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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.
161

Avaliação da atividade anti-glicação de proteína por 4-nerolidilcatecol isolado de Pothormorphe umbellata (L.) Miq. / Evaluation of the protein anti-glycation activity of 4-nerolydilcatechol isolated from Pothomorphe umbellata (L.) Miq.

Mary Sanae Nakamura 07 November 2007 (has links)
A glicação é uma reação não enzimática que ocorre entre proteínas e açúcares redutores e, é responsável pela formação de adultos e de ligações cruzadas entre proteínas, como por exemplo: a pentosidina, produto final de glicação avançada que se acumula em vários tecidos ao longo do tempo. A glicação é deletéria para o organismo e está associada a modificações estruturais em proteínas e alterações de suas funções específicas, tais como: atividade enzimática, capacidade de ligação e tempo de vida de proteínas, além de ser responsável pela produção de espécies reativas de oxigênio (EROS). O mecanismo de formação da pentosidina envolve reações oxidativas e, uma das estratégias para minimizá-Ia é o aumento da atividade antioxidante nos tecidos. A pariparoba (Pothomorphe umbellata (L.) Miq) demonstrou atividade antioxidante in vitro e in vivo quando aplicada sobre a pele. Essa atividade foi atribuída ao 4-nerolidilcatecol (4-NC), que se mostrou 10 vezes mais potente que o α-tocoferol. Os extratos de pariparoba também inibiram a lipoperoxidação espontânea da pele em camundongos sem pelo. Neste trabalho empregou-se o modelo de glicação de albumina de soro bovino (BSA) frente à D-ribose, com avaliação da fluorescência produzida pela pentosidina formada na reação. Avaliou-se igualmente a atividade do 4-NC em diferentes concentrações sobre a reação de glicação da BSA em presença de D-ribose após 24 horas, empregando-se a aminoguanidina como controle positivo. Nas condições experimentais o 4-NC não foi capaz de inibir a reação de glicação, ao contrário da aminoguanidina. Foi também utilizado modelo para avaliação da propriedade contrátil de fibroblastos em matriz tridimensional de gel de colágeno, glicado e não glicado com D-ribose. O 4-NC na concentração de 100 µM permitiu a manutenção da propriedade contrátil de fibroblastos em gel colágeno glicado. Estudos de glicação em maiores períodos de tempo devem ser realizados visando a confirmar a possível atividade anti-glicação deste composto. / Glycation is a non enzymatic reaction which occurs between proteins and reductor sugars, responsible for the formation of adducts and crosslinkers between proteins, such as, pentosidine, an advanced glycation end-product (AGE) which accumulates in many tissues during aging. AGEs accumulation is deleterious to the body and is associated with structural modifications in proteins and imbalance in their specific functions, such as: enzymatic activity, binding capacity, protein turnover and also responsible for the production of reactive oxygen species (ROS). The mechanism of pentosidine formation involves oxidative reactions. One of the strategies to reduce pentosidine formation is by increasing antioxidant activity in tissues. Pariparoba (Pothomorphe umbellata (L.) Miq. has showed antioxidant activity in vitro and in vivo when applied on the skin. This activity was attributed to 4-nerolydilcatechol (4-NC), which is 10 times more potent than α-tocopherol. Extracts of Pariparoba also inhibited the spontaneous lipid peroxidation in the skin of hairless mice. In this work, the bovine serum albumin (BSA) model for glycation with D-ribose, evaluated by pentosidine fluorescence spectroscopy was employed. The activity of 4¬NC was evaluated in different concentrations in this model after 24 hours. Aminoguanidine was used as positive control. In this experimental condition, 4-NC was not capable to inhibit the BSA glycation. We also evaluated the contractile properties of fibroblasts on tridimensional matriz of collagen gel glycated or not with D-ribose. 4-NC (100 µM) was able to keep the contractile capacity of fibroblasts in glycated collagen. Studies of glycation in longer periods of time should be made in order to further evaluate the possible anti-glycation activity of this compound.
162

Contribuição à farmacognosia de Artemisia annua L. e Bidens pilosa L. (Asteraceae). Acompanhamento da variação de metabólitos secundários em diferentes fases fenológicas, órgãos e extratos vegetais, aspectos botânicos e avaliação da atividade antileishmania in vitro / Pharmacognosy of Artemisia annua L and Bidens pilosa L. (Asteraceae). Growth stages variation of secondary metabolites in extracts from plant parts collected in different growth stages, botanical aspects and in vitro evaluation of the antileishmanial activity

Fabiana Lima Silva 29 September 2008 (has links)
Na busca por espécies vegetais com atividade antileishmania, selecionaram-se, para o estudo, duas espécies bem conhecidas da família Asteraceae: Artemisia annua L. e Bidens pilosa L. Ambas são reconhecidamente utilizadas na medicina popular, como antiprotozoárias. Apesar de terem sido amplamente estudadas em diversos aspectos, alguns permaneceram inexplorados, até o momento, e foram abordados, neste trabalho. As duas espécies foram analisadas quanto aos aspectos químico e biológico de extratos (hidroetanólico e infuso) e frações orgânicas selecionados, em função da atividade antileishmania in vitro, frente às formas promastigotas de Leishmania amazonensis. Os extratos foram obtidos a partir de órgãos vegetais, em estados de conservação diferentes (in natura, droga) e coletados em fenofases distintas. Extratos e frações orgânicas das espécies estudadas mostraram promissora atividade antileishmania in vitro e baixo nível de citotoxicidade in vitro em células epiteliais humanas (HEP-2). No estudo químico dos extratos e frações bioativos, realizaram-se análises qualitativas e/ou quantitativas de terpenos, flavonóides e de marcadores específicos (artemisinina, quercetina e rutina), avaliando-se a variação da composição dos mesmos, nas diferentes fenofases consideradas. Discutiram-se as possíveis relações existentes entre a composição química e a atividade biológica verificada. Aspectos inéditos do estudo morfoanatômico de partes aéreas de A. annua foram descritos. / Plants are potential sources of new antileishmanial drugs. Two well-known antiprotozoal species were selected, from the Asteraceae family, for this study: Artemisia annua L and Bidens pilosa L. Despite the traditional and scientific accumulated knowledge, some aspects were not investigated before and were the subject of this work. Several extracts (infusions and ethanol 96 °GL) and selected fractions from both species were evaluated according to the different parameters, such as: plant organs and/or parts, growth stages and drying state of starting materials (fresh, drug). Fractions were selected among those more active against promastigotes of Leishmania amazonensis. Ethanol extracts and their fractions showed a high level of in vitro antileishmanial activity and a low cytotoxicity on epithelial human cells (HEP-2). Qualitative and/or quantitative analysis of extracts and fractions were performed for terpenes, flavonoids and selected markers (artemisinin, quercetin and rutin) in order to characterize them and evaluate variations during the different growth stages. Correlations of the chemical composition and the biological activity were discussed. The main anatomical characters of the aerial parts of A. annua were described for the first time and illustrated by photomicrographs.
163

Meta-Analysis of Herbal Cannabis Therapy for Chronic Pain

Seneca, Michael J 01 January 2014 (has links)
Since the first so-called “medical marijuana” legislation was passed in California in 1996, a total of twenty states and the District of Columbia have passed laws permitting limited use of cannabis. Despite the changes in state laws, cannabis remains illegal for any purpose under federal law. Changes in state laws have coincided with a renewed interest in the substance for the treatment of a variety of conditions. There has been a significant increase in published data over the past twenty years examining the efficacy of cannabis as an appetite stimulant, antiemetic agent, and analgesic adjuvant. The purpose of this meta-analysis was to synthesize published data on cannabis use as an analgesic agent. Five studies meeting inclusion criteria were located through searches of online databases, review of reference lists, author correspondence, and review of clinical trials databases. Meta-analysis was conducted using fixed-effects modeling. The overall effect of mean reduction of pain intensity was -4.895 (Z-score) with an associated p value of 0.003. The combined standardized mean difference (SMD) was -0.362 (CI -0.507 to -0.217), indicating on average a moderate significant reduction in pain intensity for patients with chronic pain. As the legal status of the substance evolves, additional research is needed to establish evidence-based clinical recommendations regarding the use of medicinal cannabis in pain management.
164

"Nineteenth-Century American Medicine:The Implications of Professionalism, Capitalism, and Implicit Bias"

Gregg, Amy L. 28 June 2017 (has links)
No description available.
165

Anti-Psychotic Drug Induced Tardive Dyskinesia: A Role for the Anti-Apoptotic Molecule Curcumin

Sookram, Christal D. 10 1900 (has links)
<p>Anti-psychotic drug (APD) administration can induce movement disorders including tardive dyskinesia (TD), characterized by abnormal movements of the oro-facial region and occasionally the trunk and limbs. The most widely accepted model of TD is the APD-induced vacuous chewing movement (VCM). While the mechanism of induction of TD remains unclear, there are two prevailing hypothesis: oxidative stress and dopamine supersensitivity. Currently available APDs antagonize dopamine D2 receptors (D2R) which can result in excessive dopamine accumulation and oxidation which was demonstrated to induce striatal neurodegeneration and increased oxidative stress. The dopamine supersensitivity hypothesis proposes that APD treatment causes an up-regulation of high affinity D2Rs to compensate for D2R antagonism. Curcumin, a derivative of turmeric, has been demonstrated to affect dopamine levels and hold significant anti-apoptotic potential. Thus, the goal of this study was to investigate curcumin’s potential to prevent haloperidol-induced behavioural and biochemical abnormalities. Four groups of rats were treated daily: control; haloperidol (at 2mg/kg intra-peritoneally); curcumin (at 200mg/kg orally in jello) and curcumin plus haloperidol. VCMs, catalepsy and locomotor activity were assessed. Animals were sacrificed and tissues removed for qPCR, immunoblot, receptor binding, and UPLC assessments. At day14 there was a significant increase in VCMs and catalepsy following haloperidol treatment, which was prevented by curcumin treatment. However, curcumin did not alter locomotor activity. Curcumin was demonstrated to increase the expression of the anti-apoptotic molecule BclXL and to increase striatal D2Rs. These investigations support the potential of curcumin in the prevention of TD and provide insight into the complex pathophysiology of this disorder.</p> / Doctor of Philosophy (Medical Science)

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