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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.
181

Estudo do perfil serotoninérgico no hipocampo de pacientes com epilepsia do lobo temporal / Study of serotonergic profile in temporal lobe epilepsy patients\' hippocampus

Fonseca, Natascha Cardoso da 01 October 2018 (has links)
A epilepsia é a condição crônica mais prevalente dentre as doenças neurológicas graves, associada com taxas significativas de morbidade e mortalidade. Pacientes com epilepsia farmacorresistente possuem uma taxa de mortalidade 2 a 3 vezes maior que indivíduos sem epilepsia. A epilepsia do lobo temporal (ELT) é a principal causa de epilepsia farmacorresistente nos adultos e também o protótipo da epilepsia cirurgicamente tratável, portanto, com maior acessibilidade para estudo de possíveis mecanismos epileptogênicos. Esclerose hipocampal (EH) é o achado neuropatológico mais comum em pacientes com ELT. Evidências, baseadas em experimentos animais e estudos em humanos, sugerem que as vias serotoninérgicas desempenham um importante papel na epileptogênese. Pacientes com ELT, causadas pela EH, apresentam maior prevalência de transtornos do humor e psicose contribuindo para uma pior qualidade de vida, com consequente impacto negativo nas respostas terapêuticas farmacológicas e cirúrgicas. Além disso, alguns estudos sugerem a existência de um mecanismo patogênico operante comum entre estas condições. Portanto, esta é um importante variável para análise. O objetivo desse estudo foi correlacionar as variáveis clínicas da epilepsia e a presença de transtornos psiquiátricos coexistentes com a concentração de serotonina (5-HT), a densidade dos receptores serotoninérgicos e a densidade do transportador serotoninérgico (5-HTT) no hipocampo dos pacientes com ELT-EH, que foram submetidos à cirurgia devido à presença de epilepsia farmacorresistente. Foram avaliadas amostras de 44 hipocampos de pacientes cirurgicamente tratados para ELT-EH. A concentração de 5-HT foi avaliada por cromatografia líquida de alta eficiência (HPLC) com detecção por fluorescência. 5-HTT e os receptores serotoninérgicos 5-HT1A, 5-HT2A, 5-HT6 e 5-HT7 foram avaliados por Western Blot. Níveis mais baixos de concentração de 5-HT estiveram associados com a presença de crises TCG (Wilcoxon-Mann-Whitney; p = 0.019). A densidade aumentada do receptor 5-HT1A esteve associada com maior duração da epilepsia (coeficiente de correlação de Spearman: p = 0.040) e a densidade diminuída do receptor 5-HT6 esteve associado com presença de EME (Wilcoxon-Mann-Whitney: p = 0.0027). A densidade dos receptores 5-HT2A e 5-HT7 e do 5-HTT não estiveram associadas com variáveis clínicas da epilepsia. A concentração de 5-HT, a densidade dos receptores e a densidade de 5-HTT não estiveram associadas à presença dos transtornos psiquiátricos neste grupo de pacientes. Nossos achados sugerem que as vias serotoninérgicas estão associadas com mecanismos de epileptogênese. Não foi evidenciado associações entre as vias serotoninérgicas e a presença de comorbidades psiquiátricas neste grupo de pacientes com ELT-EH / Epilepsy is the most prevalent neurological condition and it is associated with significative morbidities and mortalities rates. Patients with refractory epilepsy have a 2- to 3-fold higher mortality rate than people without epilepsy. Temporal lobe epilepsy (TLE) is the most common form of adult drug-resistant epilepsy. It is also the prototype of a surgically treatable epilepsy and because of that it is the most accessible for studies focused in epileptogenesis. Hippocampal sclerosis (HS) is the most common neuropathological finding in patients with TLE. Evidences from experimental, clinical and image studies suggest that the serotonergic system play an important role in epileptogenesis. Patients with TLE-HS have a higher prevalence of mood disorder and psychosis contributing for a worse quality of life with and consequent negative impact in pharmacological and surgical responses. Furthermore, studies suggest a common pathogenic mechanism operant in both conditions. Therefore, this is an important analytical variable. The objective of this study was to correlate clinical variables of epilepsy and the presence of psychiatric disease with serotonin (5-HT) concentration, serotonergic receptor density and serotonergic transporter (5-HTT) density in the hippocampus of TLE-HS patients submitted for surgery due to refractory epilepsy. It was analyzed 44 hippocampal tissue samples from surgical treated TLE-HS patients. 5-HT concentration was assessed by high pressure liquid chromatography (HPLC) with fluorescence detection. 5-HTT and serotonergic receptors 5-HT1A, 5-HT2A, 5-HT6 and 5- HT7 were assessed by Western Blotting. Lower levels of 5-HT concentration were associated with the presence of generalized tonic-clonic seizures (Wilcoxon-Mann-Whitney; p = 0.019). A higher 5-HT1A receptor density was associated with longer epilepsy duration (Spearman correlation coefficient: p = 0.040). Lower 5-HT6 receptor density was associated with the presence of status epilepticus (Wilcoxon-Mann-Whitney: p = 0.0027). 5-HT2A receptor, 5- HT7 receptor and 5-HTT densities were not associated with clinical variables of epilepsy. 5-HT concentration, serotonergic receptors and transporter densities were not associated with the presence of psychiatric disease in this group of patients. Our findings suggest that the serotonergic pathways are associated with epileptogenesis mechanisms. It was not evidenced any association between serotonergic pathways and psychiatric comorbidities in this group of TLE-HS patients
182

O estudo de polimorfismos da via dopaminérgica na epilepsia do lobo temporal causada por esclerose hipocampal / The study of dopaminergic pathway polymorphisms in temporal lobe epilepsy caused by hippocampal sclerosis

Juliana Andrade Alcantara 04 October 2017 (has links)
Estudos clínicos nos pacientes com epilepsia mostram a importância da neurotransmissão modulada pela dopamina na epilepsia. Múltiplos fatores genéticos predispõem à epilepsia e há evidências de uma relação direta entre a epilepsia e as variações nos genes que codificam proteínas envolvidas na neurotransmissão dopaminérgica. O objetivo do nosso estudo foi investigar se os polimorfismos da via dopaminérgica e o Val66Met do BDNF estavam associados à ocorrência de epilepsia do lobo temporal causada por esclerose hipocampal. Para este fim, avaliamos 119 pacientes com epilepsia do lobo temporal causada por esclerose hipocampal e 113 voluntários saudáveis. Os participantes foram genotipados para os polimorfismos do gene DAT (3\'UTR e Intron 8), receptores dopaminérgicos (DRD2 e DRD4), COMT, MAO e BDNF (Val66Met). Não houve diferença entre pacientes e controles para os polimorfismos relacionados ao DAT, Íntron 8 VNTR (p 0,395) e 3\'UTR VNTR (p 0,614) e para a análise dos haplótipos (3\'UTR e Intron 8) (p 0.205). Não houve diferença entre pacientes e controles para os polimorfismos dos receptores dopaminérgicos DRD2 rs1800497 (p 0.440), DRD4 rs1800955 (p 0.548) e DRD4 VNTR (p 0.318). Não observamos diferença entre pacientes e controles quanto aos polimorfismos COMT rs4680 (p 0.482) e MAOA_uVNTR (p 0.753), metabolizadores de DA. Não observamos diferença na distribuição genotípica do polimorfismo Val66Met (rs6265) do BDNF (p 0,636) e a distribuição alélica (p 0.471) no grupo de pacientes com epilepsia do lobo temporal causada por esclerose do hipocampo. Nossos achados demonstraram que os polimorfismos da via dopaminérgica e BDNF Val66Met analisados neste estudo não parecem estar associados à epilepsia de lobo temporal causada por esclerose de hipocampo / Clinical studies in patients with epilepsy showed the role of neurotransmission modulated by dopamine in epilepsy. Multiple genetic factors predispose to epilepsy; there is evidence for a direct relationship between epilepsy and variations in genes encoding proteins involved in dopaminergic neurotransmission. The aim of our study was to investigate if the polymorphism related to the dopaminergic pathway and BDNF polymorphism Val66Met were associated with the occurrence of temporal lobe epilepsy caused by hippocampal sclerosis. We assessed 119 patients with unequivocal temporal lobe epilepsy caused by hippocampal sclerosis and 113 healthy volunteers. Individuals were genotyped for DAT gene polymorphisms (3\'UTR and Intron 8), dopaminergic receptors (DRD2 and DRD4), COMT, MAO and BDNF. There was no difference between patients and controls considering the polymorphisms related to DAT, Intron 8 VNTR (p 0,395) and 3\'UTR VNTR (p 0.614) and for the analysis of haplotypes (3\'UTR and Intron 8) (p 0.205). There was no difference between patients and controls considering the dopaminergic receptor polymorphisms DRD2 rs1800497 (p 0.440), DRD4 rs1800955 (p 0.548) and DRD4 VNTR (p 0.318). We observed no difference between patients and controls regarding COMT polymorphisms rs4680 (p 0.482) and MAOA_uVNTR (p 0.753), of dopaminergic metabolizers. We did not observe difference in the genotypic distribution of BDNF Val66Met polymorphism (rs6265) (p 0.636) and in the allelic distribution (p 0.4711) in the group with temporal lobe epilepsy caused by hippocampal sclerosis. Our findings suggest that the polymorphisms of the dopaminergic pathway evaluated in this study and BDNF Val66Me do not appear to be associated with temporal lobe epilepsy caused by hippocampal sclerosis
183

Cirurgia de epilepsia em pacientes com epilepsia do lobo temporal associada a esclerose hipocampal: uma comparação do prognóstico cognitivo com e sem ressecção do polo temporal / Epilepsy surgery in temporal lobe epilepsy associated with left hippocampal sclerosis: a comparison of cognitive outcome with or without temporal pole resection

Silva, Ana Carolina Gargaro 10 April 2019 (has links)
Sabe-se que a epilepsia do lobo temporal associada à esclerose hipocampal (ELT-EH) é uma síndrome epiléptica frequente e de difícil controle medicamentoso. Além disso, esta condição acarreta em uma série de prejuízos cognitivos aos seus portadores antes e após a cirurgia para tratamento das crisesrefratárias. Alguns trabalhos mostram que o prognóstico cognitivo pode mudar dependendo da abordagem cirúrgica realizada. Dessa forma, este trabalho teve como objetivo verificar qual o papel do polo temporal no funcionamento cognitivo. Para isso, foi realizada uma análise retrospectiva dos prontuários médicos de 146 pacientes adultos com ELT-EH esquerda, destros, avaliados no Centro de Cirurgia de Epilepsia (CIREP) do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP) - Universidade de São Paulo (USP). Os resultados mostraram um melhor desempenho na tarefa de nomeação por confronto visual nos pacientes que passaram por lobectomia temporal esquerda sem ressecção do polo (p=0.007). Quando realizada da análise do índicede mudança confiável (RCI) para verificar a relevância clínica dos achados, 39,4% dos pacientes que passaram pela cirurgia com ressecção do polo temporal mostraram uma piora significativa de desempenho no teste de nomeação por confronto visual no Boston Naming Test (BNT), enquanto apenas 16% dos que passaram pela cirurgia sem ressecção do polo mostraram piora significativa no mesmo teste (p=0.015). No entanto, este mesmo grupo mostrou um pior prognóstico de controle de crises quando comparado ao grupo com ressecção do polo (p=0.018). Assim, esses dadosindicam que o polo temporal pode estar envolvido em habilidades de nomeação. Nossos resultados sugerem, portanto, que a cirurgia para o tratamento das crises refratárias nos pacientes com ELT-EH esquerda poderiam considerar as diferenças individuais para decidir a melhor abordagem cirúrgica para cada paciente / It is known that the temporal lobe epilepsy (TLE) associated with hippocampal sclerosis (HS) is a frequent epileptic syndrome with difficult medication control. In addition, this condition leads to a series of cognitive impairments to patients before and after surgery for the treatment of refractory crises. Studies shown that cognitive prognosis may change depending on the surgical approach. Thus, this study aimed to verify the role of temporal pole in cognitive functions. A retrospective analysis of medical records from 146 adult patients with left-sided TLE-HS - evaluated at the Center for Epilepsy Surgery (CIREP) of the Clinical Hospital from Ribeirão Preto Medical School was performed. The results showed a higherperformance on visual confrontation namingtests - according to the Boston Naming Test (BNT) - in patients submitted to left temporal lobectomy without pole resection (p=0.007). Reliable change index (RCI)analysis, for clinical relevance,revealed that 39.4% of the patients submitted to temporal pole resectionshowed significantly worse performance on visual confrontation naming and only 16% of the patients without pole resection were significantly worse in the same test (p=0.015). However, this same group showed a worse prognosis of crisis control when compared to the group with pole resection (p=0.018). Altogether, the present study suggest that the temporal pole may be involved in naming skills. Our results suggest that surgery for left TLE-HS should be performed considering individual differences to decide the best surgical approach for each patient
184

Revisiting Cognitive and Neuropsychological Novelty Effects

Poppenk, Jordan 06 December 2012 (has links)
Recent proposals have attributed a key role to novelty in the formation of new episodic memories. These proposals are based on evidence of enhanced memory and greater metabolic activity in the hippocampus in response to novel relative to familiar materials. However, such novelty effects are incongruous with long-standing observations that familiar items and lists are associated with better memory than novel ones. In four experiments, I explored possible reasons for this apparent discrepancy. In Experiment 1, I directly tested whether previously observed novelty effects were the result of novelty, discrimination demands, or both. I used linguistic materials (proverbs) to replicate the novelty effect but found it occurred only when familiar items were subject to source confusion. In Experiment 2, to examine better how novelty influences episodic memory, I used experimentally familiar, pre-experimentally familiar, and novel proverbs in a paradigm designed to overcome discrimination demand confounds. Memory was better for both types of familiar proverbs. These cognitive results indicate that familiarity, not novelty, leads to better episodic memory for studied items, regardless of whether familiarity is experimentally induced or based on prior knowledge. I also conducted two fMRI experiments to evaluate the neural correlates of the encoding of novel and familiar forms of information. In Experiment 3, I compared the neural encoding correlates of source memory for novel and familiar visual scenes using fMRI. Replicating previous neuroimaging studies, I observed an anterior novelty-sensitive region of the hippocampus specialized in novelty encoding. Unlike past studies, I also probed for familiarity-encoding regions and identified such regions in the posterior hippocampus. I replicated this pattern in Experiment 4 using proverbs as stimuli. As in Experiment 2, I found the effect held whether familiarity was based on prior knowledge or experimental induction. In both fMRI experiments, anterior and posterior hippocampal regions were functionally connected with different large-scale networks, helping to explain local variation in hippocampal functional specialization in terms of different neural contexts. Together, these experiments show that stimulus familiarity enhances episodic memory for materials, and that novelty is processed differently, not preferentially, in the hippocampus. A new model of hippocampal novelty processing is proposed.
185

Revisiting Cognitive and Neuropsychological Novelty Effects

Poppenk, Jordan 06 December 2012 (has links)
Recent proposals have attributed a key role to novelty in the formation of new episodic memories. These proposals are based on evidence of enhanced memory and greater metabolic activity in the hippocampus in response to novel relative to familiar materials. However, such novelty effects are incongruous with long-standing observations that familiar items and lists are associated with better memory than novel ones. In four experiments, I explored possible reasons for this apparent discrepancy. In Experiment 1, I directly tested whether previously observed novelty effects were the result of novelty, discrimination demands, or both. I used linguistic materials (proverbs) to replicate the novelty effect but found it occurred only when familiar items were subject to source confusion. In Experiment 2, to examine better how novelty influences episodic memory, I used experimentally familiar, pre-experimentally familiar, and novel proverbs in a paradigm designed to overcome discrimination demand confounds. Memory was better for both types of familiar proverbs. These cognitive results indicate that familiarity, not novelty, leads to better episodic memory for studied items, regardless of whether familiarity is experimentally induced or based on prior knowledge. I also conducted two fMRI experiments to evaluate the neural correlates of the encoding of novel and familiar forms of information. In Experiment 3, I compared the neural encoding correlates of source memory for novel and familiar visual scenes using fMRI. Replicating previous neuroimaging studies, I observed an anterior novelty-sensitive region of the hippocampus specialized in novelty encoding. Unlike past studies, I also probed for familiarity-encoding regions and identified such regions in the posterior hippocampus. I replicated this pattern in Experiment 4 using proverbs as stimuli. As in Experiment 2, I found the effect held whether familiarity was based on prior knowledge or experimental induction. In both fMRI experiments, anterior and posterior hippocampal regions were functionally connected with different large-scale networks, helping to explain local variation in hippocampal functional specialization in terms of different neural contexts. Together, these experiments show that stimulus familiarity enhances episodic memory for materials, and that novelty is processed differently, not preferentially, in the hippocampus. A new model of hippocampal novelty processing is proposed.
186

Les bases cognitives et cérébrales du traitement sémantique des personnes célèbres : étude chez le jeune adulte et la personne âgée saine, atteinte de TCL, ou de dépression

Brunet, Julie 06 1900 (has links)
No description available.
187

Efeitos da dieta cetogênica à base de trienantina nos episódios convulsivos de ratos portadores de epilepsia induzida por pilocarpina / Effects of the ketogenic diet based on triheptanoin in sezures of rats with epilepsy induced by pilocarpine

Gomes, Tâmara Kelly de Castro 15 February 2011 (has links)
The main importance of temporal lobe epilepsy due to its high prevalence and high proportion of patients with refractory epilepsy to treatment, making it necessary in this case, the use of alternative therapies, such as the ketogenic diet. This diet is rich in fat, low in carbohydrates and proteins, and since 1921 has been used for patients unresponsive to medical therapy. This dissertation deals with the investigation of the effects of the ketogenic diet based on triheptanoin in epileptic seizures in rats and was developed in the form of two articles. The first article, The role of the ketogenic diet on oxidative stress occurring in epilepsy, presents a review of the relationship between oxidative stress and epilepsy, highlighting the possible beneficial effect of ketogenic diet in this context. Several results show that, in fact, this dietary method reduces oxidative stress markers. The second article, entitled Effects of ketogenic diet based on triheptanoin in seizures of rats with epilepsy induced by pilocarpine, describes the experimental study conducted in Wistar rats were divided into three groups, named according to the diet received, in control (standard diet AIN-93G), CetoTAGC7 (ketogenic based in triheptanoin; AIN-93G diet modified to contain 4% soybean oil, 25.79% of triheptanoin and 40% margarine) and CetoTAGsoja (ketogenic based in soybean; AIN-93G diet modified to contain 29.79% of soybean oil margarine and 40%). The ratio lipid: carbohydrate + protein ketogenic diets was 3.5:1 (control diet, 1:11,8) and experimental period lasted 19 days. It was found that the energy value of the share of feed intake and weight gain made by the three groups during the experimental period were not different (P> 0.05). There was no significant difference among the three groups regarding the ratio of feed efficiency (P> 0.05). The behavioral analysis showed no difference for the variable frequency of spontaneous recurrent seizures, however the duration of the attacks of animals belonging to the group triheptanoin was lower in the last experimental day. Future additional research are encouraged, therefore, the results of this study indicate, however modestly, to a potential beneficial effect of triheptanoin to control seizures, which could be investigated under different conditions, like a period longer than is tested by this protocol. / A principal importância da epilepsia do lobo temporal decorre de sua alta prevalência e elevada proporção de pacientes com crises epilépticas refratárias ao tratamento medicamentoso, fazendo-se necessário, neste caso, o uso de terapias alternativas, como a dieta cetogênica. Esta dieta é rica em lipídeos, pobre em carboidratos e proteínas e desde 1921 tem sido utilizada para pacientes não responsivos à terapia medicamentosa. A presente dissertação trata da investigação dos efeitos da dieta cetogênica à base de trienantina nos episódios convulsivos de ratos epilépticos e foi desenvolvida na forma de dois artigos. O primeiro artigo, O papel da dieta cetogênica no estresse oxidativo presente na epilepsia, apresenta uma revisão sobre a relação existente entre o estresse oxidativo e a epilepsia, destacando o possível efeito benéfico da dieta cetogênica neste contexto. Vários resultados atestam que, de fato, esta modalidade dietética diminui os marcadores de estresse oxidativo.O segundo artigo, intitulado Efeitos da dieta cetogênica à base de trienantina nos episódios convulsivos de ratos portadores de epilepsia induzida por pilocarpina, descreve o estudo experimental, realizado em ratos Wistar, subdivididos em três grupos, denominados, segundo a dieta recebida, em Controle (dieta padrão AIN-93G), CetoTAGC7 (cetogênico à base de trienantina; AIN-93G modificada para conter 4% de óleo de soja, 25,79% de trienantina e 40% de margarina) e CetoTAGsoja (cetogênico à base de soja; AIN-93G modificada para conter 29,79% de óleo de soja e 40% de margarina). A proporção lipídeos:carboidratos+proteína das dietas cetogênicas foi de 3,5:1 (dieta controle, 1:11,8) e o período experimental totalizou 19 dias. Verificou-se que o valor energético da cota de ração ingerida e o ganho de peso apresentado pelos três grupos, no período experimental, não foram diferentes (P>0,05). Não houve diferença significativa entre os três grupos, quanto ao coeficiente de eficiência alimentar (P>0,05). As análises comportamentais demonstraram que não houve diferença para a variável frequência de crises recorrentes espontâneas, entretanto a duração das crises dos animais pertencentes ao grupo da trienantina foi menor no último dia experimental. Pesquisas adicionais futuras são encorajadas, pois, os resultados do presente estudo apontam, ainda que modestamente, para um potencial efeito benéfico da trienantina no controle de crises epilépticas, que poderia ser investigado em condições diferentes, a exemplo de um período de tempo superior ao testado pelo presente protocolo de pesquisa.
188

Hypotalamo-hypofýzo-gonádová osa a epilepsie: vzájemné vztahy / The hypothalamic-pituitary-gonadal axis and epilepsy: mutual relationships

Čuchalová, Marcela January 2018 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Science Author: Marcela Čuchalová Supervisor: doc. MUDr. Josef Herink, DrSc. Title of diploma thesis: The hypothalamic - pituitary - gonadal axis and epilepsy: mutual relationships The content of the diploma thesis is an overview of the anatomy and physiology of the hypothalamic-pituitary-gonadal axis (HHG). Further chapters are devoted to the influence of epilepsy on HHG function, the effect of HHG hormones on epileptic activity itself. The effect of anti-epileptics on HHG functions will also be elucidated. The second part of the diploma thesis deals with separate chapters - catamenial epilepsy and epilepsy during pregnancy. Keywords: antiepileptic drugs, gonadotropin, hypothalamic-pituitary-gonadal axis, prolactin, sex hormones, temporal lobe epilepsy.
189

Estudo da ação da lovastatina no desenvolvimento do modelo experimental de epilepsia induzido pela pilocarpina em ratos / Study of lovastatin on development of experimental model of epilepsy induced by pilocarpine in rats

Gouveia, Telma Luciana Furtado [UNIFESP] 29 June 2011 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:50:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-29 / Introducao: A inflamacao tem sido relacionada a varias doencas neurodegenerativas e dados clinicos e experimentais sugerem uma funcao crucial nos processos inflamatorios no desenvolvimento da epilepsia, em particular, nos mecanismos geradores de crises (ictogenese) e na transformacao de uma rede neuronal normal a uma rede geradora de crises. A lovastatina, substancia usada na reducao da sintese do colesterol, tambem esta relacionada com a resposta inflamatoria, podendo modular a producao de citocinas e diminuir e o estresse oxidativo. Objetivos: O presente estudo teve como objetivo analisar a acao da lovastatina no desenvolvimento das diferentes fases do modelo de epilepsia, induzido por pilocarpina em ratos. Metodos: Ratos Wistar machos foram analisados nos 3 periodos do modelo da pilocarpina (350mg/kg) fases: aguda (24h), silenciosa (15 dias) e cronica (30 dias apos a 1.a crise espontanea) e para cada periodo do modelo usamos 4 grupos de animais: salina, lovastatina (Lova), pilocarpina (Pilo) e pilocarpina+lovastatina (Pilo+Lova). O tratamento com lovastatina (20 mg/kg) se iniciou 2 h apos o inicio do estado de mal epileptico e foi administrada por 15 dias, duas vezes ao dia nos animais do grupo silencioso e cronico. O cerebro foi processado para realizacao de PCR em tempo real e imuno-histoquimica de IL-1ƒÀ, IL-6, TNF-ƒ¿, IL-10, receptor B1 e B2 de cininas e quantificacao de aminoacidos no hipocampo. Alem disso, o tecido hipocampal foi processado para as tecnicas de Nissl e Neo-Timm modificado. Alem disso, foi medida a temperatura corporea na fase aguda, duracao do periodo silencioso e frequencia de crises na fase cronica. Resultados: O tratamento com a lovastatina no grupo Pilo+Lova mostrou diminuicao da expressao de RNAm e das proteinas IL-1ƒÀ e TNF-ƒ¿ nas 3 fases do modelo Notamos tambem reducao nos niveis do receptor B1 e B2 de cininas na fase aguda e de IL-6 nas fases aguda e silenciosa do modelo. Houve um aumento da expressão de IL-10 na fase crônica e não houve alteração nos níveis dos aminoácidos no hipocampo dos animais desse grupo, quando comparado ao grupo Pilo. Foi observada uma normalização da temperatura corpórea dos ratos submetidos ao SE e tratados com lovastatina. Não houve diferença significativa entre o grupo Pilo e Pilo+Lova na duração da fase silenciosa e na freqüência de crises. Foi observada uma preservação de neurônios em CA1 e também uma diminuição no brotamento de fibras musgosas no grupo Pilo+Lova, quando comparado ao grupo Pilo, na fase crônica do modelo. Conclusão: O presente estudo demonstrou que o tratamento com a lovastatina diminuiu diversos parâmetros importantes relacionados com o dano neuronal induzido pelo SE, no hipocampo de ratos nas diferentes fases do modelo experimental de epilepsia induzido pela pilocarpina. / Introduction: Inflammation has been associated with several neurodegenerative diseases and experimental and clinical data suggest a crucial role in inflammatory processes in the development of epilepsy, particularly in seizure-generating mechanisms (ictogenesis) and transformation of a normal neuronal network into a network generating seizures. Lovastatin, a drug used in the reduction of cholesterol synthesis, is also related to the inflammatory response and can modulate cytokine production reducing the oxidative stress. Objectives: This study aimed to analyze the action of lovastatin in different stages of development model of epilepsy induced by pilocarpine in rats. Methods: Male Wistar rats were analyzed in three periods of the pilocarpine-induced epilepsy (350mg/kg) into phases: acute (24h), silent (15 days) and chronic (30 days after the 1st spontaneous seizure) and for each period of this model we used 4 groups of animals: saline-treated, lovastatin (Lova), pilocarpine (Pilo) and pilocarpine + lovastatin (Pilo+ Lova). Treatment with lovastatin (20 mg / kg) begun 2 h after the onset of status epilepticus (SE) and was administered for 15 days, twice a day the animals in the silent and chronic phases. The brain was processed for performing real-time PCR and immunohistochemistry of IL-1ƒÀ, IL-6, TNF-ƒ¿, IL-10 and kinin B1 and B2 receptors and quantification of amino acids in the hippocampus. Besides, the hippocampal tissue was processed for Nissl techniques and Neo-Timm. In addition, body temperature was measured in the acute phase and the duration of the silent period and seizure frequency in chronic phase was analyzed. Results: Treatment with lovastatin in Pilo + Lova group showed decreased expression of mRNA and proteins IL-1ƒÀ and TNF-ƒ¿ in the three phases of this model, We also noted reduction of kinin B1 and B2 receptor in the acute and IL-6 into acute and silent periods. There was an increased expression of IL-10 in the chronic phase of this model. There was no change in amino acids levels in the hippocampus of rats from Pilo+Lova group when compared to Pilo group. We observed a normalization of body temperature of rats subjected to SE and treated with lovastatin. There was no significant difference between the group Pilo and Pilo + Lova on the duration of the silent phase and in seizure frequency. We observed a preservation of neurons in CA1 and also a reduction of mossy fiber sprouting in Pilo+ Lova group as compared to the Pilo group in the chronic phase of the model. Conclusion: This study demonstrated that treatment with lovastatin decreased number of important parameters related to the neuronal damage induced by SE in the hippocampus of rats at different stages of the experimental model of epilepsy induced by pilocarpine. / TEDE / BV UNIFESP: Teses e dissertações
190

2,2 -DISSELENETO DE DITIENILA, UM COMPOSTO ORGÂNICO DE SELÊNIO COM ATIVIDADE ANTIOXIDANTE E NEUROPROTETORA EM RATOS / 2,2 -DITHIENYL DISELENIDE, AN ORGANOSELENIUM COMPOUND WITH ANTIOXIDANT AND NEUROPROTECTIVE ACTIVITIES IN RATS

Bortolatto, Cristiani Folharini 02 March 2012 (has links)
Oxidative stress has been implicated in the pathophysiology of several neurological diseases since the brain is an organ highly susceptible to oxidative damage. Temporal lobe epilepsy (TLE) has been widely studied due to the high prevalence rate and refractoriness to drug treatment. In addition, the ELT can be associated with psychiatric comorbidities, such as depression. Since many organoselenium compounds have antioxidant and neuroprotective properties, this study investigated the effects of 2,2'-dithienyl diselenide (DTDS) on seizures induced by kainic acid (KA), an experimental model of TLE, as well as its antioxidant potential in vitro and antidepressant-like activity in rats. The results showed that DTDS (100 mg/kg, per oral) reduced seizures induced by KA administration (10 mg/kg, intraperitoneal), which were demonstrated by behavioral tests and electroencephalographic analysis. The increase in the hippocampal content of reactive species and protein carbonylation as well as the stimulation of Na+ K+ ATPase activity caused by KA were reduced by DTDS (50 and 100 mg/kg). In addition, DTDS (100 mg/kg) protected against hippocampal degeneration resulting from exposure of rats to KA. DTDS, at low concentrations (μM range), reduced the content of reactive species, protein carbonylation and lipid peroxidation in rat brain homogenate in vitro and presented mimetic properties to dehydroascorbate (DHA) reductase and glutathione Stransferase (GST), important enzymes for antioxidant function. The results also revealed that DTDS was effective in inhibiting the activity of monoamine oxidase (MAO) A and B in rat brain homogenate in vitro (25-100 μM) and in causing a reduction on immobility time of rats in the forced swimming test (FST) (50 and 100 mg/kg, per oral). These findings suggest that DTDS produced an anticonvulsant action in the KA model and attenuated the subsequent oxidative damage and neuronal loss in hippocampus. Furthermore, the data showed that DTDS had antioxidant and MAO non-selective inhibitor effects in rat brain in vitro and antidepressant-like action in rats. Therefore, DTDS may be useful as a therapy for the treatment of comorbidity ELT/depression. / O estresse oxidativo tem sido implicado na patofisiologia de diversas doenças neurológicas uma vez que o cérebro é um órgão altamente susceptível ao dano oxidativo. A epilepsia do lobo temporal (ELT) tem sido amplamente estudada devido à alta taxa de prevalência e refratariedade ao tratamento medicamentoso. Além disso, a ELT pode estar associada com comorbidades psiquiátricas, tais como a depressão. Tendo em vista que muitos compostos orgânicos de selênio apresentam propriedades antioxidantes e neuroprotetoras, este trabalho investigou os efeitos do 2,2 -disseleneto de ditienila (DSDT) sobre as convulsões induzidas por ácido caínico (KA), um modelo experimental de ELT, bem como seu potencial antioxidante in vitro e atividade do tipo antidepressiva em ratos. Os resultados mostraram que o DSDT (100 mg/kg, via oral) reduziu as convulsões induzidas pela administração de KA (10 mg/kg, intraperitoneal), as quais foram demonstradas a partir de testes comportamentais e análise eletroencefalográfica. O aumento do conteúdo hipocampal de espécies reativas e de carbonilação de proteínas bem como a estimulação da atividade da Na+ K+ ATPase causados pelo KA foram reduzidos por DSDT (50 e 100 mg/kg). Além disso, o DSDT (100 mg/kg) protegeu contra a degeneração hipocampal resultante da exposição de ratos ao KA. O DSDT em baixas concentrações (na faixa de μM) reduziu o conteúdo de espécies reativas, carbonilação de proteínas e peroxidação lipídica em homogenato de cérebro de ratos in vitro e apresentou propriedades miméticas à deidroascorbato (DHA) redutase e à glutationa Stransferase (GST), enzimas importantes para a função antioxidante. Os resultados também revelaram que o DSDT foi efetivo em inibir a atividade da monoamino oxidase (MAO) A e B em homogenato de cérebro de ratos in vitro (25-100 μM) e em causar uma redução no tempo de imobilidade de ratos no teste do nado forçado (TNF) (50 e 100 mg/kg, via oral). Estes achados sugerem que o DSDT produziu uma ação anticonvulsivante no modelo do KA e atenuou o subseqüente dano oxidativo e a perda neuronal em hipocampo. Além disso, os dados mostraram que o DSDT teve efeito antioxidante e inibidor não-seletivo da MAO em cérebro de ratos in vitro bem como ação do tipo antidepressiva em ratos. Portanto, o DSDT pode ser útil como uma terapia para o tratamento da comorbidade ELT/depressão.

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