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Peri-adolescent Alcohol Consumption Enhances the Reinforcing and Stimulatory Properties of Ethanol within the Adult Mesolimbic Dopamine System in Alcohol Preferring P RatsToalston, Jamie E. 07 August 2012 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Research in the alcohol preferring (P) rat has indicated that peri-adolescent alcohol (EtOH) consumption enhances the acquisition of oral operant EtOH self-administration, inhibits the extinction of responding for EtOH, augments EtOH-seeking behaviors, and increases relative reward value of EtOH during adulthood. Experiment 1 was conducted to determine if these adult effects of peri-adolescent EtOH intake could be observed using an Intracranial Self-Administration (ICSA) model. It was hypothesized that an increased sensitivity to the rewarding actions of EtOH would be manifested in peri-adolescent-EtOH-exposed subjects compared to naive subjects when the opportunity to self-administer EtOH to the posterior ventral tegmental area (pVTA) is available in adulthood. The pVTA is a primary site for EtOH’s reinforcing and rewarding properties in the mesolimbic dopamine (DA) system. Experiment 2 was a dose-response examination of the effects of EtOH administered to the pVTA on downstream DA efflux in the nucleus accumbens shell (AcbSh) via a joint Microinjection-Microdialysis (MicroMicro) procedure.
Male P rats were given 24-h free-choice exposure to 15% volume/volume EtOH from postnatal day (PD) 30 to PD 60, or remained experimentally naive, with ad lib food and water. By the end of the periadolescent exposure period, average consumption was 7.3 g/kg/day of EtOH. After PD 75, periadolescent-EtOH-exposed and naïve rats were either implanted with an injector guide cannula aimed at the right pVTA for ICSA (Experiment 1), or two cannulae, one aimed at the right pVTA (injector) and one at the ipsilateral AcbSh (microdialysis) for MicroMicro (Experiment 2). Following one week of recovery from surgery, ICSA subjects were placed in standard two-lever (active and inactive) operant chambers. Test sessions were 60 min in duration and occurred every other day for a total of 7 sessions. Rats were randomly assigned to one of 5 groups (n=4-9/group) that self-infused (FR1 schedule) either aCSF (vehicle, 0 mg%), 50, 75, 100, or 150 mg% EtOH during 4 sessions, aCSF only for sessions 5 and 6 (extinction), and the initial concentration again for session 7 (reinstatement). MicroMicro subjects received six days of recovery from surgery, probe implantation the day before testing, and then continuous microdialysis for DA with 15 min microdialysis samples collected before, during, and then two hrs after 10-min pulse microinjection of either aCSF (vehicle, 0 mg%), 50, 75, 100, or 150 mg% EtOH.
Neither EtOH-exposed nor naive groups of P rats self-infused the aCSF or 50 mg% EtOH concentration. While the naive group did not self-infuse the 75 or 100 mg% EtOH concentrations, the peri-adolescent EtOH-exposed group of P rats did readily discriminate the active lever from the inactive lever at these concentrations. Both groups self-infused the 150 mg% EtOH concentration. Pulse microinjections of EtOH during the MicroMicro procedure revealed that 75 and 100 mg% concentrations of EtOH increased downstream DA in the AcbSh of EtOH-exposed, but not naïve, subjects. 150 mg% EtOH increased downstream DA in both adolescent treatment groups.
Overall, the results indicate that consumption of EtOH by P rats during peri-adolescence increases the reinforcing properties of EtOH in the pVTA in adulthood. The results also indicate that there were differential effects of peri-adolescent EtOH exposure on DA efflux in the AcbSh. This provides evidence that peri-adolescent EtOH-exposure produces long-lasting alterations in neural circuitry involved in EtOH-reinforcement, during adulthood.
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"Brachyspira hampsonii" associated diarrhea in pigs: virulence assessment and host-pathogen interactions2016 February 1900 (has links)
This thesis aimed to verify the causal association between "B. hampsonii" and the re-emergence of mucohaemorrhagic diarrhea in North American swine farms, to investigate the role of the intestinal microbiome as a predisposing factor for infection, to develop a porcine colon in vitro culture model and to apply this model in investigating early host-pathogen interactions.
Two infection trials were conducted to determine the pathogenicity of "B. hampsonii" clade II and clade I. Weanling pigs were divided into control (n=6) and inoculated (n=12) groups. In each trial, pigs were inoculated with "B. hampsonii" clade II (tissue homogenate or pure culture) or clade I (pure culture) or sterile culture media. Animals were monitored for clinical signs of diarrhea and upon observation of bloody diarrhea they were necropsied for characterization of lesions. Fecal shedding of "B. hampsonii" was monitored throughout the trials using culture and quantitative real-time PCR. Pre and post-diarrhea fecal samples from the clade II infection trial were used to study the microbiome response to "B. hampsonii" infection and to determine if pre-inoculation microbiome composition differed between pigs that did or did not develop clinical disease. For in vitro model development, numerous factors associated with explant survivability in culture were investigated to develop a protocol for culture of porcine colon explants. The optimized model was used to study the first 12 hours of "B. hampsonii" clade II interaction with the host using a combination of histopathology and gene expression analysis.
Pigs inoculated with "B. hampsonii" clade I (9/11) and clade II (9/12 and 8/12 in the tissue homogenate and pure culture experiments, respectively) developed mucohaemorrhagic diarrhea and colitis within 14 days of inoculation. In all trials, mucohaemorrhagic diarrhea was significantly more common in inoculated pigs than controls. No significant differences in richness, diversity or taxonomic composition distinguished the pre-inoculation microbiomes of affected or unaffected clade II inoculated pigs. After the development of diarrhea, the fecal microbiome of diarrheic pigs was more dense and had a had a lower Bacteroidetes:Firmicutes ratio when compared to inoculated but unaffected or control pigs. Cultured porcine colon explants displayed differentiated epithelium and crypts after 5 days in culture, while expressing GAPDH at a constant rate. For explants to thrive in vitro our results suggested the use of distal spiral colon, processed immediately after euthanasia, and cultured in an oxygen-rich gas mix with air-liquid culture interface in media containing antibiotics and antifungals. Explants exposed to "B. hampsonii" for 12 hours had a greater number of necrotic cells and thicker catarrhal exudate than control explants. Interaction of spirochaetes with the epithelium, necrotic cells and crypts was visible under optical microscopy, and a trend of increased expression of IFN-γ and e-cadherin in inoculated explants relative to control explants was observed.
Taken together, results of this thesis demonstrate that "B. hampsonii" causes mucohaemorrhagic diarrhea in pigs and modulates their intestinal microbiome. The development of an in vitro infection model that replicates in vivo features facilitated the observation of the initial events in "B. hampsonii" interaction with the colon. When explants were exposed to "B. hampsonii" similar histological lesions to in vivo were observed. This system provides a powerful model for future studies of the pathogenesis of "B. hampsonii" and other enteric pathogens of pigs.
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Particularités de l’athérosclérose du sujet non diabétique, diabétique de type 2, et/ou stéatosique non alcoolique : de la physiopathologie aux techniques d’imagerie non invasives / Characteristics of atherosclerosis in nondiabetic, type 2 diabetic, and/or nonalcoholic steatosic subjects : from pathophysiology to noninvasive imaging techniquesLoffroy, Romaric 15 December 2010 (has links)
L’athérosclérose est un problème de santé publique majeur puisque elle représente aujourd’hui la principale cause de décès dans les pays occidentalisés. Il est donc important de comprendre les mécanismes participant à la progression et aux complications de cette entité anatomoclinique. Nous nous sommes attachés dans ce travail de thèse à démontrer la place et l’apport potentiel de l’imagerie non invasive non expérimentale dans la mise en exergue des particularités de l’athérosclérose carotidienne et/ou coronarienne, et dans la stratégie de dépistage de ses complications chez le sujet non diabétique et diabétique de type 2, en fonction de l’existence ou non d’une stéatose hépatique non alcoolique. Nous présentons notamment dans ce travail, issu en partie de l’exploitation des données cliniques, biologiques et radiologiques de trois protocoles hospitaliers de recherche clinique, les différentes publications scientifiques internationales auxquelles il a donné lieu. / Atherosclerosis is a major public health problem and is one of the major causes of death in the developed western world today. It is therefore of utmost importance that we understand the mechanisms involved in the evolution and progression of this disease and its associated complications. With the work done for this thesis, we tried to bring forth the importance of non invasive clinical imaging to study the pattern of evolution of atherosclerosis involving the carotid and/or coronary arteries. We also present the role played by imaging in prevention and early diagnosis of associated complications in non diabetic and type 2 diabetic patients, presenting with or without non alcoholic hepatic steatosis. In this study, we evaluated three different clinical research protocols used involving the clinical findings, biochemical as well as radiological examination results. The results of these protocols have been the basis for several peer reviewed international publications till date.
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Avaliação dos polimorfismos L55M e Q192R do gene PON1 e do polimorfismo 5311C do gene PON2 na doença arterial coronariana em adultos jovens / Assessment of the L55M and Q192R polimorfisms of the PON1 gene and 5311C polimorfism of the gene PON2 in the coronary artery disease in young adultsSouza, Érika Miguel de 23 February 2006 (has links)
O efeito anti-aterogênico da HDL foi sugerido ser devido, parcialmente, à ação da paraoxonase (PON) associada à HDL. Três SNPs em PON1 (L55M e Q192R) e PON2 (S311C) têm sido implicados como fatores de risco independentes para doença arterial coronariana (DAC) em alguns, mas não todos os estudos. O efeito destes três polimorfismos do gene PON na DAC e na concentração sérica de lipídios, apolipoproteínas A-I e B (apo A-I e apo B) foi investigado em 221 indivíduos sem vínculos genéticos. Os três polimorfismos genéticos (L55M, Q192R e S311C) do gene PON foram analisados por PCR-RFLP. Não houve diferença entre a distribuição genotípica e a freqüência relativa dos alelos dos polimorfismos L55M, Q192R e S311C do gene PON entre pacientes e controles. Não houve associação entre os polimorfismos da PON e a DAC na população estudada. As freqüências dos haplótipos dos pacientes foram similares às encontradas no grupo controle. O polimorfismo L55M do gene PON1 está associado com variações na concentração sérica de apo A-I dos pacientes. O polimorfismo S311C do gene PON2 não está associado com variações na concentração sérica de lipídios, apo A-I e apo B dos pacientes. / The anti-atherogtenic effect of the HDL has been suggested to be due, partially, to the action of the HDL-associated paroxonase(PON). Three SNPs in PON1 (L55M e Q192R) and PON2 (S311C) have been involved as independent risk factors for coronary artery disease (CAD), in some, but not all studies. The effect of these three polymorphisms of the PON gene on CAD and on the levei of lipids, apolipoproteins A-I e B (apo A1 and apo B) was investigated in 221 genetically unrelated individuais. The three gene polymorphismis (L55M, Q192R e S311C) of the PON gene were analyzed by PCR-RFLP. Is no significant difference between distribuition of genotype and allele frequencies of the L55M, Q192R and S311C polymorfisms of the PON gene between patient group and controls. Is no association between polymorphisms of the PON gene and CAD in the population studied. The frequencies of the haplotypes in the patients were similar to those found in the control group. The L55M polymorphism of the PON1 gene is associated with variations of the level of polipoprotein A-I at patients. The S311C polymorphism of the PON2 is not associated with variations of the level of lipids, apo A-I and apo B at patients.
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Porfiria aguda intermitente: estudo clínico de 37 casos. / Acute intermittent porphyria: clinical study of 37 cases.Puglia, Paula Marzorati Kuntz 20 April 2001 (has links)
A porfiria aguda intermitente é uma doença autossômica dominante, decorrente de um distúrbio na via biossintética do heme, causado pela redução dos níveis da enzima uroporfirinogênio-I-sintetase. As manifestações clínicas envolvem o sistema nervoso periférico e o central. O diagnóstico baseia-se na excreção urinária elevada dos precursores das porfirinas ácido d-aminolevulínico e porfobilinogênio. O objetivo deste estudo foi analisar o quadro clínico apresentado por pacientes do Hospital das Clínicas de São Paulo com porfiria aguda intermitente, atendidos no período de janeiro de 1979 a dezembro de 1999. Foram avaliados 37 pacientes, com idades entre 6 e 48 anos, na proporção de 2,7 mulheres:1 homem. A faixa etária na qual ocorreu o maior número de crises foi a terceira década. Os pacientes apresentaram 63 crises, sendo que 13 deles também tiveram manifestações de caráter crônico. As manifestações clínicas mais freqüentes foram: dor abdominal, alteração da cor da urina, mudança no ritmo intestinal, déficit motor ou sensitivo-motor, vômitos, alteração do nível de consciência ou confusão mental, crises convulsivas, quadros disautonômicos cardio-vasculares e distúrbios psiquiátricos. As crises foram classificadas em leves, moderadas e graves, segundo critérios previamente estabelecidos. Todas as manifestações crônicas foram caracterizadas como leves. A neuropatia periférica motora ou sensitivo-motora nunca foi a manifestação inicial da crise de porfiria aguda intermitente. Houve correlação entre o tipo e o número de fatores precipitantes e a manifestação da neuropatia periférica motora ou sensitivo-motora, verificando-se que as crises nas quais ela está ausente foram em geral desencadeadas por apenas um fator, mais comumente de origem endócrina ou metabólica endógena, como período menstrual e jejum, enquanto que nas crises com neuropatia periférica houve a participação de vários fatores concomitantemente, sendo estes principalmente de origem exógena, como medicamentos. Os tratamentos mais utilizados nos surtos foram a administração de glicose, aumento da ingestão de carboidratos e o uso de fenotiazínicos. / Acute intermittent porphyria is an autosomal dominant disease, caused by a disturbance in the heme biosynthetic pathway, secondary to the reduction on the levels of uroporphyrinogen-I-synthetase enzyme. Clinical manifestations involve central and peripheral nervous system. The diagnosis is based on the elevated urinary excretion of porphyrins precursors d-aminolevulinic acid and porphobilinogen. The aim of this study was to analyze the clinical manifestations of acute intermittent porphyria in patients of the Hospital das Clínicas of São Paulo, seen between January 1979 and December 1999. 37 patients were studied, from 6 to 48 years old, with a rate of 2,7 women: 1 man. The age in which most of the crisis occurred was the third decade. The patients presented 63 crisis, and 13 of them presented also with chronic manifestations. The commonest clinical presentations were: abdominal pain, change in urine color, change in bowel habits, motor or sensory-motor deficit, vomiting, alteration of consciousness or mental confusion, convulsions, dysautonomic cardiovascular signs and psychiatric disorders. The crisis were classified as mild, moderate and severe, following criteria previously established. All chronic manifestations were characterized as mild. The peripheral motor or sensory-motor neuropathy was never the initial manifestation. Correlation was found between the kind and the number of precipitating factors, and the absence of peripheral neuropathy was in general related to just one factor, more commonly of endogenous endocrine or metabolic origin, like menstrual period and starvation, while in the crisis with peripheral neuropathy multiple factors were involved at the same time, these being of exogenous origin, like drugs. The most commonly used treatments were glucose administration, elevation of carbohydrate intake, and phenothiazines use.
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Avaliação do perfil inflamatório dos pacientes pediátricos com asma grave e sua correlação com o controle da doença e parâmetros funcionais / Evaluation of inflammatory patterns of children with severe asthma andEller, Miriam Cardoso Neves 04 June 2018 (has links)
Introdução: Os mecanismos fisiopatológicos da asma grave resistente ao tratamento (STRA) em crianças não está totalmente elucidado e parece diferir do observado em adultos, justificando investigações específicas neste grupo de pacientes. O escarro induzido é método útil para identificar fenótipos e endotipos de asma grave através de marcadores inflamatórios. O objetivo deste estudo foi investigar os padrões inflamatórios de crianças com STRA através escarro induzido e comparar com um grupo de crianças com asma grave que atingiram o controle. Métodos: Crianças (6-18 anos) com diagnóstico de asma grave (critério GINA) em tratamento a pelo menos 6 meses em um centro de referência foram avaliadas em um coorte prospectivo por 3 meses (3 visitas consecutivas). Foi averiguada técnica inalatória, adesão ao tratamento e investigado as principais comorbidades. Realizado coleta de escarro induzido para análise citológica e avaliação quantitativa de citocinas do sobrenadante, espirometria, pletismografia e medidas da FeNO. Após período de seguimento, os pacientes foram classificados em dois grupos: asma grave controlada e asma grave resistente ao tratamento conforme critérios da ATS/ERS. Resultados: Foram incluídos 40 pacientes (idade média 12,8 anos; 62,5% sexo masculino), sendo 13 (32,5%) classificados como STRA após o período de seguimento. A mediana do número de exacerbações foi maior e do escore de ACT menor nos pacientes STRA e esta diferença foi significativa. Não foram encontradas diferenças significativas: nos dados demográficos, nos parâmetros funcionais espirométricos e de pletismografia (CVF, VEF1, VEF/CV, FEF 25-75%, LTC, RV, RV/LTC, resistência e condutância das vias aéreas) e nos valores de FeNO quando comparado o grupo de pacientes controlados com o de STRA. O padrão inflamatório eosinofílico foi predominante nos dois grupos de pacientes, entretanto, o grupo STRA apresentou porcentagem proporcionalmente maior de neutrófilos no escarro comparados com o grupo de asma grave controlada, na visita 3 e também na visita 1 quando analisados retrospectivamente (p < 0,05). As medianas nos níveis das citocinas IL10, GM-CSF, INFy e TNFalfa no escarro foram significativamente maiores no grupo STRA quando comparado ao grupo controlado (p < 0,05) e o GM-CSF e TNF-alfa apresentaram correlação inversa com escore de ACT. Conclusão: Nesta coorte prospectiva, os parâmetros funcionais e a FeNO não discriminaram crianças com STRA dos que atingiram o controle. A presença de neutrófilos no escarro e das citocinas IL10, INFy e, particularmente, GM-CSF e TNFalfa podem ter para um papel na resistência ao tratamento da asma grave em crianças e adolescentes. Antagonistas específicos dessas citocinas podem no futuro representar uma estratégia na terapêutica / Background: The pathophysiological mechanisms of severe therapyresistant asthma (STRA) in children are not fully elucidated and seem to differ from findings in adults, thus justifying specific research on children. Induced sputum is useful for detecting phenotypes and endotypes of severe asthma via inflammatory markers. The aim of the present study was to investigate the inflammatory patterns of children with STRA by the induced sputum method and to compare them with a group of children who achieved control of severe asthma. Methods: A prospective cohort of children (6-18 years old) diagnosed with severe asthma (Global Initiative for Asthma - GINA criteria) and in treatment for at least 6 months at a reference center was assessed for 3 months (3 consecutive visits). Inhalation technique, adherence to treatment and main comorbidities were assessed. Induced sputum samples were collected for cytology analysis and quantitative assessment of cytokines in the supernatant; the participants were also subjected to spirometry, plethysmography and fractional exhaled nitric oxide (FeNO) measurements. At the end of follow-up, the patients were classified into two groups: controlled severe asthma and STRA according to the European Respiratory Society and American Thoracic Society (ERS/ATS) criteria. Results: Forty patients were included (average age 12.8 years old; 62.5% male); 13 (32.5%) were classified as STRA at the end of follow up. The median number of exacerbations was higher and the Asthma Control Test (ACT) score was lower in the STRA group; these differences were significant. Significant differences were not found relative to demographic data, spirometry and plethysmography function parameters [forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), ratio of FEV1 to slow vital capacity (FEV1/SCV), forced expiratory flow at 25-75% of FVC (FEF 25-75%), total lung capacity (TLC), residual volume (RV), RV/TLC, airway resistance and conductance] and FeNO after comparison of the STRA and controlled asthma groups. The eosinophilic inflammatory pattern predominated in both groups; however, the STRA group showed a proportionally higher percentage of sputum neutrophils compared with the controlled asthma group at visit 3 and visit 1 upon retrospective analysis (p<0.05). The median sputum levels of the cytokines IL-10, GM-CSF, IFN-y and TNF-alpha were significantly higher in the STRA group compared with the controlled asthma group (p < 0.05); GM-CSF and TNF-? showed inverse correlations with ACT scores. Conclusion: In the analyzed prospective cohort, functional parameters and FeNO did not discriminate between children with STRA and children with controlled asthma. The presence of neutrophils and the cytokines IL-10, IFN-y and, more particularly, TNF-alpha and GM-CSF in the sputum might have a role in resistance to treatment for severe asthma among children and adolescents. Antagonists specific for these cytokines might represent a therapeutic strategy in the future
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Finite element analysis and modeling of the anterior cruciate ligament in the human kneeUnknown Date (has links)
The Anterior Cruciate Ligament (ACL) resists excessive anterior translation and
internal rotation of the tibia during athletic activities and stabilizes the knee. In the US,
annually, over 200,000 cases of ACL disruption are reported. The impact on the quality of life of the subject and its cost to healthcare is tremendous. The objectives of this study were to determine any significant associations between the size of the tibial eminence and ACL injury and to develop a finite element model for structural analysis. The results suggest that the size of the tibial eminence plays a role in loading the ACL and is therefore a risk factor. In addition to the epidemiological analysis, a finite element model of the knee was developed that with added modifications can be used for complex knee loading situations. The results in this thesis may be used to develop strategies for ACL injury prevention and rehabilitation. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
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Mechanism and treatment of restrictive cardiomyopathyUnknown Date (has links)
Restrictive cardiomyopathy (RCM) is a cardiac muscle disorder characterized by increased ventricular stiffness and diastolic dysfunction. Patients with RCM often present severe cardiac problems which usually lead to heart failure and sudden death. No effective treatment is available for RCM which makes the finding of novel efficient therapies an urgent necessity. Great progress in molecular biology techniques and advances in transgenic animal development provide great opportunities for the study of RCM and other cardiovascular diseases encountered in clinical patients.... Our laboratory is among the first to generate transgenic mouse models of RCM based on cardiac troponin I (cTnI) missense mutations. In this study, transgenic mice that suffer from RCM have been generated to understand the factors behind the diastolic dysfunction associated with that myocardial disease.... The information obtained from this study allows a better understanding of the role of troponin in RCM and the factors behind the physiopathology of the disease. It will also offer a therapeutic strategy taking into account the physiological characteristic of RCM. / by Pierre-Ives Jean-Charles. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
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cTnI N-Terminal deletion: an agent for rescuing restrictive cardiomyopathy, a disease caused by mutations of Cardiac Troponin IUnknown Date (has links)
Restrictive cardiomyopathy (RCM) is represented in part by left ventricular stiffness
and diastolic dysfunction. Missense mutations of the cardiac troponin I (cTnI) gene cause
idiopathic RCM. These mutations are located in the C-terminus of cTnI and affect cardiac
relaxation. Transgenic mouse models presenting the pathology observed in clinical
patients with RCM have been generated previously and express the mutant cTnI in their
hearts. RCM-linked mutations increase cardiac myofilament Ca2+ sensitivity and promote
diastolic dysfunction in the heart. Previous studies using double transgenic mice
(cTnI/R193H/ND) showed that ventricular relaxation is enhanced in the cTnI/R193H
transgenic mice. In this study, another double transgenic mouse model,
(cTnI/R193H/ND/KO), provides an avenue to investigate its rescuing effects on RCMlinked
mutations in the cTnI /R193H/KO mouse. Use of molecular biological techniques,
transgenic animal developments and murine echocardiography in this study has
culminated into a greater understanding of RCM and diastolic dysfunction. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
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Genetic predisposition to Alzheimer's disease: studies by linkage and hypothesis-driven candidate gene approach. / CUHK electronic theses & dissertations collectionJanuary 2006 (has links)
Alzheimer's disease (AD) is the most common form of dementia, currently affecting around 17--25 million people worldwide. The typical neuropathological hallmarks of AD are amyloid beta (Abeta) deposition, presence of neurofibrillary tangles and neuronal cell death. Evidence from ongoing studies on the pathogenesis of AD, suggests that several different mechanisms are involved in neurons loss and thus decline of cognitive function. These include the metabolism of amyloid peptide, inflammation, cholesterol metabolism, and hormonal factors. / I have focused on the role of inflammation in the progression of AD. The inflammation hypothesis is based on findings of (1) elevated levels of inflammatory cytokines, such as IL-1, IL-6, TNFalpha, (2) the reduced levels of anti-inflammatory cytokines, like IL-10 in CSF and the blood of AD patients, and (3) activated microglia in the histological section of the patient's brain. On the other hand, the effects of the ApoE gene and differential age of onset between the two sexes suggested a modulation role for cholesterol and sex hormone like estrogen, which may influence the inflammatory response in the brain, so as to modulate the risk of AD. / In this project, the genetic risk factors predisposing to AD were investigated by genetic association studies of candidate genes. Candidate genes were shortlisted by two approaches. (I) Linkage-based candidate genes: Candidate genes were identified from reported loci with linkage to AD genome scan studies. Previous linkage studies of AD families revealed linked loci at 1p36, 1q23, 3p14, 4q32, 6p21, 6q27, 9q22, 10q24, 13q32, 15q26, 19q13 and 21q22. Several candidate genes from these loci including TNFalpha-related genes, TLR2, IGF-1, IFNalpha and MTHFR were selected for this project. (II) Hypothesis-based candidate genes: Candidate genes were selected according to their possible involvement in the inflammation hypothesis of AD. Under the hypothesis-based candidate gene approach, genes that might contribute to the inflammatory response of amyloid deposition were identified. These genes were validated by their expression level in the central nervous system. A further priorization step was carried out to select those genes showing a higher degree of inter-individual variation. Therefore, these genes were more likely to have a genetic/inherited variation at the population level. In other words, they are more likely to be the predisposition genes than genes without inter-individual variation (house-keeping genes are examples of genes showing little inter-individual variation). In this project, genes involved in the inflammatory pathway in the brain, such as IL-10 and HLA-A, and also genes that interact with the inflammatory pathway such as cholesterol related enzymes and estrogen receptors were investigated under the hypothesis-based approach. / This project is based on a case-control genetic association study which comprised of NINCDS-ADRDA diagnosed Chinese patients with AD (n=259) and age-matched non-demented subjects (n=248). Three genes PTGS2 (encoding for COX-2), MxA and ESR1 were selected for an intensive study by investigating their linkage disequilibrium pattern and using tagSNP strategy. TagSNPs selected for each gene were genotyped to investigate their association with the risk of AD. / This study showed that MTHFR, IL-10, HLA-A, CYP46A1, PTGS2 (COX-2) and ESR1 were associated with the risk of AD, and MxA, identified for the first time, was associated with the age of onset of AD. In conclusion, the results of my study further suggested the roles of inflammation in the pathogenesis of AD. / Ma Suk Ling. / "June 2006." / Advisers: Linda C. W. Lam; Nelson L. S. Tang. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1417. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 169-204). / 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, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
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