• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 87
  • 73
  • 13
  • 13
  • 13
  • 13
  • 13
  • 13
  • 11
  • 5
  • 3
  • 1
  • 1
  • Tagged with
  • 213
  • 117
  • 59
  • 50
  • 49
  • 38
  • 32
  • 32
  • 30
  • 29
  • 27
  • 27
  • 26
  • 26
  • 24
  • 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.
131

Major tea catechin inhibits dendritic cell maturation in response to microbial stimulation /

Rogers, James L. January 2007 (has links)
Dissertation (Ph.D.)--University of South Florida, 2007. / Includes vita. Includes bibliographical references (leaves 70-84). Also available online.
132

The role of norepinephrine in learning : cerebellar motor learning in rats /

Paredes, Daniel A. January 2007 (has links)
Dissertation (Ph.D.)--University of South Florida, 2007. / Includes vita. Includes bibliographical references (leaves 109-141). Also available online.
133

Role of the Intestinal Immune System in the Pathogenesis of Autoimmune Diabetes in the BB Rat Model of Type 1 Diabetes Mellitus

Todd, Derrick James 11 June 2001 (has links)
The intestine is the largest lymphoid organ in the body, challenged constantly by an enonnous quantity and diversity of antigens. Distinct from peripheral lymphocytes, intestinal lymphocytes have evolved unique mechanisms of tolerance and appear to govern mucosal processes such as "chronic physiologic inflammation" and oral tolerance. Failure of mucosal tolerance has been implicated in the pathogenesis of several diseases, including inflammatory bowel disease, celiac disease, and even autoimmune diabetes. One population of intestinal lymphocytes, intraepithelial lymphocytes (IELs), exists within the intestinal epithelium itself and remains poorly characterized. IELs respond to unique activation signals and appear to be in part responsible for the maintenance of epithelial integrity and mucosal tolerance. Type 1 diabetes is one of the most common chronic childhood illnesses and causes significant morbidity and mortality. Type 1 diabetes mellitus is an autoimmune disease that results from immune-mediated destruction of insulin-producing pancreatic beta cells and is characterized by an absolute insulin deficiency. Several animal models are used to study the immunopathogenesis of type 1 diabetes, including the BB rat and NOD mouse. BBDP rats spontaneously develop autoimmune diabetes mellitus and are severely deficient in peripheral T cells. BBDR rats do not spontaneously develop autoimmune diabetes, have nonnal numbers of peripheral T cells, and can be induced to become diabetic by injections of a cytotoxic anti-ART2a mAb and low doses of poly I:C. The cause of autoimmune diabetes in BB rats and humans is still unknown, but both genetic and environmental factors appear to participate. I hypothesize that one important class of environmental factors--diet and enteromicrobial agents--participates in this pathogenic process through the mediation of the gut immune system. In this dissertation, I report a new method for the isolation of rat IELs that is based on the selective removal of intestinal epithelial cells under conditions that leave the basement membrane undisturbed. The yield of rat IELs using this method is 5-10 fold greater than that reported for other methods. Morphological and phenotypic analyses demonstrate that the purified cell population is comprised of IELs and is not contaminated with lamina propria or Peyer's patch lymphocytes. Phenotypic analysis reveals 5 major subsets of IELs, including populations of γδ T and natural killer (NK) cells present at levels not previously detected. I also report that rat intraepithelial NK (IENK) and peripheral NK cells are similar in morphology, in their ability to lyse NK-sensitive targets, and in their ability to suppress a one-way mixed lymphocyte culture. In contrast, IENK cells differ from splenic NK cells phenotypically, and a substantial fraction of IENK cells appear to spontaneously secrete IL-4 and/or IFN-γ. I conclude that rat IELs harbor a large population of NKR-P1A+ CD3-cells that function as NK cells but display an activated phenotype and unusual cytokine profile that clearly distinguish them from splenic NK cells. Their phenotypic and functional characteristics suggest that these distinctive intraepithelial NK cells may participate in the regulation of mucosal immunity. I next demonstrate that, prior to diabetes, both BBDP and ART2a-depleted BBDR rats have a reduced total number of IELs and exhibit a selective deficiency of IENK cell number and function as compared to control BBDR rats. The deficiency of BBDP rat IELs can be corrected by engraftment of bone marrow from histocompatible WF donors. These results suggest 1) that the peripheral lymphopenia in BBDP rats extends to the IEL compartment, particularly to IENK cells, 2) that in BBDR rats the diabetes-inducing treatment depletes IELs, particularly IENK cells, and 3) that the defect in BBDP rat IELs is intrinsic to hematopoietic cells, not intestinal stromal cells. I also establish that, unlike BBDR and WF rats, BBDP rats are also deficient in γδTCR+IELs, a population of T cells that may play a role in normal mucosal tolerance. In addition, I report preliminary data supporting the hypothesis that systemic autoreactivity may be initiated in the intestine; peripheral autoreactive lymphocyte populations appear to emanate first from mesenteric lymph nodes that drain the intestine, and such cells may initiate a type 2 autoimmune phenomenon driven by IL-4. Collectively, my findings support the hypothesis that a failure of mucosal tolerance in BBDP rats, perhaps secondary to deficiencies in one or more IEL subpopulations, participates in the pathogenesis of autoimmune diabetes in these animals by activating peripheral autoreactive T cells. The nature of the autoimmune response in BB rats (driven by IL-4) appears to be distinct from that of NOD mice. Despite the differences between these two well-accepted animal models of autoimmune diabetes, until more is known about the pathogenesis of type 1 DM in humans, lessons learned from both the BB rat and NOD mouse continue to be of tremendous benefit to our understanding of human disease.
134

Caracterização dos efeitos da exposição aos componentes do cigarro sobre o controle neural do sistema cardiovascular em ratos normotensos e ratos espontaneamente hipertensos / Characterization of sidestream cigarette smoke effects on neural control of cardiovascular system in normotensive and spontaneously hypertensive rats

Valenti, Vitor Engrácia [UNIFESP] 29 June 2011 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:49:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-29. Added 1 bitstream(s) on 2015-08-11T03:26:12Z : No. of bitstreams: 1 Publico-12851a.pdf: 1993449 bytes, checksum: 6fad4a58fc1b395d08412bb6e3b076ea (MD5). Added 1 bitstream(s) on 2015-08-11T03:26:12Z : No. of bitstreams: 2 Publico-12851a.pdf: 1993449 bytes, checksum: 6fad4a58fc1b395d08412bb6e3b076ea (MD5) Publico-12851b.pdf: 1501009 bytes, checksum: ab8946f01511cdc67f2383a0a9fabaac (MD5). Added 1 bitstream(s) on 2015-08-11T03:26:12Z : No. of bitstreams: 3 Publico-12851a.pdf: 1993449 bytes, checksum: 6fad4a58fc1b395d08412bb6e3b076ea (MD5) Publico-12851b.pdf: 1501009 bytes, checksum: ab8946f01511cdc67f2383a0a9fabaac (MD5) Publico-12851c.pdf: 1843176 bytes, checksum: 32033d7bc48d53d7cb1127e1ae58221f (MD5). Added 1 bitstream(s) on 2015-08-11T03:26:13Z : No. of bitstreams: 4 Publico-12851a.pdf: 1993449 bytes, checksum: 6fad4a58fc1b395d08412bb6e3b076ea (MD5) Publico-12851b.pdf: 1501009 bytes, checksum: ab8946f01511cdc67f2383a0a9fabaac (MD5) Publico-12851c.pdf: 1843176 bytes, checksum: 32033d7bc48d53d7cb1127e1ae58221f (MD5) Publico-12851d.pdf: 1909278 bytes, checksum: 7f3b132a4365c4aeab410fd8f4041429 (MD5) / Objetivos: avaliar os efeitos da fumaça lateral de cigarro (FLC) sobre o controle neural do sistema cardiovascular em ratos normotensos e ratos espontaneamente hipertensos (SHR). Método: ratos Wistar, Wistar-Kyoto (WKY) e SHR foram expostos à FLC durante três semanas, cinco dias por semana, 180 minutos por dia numa concentração de monóxido de carbono entre 100 e 300 ppm. Barorreflexo foi estimulado por uma dose vasodepressora de nitroprussiato de sódio (NPNa, 50Og/kg, i.v.) e uma dose pressora de fenilefrina (PE, 8Og/kg , i.v.). Para avaliar os efeitos da inibição da catalase no quarto ventrículo cerebral (4ºV) sobre as respostas cardiovasculares, foi injetado o inibidor de catalase 3-amino-1,2,4-triazole (ATZ, 0,01Og/100OL). Resultados: nos ratos Wistar expostos à FLC, foi observado que a inibição da catalase causou respostas mais intensas quanto a FC basal e ao pico bradicárdico. A inibição da catalase afetou de maneira mais intensa a FC basal e o pico bradicárdico, nos ratos WKY expostos à FLC. Por outro lado, nos animais SHR a exposição à FLC afetou o pico taquicárdico após inibição central de catalase de maneira mais intensa. Conclusão: a exposição à FLC altera os componentes simpáticos do barorreflexo em ratos WKY e SHR, além de causar respostas cardiovasculares mais intensas perante a inibição de catalase no 4ºV em ratos Wistar e WKY. / Objectives: To evaluate the effects of sidestream cigarette smoke (SSCS) on neural control of cardiovascular system in normotensive and spontaneously hypertensive rats (SHR). Method: Wistar, Wistar-Kyoto rats (WKY) and SHR were exposed to SSCS for three weeks, five days per week, 180 minutes per day at a concentration of carbon monoxide between 100 and 300 ppm. Baroreflex was stimulated with a vasodepressor dose of sodium nitroprusside (NPNa, 50ìg/kg, iv) and with a pressor dose of phenylephrine (PE, 8ìg/kg, iv). In order to evaluate the effects of catalase inhibition into the fourth cerebral ventricle (4th V) on cardiovascular responses, we injected the catalase inhibitor 3-amino-1,2,4-triazole (ATZ, ìg/100ìL 0.01). Results: It was observed in Wistar rats exposed to SSCS that catalase inhibition caused more intense responses on basal HR and bradycardic peak. Central catalase inhibition affected in a higher intensity baseline HR and bradycardic peak WKY rats exposed to SSCS. On the other hand, in SHR SSCS exposure affected the tachycardic peak after central inhibition of catalase in a higher intensuty. Conclusion: Exposure to SSCS alters the sympathetic component of the baroreflex in WKY and SHR and caused more severe cardiovascular responses to catalase inhibition into the 4th V in Wistar and WKY rats. / TEDE / BV UNIFESP: Teses e dissertações
135

Avaliação do efeito do atenolol no processo de reparo alveolar em ratos espontaneamente hipertensos (SHR)

Cursino, Natalia Manrique [UNESP] 20 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-20Bitstream added on 2014-06-13T19:15:14Z : No. of bitstreams: 1 cursino_nm_me_araca.pdf: 2792202 bytes, checksum: 7bc02b29243b06952aa21b86edc0566a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A hipertensao arterial representa um fator de risco sistemico e condicao desfavoravel para tratamentos dentarios, especialmente aqueles que necessitam de reparacao ossea. O objetivo deste estudo foi avaliar o reparo alveolar em ratos espontaneamente hipertensos (SHR) e o efeito do atenolol sobre este processo. Wistar e SHR tratados ou nao com 100mg/kg/dia (atenolol), foram submetidos a extracao do dente incisivo superior direito e sacrificados aos 7, 14, 21, 28 e 42 dias apos a cirurgia. As hemi-maxilas foram removidas e as imagens radiograficas foram realizadas. A analise radiografica foi obtida por meio do sistema digital Digora. Analises histologicas, histomorfometricas e reacoes imunoistoquimicas foram feitas em cortes histologicos de 5ƒÊm de espessura, os quais foram corados com hematoxilina-eosina ou submetidos a imunomarcacao para RANK, RANKL, OPG e proteinas MMP-9. A analise histologica foi realizada por microscopia optica e a analise histomorfometrica pelo software RGB / Leica Qwin Color. Os resultados densitometricos e histomorfometricos foram analisados pela Anova two-way. Na analise imunoistoquimica, utilizando um microscopio optico, foram atribuidos scores as imagens. Os resultados foram analisados pelos testes estatisticos Kruskal-Wallis e Mann Whitney. As diferencas entre os resultados foram consideradas significativas quando p<0,05. Reducao da densidade mineral ossea (DMO), menor porcentagem de osso e menor espessura do trabeculado osseo foram observadas nos periodos finais do reparo alveolar em SHR. Aumento da imunomarcacao para RANKL, RANK e MMP-9 foi observado em 28 dias apos a cirurgia no alveolo em SHR. Consistente efeito do atenolol foi observado no reparo alveolar de ratos hipertensos. O atenolol aumentou a DMO observada na maioria dos periodos analisados e aumentou a espessura do trabeculado... / Hypertension represents a systemic risk factor and unfavorable condition for dental treatments, especially treatments that require bone healing. The purpose of this study was to evaluate the alveolar wound healing in spontaneously hypertensive rats (SHR) and the atenolol effect on this process. Normotensive Wistar rats and SHR, untreated or treated with atenolol (100mg/kg/day), were submitted to the extraction of the upper right incisive tooth and sacrificed at 7, 14, 21, 28 and 42 days after surgery. The hemi-jaws were extracted and the radiographic images were obtained. Radiographic analysis was performed by using the digital system Digora. Histological, histomorphometric and immunohistochemical reactions were done in histological sections, 5 μm thick, stained with hematoxylin and eosin or subjected to immunolabeling to RANK, RANKL, OPG and MMP-9 proteins. Histological analysis was performed by light microscopy and histomorphometric analysis by Leica Qwin Color/RGB software. The densitometric and histomorphometric results were also analyzed by two-way ANOVA. In immunohistochemical analysis, using an optical microscopy, scores were assigned to the images. Results were analyzed by Kruskal-Wallis and Mann Whitney statistical tests. Differences between results were considered significant when p <0.05. Reduced bone mineral density (BMD), lower bone percentage and less thickness of trabecular bone was observed in the final periods of alveolar bone healing in SHR. Increased RANKL, RANK and MMP-9 immunolabeling were observed at 28 days after surgery in SHR alveolus. Consistent atenolol effect was observed on alveolar bone healing of hypertensive rats. Atenolol increased the BMD observed in most of the periods analyzed and increased trabecular bone thickness at 28 and 42 days in SHR alveolus. Increased OPG immunolabeling... (Complete abstract click electronic access below)
136

Imunogenicidade de vacinas de DNA codificando peptídeos conservados e promíscuos do HIV-1,  em camundongos BALB/c / Immunogenicity of DNA vaccines encoding conserved and promiscuous HIV-1 peptides, in BALB/c mice

Rafael Ribeiro Almeida 10 June 2011 (has links)
A pandemia de AIDS é um dos principais problemas de saúde pública no mundo e demanda o desenvolvimento de uma vacina eficaz. Uma abordagem vacinal ideal, baseada em resposta celular contra o HIV-1, deveria induzir uma resposta imune mediada tanto por células T CD4+ quanto CD8+. A diversidade genética do HIV-1 é uma grande preocupação para o desenvolvimento de uma vacina e sequências consenso têm sido utilizadas a fim de contornar a barreira imposta por essa diversidade. A escolha apropriada dos antígenos a comporem as construções vacinas também é relevante, visto que proteínas como Gag e Vif têm se mostrado bastante imunogênicas, enquanto alguns trabalhos têm demonstrado que Env possui características imunossupressoras e que respostas celulares contra esse antígeno podem ser danosas aos indivíduos vacinados. Nosso grupo demonstrou que uma vacina de DNA (HIVBr18) codificando 18 peptídeos para linfócitos T CD4+, promíscuos (capazes de se ligarem a múltiplas moléculas HLA-DR) e conservados na sequência consenso do subtipo B do HIV-1 foi capaz de induzir uma resposta celular ampla, polifuncional e de longa duração em camundongos BALB/c e transgênicos para moléculas HLA. Neste trabalho identificamos 34 peptídeos potencialmente reconhecidos por linfócitos T CD4+, promíscuos e conservados na sequência consenso dos consensos do grupo M do HIV-1. Uma vacina de DNA (HIVBr27) codificando 27 dos 34 peptídeos (exceto os 7 peptídeos de Env identificados) induziu uma resposta mais ampla e de maior magnitude que a vacina HIVBr18 em camundongos BALB/c. Além disso, a vacina HIVBr27 induziu maior frequência de linfócitos T CD4+ e CD8+ polifuncionais, capazes de proliferar e produzir as citocinas IFN-gama e TNF-alfa. Desenvolvemos também uma vacina de DNA (HIVenv7) codificando os 7 peptídeos de Env do HIV-1 identificados. A co-imunização de HIVenv7+HIVBr27 reduziu a amplitude da resposta celular contra peptídeos codificados pela vacina HIVBr27. Além disso, a co-imunização reduziu a magnitude da resposta e a frequência de linfócitos T CD4+ e CD8+ polifuncionais contra o pool de 27 peptídeos codificados por essa vacina. A vacina HIVBr27, desenhada para induzir uma resposta de linfócitos T CD4+ ampla e intensa contra peptídeos promíscuos e conservados da sequência consenso dos consensos do grupo M do HIV-1, é mais imunogênica e mais completa que a vacina HIVBr18, tendo potencial de conferir, em grande cobertura populacional, imunidade contra os diversos subtipos circulantes do vírus. O fenômeno observado na co-imunização com HIVenv7 sugere que a inclusão do envelope em imunógenos contra o HIV-1 possa ser prejudicial. Por outro lado, isto faz desse plasmídeo um alvo promissor para terapias imunológicas que visem indução de imunossupressão / The AIDS pandemic is a worldwide major public health problem and requires the development of an effective vaccine. An ideal vaccine approach based on cellular immune responses against HIV-1 should induce an immune response mediated by both CD4+ and CD8+ T cells. HIV-1 genetic diversity is a major concern for developing a vaccine and consensus sequences have been used to circumvent the barrier posed by this diversity. The appropriate choice of antigens to compose the vaccines is also relevant, since proteins such as Gag and Vif have been shown to be immunogenic, while some studies have shown that Env has immunosuppressive characteristics and cellular responses against this antigen can be harmful to vaccinated individuals. Our group has demonstrated that a DNA vaccine (HIVBr18) encoding promiscuous multiple HLA-DR binding, conserved B-subtype HIV-1 CD4+ T cell epitopes was able to induce a broad, polyfunctional and long lasting T cell response in BALB/c and HLA transgenic mice. In this work we identified 34 promiscuous and conserved sequences within the group M HIV-1 consensus of the consensus sequence, potentially recognized by CD4+ T cells. A DNA vaccine (HIVBr27) encoding 27 of the 34 peptides (except the 7 Env identified peptides) induced a broader and higher magnitude T cell response than HIVBr18 vaccine in BALB/c mice. Moreover, the vaccine HIVBr27 induced a higher frequency of polyfunctional CD4+ and CD8+ T cells, able to proliferate and produce the cytokines IFN-gama and TNF-alfa. We also developed a DNA vaccine (HIVenv7) encoding the 7 HIV-1 Env identified peptides. Co-immunization with HIVenv7+HIVBr27 reduced the breadth of the cellular immune response against the HIVBr27 encoded peptides. Besides, co-imunization reduced the magnitude of the response and the frequency of polyfunctional CD4+ and CD8+ T cells against the pool of 27 peptides encoded by this vaccine. The HIVBr27 vaccine, designed to induce a broad and intense CD4+ T cell response against promiscuous and conserved peptides within the group M HIV-1 consensus of the consensus sequence, is more immunogenic and more complete than the vaccine HIVBr18, having the potential to provide, with wide population coverage, immunity against various circulating subtypes of the virus. The phenomenon observed in the co-immunization with HIVenv7 suggests that the inclusion of the envelope in immunogens against HIV-1 may be harmful. On the other hand, these results suggest that HIVenv7 is a promising target for immune therapies aimed at inducing immunosuppression
137

Estratégias de melhoramento do feijoeiro-comum para altos teores de ferro e zinco / Common beans breeding strategies for high iron and zinc content

Martins, Saulo Muniz 20 February 2015 (has links)
Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-09-02T16:55:01Z No. of bitstreams: 2 Dissertação - Saulo Muniz Martins - 2015.pdf: 2299798 bytes, checksum: 7f9c71420497f5dfb48e9fc9a61b5bed (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-06T13:31:17Z (GMT) No. of bitstreams: 2 Dissertação - Saulo Muniz Martins - 2015.pdf: 2299798 bytes, checksum: 7f9c71420497f5dfb48e9fc9a61b5bed (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-06T13:31:17Z (GMT). No. of bitstreams: 2 Dissertação - Saulo Muniz Martins - 2015.pdf: 2299798 bytes, checksum: 7f9c71420497f5dfb48e9fc9a61b5bed (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / During 85 years, the common beans breeding was dedicated efforts to important agronomic, industrial and cooking traits. During this period, the nutritional quality of primary food was not worked. However, with malnutrition rates rising, research entities directed resources in this new strategy, known as biofortification. The objectives of this study were: to estimate the genetic and phenotypic parameters among inbred lines for iron (TFe) and zinc content (TZn) in grain; verify the presence of genotypes with environments interaction for TFe and TZn in the grain; select strains that add both high nutritional quality in the grain and high agronomic potential; check for genetic relationship between TFe and the TZn; and verify the need for testing in various environments for TFe and TZn. Initially, 140 lines were evaluated, 68 of carioca, 30 black, 16 pinto, 14 early carioca and 12 purple type. Each preliminary test was carried out separately by grain type, in some environments, in 2011 year, in case blocks with three replications. Agronomic traits were evaluated in multiple environments and levels of iron and zinc, in one of these environments. Individual analyses of variance were performed and estimated genetic and phenotypic parameters for commercial grain type. Of the 140 lines evaluated were initially identified 22 with high TFe and TZn in the grain, to compose the validation test, which was installed in 2013 year in five environments, in a randomized block design, with two replications for evaluation of TFe and TZn. The data were submitted to individual variance analysis and joint analysis. Also adaptability and phenotypic stability was evaluated using the method of Nunes et al. (2005). Estimates were obtained from phenotypic and genetic correlations between TFe and TZn in grain, correlation between environments estimates were also obtained to identify the most representative. The condition for selection of inbred lines with higher TFe and TZn the grain is favorable, as showed high heritability and expressive expected gains with the selection. There was a predominance of the interaction of simple type between TFe and TZn with the environments. The inbred lines CNFP 15701, CNFC 15865, CNFM 15632 and CNFRx 15602 are indicated as parents in developing cultivars, for added good nutritional composition in the grain. The inbred lines CNFC 15833, CNFC 15703, CNFP 15676 and CNFRx 15602 been selected as candidates in developing biofortified crops because allied agronomic and nutritional characters. Was detected positive genetic association and intermediate magnitude between TFe and TZn in common bean grain. The environment Ponta Grossa-PR in the dry season, It was nominated as the best review site for nutritional characters. The display of biofortified cultivate cultivation environment should be considered, since this strongly influences the expression of genetic potential. / Durante 85 anos o melhoramento genético de feijoeiro-comum dedicou-se esforços aos caracteres de importância agronômica, industrial e culinária. Nesse período, a qualidade nutricional dos alimentos primários não foi trabalhada. No entanto, com os índices de subnutrição subindo, as entidades de pesquisa direcionaram recursos nessa nova estratégia, conhecida como biofortificação. O presente estudo teve como objetivos: obter estimativas de parâmetros genéticos e fenotípicos entre linhagens elite para teor de ferro (TFe) e teor de zinco (TZn) no grão; verificar a presença de interação de genótipos com ambientes para TFe e TZn no grão; selecionar linhagens que agreguem, simultaneamente, alta qualidade nutricional no grão e alto potencial agronômico; verificar se existe relação genética entre o TFe e o TZn; e verificar a necessidade de realização de ensaios em vários ambientes para TFe e TZn. Inicialmente, foram avaliadas 140 linhagens, sendo 68 do tipo carioca, 30 do tipo preto, 16 mulatinho, 14 do tipo carioca precoce e 12 roxinho. Cada ensaio preliminar foi conduzido separadamente, por tipo de grão, em vários ambientes, no ano de 2011, em blocos ao caso com três repetições. Foram realizadas avaliações agronômicas em múltiplos ambientes e os teores de ferro e zinco, em um ambiente. Foram realizadas análises de variância individuais e estimados os parâmetros genéticos e fenotípicos, por tipo comercial de grão. Das 140 linhagens avaliadas inicialmente foram identificadas 22 com altos TFe e TZn no grão, para compor o ensaio de validação, que foi instalado no ano de 2013, em cinco ambientes, em blocos ao acaso com duas repetições, para avaliação específica do TFe e TZn. Os dados foram submetidos à análises de variância individuais e conjunta. Foi avaliada a adaptabilidade e estabilidade fenotípica, utilizando-se o método de Nunes et al. (2005). Foram obtidas estimativas de correlações fenotípicas e genéticas entre os TFe e TZn no grão, e correlação entre ambientes para identificar o mais representativo. A condição para seleção de linhagens elite com maiores TFe e TZn no grão é favorável, pois foi observada alta herdabilidade e expressivos ganhos com a seleção. Verificou-se a predominância da interação do tipo simples entre os TFe e TZn com os ambientes. As linhagens CNFP 15701, CNFC 15865, CNFM 15632 e CNFRx 15602 são indicadas como genitoras no desenvolvimento de cultivares, pois agregaram boa composição nutricional no grão. As linhagens CNFC 15833, CNFC 15703, CNFP 15676 e CNFRx 15602 foram selecionadas como candidatas no desenvolvimento de cultivares biofortificadas, pois aliaram caracteres agronômicos e nutricionais. Foi detectado associação genética positiva e de magnitude intermediária entre os TFe e TZn no grão de feijoeiro-comum. O ambiente Ponta Grossa-PR na safra da seca foi indicado como o melhor sítio de avaliação para caracteres nutricionais. Na indicação de cultivar biofortificada o ambiente de cultivo deve ser considerado, visto que esse influencia fortemente na expressão do potencial genético.
138

Terapia gênica na paracoccidioidomicose experimental utilizando vetor de expressão de HSP60 E mIL-12 / Gene therapy in experimental paracoccidioidomycosis using HSP60 expression vector and mIL-12

Thor Andreas Silva Di Sessa 02 December 2013 (has links)
A paracoccidioidomicose (PCM) é uma doença sistêmica de caráter granulomatoso, causada pelo fungo termodimórfico Paracoccidioides spp. A PCM é endêmica na America Latina e aproximadamente 80% do pacientes vivem no território brasileiro. O tratamento medicamentoso é eficiente, entretanto, é longo e vários pacientes acabam abandonando e recidivas são comuns neste grupo. A utilização de uma vacina terapêutica poderia resultar na redução do tempo de tratamento assim como, recuperar a resposta imune do hospedeiro frente ao fungo. As vacinas de DNA são uma abordagem promissora na imunoterapia e podem ser injetadas por via intramuscular, intradérmica ou via mucosa. As proteínas de choque térmico (HSPs) são proteínas que estão ligadas a homeostase celular e também possuem efeitos imunológicos em diversos casos como doenças infecciosas e autoimunes. No presente trabalho, analisamos o esquema vacinal terapêutico em camundongos BALB/c previamente infectados intratraquealmente com 3x105 leveduras de P. brasiliensis Pb18, 60 dias depois, submetidos a imunização com pcDNA3 contendo sequências codificadoras de PbHSP60 e/ou IL-12 murina e/ou vetor vazio. Foi observada redução significativa no número de unidades formadoras de colônia (UFCs) nos pulmões de camundongos imunizados com PbHSP60. Os grupos que receberam PbHSP60+pcDNA3 vazio ou PbHSP60x2 apresentaram os maiores índices de redução da cargas fúngicas. A inclusão do plasmídeo contendo o inserto de mIL-12, resultou em um efeito deletério. A análise dos cortes histológicos indicou que os animais vacinados apresentavam áreas bem preservadas e com poucos ou nenhum foco de granuloma. Detectamos um perfil de citocinas típico Th1/Th2. Nossos resultados sugerem que a imunização utilizando plasmídeo contendo o inserto HSP60, tem grande potencial vacinal / The paracoccidioidomycosis (PCM) is a systemic granulomatous disease of character, caused by the thermally dimorphic fungus Paracoccidioides spp. The PCM is endemic in Latin America and approximately 80% of patients are living in Brazil. The medical treatment is effective, however, is long and many patients end up abandoning and relapses are common in this group.The use of a therapeutic vaccine could result in the reducing time of treatment as well as recover the host immune response against the fungus. DNA vaccines are a promising approach for immunotherapy and can be injected by intramuscular, intradermal, or mucosal route. The heat shock proteins (HSPs) are proteins that are linked to cellular homeostasis and also have immunological effects in many cases as infectious and autoimmune diseases. In the present study, we analyzed the therapeutic vaccine schedule in BALB/c mice previously infected intratracheally with 3x105 yeast of P. brasiliensis strain 18, and 60 days after, undergoing immunization with pcDNA3 containing coding sequences PbHSP60 and / or murine IL-12 and / or empty vector. Significant reduction was observed in the number of colony forming units (CFU) in the lungs of mice immunized with PbHSP60. The groups that received empty pcDNA3 and PbHSP60 or PbHSP60x2 have higher rates of reduced fungal loads. The inclusion of the plasmid containing the insert mIL-12 resulted in a deleterious effect. The analysis of histological sections indicated that vaccinated animals had wellpreserved, with few or no focus of granuloma areas. It was detected a profile typical Th1/Th2 cytokines. Our results suggest that immunization using plasmid containing the insert HSP60 vaccine has great potential
139

Efeitos do ácido 3-nitropropiônico (3-NP) na inervação extrínseca do coração de camundongos - modelo experimental para a doença de Huntington / Effects of 3-nitropropionic acid (3-NP) on the extrinsic innervation of the mice heart - experimental model for Huntington\'s disease

Amanda Lopez Moreira 05 June 2017 (has links)
A doença de Huntington (DH) é um distúrbio neurodegenerativo hereditário e autossômico dominante e tem como características alterações motoras e mentais progressivas. Recentemente, além das alterações verificadas no sistema nervoso central, também têm sido descritas alterações em órgãos periféricos, tais como osteoporose, atrofia muscular, problemas intestinais, alterações cardíacas e, sobretudo, alterações no sistema nervoso autônomo. São evidentes as alterações autonômicas do coração nos portadores da DH, as quais, são, sobretudo, um risco potencial, tornando os pacientes suscetíveis a problemas cardiovasculares. No entanto, os mecanismos pelos quais a doença afeta os componentes autonômicos do coração não são totalmente conhecidos, por isso a importância de se estudar os componentes da inervação cardíaca, sobretudo o gânglio estrelado (GE). A DH pode ser induzida através do ácido 3-nitropropiônico (3-NP), pois essa substância produz efeitos neurotóxicos inibindo a succinato desidrogenase. Esta pesquisa objetiva analisar, por meio da indução através do 3-NP, os efeitos da DH no GE, identificando possíveis alterações morfoquantitativas dos neurônios ganglionares, com uso de técnicas baseadas em delineamento estereológico 3D e de bioimagem associadas à teste comportamental e perfil hemodinâmico, a fim de contribuir para o entendimento de como a doença age na inervação do coração. Para isso foram utilizados 14 camundongos C57BL-6 machos que foram alocados em dois grupos: Grupo Controle com 7 animais induzidos com solução salina (0,9%); Grupo 3NP com 7 animais induzidos com doses subagudas de 60 mg.kg-1dia-1 de 3-NP. Foram realizados o teste comportamental, a avaliação cardíaca e a análise estereológica. Os principais achados dessa pesquisa foram: (I) diminuição da atividade exploratória dos animais; (II) prejuízo da função sistólica; (III) aumento de 76% no volume ganglionar; (IV) aumento de 70% no volume médio dos neurônios, concluindo-se que o 3-NP produz efeitos na função cardíaca, ocasionando hipertrofia do gânglio / Huntington\'s disease (HD) is a hereditary and autosomal dominant neurodegenerative disorder and is characterized by progressive motor and mental changes. Recently, in addition to changes in the central nervous system, alterations in peripheral organs such as osteoporosis, muscular atrophy, intestinal problems, cardiac alterations and, above all, changes in the autonomic nervous system have also been described. Autonomic heart alterations in DH patients are evident, which are a potential risk, making patients susceptible to cardiovascular problems. However, the mechanisms by which the disease affects the autonomic components of the heart are not fully understood, therefore, the importance of studying the components of cardiac innervation, especially the stellate ganglion (SG). HD can be induced through 3-nitropropionic acid (3-NP), as this substance produces neurotoxic effects inhibiting succinate dehydrogenase. The aim of this research was to analyze the effects of HD on the SG by means of 3-NP induction, identifying possible morpho-quantitative changes in ganglion neurons, using techniques based on 3D stereological and bioimaging techniques associated with behavioral and hemodynamic profile, In order to contribute to the understanding of how the disease acts in the heart innervation. For this, 14 male C57BL-6 mice were used, which were allocated in two groups: Control Group with 7 animals induced with saline solution (0.9%); Group 3NP with 7 animals induced with subacute doses of 60 mg.kg-1day-1 of 3-NP. Behavioral test, cardiac evaluation and stereological analysis were performed. The main findings of this research were: (I) decrease in the exploratory activity of the animals; (II) impairment of systolic function; (III) 76% increase in ganglion volume; (IV) increase of 70% in the mean volume of the neurons, concluding that 3-NP produces effects on cardiac function, causing hypertrophy of the ganglion
140

Uso de linhagens parcialmente endogâmicas S3 para a produção de híbridos simples de milho. / Use of partly inbred s3 lines for the production of maize single-crosses.

Alexander Chavez Cabrera 03 December 2001 (has links)
Linhagens endogâmicas (F@1,0) são usualmente utilizadas para a produção de híbridos de milho. Devido a elevada depressão por endogamia no milho, as linhagens endogâmicas apresentam baixa produtividade, encarecendo o custo das sementes de híbridos simples e tornando-os inacessíveis para grande parte dos agricultores dos países em desenvolvimento. Uma alternativa para contornar o problema seria utilizar linhagens parcialmente endogâmicas (0,0 < F < 1,0), selecionadas para capacidade de combinação e uniformidade. Relatos de literatura mostram que (a) híbridos simples de linhagens S3 (F=0,875) devem apresentar performances superiores as de híbridos triplos e duplos de linhagens endogâmicas; (b) a correlação genética entre híbridos simples de linhagens S3 e de linhagens endogâmicas (F@1,0) é elevada (r=0,94); e (c) a produtividade de linhagens S3 é em média 20% superior a de linhagens endogâmicas. Entretanto, a maior dificuldade em se produzir híbridos simples de linhagens parcialmente endogâmicas refere-se à manutenção destas, por apresentarem variabilidade genética. Devido a isto, o objetivo deste estudo foi avaliar a viabilidade de se produzir e utilizar híbridos simples de linhagens parcialmente endogâmicas S3. Para isso, oito linhagens S3 da população BR-105 e dez linhagens da população BR-106, as quais estão alocadas em grupos heteróticos distintos, selecionadas para capacidade de combinação e uniformidade, originais e mantidas por intercruzamentos e seleção moderada por cinco gerações, foram utilizadas. Durante as gerações de manutenção, pelo menos 50 plantas foram usadas. Estas linhagens e cruzamentos destas com dois testadores de grupos heteróticos diferentes, foram avaliados em quatro ambientes no ano agrícola de 1999/2000. Além disso, as linhagens originais e mantidas foram genotipadas utilizando o marcador molecular AFLP para estimar a similaridade genética entre elas. Os resultados obtidos mostraram que, excetuando-se uma linhagem da população BR-105 em que provavelmente ocorreu contaminação, apenas dois caracteres nas linhagens per se e apenas um caráter nos cruzamentos apresentaram alterações positivas e significativas, de treze caracteres avaliados. Entretanto estas alterações são muito pequenas para serem detectadas visualmente. Os resultados das similaridades genéticas entre as linhagens originais e mantidas, mostraram valores elevados, sendo que o limite superior do intervalo de confiança para a maioria das linhagens atingiu o valor 1,0, indicando que a manutenção das linhagens da forma como foi conduzida as suas integridades genéticas foram mantidas. Estes resultados permitiram concluir que seria viável a utilização de linhagens parcialmente endogâmicas S3 para a produção comercial de híbridos simples de milho. / Inbred lines (F@1.0) are usually used for the production of maize single-crosses. Because of the high inbreeding depression in maize, the inbred lines are lower yielding, which causes the seed prices to be costly and then inaccessible for most of the farmers in the developing countries. One way to circumvent the problem would be the use of partly inbred lines (0.0< F<1.0) selected for combining ability and for uniformity within the lines. Reported results have shown that: (a) theoretically, single-crosses from S3 lines (F=0.875) are expected to have superior performance than that of three-way and double-crosses; (b) the genetic correlation of single-crosses from S3 lines and from their inbred lines (F@1.0) counterparts is fairly high (r=0.94); and (c) S3 lines are on the average 20% higher yielding than highly inbred lines. However, the main difficulty in the production of single-cross from partly inbred lines is the maintenance of their genetic integrity because of the variability within them. Therefore, the ob-jective of this research was to study the feasibility of the development and the production of single-crosses from S3 lines. The genetic material included eight original S3 lines from the BR-105 population, and ten original S3 lines from the BR-106 population, selected for combining ability and for uniformity within them, and their counterparts maintained by sib-mating and mild selection for five generations. During the generations of maintenance at least 50 plants per line were used. The populations BR-105 and BR-106 have been assigned to distinct heterotic groups. The original, the maintained lines and their crosses with testers from different heterotic groups were evaluated in four environments in the growing season of 1999/2000. Also, the S3 lines were genotyped with the AFLP molecular marker in order to estimate the genetic similar-ity between the original and their maintained counterparts. The results showed that out of the 13 traits evaluated only two traits in the lines per se, and only one trait in the crosses changed significantly from the original lines to the maintained counterparts. However those changes are too low to be visually detected. The estimates of the genetic similarities between the original and their maintained counterparts S3 lines were high, and the upper bound of the confidence interval for most of the lines reach the limit value, i.e., 1.0. These results showed that the ap-proach uses for the maintenance of the S3 lines was effective and thus the genetic integrity of the lines were maintained. The results of this research could allow one to expect that would be feasible the use of partly inbred S3 lines for the commercial production of maize single-crosses.

Page generated in 0.0551 seconds