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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.
11

Ribonucleotide reductase from E. coli : mechanistic studies of hydroxyurea resistance /

Sneeden, Jessica Leigh, January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 71-80).
12

Metabolic effects of 5α-reductase inhibition in humans

Upreti, Rita January 2013 (has links)
5α-reductases (5αRs) catalyse reduction of 4-pregnene steroids, most notably the androgen testosterone to its more potent metabolite dihydrotestosterone (DHT). Well-characterised isozymes of 5αR are designated 5αR1 and 5αR2. Inhibitors of 5αR, finasteride (a 5αR2 inhibitor) and dutasteride (a dual 5αR1 and 5αR2 inhibitor), are utilised in conditions where a reduction in androgen action is desired, including benign prostatic hyperplasia. Although 5αR2 is predominantly expressed in reproductive tissues, both isozymes, but particularly 5αR1, are expressed in metabolic tissues including liver and adipose and both metabolise glucocorticoids as well as androgens; therefore inhibition of 5αR may have consequences for metabolic health. This thesis addresses the hypotheses that 5αR1 inhibition with dutasteride decreases insulin sensitivity and causes dysregulation of the HPA axis in humans. Metabolism and the HPA axis were studied in men prior to and following 3 months of dutasteride (0.5 mg daily; n=16), finasteride (5 mg daily; n=16) or control (tamsulosin MR; 0.4 mg daily; n=14). Glucose disposal during hyperinsulinaemia was the primary endpoint, measured during a hyperinsulinaemic euglycaemic clamp, with d2-glucose and d5-glycerol tracers. Peripheral insulin sensitivity for both glucose uptake and NEFA suppression decreased with dutasteride versus both finasteride and control, while hepatic insulin sensitivity was preserved. Body fat increased with dutasteride, though was not accompanied by changes in metabolic or inflammatory gene transcript abundance in subcutaneous adipose biopsies, nor any differences in abdominal adipose depots on post-treatment MRI. Subtle dysregulation of the HPA axis was evident with both 5αR inhibitors, though to a greater degree with dutasteride and changes were largely compensated for. In support of this study, this thesis also describes the development, validation and application of two novel liquid chromatography tandem mass spectrometry assays; establishing compliance by measuring serum drug levels, and demonstrating effects of 5αR inhibitors on androgen metabolism and adrenal steroidogenesis by measurement of testosterone, DHT and androstenedione. In conclusion, 5αR1 inhibition with dutasteride, but not finasteride, induces peripheral insulin resistance and increases body fat. Findings presented may have important implications for patients prescribed dutasteride for benign prostatic hyperplasia.
13

The Effects of MsrA and MsrB in Anoxia Tolerance in Aging Drosophila melanogaster

Unknown Date (has links)
Drosophila melanogaster tolerates several hours of anoxia (the absence of oxygen) by entering a protective coma. A burst of reactive oxygen species (ROS) is produced when oxygen is reintroduced to the cells. ROS causes oxidative damage to critical cellular molecules, which contribute to aging and development of certain agerelated conditions. The amino acid, methionine, is susceptible to oxidation, although this damage can be reversed by methionine sulfoxide reductases (Msr). This project investigates the effect of Msr-deficiency on anoxia tolerance in Drosophila throughout the lifespan of the animal. The data show that the time for recovery from the protective comma as well as the survival of the animals lacking any Msr activity depends on how quickly the coma is induced by the anoxic conditions. Insight into the roles(s) of Msr genes under anoxic stress can lead us to a path of designing therapeutic drugs around these genes in relation to stroke. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
14

O impacto das revisões de literatura na ciência odontológica e na clínica periodontal : o exemplo de uma revisão sistemática de estatinas como adjuvante à terapia periodontal

Muniz, Francisco Wilker Mustafa Gomes January 2017 (has links)
As revisões sistemáticas são consideradas os desenhos experimentais capazes de guiar os cuidados em saúde. Contudo, as revisões narrativas ainda são largamente publicadas até o presente momento. No âmbito do tratamento das doenças periodontais, diversos estudos têm reportado que o uso adjuvante de estatinas à terapia periodontal mecânica pode acarretar melhorias nos parâmetros clínicos periodontais, como adicionais reduções de profundidade de sondagem e ganhos de inserção clínica. O objetivo deste trabalho é contextualizar a informação advinda de uma revisão sistemática realizada sobre um tema clínico significativo e compreender qual o seu papel como suporte da atenção ao paciente periodontal, a partir da compreensão obtida no estudo bibliométrico de revisões de literatura. No estudo bibliométrico, uma amostra representativa das revisões de literatura, publicadas na base Scopus, foi selecionada. Tipo de revisão, número de citações, ano de publicação, temática do estudo e outras variáveis foram coletadas. Nesse estudo, observou-se que o número de revisões sistemática tem aumentado significativamente ao longo dos anos quando comparados com o número de revisões narrativas. Apesar disso, o número ajustado de citações das revisões sistemáticas não difere significativamente das recebidas nas revisões narrativas. Já na revisão sistemática de uso adjuvante de estatinas, uma estratégia de busca nas bases Pubmed, Scopus e Embase foi realizada para identificar todos os ensaios clínicos que tenham utilizado estatinas como adjuvantes ao tratamento periodontal mecânico em comparação à terapia periodontal mecânica isolada ou associada a placebo. Quinze estudos foram selecionados. Observou-se que, na maioria dos estudos, o uso adjuvante de estatina apresentou adicionais reduções de profundidade de sondagem e ganhos de inserção clínica quando comparado com seus respectivos grupos controles. Contudo, a alta heterogeneidade desse resultado e o grande número de estudos ser executado por um mesmo grupo de pesquisa são fatores limitadores dessa revisão sistemática. Dessa maneira, pode-se concluir que o número de revisões sistemáticas vem aumentando a longo do tempo, porém o seu número de citações parece não acompanhar as mesmas tendências. Além disso, o uso adjuvante de estatina na terapia periodontal ainda não deve ser recomendado até a execução de outros estudos com melhor qualidade. / Systematic review is considered the experimental design capable of guiding the health care. However, narrative reviews are broadly published nowadays. Regarding periodontal diseases treatment, several studies reported that the adjuvant use of statins to mechanical periodontal treatment may promote additional improvements in clinical periodontal parameters, such as additional reduction in probing depth and clinical attachment gain. This study aimed to contextualize the information obtained in a systematic review about a significant clinical thematic and comprehend is its role in the periodontal care, through information gathered in a bibliometric study of literature review studies in Dentistry. In the bibliometric study, a representative sample of literature reviews studies, published in Scopus database, was selected. Type of review, number of citations, year of publication, study thematic, and other variables were collected. It was showed that the number of systematic reviews increased throughout the years in comparison to narrative reviews. Additionally, the Dentistry clinical fields presented the highest number of published systematic reviews. Despite of that, the mean adjusted number of citations granted for systematic reviews did not differ from the narrative ones. Regarding the performed systematic review, a search strategy was conducted on Pubmed, Scopus, and Embase databases to identify all clinical trials that used statins as adjuvant to mechanical periodontal treatment in comparison to mechanical periodontal treatment alone or in association with placebo. Fifteen studies were included. It was showed that most of the included studies presented additional reduction in probing depth and clinical attachment gain in comparison to their control groups. However, the high heterogeneity among the studies and the high number of studies conducted by the same research group are limitations of the present systematic review. It was concluded that the number of systematic review are increasing dramatically throughout the years, but this trend is not followed by the number of citations granted to this type of study. Furthermore, the adjuvant use of statin in the mechanical periodontal therapy may not be recommended until further well-designed studies have been published.
15

Atividade antifÃngica in vitro de estatinas sobre espÃcies de Candida e Cryptococcus. / Antifungal activity in vitro of statin on species Candida and Cryptcoccus

Elizabeth Ribeiro Yokobatake Souza 29 September 2011 (has links)
nÃo hà / O aumento nos Ãltimos anos de indivÃduos imunocomprometidos, como portadores da SÃndrome da ImunodeficiÃncia Adquirida, de doenÃas malignas, transplantados e outros usuÃrios de terapias imunossupressoras, favorece o surgimento de infecÃÃes oportunistas, principalmente as de teor fÃngico, como a candidÃase e a criptococose. Apesar de a terapia antifÃngica atual ser eficiente na maioria dos casos, algumas vezes fazem-se necessÃrias novas drogas que atuem como alternativa ou como coadjuvantes no tratamento para potencializar o efeito dos antifÃngicos utilizados. As estatinas sÃo fÃrmacos hipolipemiantes mais prescritos mundialmente para doenÃas cardiovasculares. Entretanto, recentemente, tem sido descritos outros efeitos benÃficos destas drogas, como, por exemplo, o controle de infecÃÃes. Este trabalho teve como objetivo determinar a atividade antifÃngica in vitro das estatinas ante 51 cepas de Candida, sendo 16 de C. albicans, 11 de C. krusei, 12 de C. tropicalis e 12 de C. parapsilosis, e 25 cepas de Cryptococcus, sendo 12 de C. gattii e 13 de C. neoformans, por meio de testes de microdiluiÃÃo em caldo, segundo documento M27-A3 padronizado pelo CLSI. O intervalo de concentraÃÃo testado para pravastatina foi de 50 a 0,0977 mg/mL, para sinvastatina, 1 a 0,0020 mg/mL e para atorvastatina, 10 a 0,0200 mg/mL. Pravastatina inibiu 37 leveduras do gÃnero Candida apresentando concentraÃÃo inibitÃria mÃnima (CIM) na faixa de 1,56 a 6,25 mg /mL e as cepas restantes nÃo foram inibidas mesmo na maior concentraÃÃo testada (50 mg /mL), enquanto que sinvastatina e atorvastatina apresentaram atividade antifÃngica sobre todas as 51 cepas avaliadas, apresentando CIMs de 0,02 a 1 mg / mL e 0,04 a 5,00 mg / mL, respectivamente. Para o gÃnero Cryptococcus, apenas 4 cepas foram inibidas ante a pravastatina (CIM = 25 mg / mL), por outro lado, sinvastatina inibiu todas as 25 cepas (CIM = 0,06 a 1 mg / mL), e atorvastatina apenas 8 cepas (CIM = 0,62 a 2,5 mg / mL), sendo que as 17 restantes nÃo foram inibidas mesmo na maior concentraÃÃo testada ( ≥ 10 mg / mL). Foi determinada concentraÃÃo fungicida mÃnima (CFM) de pravastatina sobre 15 cepas do gÃnero Candida (CFM = 3,12 a 25 mg / mL), de sinvastatina sobre 34 cepas (CFM = 0,03 a 1 mg / mL), e de atorvastatina sobre 16 cepas (CFM = 0,04 a 0,31 mg / mL). Para o gÃnero Cryptococcus, das 25 cepas testadas, pravastatina exibiu CFM sobre apenas 3 cepas (CFM = 50 mg / mL), sinvastatina sobre 21 cepas (CFM = 0,12 a 1 mg / mL), e atorvastatina sobre 1 cepa (CFM = 1 mg / mL). Esta atividade inibitÃria in vitro de estatinas sobre espÃcies de Candida e Cryptococcus, abre uma perspectiva importante para a investigaÃÃo do possÃvel uso destas drogas com finalidade antifÃngica in vivo. / In the past years, fungal opportunistic infections, especially, candidiasis and cryptococcosis, have become more frequent because of the increase in the number of immunocompromised individuals, such as AIDS, transplant and cancer patients and those that are on immunosuppressive therapy. In spite of being effective, sometimes it is necessary to use new drugs as alternatives or as adjuvants in order to potentiate the effect of the classical antifungal therapy. Statins are the most prescribed hypolipemiant drugs worldwide for preventing cardiovascular diseases. However, other benefic effects for these drugs have been described, such as the control of infections. This work aimed at determining the antifungal activity of statins against Candida spp. and Cryptococcus spp. The minimum inhibitory concentrations (MICs) for three different statins (pravastatin, simvastatin and atorvastatin) were determined against 51 strains of Candida spp. (16 C. albicans, 11 C.krusei, 12 C. tropicalis and 12 C. parapsilosis) and 25 strains of Cryptococcus spp. (12 C. gattii and 13 C. neoformans), through broth microdilution assay, according to the Clinical Laboratory Standards Institute (CLSI - Document M27-A3). The concentration tested for pravastatin ranged from 50 to 0.0977 mg/mL, for simvastatin, it ranged from 1 to 0.0020 mg/mL and, for atorvastatin, it varied from 10 to 0.0200 mg/mL. Pravastatin inhibited 37 Candida strains, with MICs varying from 1.56 to 6.25 mg/mL and the remaining strains were not inhibited, even at the highest concentration tested (50 mg/mL). Simvastatin and atorvastatin, on the other hand, inhibited all 51 Candida strains evaluated, presenting MICs ranging from 0.02 to 1 mg/mL and from 0.04 to 5 mg/mL, respectively. Concerning Cryptococcus spp., only four strains were inhibited by pravastatin (MIC=25 mg/mL), while all 25 strains were inhibited by simvastatin (0.06≤MIC≤1 mg/mL) and eight were inhibited by atorvastatin (0.62≤MIC≤2.5 mg/mL) and the remaining 17 were not susceptible to the highest atorvastatin concentration tested (10 mg/mL). The minimum fungicidal concentrations (MFCs) for the tested statins were also determined. The MFC for pravastatin against Candida spp. was determined against 15 strains (3.12≤MIC≤25 mg/mL). The MFC values for simvastatin were determined for 34 strains of Candida spp. (0.03≤MFC≤1 mg/mL), while those for atorvastatin were determined against 16 strains (0.04≤MFC≤0,31 mg/mL). Concerning Cryptococcus spp., the 25 strains tested, MFC values for pravastatin were found against three strains (MFC=50 mg/mL), while those for simvastatin were determined against 21 strains (0.12≤MFC≤1 mg/mL) and those for atorvastatin were determined against one single strain (MFC=1 mg/mL). This in vitro inhibitory activity of statins against Candida spp. and Cryptococcus spp. creates an important perspective for the use of these drugs in vivo in order to control fungal infections.
16

Homing endonucleases and horizontal gene transfer in bacteria and bacteriophages /

Nord, David, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Univ., 2007. / Härtill 4 uppsatser.
17

Genetic markers of neurodegeneration a role for 3-hydroxy-3-methylglutaryl-coenzyme A reductase in sporadic Alzheimer's disease /

Legault, Véronique. January 1900 (has links)
Thesis (M.Sc.). / Written for the Dept. of Neurology and Neurosurgery. Title from title page of PDF (viewed 2008/05/14). Includes bibliographical references.
18

The dynamic interactome : a proteomic investigation of ligand-dependent HSP90 complexes /

Gano, Jacob J. January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 132-147).
19

Occupancy and function of the hepatic HMG-CoA reductase promoter

Lagor, William Raymond. January 2006 (has links)
Dissertation (Ph.D.)--University of South Florida, 2006. / Includes vita. Includes bibliographical references. Also available online.
20

Defining the cis-acting requirements in the HMG-CoA reductase gene for karmellae biogenesis /

Profant, Deborah Ann. January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 82-90).

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