Thèse (M.Sc.)--Université Laval, 2000. / Bibliogr.: f. 127-134.A. Publié aussi en version électronique.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 64-83).

Thesis (Ph.D.) - University of Queensland, 2006. / Includes bibliographical references.

Thesis (Ph. D.)--University of Rhode Island, 2005. / Typescript. Includes bibliographical references (leaves 129-140).

Thesis (Ph. D.)--University of Washington, 2006. / Includes bibliographical references (leaves 180-197).

Thesis (Ph. D.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains xiv, 150 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 104-120).

Cytochrome P-450, the terminal oxidase of the metabolic mono-oxygenase system, is thought to exist in multiple forms, which have differing substrate specificities, and are variably inducible by different enzyme inducers. Many mutagens, themselves unreactive, require metabolic activation by one or more of these cytochrome P-450-dependent microsomal enzymes for mutagenic activity. Such mutagens may be detected in the Salmonella mutagenicity test only by the incorporation of an hepatic microsomal (59) fraction into the assay (as a first approximation to in vivo metabolism). Induction of the microsomal enzymes by different agents enhances the metabolic activation of mutagens; in fact, many mutagens are only detected when the 59 fraction has been induced by appropriate agents. Inducers of the phenobarbital-type are known to enhance microsomal steroid hydroxylation when administered at supraphysiological levels, inducers of several mono-oxygenase activities. In turn, the steroids, have been reported to be The inductive effects of the female sex-steroids and the combined effects of steroid and phenobarbital (PB) pretreatment on the metabolic activation of four mutagens have been investigated using the Salmonella assay. Female Sprague-Dawley rats were pret reated with 17a-oestradiol (E2) or progesterone (PRG) , at a level of either 1 mg/kg or 20 mg / kg daily for 14 days. A duplicate set of similarly pretreated groups were also induced with PB. Hepatic microsomal fractions were prepared from each group and incubated with each of the te st mutagens in the presence of a tester strain known to detect each particular type of mutagen. Induction of the hepatic metabolizing system by PB increased the activation of the mutagens significantly (as reflected by an increased number of revertant prototrophic S .typhimurium colonies). The administration of PRG also caused significant, and dose-dependent, induction of the activation of af l atoxin B1, benzo(a)pyrene, and dimethylnitrosamine. In general, E2 exhibited no inductive effect, but it did produce an increase in the activation of aflatoxin B1 (a reaction which is known to be catalysed by a mono-oxygenase prefe rentially inducible by PB). When use was made of a microsomal fraction that was prepared from animals which were both steroidpretreated and induced by PB, mutagenic activation was of the same order of magnitude as that observed when induction was brought about by PB alone. The absence of additive effect, taken together with the observations already mentioned, indicate that steroids induce the same cytochrome isozymes that are induced by PB. The implications of sex-hormonal regulation of the metabolic activation of mutagens are briefly discussed. / KMBT_363 / Adobe Acrobat 9.53 Paper Capture Plug-in

A interação do citocromo c com a cardiolipina ocorre por interações eletrostáticas e hidrofóbicas. A formação do complexo citocromo c/ cardiolipina promove uma pequena mudança estrutural na proteína, que proporciona atividade peroxidásica ao citocromo c e consequentemente capacidade de oxidar substratos orgânicos, incluindo a cardiolipina. A oxidação da cardiolipina acompanhada da inserção de um grupo peróxido vem sendo relacionada à perda da interação hidrofóbica entre o complexo citocromo c/cardiolipina, que resulta no desligamento do citocromo c da membrana e na sua saída do espaço intermembranas para o citosol, onde essa proteína induz a cascata de apoptose. Neste trabalho foi avaliada a ligação do citocromo c a lipossomos contendo cardiolipina oxidada e a reatividade desta proteína com o mono-hidroperóxido da cardiolipina (TLCL(OOH)1) presente na membrana. Nossos dados mostraram que ocorre uma diminuição significativa na ligação do citocromo c a membrana oxidadas apenas quando 100% da cardiolipina presente na membrana está na forma de TLCL(OOH)1, condição que extrapolaria o que seria esperado para o sistema biológico. Análises por SDS-PAGE revelaram que o citocromo c sofre agregação na presença de membranas contendo TLCL(OOH)1, indicando que a proteína reage com este peróxido. De fato, determinamos a velocidade de reação do citocromo c com o TLCL(OOH)1 e com hidroperóxido do ácido linoléico, inseridos em membrana contendo cardiolipina (9,58 ± 0,16 x 102 M-1.s-1 e 6,91 ± 0,30 x 102 M-1.s-1, respectivamente). As velocidades de reação com os peróxidos de lipídio foram pelo menos 10 vezes superiores à velocidade medida com o peróxido de hidrogênio (5,91 ± 0,18 x101 M-1.s-1). Assim, mostramos que o citocromo c liga-se à membrana contendo hidroperóxido de cardiolipina e que reage com o mesmo promovendo a formação de agregado protéico de alto peso molecular / The interaction of cytochrome c with cardiolipin is promoted by electrostatic and hydrophobic interactions. The cytochrome c / cardiolipin complex formation causes structural changes in the protein that activates cytochrome c peroxidase activity, giving it the ability to oxidize organic substrates, including cardiolipin. The oxidation of cardiolipin coupled with a peroxide group insertion has been related to the loss of hydrophobic interactions between the cytochrome c / cardiolipin complex, resulting in cytochrome c release from the membrane and in its translocation from intermembranes space to cytosol, where this protein induces apoptosis cascade. In this work the binding of cytochrome c to liposomes containing oxidized cardiolipin and its reactivity with the membrane mono-hydroperoxides (TLCL(OOH)1) were evaluated. Our data showed a significant decrease in cytochrome c binding to oxidized membranes only when 100% of the membrane cardiolipin is in the TLCL(OOH)1 form, a condition that would extrapolate the expected concentrations that would be found in a biological system. SDS-PAGE analysis revealed that cytochrome c undergoes aggregation in the presence of membranes containing TLCL(OOH)1, indicating that this protein reacts with the peroxide. In fact, we determined the rate of cytochrome c reaction with TLCL(OOH)1 and linoleic acid hydroperoxide inserted into cardiolipin containing membranes (9.58 ± 0.16 x 102 M-1s-1 and 6.91 ± 0.30 x 102 M-1s-1,respectively). The reaction rates obtained with lipid peroxides were at least 10 times higher than that obtained with hydrogen peroxide (5.91 ± 0.18 x 101 M-1s-1).Thus we show that cytochrome c binds to membrane containing cardiolipin hydroperoxides and reacts with it promoting the formation of high molecular weight protein aggregates.

Made available in DSpace on 2014-06-11T19:27:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-01-27Bitstream added on 2014-06-13T20:36:33Z : No. of bitstreams: 1 gardim_s_me_arafcf.pdf: 1853681 bytes, checksum: 3bd67f0a8ef8c760824f1c5ffaea5e3e (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / A doença de Chagas tem como agente etiológico o protozoário Trypanosoma cruzi, cujos vetores pertencem à subfamília Triatominae. Os triatomíneos distribuem-se distribuídos por toda região Neotropical e epidemiologicamente se destacam as espécies dos gêneros Panstrongylus, Rhodnius e Triatoma. O gênero Triatoma é o mais numeroso e foi subdividido em complexos específicos de acordo com semelhanças morfológicas e distribuição geográfica de suas espécies. As sete espécies estudadas podem ser encontradas na região Centro-Oeste do Brasil, das quais seis pertencem ao subcomplexo matogrossensis (T. baratai, T. costalimai, T. guazu, T. matogrossensis, T. vandae e T. williami). A outra espécie, T. sordida pertence ao subcomplexo sordida. O objetivo deste estudo foi determinar a posição filogenética das sete espécies ocorrentes na região Centro-Oeste, por meio de comparação das sequências dos fragmentos citocromo b e 16S do DNA mitocondrial, visto que até o momento não foi determinada a posição de T. baratai e T. vandae com base em dados moleculares. Os exemplares avaliados são oriundos de colônias mantidas junto ao Insetário de Triatominae da Faculdade de Ciências Farmacêuticas/UNESP - Araraquara. Após a extração do DNA genômico e da amplificação dos fragmentos 16S e Cytb, procedeu-se o sequenciamento do DNA em sqüenciador automático, modelo ABI 377. As sequências obtidas juntamente com outras sequências (do mesmo fragmento) já disponíveis no GenBank, foram alinhadas com auxílio do programa Clustal W do BioEdit e as inferências filogenéticas foram conduzidas utilizando-se análises de parcimônia e de distância com o programa MEGA 3.1. De acordo com os resultados encontrados, T. costalimai mostrou-se mais distante das demais espécies e foi posicionada como grupo externo. As outras espécies distribuíram-se em dois grupos:.. / The protozoan Trypanosoma cruzi, the etiologic agent of Chagas' disease, is transmitted by vectors that belong to the subfamily Triatominae. The triatomines are distributed throughout the Neotropical region and species from Panstrongylus, Rhodnius and Triatoma genus stand out epidemiologically. The Triatoma genus is the largest and was divided in specific complexes according to morphological similarities and geographical distribution of its species. The seven species studied can be found in the Central West Region of Brazil, of which six belong to the matogrossensis subcomplex (T. baratai, T. costalimai, T. guazu, T. jurbergi, T. matogrossensis, T. vandae and T. williami). The other specie, T. sordida belong sordida subcomplex. The aim of this study was to determine the phylogenetic position of the seven species from Central West Region by comparing the 16S and Cytb fragments sequences of the mitochondrial DNA, since so far not been given the position of T. baratai and T. vandae based DNA sequences. The specimens evaluated came from colonies maintained at the Insectarium of Triatominae, Faculdade de Ciências Farmacêuticas / UNESP - Araraquara. After extraction of genomic DNA and amplification of the 16S and Cytb fragments, it was sequenced in an automatic DNA sequencer, model ABI 377. The sequences obtained and other sequences (of the same fragment) already available in GenBank were aligned using the Clustal W program of BioEdit and the phylogenetic inferences were conducted using the analysis of parsimony and distance with the MEGA 3.1 program. According to the results, T. costalimai was more distant from other species and was placed as an outside group. Other species are distributed in two groups, the first comprising the species T. vandae very close to T. matogrossensis and external of these, T. sordida. The second group includes T. guazu strongly related to T. williami... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:27:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-12Bitstream added on 2014-06-13T18:56:49Z : No. of bitstreams: 1 rocha_cs_me_arafcf.pdf: 697628 bytes, checksum: 703b47e347bee1b853ea18538df8a3e2 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Atualmente são admitidas 143 espécies da subfamília Triatominae que estão agrupadas em 18 gêneros e seis tribos. Essa classificação baseia-se principalmente em características morfológicas. Dentre essas espécies temos Triatoma rubrovaria, que pode ser encontrado no Estado do Rio Grande do Sul (Brasil), Uruguai e em algumas regiões da Argentina. Algumas espécies de Triatominae apresentam coloração e características morfológicas semelhantes, o que dificulta a identificação dos exemplares. Ferramentas como a morfometria, citogenética, retrocruzamentos e técnicas de biologia molecular são metodologias importantes para a identificação dessa subfamília. Estudos morfométricos prévios realizados com três populações de T. rubrovaria mantidas no Insetário de Triatomíneos do Laboratório de Parasitologia da Faculdade de Ciências Farmacêuticas revelaram a existência de diferenças morfométricas estatisticamente significativas entre a colônia de Caçapava do Sul (CS) e as duas colônias de Quaraí (QI e QII). Diferenças no padrão de cor do pronoto entre as três populações também foram observadas. A fim de avaliar a variabilidade genética dessas populações, analisaram-se as seqüências nucleotídicas do Citocromo B (Cyt B) e 16S, pertencentes ao DNA mitocondrial e o 28S, ao DNA nuclear. Dentre os marcadores utilizados, o Cyt B apresentou maior variabilidade, seguido do 28S e 16S, respectivamente. Devido ao seu maior polimorfismo o Cyt B mostrou-se um marcador eficaz para estudos de variabilidades... / Currently 143 species of the subfamily Triatominae, grouped into 16 genera and 6 tribes are recognized. This classification is mainly based on morphological characteristics. These species include Triatoma rubrovaria, which can be found in the state of Rio Grande do Sul (Brazil), Uruguay and some regions of Argentina. Some species of Triatominae have similar color and morphological characteristics, which complicates the identification of specimens. Morphometry, cytogenetics, backcrossing and molecular biology techniques are important methods for the identification of this subfamily. Previous morphometric studies carried out on three populations of T. rubrovaria maintained in the Insetário de Triatomíneos do Laboratório de Parasitologia of the Faculdade de Ciências Farmacêuticas have revealed the existence of statistically significant morphometric differences among the colony from Caçapava do Sul (CS) and the two colonies from Quaraí (QI and QII). Differences were also observed in the color patterns of the pronotum among the three populations. The sequences of Cytochrome B (Cyt B) and 16S, belonging to the mitochondrial DNA and 28S, the nuclear DNA, were analyzed to assess the genetic variety of these populations . The Cyt B showed the greatest variability, followed by 28S and 16S. It was concluded that Cyt B is the best marker for effective studies of population variability by virtue of its grater polymorphis ...(Complete abstract click electronic access below)