• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 40
  • 29
  • 5
  • 4
  • 3
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 94
  • 42
  • 30
  • 19
  • 18
  • 17
  • 14
  • 10
  • 9
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • 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.
51

Behavioral outcomes and molecular marker modulation during learning and memory formation following developmental exposure to organophoshorus insecticides

Johnson, Frank Orlando, January 2007 (has links)
Thesis (Ph.D)--Mississippi State University. College of Veterinary Medicine. / Title from title screen. Includes bibliographical references.
52

Assessing the Safety of Cholinesterase Inhibitor Discontinuation in Patients with Moderate to Severe Alzheimer’s Disease in a Long Term Care Setting

O'Regan, Jordana 19 March 2014 (has links)
Cholinesterase inhibitors (ChEIs) are the first line pharmacotherapy for the symptoms of Alzheimer’s disease (AD). Though ChEIs offer modest cognitive benefits in early AD, literature addressing their continued use in severe AD is scarce. This study assessed the safety of discontinuing ChEIs in institutionalized moderate-severe AD patients. Twenty-six patients were randomized, double-blind to ChEI continuation or placebo for 8-weeks. Vitals, weight (kg) and adverse events (AEs) were monitored biweekly. Chi-square test revealed no significant association between semi-blinded treatment allocation and AE occurrence (χ²=(1,26)=0.99, p=0.32). Groups showed no differences on clinically significant weight loss (χ²=(1,26) =1.9, p=0.17), mean weight loss (F=.531, p= .473), pulse rate (F=.624, p=.437), or side effects (F=.224, p=.640). Preliminary results suggest that either ChEIs are well tolerated or that these drugs are no longer providing therapeutic benefit. Study completion (recruitment of 60 patients and unblinding) will generate more comprehensive data for determination of safe ChEI discontinuation guidelines.
53

Assessing the Safety of Cholinesterase Inhibitor Discontinuation in Patients with Moderate to Severe Alzheimer’s Disease in a Long Term Care Setting

O'Regan, Jordana 19 March 2014 (has links)
Cholinesterase inhibitors (ChEIs) are the first line pharmacotherapy for the symptoms of Alzheimer’s disease (AD). Though ChEIs offer modest cognitive benefits in early AD, literature addressing their continued use in severe AD is scarce. This study assessed the safety of discontinuing ChEIs in institutionalized moderate-severe AD patients. Twenty-six patients were randomized, double-blind to ChEI continuation or placebo for 8-weeks. Vitals, weight (kg) and adverse events (AEs) were monitored biweekly. Chi-square test revealed no significant association between semi-blinded treatment allocation and AE occurrence (χ²=(1,26)=0.99, p=0.32). Groups showed no differences on clinically significant weight loss (χ²=(1,26) =1.9, p=0.17), mean weight loss (F=.531, p= .473), pulse rate (F=.624, p=.437), or side effects (F=.224, p=.640). Preliminary results suggest that either ChEIs are well tolerated or that these drugs are no longer providing therapeutic benefit. Study completion (recruitment of 60 patients and unblinding) will generate more comprehensive data for determination of safe ChEI discontinuation guidelines.
54

Cholinesterase Inhibitors: A population-based assessment of resource utilization for patients with Alzheimer's dementia in Ontario

FONG, RAYMOND 02 November 2011 (has links)
Background: Dementia leads to progressive cognitive and functional decline. Population aging is a concern, and the healthcare system must refocus its limited resources to keep up with service demands. Three cholinesterase inhibitors (ChEIs) – donepezil, galantamine and rivastigmine – have been approved for the treatment of dementia and are covered under Ontario’s formulary plan, but there has been little research regarding their economic impact. Methods: The purpose of this study was to describe the patterns of use of ChEIs, and to assess associated health resource utilization and costs to Ontario’s healthcare system. Anonymized patient-level data from seven provincial administrative databases were linked at the Institute for Clinical and Evaluative Sciences at Queen’s University. First-time users of ChEIs aged 66 years and older were identified between April 1st, 2004 and March 31st, 2009, and were followed until treatment discontinuation or up to one year following their index date. Health resource use was classified into six care categories: prescription drugs, physicians, long-term care, home care nursing, emergency department, and hospitalizations. Chi-square, Kruskal-Wallis ANOVA and linear regression were employed to compare resource use between users of the three ChEIs. Results: In the cohort (N=40,057), the majority were prescribed donepezil (n=24,347), were female (60.5%) and had at least one other co-morbid disease. The odds of discontinuation were 1.47 (1.36, 1.60) and 1.26 (1.17, 136), higher for rivastigmine users than galantamine and donepezil users, respectively. Between 2005 and 2008, overall healthcare costs increased from $95.2 million to $106.1 million. Prescription drugs comprised 33% of all healthcare costs. ChEIs accounted for half of all prescription drug costs. Overall mean annual healthcare system cost per patient was $12,679.47 ($12,510.86, $12,848.08). Predictors of overall healthcare costs included long-term care, co-morbidity status, hospitalization and hip fractures. Conclusions: Prescription drugs account for a substantial proportion of healthcare costs for patients with dementia, and the amount attributable to ChEIs alone is significant. Knowing the health service utilization patterns for dementia patients can help healthcare professionals and decision-makers plan patient care and timely resource allocation. The results stress the utility of administrative databases and the need for further research for this disease. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2011-11-01 15:49:58.417
55

Novel pharmacological treatment alternatives for schizophrenia /

Wiker, Charlotte, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.
56

Purificação parcial de colinesterase de prochilodus brevis para emprego biotecnológico / Partial Purification of Cholinesterase of Prochilodus brevis for Biotechnological Application

Leoncini, Giovanni Ortiz 31 May 2016 (has links)
The cholinesterase (ChE) play an important role in the organophosphates and carbamates detection substances that are of high interest for environmental control, because these compounds are present in most pesticides applied to crops. The development of ChE biosensors to detect these contaminants with greater speed, sensitivity and selectivity, has the ability to quantify from a suitable transducer, the reduction of enzyme activity caused by contaminants. This study aimed to purify and characterize AChE of Prochilodus brevis brain for use in electrochemical tests. Gradients of pH, ionic strength and temperature, showed high activities in pH 8,5, 0,08M at ionic strength, 28Cº of temperature optimum and 37ºC of thermal stability for cell-free extract. Was applied salting out method in fractions 0-70% followed by 0-40% of (NH4)2SO4 as a refinement to liquid chromatography. The purification protocol 1 showed specific activity of 1.41 U/mg in 0-70% and 0-40% was 1.94 U/mg. The purification protocol 2, the 0-70% fraction had specific activity of 0.31 U/mg and 0-40% with 1.77 U/mg. After Sephacryl S-200 chromatography, showed specific activity for protocols 1 and 2 of 0,128U/mg and 0.2869 U/mg, respectively. The next stage of the Protocol 2 with DEAE-Sepharose was eluted peak with specific activity of 0.01326 U/mg. In the purification protocol 3, 0-70% have specific activity 0.310 U / mg, followed by 1,774 U/mg in 0-40%. After Sephacryl S-100, was obtain two peaks with a specific activity of 0.194 U/mg (ChE1) and 0.0873 U/mg (ChE2). SDS-PAGE of ChE 1 showed somewhat visible band of approximately 67kDa. Inhibition assays with ChE 1 had higher specificity for BW 284c51. Electrochemical tests with cell-free extract, dialyzed, ChE1 and ChE2, showed thiocholine (TCh) oxidation with better limits of detection and quantification limits for ChE1 and ChE2. The molecular modeling experiments showed favorable results in complex formation ChE-NTCPM. The study showed the isolation of ChE with catalytic activity for both enzymes, AChE and BuChE, with favorable adsorption properties in NTCPM in the development of enzymatic biosensor for environmental monitoring. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / As colinesterases (ChE) desempenham um papel importante na detecção de organofosforados e carbamatos que são substâncias de alto interesse para o controle ambiental, pois estes compostos estão presentes na maioria dos pesticidas aplicados em lavouras. O desenvolvimento de biossensores a base de ChE para a detecção destes contaminantes com maior rapidez, sensibilidade e seletividade, tem a capacidade de quantificar, a partir de um transdutor adequado, a diminuição da atividade enzimática causada pelos contaminantes. Este trabalho teve como objetivo de purificar e caracterizar AChE de cérebro de Prochilodus brevis para o emprego em testes eletroquímicos. Os gradientes de pH, força iônica e temperatura, mostraram maiores atividades em pH 8,5, força iônica de 0,08M, temperatura ótima 28°C e estabilidade térmica de 37°C para extrato livre de células. Foi aplicado o método de precipitação salina em frações de 0-70% seguido de 0-40% de (NH4)2SO4 como refinamento para cromatografia líquida. O protocolo de purificação 1 apresentou atividade específica de 1,41 U/mg em 0-70%, enquanto 0-40% apresentou 1,94 U/mg. O protocolo de purificação 2, a fração 0-70% teve atividade específica de 0,31 U/mg e 0-40% de 1,77 U/mg. Após a cromatografia de sephacryl S-200 apresentou atividade específica para os protocolos 1 e 2 de 0,128U/mg e 0,2869 U/mg, respectivamente. Na continuidade do protocolo 2 com DEAE-sepharose o pico eluído apresentou atividade específica de 0,01326 U/mg. No protocolo de purificação 3, 0-70% tem atividade específica 0,310 U/mg, seguido de 1,774 U/mg em 0-40%. Após Sephacryl S-100 foi obtido dois picos com atividade específica de 0,194 U/mg (ChE1) e 0,0873 U/mg (ChE2). Eletroforese SDS-PAGE de ChE1 apresentou banda pouco visível de aproximadamente 67KDa. Os ensaios de inibição com ChE1 apresentaram maior especificidade para BW 284c51. Os testes eletroquímicos com extrato livre de célula, dialisado, ChE1 e ChE2, mostraram oxidação de tiocolina (TCh) com melhores limites de detecção e quantificação para ChE1 e ChE2. Os experimentos de modelagem molecular apresentaram resultados favoráveis na formação do complexo ChE-NTCPM. O estudo mostrou o isolamento de ChE com atividade catalítica para as duas enzimas, AChE e BuChE, com propriedades de adsorção favoráveis em NTCPM no desenvolvimento de biossensor enzimático para monitoramento ambiental.
57

Influência da neuromodulação parassimpática durante a indução da periodontite em camundongos / Influence of parasympathetic neuromodulation during periodontitis induction in mice

Santana, Juliana Bueno [UNESP] 22 February 2016 (has links)
Submitted by JULIANA BUENO SANTANA null (juli_bsantana@hotmail.com) on 2016-05-05T15:29:58Z No. of bitstreams: 1 Dissertação final.pdf: 1846480 bytes, checksum: 4a7009afba6cc2b58f17ba4282681092 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-09T13:47:58Z (GMT) No. of bitstreams: 1 santana_jb_me_sjc.pdf: 1846480 bytes, checksum: 4a7009afba6cc2b58f17ba4282681092 (MD5) / Made available in DSpace on 2016-05-09T13:47:58Z (GMT). No. of bitstreams: 1 santana_jb_me_sjc.pdf: 1846480 bytes, checksum: 4a7009afba6cc2b58f17ba4282681092 (MD5) Previous issue date: 2016-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A doença periodontal (DP) é uma das infecções mais comuns dos seres humanos e é caracterizada pela destruição dos tecidos de suporte dentários, incluindo o osso alveolar. Recentemente tem sido demonstrado que a regulação sistêmica da remodelação óssea é feita também por duas ramificações do Sistema Nervoso Autônomo: a simpática, que favorece a perda óssea, e a parassimpática, que favorece o acréscimo de massa óssea. O objetivo desse trabalho foi verificar, através da administração de inibidores da acetilcolinesterase, o efeito da neuromodulação parassimpática na DP induzida e no tecido ósseo em camundongos. Foram utilizados 40 camundongos machos, divididos em 4 grupos: (1) Grupo Galantamina (G), dez animais com DP induzida e tratados com 3 mg/Kg/dia de Galantamina; (2) Grupo Donepezil (D), dez animais com DP induzida e tratados com 2 mg/Kg/dia de donepezil; (3) Grupo Ligadura (L), dez animais com DP induzida; e (4) Grupo Controle (C). A indução da doença periodontal foi realizada com a inserção de fio de algodão ao redor dos primeiros molares inferiores e o tratamento durou 42 dias. No dia do sacrifício, amostras de sangue foram coletadas para análise sorológica do fator nuclear κB ligante (RANKL) e osteoprotegerina (OPG). As hemimandíbulas esquerdas foram submetidas à análise histomorfométrica e os fêmures esquerdos, ao teste de flexão em três pontos para avaliação das propriedades extrínsecas e intrínsecas. O uso dos medicamentos não reduziu a perda óssea alveolar dos grupos tratados. Também não foram observadas diferenças estatísticas significantes com relação às propriedades biomecânicas dos fêmures ou à concentração sérica de RANKL e OPG. Concluímos que a galantamina e o donepezil, nas doses e período utilizados, não influenciaram a patogênese da DP ou a remodelação óssea sistêmica. / Periodontal disease (PD) is one of the most common infections of human beings, and it is characterized by destruction of tooth supporting tissues, including alveolar bone. Recently it has been shown that the systemic regulation of bone remodeling is also made by two branches of the autonomic nervous system: the sympathetic, favoring bone loss and the parasympathetic, which promotes increase of bone mass. The aim of this study was to verify, through the administration of acetylcholinesterase inhibitors, the effect of parasympathetic neuromodulation in induced periodontitis and bone tissue in mice. Forty male mice were divided into 4 groups: (1) Group Galantamine (G), ten animals with induced PD and treated with 3 mg/ kg/day of galantamine; (2) Donepezil group (D), ten animals with induced PD and treated with 2 mg/kg/day of donepezil; (3) Ligature group (L), ten animals with induced PD; and (4) control group (C). The induction of periodontal disease was carried out with a cotton thread insertion around the lower first molars and the treatment lasted 42 days. On the day of sacrifice, animalsblood samples were collected for serological analysis of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG). The left hemimandibles were submitted to histomorphometric analysis and the left femur to the three point bending test for assessment of extrinsic and intrinsic properties. The use of the drugs did not reduce alveolar bone loss in treated groups. No statistically significant differences regarding the biomechanical properties of femurs or serum RANKL and OPG were observed. We conclude that galantamine and donepezil, at doses and time used, did not influence the pathogenesis of PD or systemic bone remodeling. / CNPq: 459759/2014-0
58

AVALIAÇÃO DOS SISTEMAS PURINÉRGICO E COLINÉRGICO NO PROCESSO INFLAMATÓRIO DE PACIENTES COM SÍNDROME METABÓLICA / ASSESSMENT OF PURINERGIC AND CHOLINERGIC SYSTEMS IN INFLAMMATORY PROCESS OF METABOLIC SYNDROME PATIENTS

Martins, Caroline Curry 28 August 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Metabolic syndrome (MetS) is characterized by the presence of set cardiovascular risk factors such as hypertension, hyperglycemia, dyslipidemia and abdominal obesity. This pathology has been widely discussed due to the impact of cardiovascular disease (CVD), has been a concern for public health. In addition to the classic risk factors of this syndrome, has been indicated the presence of a low-grade chronic inflammation in their patients, which is considered a key point in the development of atherosclerosis and CVD. Some inflammatory markers has been used in order to diagnose cardiovascular asymptomatic patients at risk, as the levels of C-reactive protein (CRP) and uric acid and the activity of myeloperoxidase enzyme (MPO). In addition, studies have shown close relation of the purinergic and cholinergic systems in control of the inflammatory process. The ATP molecule has been considered a pro-inflammatory, while adenosine, which is the end product of ATP hydrolysis, appears to play protective action and anti-inflammatory. Acetylcholine (ACh), in turn, performs anti-inflammatory functions to inhibit secretion of cytokines by immune cells. In this context, the objective of this study was to investigate in serum and lymphocytes of 20 patients with MetS, the activity of the enzymes nucleoside triphosphate diphosphohydrolase (NTPDase), ectonucleotídeo pyrophosphatase / phosphodiesterases (E-NPP), adenosine deaminase (ADA), which control ATP and adenosine extracellular levels, and to analyze the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes, which control the extracellular ACh level in order to effect the purinergic and cholinergic systems in patients with inflammatory action MetS. The results showed a decreased activity of the enzymes NTPDase and ADA in lymphocytes from patients with MetS. Moreover, we observed an increase in activity of the E-NPP and ADA in the serum of these patients. In addition, an increase in activity of both cholinesterase AChE and BuChE was observed in lymphocytes and serum, respectively. Finally, patients with MetS showed higher levels of CRP and uric acid as well as increased activity of MPO. Thus, the present results show the presence of an inflammatory state in patients with MetS by both the increase in inflammatory markers classics, and by immunomodulation triggered by purinergic and cholinergic systems. The lower activity of NTPDase in lymphocytes results in increased availability of extracellular ATP to stimulate inflammation and to influence the activity of other enzymes purinergic. Likewise, the high cholinesterase activities results in decreased availability of ACh extracellular, reducing the anti-inflammatory cholinergic effect. Thus, one may indicate that the purinergic and cholinergic systems have important effects in modulating the inflammatory process present in MetS, and the parameters mentioned in this research can useful in clinical medicine, to monitor the disease. / A Síndrome Metabólica (SMet) caracteriza-se pela presença de um conjunto de fatores de risco cardiovasculares, como hipertensão, hiperglicemia, dislipidemia e obesidade abdominal. Essa patologia tem sido amplamente discutida em virtude do impacto das doenças cardiovasculares (DCVs), já sendo uma preocupação em termos de saúde pública. Além dos fatores de riscos clássicos dessa síndrome, indica-se a presença de uma inflamação crônica de baixo grau nos seus portadores, a qual é considerada ponto chave no desenvolvimento de aterosclerose e de DCVs. Alguns marcadores inflamatórios têm sido utilizados com o intuito de diagnosticar pacientes assintomáticos sob risco cardiovascular, como os níveis de proteína C-reativa (PCR) e de ácido úrico, bem como a atividade da enzima mieloperoxidase (MPO). Além disso, pesquisas têm demonstrado estreita relação dos sistemas purinérgico e colinérgico com o controle do processo inflamatório. O ATP tem sido considerado uma molécula pró-inflamatória, enquanto que a adenosina, produto final da hidrólise do ATP, parece desempenhar ações protetoras e anti-inflamatórias. A acetilcolina (ACh), por sua vez, desempenha funções anti-inflamatórias por inibir a secreção de citocinas pelas células imunes. Nesse contexto, o objetivo deste trabalho foi verificar, em soro e linfócitos de 20 pacientes com SMet, a atividade das enzimas nucleotídeo trifosfato difosfoidrolase (NTPDase), ectonucleotídeo pirofosfatase/fosfodiesterases (E-NPP), adenosina desaminase (ADA), as quais controlam os níveis de ATP e adenosina extracelulares, assim como analisar a atividade das enzimas acetilcolinesterase (AChE) e butirilcolinesterase (BuChE), as quais controlam o nível extracelular de ACh, tendo em vista o efeito dos sistemas purinérgico e colinérgico nas ações inflamatórias dos pacientes com SMet. Os resultados obtidos demonstraram uma diminuição da atividade das enzimas NTPDase e ADA em linfócitos de pacientes com SMet. Por outro lado, observou-se um aumento na atividade da E-NPP e ADA em soro desses pacientes. Em adição, um aumento na atividade de ambas as colinesterases AChE e BuChE foi observado em linfócitos e soro , respectivamente. Além disso, os pacientes com SMet apresentaram níveis maiores de PCR e ácido úrico, bem como maior atividade da enzima MPO. Com isso, os resultados deste trabalho evidenciam a presença de um estado inflamatório nos pacientes com SMet tanto pelo aumento dos marcadores inflamatórios clássicos, quanto pela imunomodulação desencadeada pelos sistemas purinérgico e colinérgico. A menor atividade da NTPDase em linfócitos resulta em maior disponibilidade de ATP extracelular para estimular a inflamação, influenciando a atividade das demais enzimas purinérgicas. Da mesma forma, uma maior atividade das colinesterases resulta em menor disponibilidade de ACh extracelular, diminuindo o efeito colinérgico anti-inflamatório. Dessa forma, pode-se indicar que os sistemas purinérgico e colinérgico apresentam importantes efeitos na modulação do processo inflamatório presente na SMet, podendo ser úteis na clínica médica e no monitoramento da patologia.
59

Efeito da N-acetilcisteína no déficit cognitivo induzido pela estreptozotocina em camundongo / N-acetylcysteine effect on the cognitive defict induced by streptozotocin in mice

Costa, Michael Daniel da 15 July 2016 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Cognitive impairment is a mental disorder which is associated with neurodegenerative diseases such as Alzheimer's disease (AD), which is the most common form of dementia. Currently there are no consistent evidence who allow support any measure for the prevention of this disease (DAVIGLUS et al., 2010). As for its treatment, there are methods which can provide relative relief of the symptoms, however, only of palliative nature. Thus, this study aimed to evaluate the n-acetylcysteine (NAC), a molecule with neuroprotective properties, in the treatment and prevention of subsequent dementia of AD, using an experimental model of dementia induced by streptozotocin (STZ) in mice. Initially the effect of NAC on the activity of acetylcholinesterase (AChE) activity in vitro mouse brain was evaluated. The ideal dithiobisnitrobenzoate (DTNB) concentration and pH was 0.3 mM and 7.4, respectively. Linearity in enzyme activity was obtained at acetylthiocholine (ATCh) concentrations ranging from 0.025 to 0.450 mM. Sixty sec prior to the addition of ATCh range to avoid interference DTNB NAC interaction was added to the method. NAC interfered with AChE Vmax starting at the concentration of 75 uM without affecting the Km, featuring a non-competitive inhibition. In a second instance, we evaluated the NAC effect on the short-term cognitive impairment in mice. For this, the animals were divided into four groups and were treated with NAC (50 mg/kg /day v.o.) or saline for nine consecutive days, and with STZ (2.5 mg/kg i.c.v.) or aCSF at the first and third days. The results show that NAC treatment: 1) normalized the latency to find the platform in the water maze (MWM) and to get off the platform in passive avoidance (SDPA) that had been altered in animals that received STZ; 2) normalized the AChE and butyrylcholinesterase (BChE) and restored the acetylcholine (ACh) levels in cortical and hippocampal enzymatic activity potentiated by STZ; 3) protected the brain energy metabolism imbalance induced by STZ. Finally, we evaluated the effect of NAC on the long-term cognitive impairment in mice. To this end, animals were treated with NAC (5 mg/kg/day v.o.) or saline for 30 consecutive days, and with STZ (2.5 mg/kg i.c.v.) or aCSF the first and third days. A treatment with physostigmine (PHY; 0.25 mg / kg / day V.O.) was done in parallel as a positive control measure. Totalizing six groups. Both treatments with NAC and PHY: 1) reduced the latency to find the platform in the water maze (MWM) and increased exploratory time on the new object task (NOR) of those animals that received STZ; 2) normalized the cortical and hippocampal AChE enzymatic activity enhanced by STZ; 3) rescued the synaptic plasticity, recovering the synaptophysin (SYN), microtubule-associated protein type 2 (MAP2) and glial fibrillary acidic protein (GFAP) levels reduced by STZ. Thus, the NAC treatment protected from the cognitive impairment induced by STZ in mice, normalizing the cholinergic activity and reestablishing synaptic plasticity. / O déficit cognitivo é uma desordem mental que está associado a doenças neurodegenerativas, como é a doença de Alzheimer (DA) a qual é a forma mais comum de demência. Atualmente não existem evidências consistentes quem permitam apoiar qualquer medida para a prevenção desta doença (DAVIGLUS e col., 2010). Já para o seu tratamento, existem métodos os quais proporcionam alívio relativo dos sintomas, contudo, de natureza paliativa1. Assim, o presente trabalho visou avaliar a n-acetilcisteína (NAC), uma molécula com propriedades neuroprotetora, no tratamento e prevenção da demência consequente da DA, utilizando-se de um modelo experimental de demência induzida pela estreptozotocina (STZ) em camundongos. Inicialmente avaliou-se o efeito da NAC sobre a atividade da acetilcolinesterase (AChE) cerebral de camundongos in vitro. A concentração de ditiobisnitrobenzoato (DTNB) e pH ideais foi de 0,3 mM e 7,4, respectivamente. Obteve-se linearidade na atividade enzimática com concentrações de 0,025 a 0,450 mM de acetiltiocolina (ATCh). Foram adicionados 60 sec de intervalo prévios à adição da ATCh para evitar a interferência da interação DTNB-NAC. A NAC interferiu na Vmax da AChE a partir da concentração de 75 μM sem modificar a Km, caracterizando uma inibição de forma não-competitiva. Em uma segunda instância, avaliou-se o efeito da NAC sobre o déficit cognitivo a curto prazo em camundongos. Para isso, os animais foram divididos em quatro grupos e foram tratados com NAC (50 mg/kg/dia v.o.) ou salina por nove dias consecutivos e com STZ (2.5 mg/kg i.c.v.) ou FCEa no primeiro e terceiro dias. Os resultados mostram que o tratamento com NAC: 1) diminuiu a latência para achar a plataforma no labirinto aquático (MWM) e aumentou a latência para descer da plataforma na esquiva passiva (SDPA) dos animais que apresentaram-se alteradas nos animais que receberam STZ; 2) restaurou a atividade enzimática da AChE e butirilcolinesterase (BChE) e os níveis de acetilcolina (ACh) corticais e hipocampais potencializadas pela STZ; e 3) protegeu do desequilíbrio do metabolismo energético cerebral induzido pela STZ. Finalmente, foi avaliado o efeito da NAC sobre o déficit cognitivo a longo prazo em camundongos. Para tal, os animais foram tratados com NAC (5 mg/kg/dia v.o.) ou salina por 30 dias consecutivos e com STZ (2.5 mg/kg i.c.v.) ou FCEa no primeiro e terceiro dias. Um tratamento com fisostigmina (PHY; 0,25 mg/kg/dia v.o.) foi realizado em paralelo como medida de controle positivo. Totalizando assim seis grupos. Ambos os tratamentos com NAC e PHY: 1) diminuíram a latência para achar a plataforma no labirinto aquático (MWM) e aumentaram o tempo de exploração no novo objeto (NOR) que apresentaram-se alteradas nos animais que receberam STZ; 2) normalizaram a atividade enzimática da AChE cortical e hipocampal potencializada pela STZ; 3) resgataram a plasticidade sináptica, recuperando os níveis de sinaptofisina (SYN), proteína associada aos microtúbulos do tipo 2 (MAP2) e proteína ácida fibrilar glial (GFAP) diminuídas pela STZ. Desta forma, o tratamento com NAC protegeu do déficit cognitivo induzido pela STZ em camundongos, normalizando a atividade colinérgica e reestabelecendo a plasticidade sináptica.
60

Modelagem MIA-QSAR de inibidores de acetilcolinesterase = MIA-QSAR modeling of inhibitors actylcholinesterase / MIA-QSAR modeling of inhibitors actylcholinesterase

Bitencourt, Michelle, 1985- 09 April 2012 (has links)
Orientador: Roberto Rittner Neto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T10:40:13Z (GMT). No. of bitstreams: 1 Bitencourt_Michelle_M.pdf: 771721 bytes, checksum: 1771939b9c0680c7375ae9953fca996f (MD5) Previous issue date: 2012 / Resumo: O presente trabalho trata de um estudo sobre compostos que se comportam como inibidores da acetilcolinesterase, uma importante enzima do processo de cognição. A acetilcolinesterase atua na hidrólise da acetilcolina, responsável pela comunicação entre os neurônios. Uma das modalidades para o design racional de fármacos é a estimativa de propriedades biológicas de novas moléculas utilizando métodos computacionais. Análise quantitativa entre estrutura química e atividade biológica (QSAR) é uma dessas técnicas. No presente trabalho, análise multivariada de imagens aplicada em QSAR (MIA-QSAR) foi utilizada para se construírem modelos QSAR preditivos para uma série congênere de carbamatos com atividade anticolinesterásica. Os bons resultados estatísticos da modelagem credenciaram o modelo MIA-QSAR construído a predizer a atividade biológica de alguns novos derivados, potencialmente úteis para o tratamento do Mal de Alzheimer / Abstract: The present work describes the study of some compounds which act as acetylcholinesterase inhibitors a very important enzyme in the cognitive process. zAcetylcholinesterase is responsible by the hydrolysis of acetylcholine, which accounts for the communication among the neurons. One of the approaches for the rational pharmaceuticals design is the estimation of the biological properties of new molecules using computational methods. The quantitative analysis between chemical structure and biological activity (QSAR) is one of these techniques. In the present work, the multivariate analysis of images applied in QSAR (MIA-QSAR) was employed for building predictable QSAR models for a congenial series of carbamates which exhibit anticholinesterase activity. The significant statistical results from this treatment enabled the MIA-QSAR model thus obtained to reliably predict the biological activity of some new derivatives, as potentially useful for the Alzheimer Disease treatment / Mestrado / Ciencias Biomedicas / Mestra em Ciências Médicas

Page generated in 0.0954 seconds