the presence of NOS in mitochondria that could play a role in Ca2+ induced mitochondrial dysfunction and potentially leading to cell death as relevant to aging and neurodegenerative diseases.
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APPLYING SPECIFIC ARTS ACTIVITIES TO IMPROVE THE QUALITY OF LIFE FOR INDIVIDUALS WITH ALZHEIMER’S DISEASE AND DEMENTIATietyen, Ann Christianson 01 January 2012 (has links)
This study examined the effectiveness of a combination of seven different visual art activities, hat decoration, collage, embossing, painting, ceramics, photography, and printmaking, on quality of life for eight veterans with Alzheimer’s disease and dementia. The eight veterans were selected from the population of residents at the Thomson‐ Hood Veterans facility in Wilmore, Kentucky. These veterans were administered the seven art activities mentioned above, which ranged from less difficult to increasing difficulty. Three standard self‐reporting instruments, the Quality of Life‐AD, the Rosenberg Self‐Esteem Scale, and the Smiley‐Face Mood Assessment, as well as systematic observation and surveys were used to explore the effectiveness of the activities in improving quality of life and to identify other relevant domains. The results suggest that the combination of art activities improved the quality of life of the participants, including observed domains of focus and concentration, problem‐solving skills, memory, imagination, motor skills, self‐esteem, mood, and social interaction. The educational approach used simple to more complex problem‐solving skills and seemed to enhance cognitive performance and contribute to improved quality of life.
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Loss of Bace1 in mice does not alter the severity of caerulein induced pancreatitisHeindl, Mario, Tuennemann, Jan, Sommerer, Ines, Mössner, Joachim, Hoffmeister, Albrecht 11 May 2015 (has links) (PDF)
Context: Beta-site alpha-amyloid protein cleaving enzyme1 (BACE1) plays a key role in the pathogenesis of Alzheimer’s disease. Additional to its moderate expression in the brain, high levels of BACE1 mRNA were found in the pancreas. Murine Bace1 has been immunohistochemicaly detected at the apical pole of acinar cells within the exocrine pancreas of mice and Bace1 activity was observed in pancreatic juice. In vitro experiments revealed enteropeptidase as a
putative substrate for Bace1 suggesting a role in acute pancreatitis.
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Dysfagi vid lindrig till måttlig Alzheimers sjukdom : En undersökning med icke-invasiv metodWikberg, Linda January 2012 (has links)
Dysfagi, sväljningssvårigheter, är en vanlig komplikation vid Alzheimers sjukdom och är väl utforskat i det sista av de tre stadierna vid demens (lindrig, måttlig och svår). Sväljningssvårigheter som har kopplats samman med Alzheimers sjukdom är ett förändrat ätbeteende, reducerad höjning av larynx och en längre oral fas. Syftet med studien var att undersöka om och vilka symtom vid dysfagi som kan ses i de tidigare stadierna av Alzheimers sjukdom vid användning av icke-invasiva undersökningsmetoder. En enkätundersökning med 16 deltagare och en sväljningsscreening med fyra deltagare genomfördes. Sväljningsscreeningen bestod av fyra delar: oralmotorik, sväljningstest och sväljningskapacitetstest med vatten och tuggfunktion. Resultaten från enkäten visade ingen högre andel med sväljningssvårigheter i den testade gruppen jämfört med tidigare forskning av normalpopulationen. Inga signifikanta samband mellan olika parametrar såsom poäng på Mini Mental Test (MMT), tid för diagnos och poäng på enkäten hittades. Resultaten från sväljningsscreeningen visade en tendens till förlängd orofaryngeal fas vid ett sväljningskapacitetstest vilket indikerar att undersökning av sväljningskapacitet kan vara en användbar metod för att identifiera tidiga sväljningssvårigheter vid Alzheimers sjukdom. Testet är lätt att genomföra och inte tidskrävande. / Dysphagia, eating disorders, is a common complication associated with Alzheimer’s disease and has been studied extensively in the three late stages of dementia (mild, moderate and severe). Eating disorders that have been linked to Alzheimer’s disease are a changed eating behaviour, reduced laryngeal elevation and a prolonged oral phase. The purpose of this study was to investigate if and which symptoms of dysphagia can be identified using non-invasive methods. A survey with 16 participants and a swallowing screening with four participants were conducted. The swallowing screening consisted of four parts: oral motor abilities, a swallowing test and a swallowing capacity test with water and chewing function. The results from the survey did not show an increased prevalence of eating disorders in the test group compared to what previous research suggests could be expected for the normal population. No significant correlations between parameters such as Mini Mental Test (MMT), time elapsed since diagnosis or score of the survey were found. The results from the swallowing screening showed a tendency towards a prolonged oropharyngeal phase in a swallowing capacity test, indicating that examination of swallowing capacity could be a useful method for identifying early eating disorders in Alzheimers disease. The test is easy to perform and is not time consuming.
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Anhörigas upplevelser av att vårda en familjemedlem som lider av Alzheimers sjukdom : En litteraturstudie / Relatives' experiences of caring for a family member suffering from Alzheimer's disease : A literature reviewStröm, Caroline January 2008 (has links)
<p>Alzheimers sjukdom påverkar både patienten och den som vårdar honom eller henne. En anhörig vårdar ofta patienten och det har visat sig att de är utsatta för olika svårigheter. Syftet med denna studie var att beskriva anhörigas upplevelser av att vårda en familjemedlem med Alzheimers sjukdom. Metoden som användes för att besvara syftet var att göra en litteraturstudie enligt Polit och Becks (2004) beskrivning av genomförandet av en litteraturstudie. Dataanalysen skedde med kvalitativ ansats genom att artiklarna lästes igenom noggrant och gemensamheter och mönster bland anhörigvårdares upplevelser söktes. Studiens resultat baserades på åtta vetenskapliga artiklar från vilka fem teman framkom. Resultatet visade att många anhörigvårdare upplevde en förlust av relationer. De saknade relationen både med patienten och med vänner. De tyckte även att det var viktigt att ha fritid och tid för sig själva, vilket ofta var svårt att åstadkomma. Viljan till att söka ny kunskap blev stor när de tog på sig rollen som anhörigvårdare, och många upplevde olika lidanden och besvär såsom skuld och depression. Upplevelserna i resultatet åskådliggjorde att en stor del av de anhöriga inte kände välbefinnande. Detta resultat pekar på vikten av att sjuksköterskor är medvetna om de upplevelser och känslor anhörigvårdare har.</p> / <p>Alzheimer’s disease afflicts both the patient and the person caring for him or her. A relative often provides care for the patient and it appears as though they are exposed to different adversities. The aim of this study was to describe the experiences of relatives which care for a family member suffering from Alzheimer’s disease. The method used to answer the aim was to do a literature review by using Polit and Becks (2004) description of how to make a literature review. The data analysis was made with a qualitative approach by reading the articles accurately and patterns among the experiences family caregivers have been sought. The results of the study are based on eight scientific articles. Five themes emerged from these articles. The results show that many family caregivers experienced a loss of relationships. They missed the relationship with the patient as well as the relationship with friends. They also thought that it was important to have leisure, which often is hard to accomplish. The desire to seek for new knowledge became large when they became family caregivers, and many of them experienced different sufferings and troubles such as guilt and depression. The results show that many of the relatives did not experience well-being. On account of this it is important that nurses know about the experiences and feelings family caregivers have.</p>
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THE CELLULAR NUCLEIC ACID BINDING PROTEIN REGULATES THE ALZHEIMER’S DISEASE β-SECRETASE PROTEIN BACE1Holler, Christopher J 01 January 2012 (has links)
Alzheimer’s disease (AD) is the most common neurodegenerative disease affecting the elderly population and is believed to be caused by the overproduction and accumulation of the toxic amyloid beta (Aβ) peptide in the brain. Aβ is produced by two separate enzymatic cleavage events of the larger membrane bound amyloid precursor protein, APP. The first, and rate-limiting, cleavage event is made by beta-secretase, or BACE1, and is thus an attractive therapeutic target. Our lab, as well as many others, has shown that BACE1 protein and activity are increased in late-stage sporadic AD. We have extended these findings to show that BACE1 is increased in the earliest stages of AD before the onset of significant Aβ accumulation, indicating a potential causal role in the disease. Interestingly, BACE1 mRNA levels are unchanged in AD, leading to reason that a post-transcriptional method of BACE1 regulation is altered in disease. To date, the mechanism for this aberrant post-transcriptional regulation has not been elucidated. This study has implicated the cellular nucleic acid binding protein (CNBP), a highly conserved RNA binding protein, as a positive regulator of BACE1 translation, with implications for the etiology of sporadic AD. CNBP overexpression in cultured cells or spiked into a cell-free in vitro translation system increased BACE1 protein expression without affecting BACE1 mRNA levels. Knockdown of CNBP reduced BACE1 protein and mRNA slightly. Furthermore, CNBP associated with BACE1 mRNA in cell lysates and bound directly to the BACE1 5’ UTR in vitro, which confers most of the regulatory activity. Importantly, CNBP was increased in the progression of AD and correlated with BACE1 expression. Cellular stressors (such as glucose deprivation and oxidative stress) that occur in the AD brain increase BACE1 translation and we have found that these stressors increased CNBP expression as well. Early experimental evidence suggests that CNBP may enhance BACE1 translation through a cap-independent mechanism, which is an alternative translational pathway activated by cell stress. These studies indicate that the RNA binding protein CNBP is a novel trans-acting factor important for the regulation of BACE1 protein production and may be a viable therapeutic target for AD.
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New innovations in dementia research : from a new assessment of premorbid functioning to a review of the evidence base for post-diagnostic Cognitive RehabilitationPhillips, Joanne January 2013 (has links)
Background Dementia is a national priority for Scotland, and as such, fast and accurate diagnosis plus responsive and well-evidenced interventions post-diagnosis are key. Accurately estimating an individual’s level of premorbid functioning can be a crucial part of establishing that cognitive decline has taken place, enabling clinicians to be more confident and accurate in their diagnosis. Measures that assess premorbid ability should be able to 1) capture current ability in healthy controls and 2) resist the effects of cognitive decline when used in individuals with dementia. At the post-diagnostic stage, there is a growing evidence base for non-pharmacological, tailored interventions for individuals with dementia. However, the evidence base is limited, particularly so for Cognitive Rehabilitation. Objectives An empirical study was conducted in order to assess whether a newly developed measure that aims to capture lifelong cognitive reserve (the brain’s ability to withstand pathological change), the Cognitive Reserve Index Questionnaire (CRIq), can capture premorbid ability. Three research questions were addressed; 1) does the CRIq capture current ability in healthy controls? 2) is it resistant to cognitive decline when used with a patient group with dementia? and 3) how does the CRIq compare to a traditional measure of premorbid ability, the NART (National Adult Reading Test)? Another focus of development and innovation in dementia research is that of post-diagnostic interventions. A systematic review was therefore conducted in order to evaluate the effectiveness of Cognitive Rehabilitation for mild-moderate dementia (Alzheimer disease or mixed dementia) in relation to cognitive and functional outcomes. Due to the limited number of RCTs in this field precluding a clear understanding of the evidence base, the additional contribution of non-RCTs was also evaluated. Method For the empirical study N=20 healthy older controls and N=13 patients with dementia were recruited. In order to appropriately address the three research questions both groups were assessed using the NART, the CRIq and the MOCA (Montreal Cognitive Assessment). In addition, the control group were assessed on a measure of current ability, the WAIS-IV Perceptual Reasoning Index. For the systematic review of Cognitive Rehabilitation the CDCIG Specialised Register, ALOIS, was searched in order to identify relevant studies. In addition, previous reviews were searched to identify studies excluded on the basis that they were not an RCT. Results Results for the empirical study show both CRIq and NART were strongly correlated to current ability (performance on WAIS-IV PRI) in controls, although both significantly overestimated ability. CRIq performance was not affected by the presence of dementia whereas NART predicted premorbid ability was. CRIq and NART showed a different pattern of results between controls and patients, indicating that CRIq may more resistant to the effects of cognitive decline. Ten studies were identified for the systematic review; five RCT and five non-RCT. Study quality was assessed using a well-validated quality assessment tool, and indicated large variability. Eight of the ten studies reported a positive effect of Cognitive Rehabilitation. However, several studies were of poor quality and included aspects of other approaches in their intervention (e.g. Cognitive Training, Cognitive-Behaviour Therapy). Conclusions The empirical study found that CRIq over-estimated current ability in controls, but was resistant to cognitive decline in patients. The over-estimation of current ability may be accounted for by the CRIq being normed on an Italian population, thus not reflecting UK cultural norms (e.g. for length of schooling). When the NART and the CRIq were directly compared, the two measures were found to be related, but yet produced significantly different estimates of premorbid ability. This suggests that they may capture different facets of premorbid functioning, with the NART being primarily a verbal performance-based measure, and the CRIq capturing aspects of global cognitive functioning. Clinical implications include the potential utility of the CRIq for patients with language impairment. However the study conclusions are limited by a low N, and therefore have restricted generalisability. In the systematic review, the literature was exhaustively searched and evidence was found for the effectiveness of Cognitive Rehabilitation for mild-moderate Alzheimer disease and mixed dementia. Methodological limitations of the included studies are discussed, and clinical implications are identified. Both the empirical study and the systematic review highlight the need for greater research and development of methods by which dementia care is supported; through more effective methods of diagnosis, to a better evidence base for post-diagnostic interventions.
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Traitement de l'angoisse du sujet dément : Exorde pour une métapsychologie de la démence au stade sévère / The treatment of anxiety about the demented subject : Exorde for a metapsychology of dementia in severe stageGuentcheff, Ianis 20 December 2014 (has links)
L'interaction complexe des différentes fonctions cognitives ne permet pas de trouver la source précise des manifestations démentielles dans l'organe du cerveau. Dans une perspective organiciste, ne répondant pas aux critères d'inclusion, ils sont la part énigmatique d'un tableau démentiel dans lequel ils ne trouvent pas à strictement s'insérer. On les dit donc «associés». Nous tentons dans ce travail de souligner la complexité d’avoir à penser la cause d’un comportement de manière univoque et nous avançons l’idée selon laquelle la démence sévère se motive d’un rapport nouveau à la «cause» comme telle. Nous posons la démence comme produisant l’être dément : effet d’un délitement du langage dont le sujet n’est ni comptable, ni l’observateur passif. Le sujet dément se trouverait donc pris dans une situation qui engage son être en tant qu’il est non-causé par la métamorphose qui le caractérise pourtant. Une fois posée la démence sévère comme la manifestation d’un manque réel au champ du manque dans l’Autre, il nous sera possible de saisir dans une même logique l’effondrement de la dimension réflexive de l’identité et celle du désir. Nous orientant de l’angoisse que suscite la destruction du code de l’Autre et de l’aliénation imaginaire, nous postulerons que les manifestations psycho-comportementales démentielles ont valeurs de tentatives d’injection du manque au champ de l’Autre. Ces tentatives, par définitions subjectives et singulières, devront donc être entendues avant que d’être comprises, puis accompagnées. De ce point de vue, la démence sévère ne se qualifierait pas de ses déficits, mais de ce qui du manque lui fait défaut. / The complex interaction of the various cognitive functions does not allow finding the precise source of insane events in the brain organ. In organismic perspective which does not cater for the inclusion criteria, they are enigmatic part from an insane board into which they fail to fit strictly. That’s why they are called "associates".We attempt in this work to emphasize the complexity of having to think about the cause of a behavior in an unambiguous way, and we advance the idea that severe dementia motivates a new report to the "cause" as such. We argue dementia as producing be denied: effect of a disintegration of the language whose the subject is neither accountant, nor passive observer. The insane subject would therefore be caught in a situation that involves his (her) being as it is not caused by the transformation which characterizes him (her) nevertheless.Once installed severe dementia as the manifestation of a real lack face to the Lack in the Other, we will be able to apprehend, in the same sense, the collapse of reflective dimension of identity and that of desire. By directing us the distress generated by the destruction of the code of the Other and of the imaginary alienation, we will postulate that insane psycho-behavioral symptoms would in fact be injection attempts of lack in the field of the Other. These attempts, by subjective and singular definitions, will have to be heard before being understood, then accompanied. From this point of view, severe insanity would not be qualified by its deficits, but by what of lack default.
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