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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.
1

Conservation Genetics of Freshwater Turtles

Davy, Christina M. 19 March 2013 (has links)
Turtles have long life spans, overlapping generations and promiscuous mating systems. Thus, they are an ideal system with which to investigate the application of conservation genetics methods and assumptions to long-lived organisms. Turtles are also one of the most threatened groups of vertebrates and conservation genetics studies are essential to effective recovery of turtle species. This thesis has two main objectives: 1) to evaluate some common population genetics assumptions with respect to turtles and other long-lived organisms, and 2) to collect important information on the population genetics of threatened turtles in Ontario, which can be used to inform species recovery. In Chapters Two and Three, I describe the development of novel microsatellite markers for the snapping turtle and spiny softshell. In Chapter Four I demonstrate significant genetic structure in populations of the endangered spotted turtle in Ontario, and find that “bottleneck tests” may fail to detect recent population declines in small turtle populations. I also show that spotted turtles do not show the typical correlation between population size and genetic diversity. In Chapter Five I use microsatellite markers developed in Chapter Two and document population structure in the widespread snapping turtle for the first time. I compare these results with results from Chapter Four to test the traditionally accepted hypothesis that genetic diversity is reduced in small, isolated populations compared to large, connected populations. As in Chapter Four, my results suggest that the usual patterns of genetic structure and loss of diversity may not apply to turtles. In Chapter Six I conduct a conservation genetics study of the endangered Blanding’s turtle. Finally, in Chapter Seven I combine results from spotted, snapping and Blanding’s turtles to test whether vagility predicts population structure, genetic diversity and significant barriers to gene flow in three species sampled across a single landscape. Analyses reveal minimal congruence in barriers to gene flow and the three species show unexpected and contrasting patterns of diversity across the landscape. Discordant patterns among species highlight areas for further research and shed light on possible cryptic behaviour, and I discuss potential further directions for research in the Summary.
2

Chemical Constituents and Cytotoxicity of Formosan Soft Corals Lemnalia Cervicorni and Dendronephthya spinifera

Sung, Pei-Ying 10 July 2002 (has links)
Chromatographic separation of methylene chloride extracts of Formosan soft coral Lemnalia cervicorni May (collected at Green Island off Taiwan) led to the isolation of four ylangene sesquiterpenoids, GN40-29 (1), GN40-79 (3), GN40-169 (4), and GN40-173 (5). Acetylation of GN40-29 (1) gave a derivative GN40-29a (2). Compounds 3-5 were new compounds. Compound 1 showed cytotoxicity against HT-29 cell, while compound 5 was cytotoxic to P-388 cells. The methylene chloride extracts of Formosan soft coral Dendronephthya spinifera Holm (collected at Green Island off Taiwan) were found to contain a new cadinene sesquiterpene, GN43-4 (6).
3

Conservation Genetics of Freshwater Turtles

Davy, Christina M. 19 March 2013 (has links)
Turtles have long life spans, overlapping generations and promiscuous mating systems. Thus, they are an ideal system with which to investigate the application of conservation genetics methods and assumptions to long-lived organisms. Turtles are also one of the most threatened groups of vertebrates and conservation genetics studies are essential to effective recovery of turtle species. This thesis has two main objectives: 1) to evaluate some common population genetics assumptions with respect to turtles and other long-lived organisms, and 2) to collect important information on the population genetics of threatened turtles in Ontario, which can be used to inform species recovery. In Chapters Two and Three, I describe the development of novel microsatellite markers for the snapping turtle and spiny softshell. In Chapter Four I demonstrate significant genetic structure in populations of the endangered spotted turtle in Ontario, and find that “bottleneck tests” may fail to detect recent population declines in small turtle populations. I also show that spotted turtles do not show the typical correlation between population size and genetic diversity. In Chapter Five I use microsatellite markers developed in Chapter Two and document population structure in the widespread snapping turtle for the first time. I compare these results with results from Chapter Four to test the traditionally accepted hypothesis that genetic diversity is reduced in small, isolated populations compared to large, connected populations. As in Chapter Four, my results suggest that the usual patterns of genetic structure and loss of diversity may not apply to turtles. In Chapter Six I conduct a conservation genetics study of the endangered Blanding’s turtle. Finally, in Chapter Seven I combine results from spotted, snapping and Blanding’s turtles to test whether vagility predicts population structure, genetic diversity and significant barriers to gene flow in three species sampled across a single landscape. Analyses reveal minimal congruence in barriers to gene flow and the three species show unexpected and contrasting patterns of diversity across the landscape. Discordant patterns among species highlight areas for further research and shed light on possible cryptic behaviour, and I discuss potential further directions for research in the Summary.
4

Nanoemulsões de anfotericina B e itraconazol : avaliação da atividade antifúngica in vitro e in vivo em agentes da cromoblastomicose

Daboit, Tatiane Caroline January 2013 (has links)
Cromoblastomicose é uma micose crônica que acomete a pele e o tecido subcutâneo. Vários tratamentos têm sido utilizados, mas a eficácia é extremamente baixa, não permitindo eleger uma terapia de escolha. No presente trabalho foram realizados: I – ensaios de suscetibilidade in vitro de agentes da cromoblastomicose contra antifúngicos comerciais; II - caracterização molecular de amostras oriundas de casos clínicos, bem como a descrição destes casos; III - a produção e caracterização de duas nanoemulsões, uma de anfotericina B e uma de itraconazol produzidas pela técnica de homogeneização à alta pressão; IV - a avaliação da atividade antifúngica destas nanoemulsões in vitro e in vivo em agentes da cromoblastomicose; V - a verificação do nível de comprometimento renal e hepático causados pelas nanoemulsões; VI - a avaliação da toxicidade das formulações produzidas. De modo geral, os agentes da cromoblastomicose, apresentaram maior suscetibilidade à terbinafina e ao itraconazol, respectivamente. A combinação de anfotericina B e terbinafina foi sinérgica para quatro dos cinco grupos avaliados. Quanto aos casos clínicos, no primeiro foi identificada uma infecção por E. spinifera e no segundo uma por Fonsecaea monophora. As nanoemulsões foram elaboradas com composição passível de administração parenteral, uma de anfotericina B e uma de itraconazol, pelo método de homogeneização à alta pressão. Não foi possível determinar as CIMs da nanoemulsão de anfotericina B e Abelcet® in vitro, enquanto que a nanoemulsão de itraconazol apresentou CIMs muito semelhantes às do fármaco livre. Em modelo animal de cromoblastomicose, a nanoemulsão de anfotericina B foi mais ativa que o fármaco livre, Fungizone® e Abelcet®. A nanoemulsão de itraconazol também apresentou melhor atividade quando comparada com o fármaco livre. Os níveis de uréia foram mais elevados nos animais que receberam anfotericina B livre e Fungizone®. A enzima alanina aminotransferase foi encontrada em níveis menores nos animais tratados com a nanoemulsão de itraconazol do que naqueles que receberam itraconazol livre. A anfotericina B livre e Fungizone® causaram graves danos aos rins. Nos animais tratados com Abelcet® e com a nanoemulsão de anfotericina B foi possível verificar apenas necrose focal. Da mesma forma, a nanoemulsão de itraconazol protegeu os animais contra danos hepáticos quando comparada com o fármaco livre. Em relação aos ensaios de toxicidade, a anfotericina B foi citotóxica em concentrações a partir de 4μg/mL, sendo que com a nanoemulsão esta toxicidade não foi observada em concentrações mais elevadas. O itraconazol foi citotóxico, sendo que este efeito não foi visto com a nanoemulsão. É de extrema importância a avaliação da suscetibilidade dos agentes da cromoblastomicose a fim de orientar a clínica. A identificação molecular de agentes isolados de casos clínicos pode contribuir para delinear o perfil epidemiológico da doença. As nanoemulsões de anfotericina B e itraconazol apresentaram atividades superiores in vivo quando comparadas aos demais tratamentos e foram capazes de reduzir os efeitos adversos causados por estes antifúngicos. Através de ensaios in vitro foi confirmada a redução da citotoxidade do fármaco quando veiculado na nanoemulsão. Assim, as nanoemulsões produzidas poderiam ser alternativas terapêuticas para o tratamento da cromoblatomicose. / Chromoblastomycosis is a chronic mycosis that affects the skin and subcutaneous tissue. Various treatments have been used, but the efficacy is extremely low and does not allow choosing a therapy of choice. In the present work was performed: I - in vitro susceptibility testing for chromoblastomycosis agents against commercial antifungal; II - molecular characterization of samples from clinical cases as well as the description of these cases III - production and characterization of two nanoemulsions , one of amphotericin B and one of itraconazole, produced by high pressure homogenization technique; IV - assessing the in vitro and in vivo antifungal activity of these nanoemulsions against chromoblastomycosis agents; V - checking the level of impairment caused in the kidney and liver by nanoemulsions; VI - evaluation of toxicity of the formulations produced. In general, the chromoblastomycosis agents showed greater susceptibility to terbinafine and to itraconazole, respectively. The combination of amphotericin B and terbinafine was synergistic to four of the five groups. As for clinical cases, in the first was identified an infection by E. spinifera and in the second one by Fonsecaea monophora. The nanoemulsions were prepared with composition amenable of parenteral administration, one of amphotericin B and one of itraconazole, by the at high pressure homogenization method. Could not be determined the MIC of amphotericin B nanoemulsion and Abelcet® in vitro, while the itraconazole nanoemulsion showed MICs very similar to free drug. In a chromoblastomycosis animal model, the amphotericin B nanoemulsion was more active than free drug, Abelcet® and Fungizone®. The nanoemulsion of itraconazole also showed better activity compared to the free drug. Urea levels were higher in the animals receiving amphotericin B free and Fungizone®. The enzyme alanine aminotransferase was found in lower levels in animals treated with itraconazole nanoemulsion than in those who received itraconazole free. Amphotericin B free and Fungizone® caused severe damage to the kidneys. Already in animals treated with Abelcet® and the amphotericin B nanoemulsion was verified only focal necrosis. Likewise, the itraconazole nanoemulsion protected against liver damage when compared with the free drug. Regarding toxicity assays, amphotericin B was cytotoxic at concentrations from 4 μg/mL, while with the nanoemulsion this toxicity was not observed at higher concentrations. Itraconazole was cytotoxic, and this effect was not observed with the nanoemulsion. It is extremely important to evaluate the susceptibility of chromoblastomycosis agents to guide the clinic. Molecular identification of agents isolated from clinical cases can contribute to outline an epidemiological profile of the disease. The amphotericin B and itraconazole nanoemulsions showed higher activities in vivo when compared to other treatments and were able to reduce the adverse effects caused by these antifungals. Through in vitro assays were confirmed the reduction of the cytotoxicity of the drug when vehiculated in the nanoemulsion. Therefore, the nanoemulsions may be produced therapeutic alternatives for the chromoblastomycosis treatment.
5

Nanoemulsões de anfotericina B e itraconazol : avaliação da atividade antifúngica in vitro e in vivo em agentes da cromoblastomicose

Daboit, Tatiane Caroline January 2013 (has links)
Cromoblastomicose é uma micose crônica que acomete a pele e o tecido subcutâneo. Vários tratamentos têm sido utilizados, mas a eficácia é extremamente baixa, não permitindo eleger uma terapia de escolha. No presente trabalho foram realizados: I – ensaios de suscetibilidade in vitro de agentes da cromoblastomicose contra antifúngicos comerciais; II - caracterização molecular de amostras oriundas de casos clínicos, bem como a descrição destes casos; III - a produção e caracterização de duas nanoemulsões, uma de anfotericina B e uma de itraconazol produzidas pela técnica de homogeneização à alta pressão; IV - a avaliação da atividade antifúngica destas nanoemulsões in vitro e in vivo em agentes da cromoblastomicose; V - a verificação do nível de comprometimento renal e hepático causados pelas nanoemulsões; VI - a avaliação da toxicidade das formulações produzidas. De modo geral, os agentes da cromoblastomicose, apresentaram maior suscetibilidade à terbinafina e ao itraconazol, respectivamente. A combinação de anfotericina B e terbinafina foi sinérgica para quatro dos cinco grupos avaliados. Quanto aos casos clínicos, no primeiro foi identificada uma infecção por E. spinifera e no segundo uma por Fonsecaea monophora. As nanoemulsões foram elaboradas com composição passível de administração parenteral, uma de anfotericina B e uma de itraconazol, pelo método de homogeneização à alta pressão. Não foi possível determinar as CIMs da nanoemulsão de anfotericina B e Abelcet® in vitro, enquanto que a nanoemulsão de itraconazol apresentou CIMs muito semelhantes às do fármaco livre. Em modelo animal de cromoblastomicose, a nanoemulsão de anfotericina B foi mais ativa que o fármaco livre, Fungizone® e Abelcet®. A nanoemulsão de itraconazol também apresentou melhor atividade quando comparada com o fármaco livre. Os níveis de uréia foram mais elevados nos animais que receberam anfotericina B livre e Fungizone®. A enzima alanina aminotransferase foi encontrada em níveis menores nos animais tratados com a nanoemulsão de itraconazol do que naqueles que receberam itraconazol livre. A anfotericina B livre e Fungizone® causaram graves danos aos rins. Nos animais tratados com Abelcet® e com a nanoemulsão de anfotericina B foi possível verificar apenas necrose focal. Da mesma forma, a nanoemulsão de itraconazol protegeu os animais contra danos hepáticos quando comparada com o fármaco livre. Em relação aos ensaios de toxicidade, a anfotericina B foi citotóxica em concentrações a partir de 4μg/mL, sendo que com a nanoemulsão esta toxicidade não foi observada em concentrações mais elevadas. O itraconazol foi citotóxico, sendo que este efeito não foi visto com a nanoemulsão. É de extrema importância a avaliação da suscetibilidade dos agentes da cromoblastomicose a fim de orientar a clínica. A identificação molecular de agentes isolados de casos clínicos pode contribuir para delinear o perfil epidemiológico da doença. As nanoemulsões de anfotericina B e itraconazol apresentaram atividades superiores in vivo quando comparadas aos demais tratamentos e foram capazes de reduzir os efeitos adversos causados por estes antifúngicos. Através de ensaios in vitro foi confirmada a redução da citotoxidade do fármaco quando veiculado na nanoemulsão. Assim, as nanoemulsões produzidas poderiam ser alternativas terapêuticas para o tratamento da cromoblatomicose. / Chromoblastomycosis is a chronic mycosis that affects the skin and subcutaneous tissue. Various treatments have been used, but the efficacy is extremely low and does not allow choosing a therapy of choice. In the present work was performed: I - in vitro susceptibility testing for chromoblastomycosis agents against commercial antifungal; II - molecular characterization of samples from clinical cases as well as the description of these cases III - production and characterization of two nanoemulsions , one of amphotericin B and one of itraconazole, produced by high pressure homogenization technique; IV - assessing the in vitro and in vivo antifungal activity of these nanoemulsions against chromoblastomycosis agents; V - checking the level of impairment caused in the kidney and liver by nanoemulsions; VI - evaluation of toxicity of the formulations produced. In general, the chromoblastomycosis agents showed greater susceptibility to terbinafine and to itraconazole, respectively. The combination of amphotericin B and terbinafine was synergistic to four of the five groups. As for clinical cases, in the first was identified an infection by E. spinifera and in the second one by Fonsecaea monophora. The nanoemulsions were prepared with composition amenable of parenteral administration, one of amphotericin B and one of itraconazole, by the at high pressure homogenization method. Could not be determined the MIC of amphotericin B nanoemulsion and Abelcet® in vitro, while the itraconazole nanoemulsion showed MICs very similar to free drug. In a chromoblastomycosis animal model, the amphotericin B nanoemulsion was more active than free drug, Abelcet® and Fungizone®. The nanoemulsion of itraconazole also showed better activity compared to the free drug. Urea levels were higher in the animals receiving amphotericin B free and Fungizone®. The enzyme alanine aminotransferase was found in lower levels in animals treated with itraconazole nanoemulsion than in those who received itraconazole free. Amphotericin B free and Fungizone® caused severe damage to the kidneys. Already in animals treated with Abelcet® and the amphotericin B nanoemulsion was verified only focal necrosis. Likewise, the itraconazole nanoemulsion protected against liver damage when compared with the free drug. Regarding toxicity assays, amphotericin B was cytotoxic at concentrations from 4 μg/mL, while with the nanoemulsion this toxicity was not observed at higher concentrations. Itraconazole was cytotoxic, and this effect was not observed with the nanoemulsion. It is extremely important to evaluate the susceptibility of chromoblastomycosis agents to guide the clinic. Molecular identification of agents isolated from clinical cases can contribute to outline an epidemiological profile of the disease. The amphotericin B and itraconazole nanoemulsions showed higher activities in vivo when compared to other treatments and were able to reduce the adverse effects caused by these antifungals. Through in vitro assays were confirmed the reduction of the cytotoxicity of the drug when vehiculated in the nanoemulsion. Therefore, the nanoemulsions may be produced therapeutic alternatives for the chromoblastomycosis treatment.
6

Nanoemulsões de anfotericina B e itraconazol : avaliação da atividade antifúngica in vitro e in vivo em agentes da cromoblastomicose

Daboit, Tatiane Caroline January 2013 (has links)
Cromoblastomicose é uma micose crônica que acomete a pele e o tecido subcutâneo. Vários tratamentos têm sido utilizados, mas a eficácia é extremamente baixa, não permitindo eleger uma terapia de escolha. No presente trabalho foram realizados: I – ensaios de suscetibilidade in vitro de agentes da cromoblastomicose contra antifúngicos comerciais; II - caracterização molecular de amostras oriundas de casos clínicos, bem como a descrição destes casos; III - a produção e caracterização de duas nanoemulsões, uma de anfotericina B e uma de itraconazol produzidas pela técnica de homogeneização à alta pressão; IV - a avaliação da atividade antifúngica destas nanoemulsões in vitro e in vivo em agentes da cromoblastomicose; V - a verificação do nível de comprometimento renal e hepático causados pelas nanoemulsões; VI - a avaliação da toxicidade das formulações produzidas. De modo geral, os agentes da cromoblastomicose, apresentaram maior suscetibilidade à terbinafina e ao itraconazol, respectivamente. A combinação de anfotericina B e terbinafina foi sinérgica para quatro dos cinco grupos avaliados. Quanto aos casos clínicos, no primeiro foi identificada uma infecção por E. spinifera e no segundo uma por Fonsecaea monophora. As nanoemulsões foram elaboradas com composição passível de administração parenteral, uma de anfotericina B e uma de itraconazol, pelo método de homogeneização à alta pressão. Não foi possível determinar as CIMs da nanoemulsão de anfotericina B e Abelcet® in vitro, enquanto que a nanoemulsão de itraconazol apresentou CIMs muito semelhantes às do fármaco livre. Em modelo animal de cromoblastomicose, a nanoemulsão de anfotericina B foi mais ativa que o fármaco livre, Fungizone® e Abelcet®. A nanoemulsão de itraconazol também apresentou melhor atividade quando comparada com o fármaco livre. Os níveis de uréia foram mais elevados nos animais que receberam anfotericina B livre e Fungizone®. A enzima alanina aminotransferase foi encontrada em níveis menores nos animais tratados com a nanoemulsão de itraconazol do que naqueles que receberam itraconazol livre. A anfotericina B livre e Fungizone® causaram graves danos aos rins. Nos animais tratados com Abelcet® e com a nanoemulsão de anfotericina B foi possível verificar apenas necrose focal. Da mesma forma, a nanoemulsão de itraconazol protegeu os animais contra danos hepáticos quando comparada com o fármaco livre. Em relação aos ensaios de toxicidade, a anfotericina B foi citotóxica em concentrações a partir de 4μg/mL, sendo que com a nanoemulsão esta toxicidade não foi observada em concentrações mais elevadas. O itraconazol foi citotóxico, sendo que este efeito não foi visto com a nanoemulsão. É de extrema importância a avaliação da suscetibilidade dos agentes da cromoblastomicose a fim de orientar a clínica. A identificação molecular de agentes isolados de casos clínicos pode contribuir para delinear o perfil epidemiológico da doença. As nanoemulsões de anfotericina B e itraconazol apresentaram atividades superiores in vivo quando comparadas aos demais tratamentos e foram capazes de reduzir os efeitos adversos causados por estes antifúngicos. Através de ensaios in vitro foi confirmada a redução da citotoxidade do fármaco quando veiculado na nanoemulsão. Assim, as nanoemulsões produzidas poderiam ser alternativas terapêuticas para o tratamento da cromoblatomicose. / Chromoblastomycosis is a chronic mycosis that affects the skin and subcutaneous tissue. Various treatments have been used, but the efficacy is extremely low and does not allow choosing a therapy of choice. In the present work was performed: I - in vitro susceptibility testing for chromoblastomycosis agents against commercial antifungal; II - molecular characterization of samples from clinical cases as well as the description of these cases III - production and characterization of two nanoemulsions , one of amphotericin B and one of itraconazole, produced by high pressure homogenization technique; IV - assessing the in vitro and in vivo antifungal activity of these nanoemulsions against chromoblastomycosis agents; V - checking the level of impairment caused in the kidney and liver by nanoemulsions; VI - evaluation of toxicity of the formulations produced. In general, the chromoblastomycosis agents showed greater susceptibility to terbinafine and to itraconazole, respectively. The combination of amphotericin B and terbinafine was synergistic to four of the five groups. As for clinical cases, in the first was identified an infection by E. spinifera and in the second one by Fonsecaea monophora. The nanoemulsions were prepared with composition amenable of parenteral administration, one of amphotericin B and one of itraconazole, by the at high pressure homogenization method. Could not be determined the MIC of amphotericin B nanoemulsion and Abelcet® in vitro, while the itraconazole nanoemulsion showed MICs very similar to free drug. In a chromoblastomycosis animal model, the amphotericin B nanoemulsion was more active than free drug, Abelcet® and Fungizone®. The nanoemulsion of itraconazole also showed better activity compared to the free drug. Urea levels were higher in the animals receiving amphotericin B free and Fungizone®. The enzyme alanine aminotransferase was found in lower levels in animals treated with itraconazole nanoemulsion than in those who received itraconazole free. Amphotericin B free and Fungizone® caused severe damage to the kidneys. Already in animals treated with Abelcet® and the amphotericin B nanoemulsion was verified only focal necrosis. Likewise, the itraconazole nanoemulsion protected against liver damage when compared with the free drug. Regarding toxicity assays, amphotericin B was cytotoxic at concentrations from 4 μg/mL, while with the nanoemulsion this toxicity was not observed at higher concentrations. Itraconazole was cytotoxic, and this effect was not observed with the nanoemulsion. It is extremely important to evaluate the susceptibility of chromoblastomycosis agents to guide the clinic. Molecular identification of agents isolated from clinical cases can contribute to outline an epidemiological profile of the disease. The amphotericin B and itraconazole nanoemulsions showed higher activities in vivo when compared to other treatments and were able to reduce the adverse effects caused by these antifungals. Through in vitro assays were confirmed the reduction of the cytotoxicity of the drug when vehiculated in the nanoemulsion. Therefore, the nanoemulsions may be produced therapeutic alternatives for the chromoblastomycosis treatment.

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