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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

Influencia dos polimorfismos nos genes CYP1A1, CYP1B1 e CYP2C9 na suscetibidade ao adenocarcionama colorretal esporadico / Influence polymorphisms in the genes CYP1A1, CYP1B1 and CYP2C9 susceptibility to colorectal cancer

Rossanese, Lillian Barbosa de Queiroz, 1980- 29 August 2007 (has links)
Orientador: Carmen Silvia Bertuzzo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-11T03:13:51Z (GMT). No. of bitstreams: 1 Rossanese_LillianBarbosadeQueiroz_M.pdf: 1133308 bytes, checksum: 4ba5139d2469cc3760a205f431d4a222 (MD5) Previous issue date: 2007 / Resumo: O Câncer colorretal (CCR) refere-se a uma neoplasia que atinge o cólon e o reto, apesar das diferenças epidemiológicas e biológicas entre o câncer do cólon e reto, as duas condições são combinadas, pois não se faz uma separação clara dos dois locais anatômicos; assim, o câncer do colón e/ou do reto é classificado como câncer colorretal. Dados epidemiológicos atestam a importância de fatores ambientais na patologia do CCR Esporádico. Os polimorfismos de P450 e a suscetibilidade ao câncer podem estar associados ainda, pelo fato dessas isoenzimas participarem também de transformação de compostos endógenos relevantes durante o processo de diferenciação da célula transformada, até o estágio maligno. O objetivo deste trabalho foi avaliar a prevalência dos polimorfismos m1 e m2 no gene CYP1A1, 2C9*2 e 2C9*3 no gene CYP2C9 e o 1B1*3 no CYP1B1 e correlacionar a presença desses polimorfismos com o hábito tabagista e o estadiamento clínico da doença. A análise dos polimorfismos foi realizada por meio da Reação em Cadeia da Polimerase associada a digestões enzimáticas específicas. Foram avaliados 102 pacientes com CCR esporádico e 230 portadores de sangue sem história familial de CCR. Nossos resultados indicaram que indivíduos sem os alelos M1 e M2 do gene CYP1A1 teriam um efeito protetor com relação ao CCR, enquanto que os indivíduos portadores de um alelo M1 ou M2 e os homozigotos M2 teriam um aumento de risco que seriam respectivamente de 6, quase 3 (2,89) e quase 4 vezes (3.70). Com relação ao gene CYP2C9, o genótipo N/N (sem as mutações *2 e *3) teria um efeito protetor, enquanto que o heterozigoto *3 traria um risco 6 vezes maior (5.90) e o homozigoto *3 , três vezes. A presença dos alelos M1 e M2 parecem estar relacionados a um pior prognóstico da doença, enquanto que *3 do CYP2C9 traria um melhor prognóstico. Maiores estudos são necessários para confirmar esses achados. No caso do polimorfismo 1B1*3 do gene CYP1B1, parece não haver relação com o fenótipo CCR / Abstract: The colorectal cancer (CRC) characterizes a neoplasia which reaches the colon and the rectum tissues. It is classified as so, despites the biological and epidemiological differences between the colon and rectum cancer, because there is not a clear anatomical separation of these areas. The importance of external factors in the pathology of the sporadical CRC has been certified by epidemiological data. Thus, P450 polymorphisms might be associated to cancer due to the fact that these proteins play a role in transforming endogenous compounds during the process of differentiation of transformed cells, until its malignant stage. The objective of this work was to evaluate the prevalence of the polymorphisms M1 and M2 in CYP1A1 gene, 2C9*2 and 2C9*3 in CYP2C9 gene and 1B1*3 in CYP1B1 gene. Also, the correlation among the presence of these polymorphisms, the tobaccoism and the clinical stagnancy of the illness was performed. Polymerase chain reactions (PCRs) followed by specific enzymatic digestions were performed in order to analyze the polymorphisms. We evaluated 102 patients with sporadical CRC and 230 control individuals without familial history of CRC. Our results indicated that individuals that did not carry M1 and M2 variants of CYP1A1 gene presented a protective effect against CRC, while individuals who presented M1 or M2 variants had a 6 and almost 3 (2.89) times increasing of the risk, respectively, while patients with both M2 alleles had an almost 4 times (3.70) increasing risk. Analysis of CYP2C9 gene showed that genotype N/N (without * 2 and * 3 mutations) presented a protective effect, while individuals heterozygotes for * 3 mutation had an increase close to 6 times (5.90) of their risk. Homozygotes for the same mutation would present a 3 times increased risk. M1 and M2 alleles presence seems to be related to a worse prognostic of the illness, while the presence of * 3 mutation in CYP2C9 gene would result in a better prognostic. Other studies are necessary to confirm these findings. Polymorphism 1B1*3 of CYP1B1 gene does not seem to be related to CRC phenotype / Mestrado / Mestre em Farmacologia
2

Esteroidogênese testicular durante o desenvolvimento sexual pós-natal em Galea spixii (Wagler, 1831) / Testicular steroidogenesis during post-natal sexual development in Galea spixii (Wagler, 1831)

Santos, Paulo Ramos da Silva 04 November 2016 (has links)
O desenvolvimento testicular e a manutenção da espermatogênese são controlados por gonadotrofinas e testosterona, cujos efeitos são modulados por uma rede complexa de fatores produzidos localmente e, entre eles, os estrógenos estão em causa. Uma compreensão da dinâmica dos hormônios esteroides sexuais mostra-se importante para revelar as funções durante o desenvolvimento testicular. Sendo assim, este trabalho teve como objetivo aprofundar os conhecimentos sobre a espermatogênese do Galea spixii, associando a atuação das enzimas do complexo citocromo P450: P450 aromatase e P450c17 (17-α-hidroxilase/17,20-liase) importantes para a biossíntese de hormônios ligados à reprodução durante o desenvolvimento sexual pós-natal. Fragmentos de testículos de preás machos nas fases impúbere, pré-púbere, púbere e pós-púbere foram coletados no Centro de Multiplicação da Universidade Federal Rural do Semiárido, Mossoró, RN, fixados em Paraformoaldeido 4% e RNAlater, e processados para Imunohistoquímica e PCR em tempo real. A expressão gênica das enzimas esteroidogênicas foram cruciais da prépuberdade para a puberdade. Durante as fases do desenvolvimento sexual a enzima P450c17 apresentou imunomarcação positiva apenas nas células de Leydig. A imunomarcação da enzima P450 aromatase foi positiva em diferentes tipos celulares ao longo do desenvolvimento sexual. A síntese de estrógenos no parênquima testicular não ficou restrita às células somáticas, as células germinativas também mostraram capacidade de converter andrógenos em estrógenos / The testis development and maintenance of spermatogenesis are controlled by gonadotropins and testosterone, whose effects are modulated by a complex factor locally produced, and the estrogens are involved. An understanding of the dynamics of sex steroid hormones shown to be important to reveal the functions during testicular development. Thus, the aimed was study the spermatogenesis of Galea spixii, associating the performance of cytochrome P450 complex: P450 aromatase and P450c17 (17-α-hydroxylase / 17,20-lyase) important for the biosynthesis of hormones related to reproduction during postnatal sexual development. Fragments of testes of immature, prepubertal, pubertal and post-pubertal were collected at Centro de Multiplicação da Universidade Federal Rural do Semiárido, Mossoró, RN, fixed in Paraformaldehyde 4% and RNAlater, processed for immunohistochemistry and real time PCR. The steroidogenic enzymes gene expression were significant from prepubertal to pubertal stage. Cytochrome P450c17 expression in testicular parenchyma showed a positive reaction only in Leydig cell clusters. The expression of cytochrome P450 aromatase in testicular parenchyma were different during the sexual development of Galea spixii. During sexual development was observed that estrogen synthesis was not restricted to somatic cells (Leydig cells / Sertoli cells), the germ cells have also shown to be capable to convert androgens into estrogens via aromatase
3

Esteroidogênese testicular durante o desenvolvimento sexual pós-natal em Galea spixii (Wagler, 1831) / Testicular steroidogenesis during post-natal sexual development in Galea spixii (Wagler, 1831)

Paulo Ramos da Silva Santos 04 November 2016 (has links)
O desenvolvimento testicular e a manutenção da espermatogênese são controlados por gonadotrofinas e testosterona, cujos efeitos são modulados por uma rede complexa de fatores produzidos localmente e, entre eles, os estrógenos estão em causa. Uma compreensão da dinâmica dos hormônios esteroides sexuais mostra-se importante para revelar as funções durante o desenvolvimento testicular. Sendo assim, este trabalho teve como objetivo aprofundar os conhecimentos sobre a espermatogênese do Galea spixii, associando a atuação das enzimas do complexo citocromo P450: P450 aromatase e P450c17 (17-α-hidroxilase/17,20-liase) importantes para a biossíntese de hormônios ligados à reprodução durante o desenvolvimento sexual pós-natal. Fragmentos de testículos de preás machos nas fases impúbere, pré-púbere, púbere e pós-púbere foram coletados no Centro de Multiplicação da Universidade Federal Rural do Semiárido, Mossoró, RN, fixados em Paraformoaldeido 4% e RNAlater, e processados para Imunohistoquímica e PCR em tempo real. A expressão gênica das enzimas esteroidogênicas foram cruciais da prépuberdade para a puberdade. Durante as fases do desenvolvimento sexual a enzima P450c17 apresentou imunomarcação positiva apenas nas células de Leydig. A imunomarcação da enzima P450 aromatase foi positiva em diferentes tipos celulares ao longo do desenvolvimento sexual. A síntese de estrógenos no parênquima testicular não ficou restrita às células somáticas, as células germinativas também mostraram capacidade de converter andrógenos em estrógenos / The testis development and maintenance of spermatogenesis are controlled by gonadotropins and testosterone, whose effects are modulated by a complex factor locally produced, and the estrogens are involved. An understanding of the dynamics of sex steroid hormones shown to be important to reveal the functions during testicular development. Thus, the aimed was study the spermatogenesis of Galea spixii, associating the performance of cytochrome P450 complex: P450 aromatase and P450c17 (17-α-hydroxylase / 17,20-lyase) important for the biosynthesis of hormones related to reproduction during postnatal sexual development. Fragments of testes of immature, prepubertal, pubertal and post-pubertal were collected at Centro de Multiplicação da Universidade Federal Rural do Semiárido, Mossoró, RN, fixed in Paraformaldehyde 4% and RNAlater, processed for immunohistochemistry and real time PCR. The steroidogenic enzymes gene expression were significant from prepubertal to pubertal stage. Cytochrome P450c17 expression in testicular parenchyma showed a positive reaction only in Leydig cell clusters. The expression of cytochrome P450 aromatase in testicular parenchyma were different during the sexual development of Galea spixii. During sexual development was observed that estrogen synthesis was not restricted to somatic cells (Leydig cells / Sertoli cells), the germ cells have also shown to be capable to convert androgens into estrogens via aromatase
4

Taxonomical study of predatory and plant-parasitic mites associated with South African Solanaceae / Candice Ceustermans

Ceustermans, Candice January 2015 (has links)
Plant-feeding mites represent major pests in agriculture that are of importance to crops world-wide, as large populations of mites reduce the quality and quantity of yields. Alternatives to the use of pesticides are needed due to their negative effects and bio-control agents (predatory mites) remain advantages as they suppress spider mites and other plant pests. This study aims to determine species status of plant-feeding and predatory mites on plants of the family Solanaceae and to apply morphological and molecular data to determine phylogenetic relationships among economically important Phytoseiidae, Stigmaeidae and Tetranychidae. The material for this study was collected through plant beating and specimens were preserved in 75% and 96% ethanol respectively and mounted in Heinz’s PVA medium on microscope slides. A survey was conducted during peak seasons to provide enough samples of pest and predatory species. Morphological analysis was performed and initial results indicate that 94% of the species identified were parasitic and 6% were predatory, which led to a predator:prey ratio of 1:17, where Tetranychus evansi Baker & Pritchard had the highest frequency of appearance. A modified Qiagen DNeasy tissue kit extraction protocol was used and Polymerase Chain Reaction was performed to amplify ribosomal ITS and mitochondrial COI gene fragments. The nucleotide sequence of a 700-bp fragment for ITS was determined by direct sequencing as well as for a 700-bp and 800-bp fragments for COI. The resulting data included 4 isolates that corresponded morphologically and molecularly with Phytoseiidae and 10 with Stigmaeidae. The phylogenetic trees agreed with the morphological data. For species that lack morphological descriptions in GenBank and are not placed within expected clades, one has to accept the possibility of miss identification and highlights the need to combine morphological and molecular approaches to guarantee solid species diagnosis. Ultimately, Solanaceae contain various parasitic mites, but predators seem low in numbers. This could be problamatic in finding effective bio-control agents. / MSc (Zoology), North-West University, Potchefstroom Campus, 2015
5

Taxonomical study of predatory and plant-parasitic mites associated with South African Solanaceae / Candice Ceustermans

Ceustermans, Candice January 2015 (has links)
Plant-feeding mites represent major pests in agriculture that are of importance to crops world-wide, as large populations of mites reduce the quality and quantity of yields. Alternatives to the use of pesticides are needed due to their negative effects and bio-control agents (predatory mites) remain advantages as they suppress spider mites and other plant pests. This study aims to determine species status of plant-feeding and predatory mites on plants of the family Solanaceae and to apply morphological and molecular data to determine phylogenetic relationships among economically important Phytoseiidae, Stigmaeidae and Tetranychidae. The material for this study was collected through plant beating and specimens were preserved in 75% and 96% ethanol respectively and mounted in Heinz’s PVA medium on microscope slides. A survey was conducted during peak seasons to provide enough samples of pest and predatory species. Morphological analysis was performed and initial results indicate that 94% of the species identified were parasitic and 6% were predatory, which led to a predator:prey ratio of 1:17, where Tetranychus evansi Baker & Pritchard had the highest frequency of appearance. A modified Qiagen DNeasy tissue kit extraction protocol was used and Polymerase Chain Reaction was performed to amplify ribosomal ITS and mitochondrial COI gene fragments. The nucleotide sequence of a 700-bp fragment for ITS was determined by direct sequencing as well as for a 700-bp and 800-bp fragments for COI. The resulting data included 4 isolates that corresponded morphologically and molecularly with Phytoseiidae and 10 with Stigmaeidae. The phylogenetic trees agreed with the morphological data. For species that lack morphological descriptions in GenBank and are not placed within expected clades, one has to accept the possibility of miss identification and highlights the need to combine morphological and molecular approaches to guarantee solid species diagnosis. Ultimately, Solanaceae contain various parasitic mites, but predators seem low in numbers. This could be problamatic in finding effective bio-control agents. / MSc (Zoology), North-West University, Potchefstroom Campus, 2015

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