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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.
171

Motion Supports Object Recognition: Insight into possible interactions between the two primary pathways of the human visual system.

January 2011 (has links)
abstract: The present study explores the role of motion in the perception of form from dynamic occlusion, employing color to help isolate the contributions of both visual pathways. Although the cells that respond to color cues in the environment usually feed into the ventral stream, humans can perceive motion based on chromatic cues. The current study was designed to use grey, green, and red stimuli to successively limit the amount of information available to the dorsal stream pathway, while providing roughly equal information to the ventral system. Twenty-one participants identified shapes that were presented in grey, green, and red and were defined by dynamic occlusion. The shapes were then presented again in a static condition where the maximum occlusions were presented as before, but without motion. Results showed an interaction between the motion and static conditions in that when the speed of presentation increased, performance in the motion conditions became significantly less accurate than in the static conditions. The grey and green motion conditions crossed static performance at the same point, whereas the red motion condition crossed at a much slower speed. These data are consistent with a model of neural processing in which the main visual systems share information. Moreover, they support the notion that presenting stimuli in specific colors may help isolate perceptual pathways for scientific investigation. Given the potential for chromatic cues to target specific visual systems in the performance of dynamic object recognition, exploring these perceptual parameters may help our understanding of human visual processing. / Dissertation/Thesis / M.A. Psychology 2011
172

Hybridní zóna kuněk Bombina bombina a B. variegata v jižních Čechách / Hybrid zone of the fire-bellied toads Bombina bombina and B. variegata in southern Bohemia

STRAKOVÁ, Helena January 2012 (has links)
In this paper I focused on the examination of chosen localities inside the hybrid zone of the fire-bellied toads, where the occurrence of these species and their hybrids was confirmed in previous research. The goal is to follow the development of these habitats, suitable for the presence of a threatened species, and trends in quantities of these toads. Another aim was to calculate the hybrid index of each individual based on the ventral spots and so to classify the populations on each locality according to species.
173

Comparação entre posiçao prona e posiçao supina, associadas à ventilação oscilatória de alta frequência, em modelo experimental de lesão pulmonar aguda

Pires, Rafaelle Batistella [UNESP] 20 February 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:25:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-20Bitstream added on 2014-06-13T18:29:07Z : No. of bitstreams: 1 pires_rb_me_botfm.pdf: 268409 bytes, checksum: a7f99374144af3decea275454b7e5df4 (MD5) / A Síndrome do Desconforto Respiratório Agudo (SDRA) cursa com alta mortalidade apesar do melhor entendimento de sua fisiopatologia e avanços no tratamento. A Ventilação Oscilatória de Alta Frequência (VOAF) é método protetor por utilizar baixos volumes correntes (VC). Existem terapias adjuvantes à ventilação, dentre as quais se destaca a posição prona, que possibilita homogeneização da distribuição do VC e promove recrutamento alveolar. O objetivo foi investigar o efeito da posição prona associada à VOAF sobre a oxigenação, inflamação, histologia e dano oxidativo pulmonares, comparando-a com a posição supina neste mesmo modo ventilatório em modelo experimental de lesão pulmonar aguda (LPA) induzida em coelhos. Trinta coelhos foram instrumentados com traqueostomia e acessos vasculares e ventilados. A LPA foi induzida por infusão traqueal de salina aquecida (30mL/Kg, 38°C). Os coelhos foram submetidos à VOAF e divididos em dois grupos (n=15), um ventilado em posição supina (GS) e outro em posição prona (GP). VOAF foi iniciada com pressão aérea média de 16 cmH2O, que foi diminuída a cada 30 minutos até 10-11 cmH2O. Nos últimos 30 minutos os coelhos foram reposicionados em posição supina. Parâmetros ventilatórios e hemodinâmicos foram registrados a cada 30 minutos durante 150 minutos. Os desfechos foram: oxigenação, avaliada pela relação PaO2/FiO2 e índice de oxigenação (IO); inflamação pulmonar, avaliada pela porcentagem de polimorfonucleares (PMN) no lavado broncoalveolar (BAL) e pelo nível de TNF-alfa medido no BAL e no tecido pulmonar nas áreas ventral e dorsal; estresse oxidativo tecidual pulmonar, determinado pelo método de peroxidação lipídica (malondialdeído); e lesão tecidual pulmonar, determinada por escore histológico de lesão por área pulmonar. O nível de significância avaliado... / Acute respiratory distress syndrome (ARDS) has been associated to high mortality rate despite better understanding of its pathophysiology and advances in treatment. High-frequency oscillatory ventilation (HFOV) is a protective ventilatory method because of using low tidal volume (VT). There are also many adjunctive therapies, of which prone position is known to allow homogenization of VT distribution and to promote alveolar recruitment. The objective was to investigate the prone position and HFOV association effects on oxygenation, inflammation, oxidative damage and lung histology, comparing to the supine position in this same ventilation mode, in experimental acute lung injury (ALI) induced in rabbits. Thirty rabbits were instrumented with tracheotomy and vascular catheters and ventilated. ALI was induced by tracheal infusion of warm saline (30mL/Kg, 38°C). Rabbits were submitted to HFOV and divided in two groups (n=15), one ventilated in supine position (SG), and the other in prone position (PG). HFOV was initiated with mean airway pressure of 16 cmH2O, which was decreased each 30 minutes until 10-11 cmH2O. In the last 30 minutes, all rabbits were repositioned to supine position. Ventilatory and hemodynamic parameters were recorded every 30 minutes for 150 minutes. The outcomes were: oxygenation, measured by PaO2/FiO2 ratio and oxygenation index (OI); lung inflammation, assessed by the percentage of polymorphonuclear cells (PMN) in bronchoalveolar lavage fluid (BAL) and by the level of TNF- alpha measured in BAL and in lung tissue, in ventral and dorsal areas; lung tissue oxidative stress, determined by the method of lipid peroxidation (malondialdehyde); and lung tissue damage, as determined by a histological score of injury, in each lung area. A significance level of 5% was... (Complete abstract click electronic access below)
174

Comparação entre os efeitos da posição prona e do óxido nítrico inalatório sobre oxigenação, mecânica respiratória, lesão histopatológica e inflamação na lesão pulmonar aguda induzida experimentalmente

Satrapa, Débora Avellaneda Penatti [UNESP] 25 February 2014 (has links) (PDF)
Made available in DSpace on 2014-08-13T14:50:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-25Bitstream added on 2014-08-13T17:59:51Z : No. of bitstreams: 1 000771322.pdf: 795316 bytes, checksum: e03e738556583e78c68280d321cd6c8e (MD5) / Fundamentação/Objetivos: A Síndrome do Desconforto Respiratório Agudo (SDRA) cursa com altos índices de mortalidade apesar do melhor entendimento de sua fisiopatologia e avanços no tratamento. Existem várias terapias adjuvantes à ventilação mecânica (VM), dentre as quais se destaca a posição prona, que possibilita homogeneização da distribuição do volume corrente (VC) e promove recrutamento alveolar, e o óxido nítrico inalatório (NOi) que promove vasodilatação pulmonar seletiva direcionando o fluxo sanguíneo de áreas mal ventiladas para áreas bem ventiladas e com perfusão diminuída, otimizando a relação ventilação/perfusão e melhorando a oxigenação, com diminuição da resistência vascular pulmonar. Pela melhora da relação ventilação/perfusão, o gás pode permitir o emprego de VM menos agressiva, que, por sua vez, pode diminuir o risco de lesão pulmonar induzida pela VM e a morbidade. Objetivo: comparar os efeitos da posição prona com os do NOi sobre a oxigenação, mecânica respiratória, lesão histopatológica e inflamatória em modelo experimental de lesão pulmonar aguda (LPA). Métodos: Cinquenta coelhos foram instrumentados com traqueostomia e acessos vasculares e ventilados mecanicamente. A LPA foi induzida por infusão traqueal de salina aquecida (30mL/Kg, 38°C). Os coelhos foram submetidos à VMC protetora e distribuídos em quatro grupos: 1) animais com LPA em VMC protetora em posição supina (GVMS; n=15); 2) animais com LPA em VMC protetora + posição prona (GVMP; n=15); 3) animais com LPA em VMC protetora + NOi em posição supina (GVNO; n=15) e 4) animais sem lesão pulmonar submetidos à VMC protetora (sadio – GS; n=5). Os desfechos foram: oxigenação, avaliada pela relação PaO2/FiO2 e índice de oxigenação (IO); inflamação pulmonar, avaliada pela porcentagem de polimorfonucleares (PMN) no lavado broncoalveolar (BAL) e pelo nível de TNF-alfa medido no BAL e lesão ... / Background/Objectives: The Acute Respiratory Distress Syndrome (ARDS) is associated with high mortality rate despite better understanding of its pathophysiology and treatment advances. There are several adjuvant therapies that can be associated to mechanical ventilation (MV), among which stands out the prone position, which allows homogeneous tidal volume (VT) distribution and promotes alveolar recruitment; and inhaled nitric oxide (iNO) which promotes selective pulmonary vasodilation directing blood flow from areas poorly ventilated to well-ventilated areas and decreased perfusion, optimizing the ventilation/perfusion ratio and improving oxygenation with reduced pulmonary vascular resistance. Improved ventilation/perfusion ratio, allows the use of lesser aggressive mechanical ventilation (MV) treatment, which reduces the risk of lung injury induced by MV and morbidity. Objective: To compare the effects of prone position with iNO on oxygenation, respiratory mechanics, inflammatory and histological injury in an experimental model of acute lung injury (ALI). Methods: Fifty rabbits were instrumented with tracheotomy and vascular access and mechanically ventilated. ALI was induced by tracheal infusion of warm saline (30mL/kg, 38°C). Rabbits underwent protective conventional mechanical ventilation (CMV) were divided in four groups: 1) Animals with ALI in protective CMV + supine position (GVMS, n=15), 2) animals with ALI in protective CMV + prone position (GVMP, n=15) and 3) animals with ALI in protective CMV + iNO in supine position (GVNO, n=15). Additionally, there were five animals without lung injury submitted to protective CMV (Healthy group - GS, n=5). The outcomes were oxygenation, measured by PaO2/FiO2 ratio and oxygenation index (OI), lung inflammation assessed by the percentage of polymorphonuclear cells (PMN) in bronchoalveolar lavage (BAL) and TNF-alpha measured in BAL, and histological pulmonary injury determined by a injury ...
175

Comparação entre os efeitos da posição prona e do óxido nítrico inalatório sobre oxigenação, mecânica respiratória, lesão histopatológica e inflamação na lesão pulmonar aguda induzida experimentalmente /

Satrapa, Debora Avellaneda Penatti. January 2014 (has links)
Orientador: José Roberto Fioretto / Banca: Marcelo Barciela Brandão / Banca: Marcos Aurélio de Moraes / Resumo: Fundamentação/Objetivos: A Síndrome do Desconforto Respiratório Agudo (SDRA) cursa com altos índices de mortalidade apesar do melhor entendimento de sua fisiopatologia e avanços no tratamento. Existem várias terapias adjuvantes à ventilação mecânica (VM), dentre as quais se destaca a posição prona, que possibilita homogeneização da distribuição do volume corrente (VC) e promove recrutamento alveolar, e o óxido nítrico inalatório (NOi) que promove vasodilatação pulmonar seletiva direcionando o fluxo sanguíneo de áreas mal ventiladas para áreas bem ventiladas e com perfusão diminuída, otimizando a relação ventilação/perfusão e melhorando a oxigenação, com diminuição da resistência vascular pulmonar. Pela melhora da relação ventilação/perfusão, o gás pode permitir o emprego de VM menos agressiva, que, por sua vez, pode diminuir o risco de lesão pulmonar induzida pela VM e a morbidade. Objetivo: comparar os efeitos da posição prona com os do NOi sobre a oxigenação, mecânica respiratória, lesão histopatológica e inflamatória em modelo experimental de lesão pulmonar aguda (LPA). Métodos: Cinquenta coelhos foram instrumentados com traqueostomia e acessos vasculares e ventilados mecanicamente. A LPA foi induzida por infusão traqueal de salina aquecida (30mL/Kg, 38°C). Os coelhos foram submetidos à VMC protetora e distribuídos em quatro grupos: 1) animais com LPA em VMC protetora em posição supina (GVMS; n=15); 2) animais com LPA em VMC protetora + posição prona (GVMP; n=15); 3) animais com LPA em VMC protetora + NOi em posição supina (GVNO; n=15) e 4) animais sem lesão pulmonar submetidos à VMC protetora (sadio - GS; n=5). Os desfechos foram: oxigenação, avaliada pela relação PaO2/FiO2 e índice de oxigenação (IO); inflamação pulmonar, avaliada pela porcentagem de polimorfonucleares (PMN) no lavado broncoalveolar (BAL) e pelo nível de TNF-alfa medido no BAL e lesão... / Abstract: Background/Objectives: The Acute Respiratory Distress Syndrome (ARDS) is associated with high mortality rate despite better understanding of its pathophysiology and treatment advances. There are several adjuvant therapies that can be associated to mechanical ventilation (MV), among which stands out the prone position, which allows homogeneous tidal volume (VT) distribution and promotes alveolar recruitment; and inhaled nitric oxide (iNO) which promotes selective pulmonary vasodilation directing blood flow from areas poorly ventilated to well-ventilated areas and decreased perfusion, optimizing the ventilation/perfusion ratio and improving oxygenation with reduced pulmonary vascular resistance. Improved ventilation/perfusion ratio, allows the use of lesser aggressive mechanical ventilation (MV) treatment, which reduces the risk of lung injury induced by MV and morbidity. Objective: To compare the effects of prone position with iNO on oxygenation, respiratory mechanics, inflammatory and histological injury in an experimental model of acute lung injury (ALI). Methods: Fifty rabbits were instrumented with tracheotomy and vascular access and mechanically ventilated. ALI was induced by tracheal infusion of warm saline (30mL/kg, 38°C). Rabbits underwent protective conventional mechanical ventilation (CMV) were divided in four groups: 1) Animals with ALI in protective CMV + supine position (GVMS, n=15), 2) animals with ALI in protective CMV + prone position (GVMP, n=15) and 3) animals with ALI in protective CMV + iNO in supine position (GVNO, n=15). Additionally, there were five animals without lung injury submitted to protective CMV (Healthy group - GS, n=5). The outcomes were oxygenation, measured by PaO2/FiO2 ratio and oxygenation index (OI), lung inflammation assessed by the percentage of polymorphonuclear cells (PMN) in bronchoalveolar lavage (BAL) and TNF-alpha measured in BAL, and histological pulmonary injury determined by a injury ... / Mestre
176

Caracteriza??o citoarquitet?nica e por imunoistoqu?mica para tirosina-hidroxilase da subst?ncia negra, ?rea tegmentar ventral e zona retrorubral do Sagui (Callithrix jacchus)

Cavalcanti, Jos? Rodolfo Lopes de Paiva 30 April 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-08T23:56:19Z No. of bitstreams: 1 JoseRodolfoLopesDePaivaCavalcanti_TESE.pdf: 2156602 bytes, checksum: 000c3eafedc8a66a1a55425b0168fd4a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-11T23:46:45Z (GMT) No. of bitstreams: 1 JoseRodolfoLopesDePaivaCavalcanti_TESE.pdf: 2156602 bytes, checksum: 000c3eafedc8a66a1a55425b0168fd4a (MD5) / Made available in DSpace on 2016-04-11T23:46:45Z (GMT). No. of bitstreams: 1 JoseRodolfoLopesDePaivaCavalcanti_TESE.pdf: 2156602 bytes, checksum: 000c3eafedc8a66a1a55425b0168fd4a (MD5) Previous issue date: 2015-04-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Sabe-se que o grupo das catecolaminas ? integrado pela dopamina, noradrenalina e adrenalina e que a s?ntese dessas subst?ncias se d? de modo sequencial, sendo a enzima tirosina-hidroxilase reguladora da fase inicial deste processo. Neste sentido, a 3- hidroxitiramina/dopamina ? precursora da s?ntese de noradrenalina e adrenalina e ainda possui a capacidade de atuar como neurotransmissor na por??o central do sistema nervoso. Os tr?s principais n?cleos dopamin?rgicos, chamados zona retrorubral (grupo A8), subst?ncia negra pars compacta (grupo A9) e ?rea tegmentar ventral (grupo A10), est?o dispostos na por??o die-mesencef?lica e est?o envolvidos em tr?s vias, a mesostriatal, mesol?mbica e mesocortical. Estas vias est?o relacionadas diretamente com diversas manifesta??es comportamentais como controle da motricidade, sinaliza??o de recompensa na aprendizagem comportamental, motiva??o e nas manifesta??es patol?gicas da Doen?a de Parkinson e esquizofrenia. Considerando-se a relev?ncia desses, o objetivo do trabalho foi caracterizar morfologicamente os n?cleos dopamin?rgicos (A8, A9 e A10) do sagui (Callithrix jacchus) mediante estudo citoarquitet?nico e imunoistoqu?mico contra tirosina-hidroxilase. O sag?i ? um primata neotropical, cujas caracter?sticas morfofuncionais repercutem na adequabilidade de uso deste animal em pesquisas de ordem biom?dica. Sec??es coronais dos enc?falos de seis animais foram submetidas ? colora??o pelo m?todo de Nissl e immunoistoqu?mica para tirosinsa-hidroxilase. Com base na morfologia dos neur?nios, foi poss?vel subdividir o grupo A10 em sete regi?es: n?cleo interfascicular, linear rostral e linear caudal, situados na linha m?dia; paranigral e o parainterfascicular, situados na zona intermedi?ria; a por??o rostral da ?rea tegmentar ventral e o n?cleo parabraquial pigmentado, situados na por??o dorsolateral do tegmento mesencef?lico. O grupo A9 foi subdividido em quatro regi?es: subst?ncia negra camadas dorsal e ventral; subst?ncia negra conjuntos lateral e medial. Por ?ltimo, n?o foram indentificadas subdivis?es no grupo A8. Conclu?-se que A8, A9 e A10 s?o filogeneticamente conservados entre as esp?cies, por?m percebe-se a necessidade de se ampliar os estudos acerca das organiza??es subnucleares, seja investigando a sua ocorr?ncia em outras esp?cies de primatas, seja investigando a sua relev?ncia funcional. / It is known that the catecholamine group is constituted by dopamine, noradrenaline and adrenaline, in which the synthesis is regulated by an enzyme named tyrosine hydroxylase. Thus, 3-hydroxytyramine/dopamine (DA) is a precursor of the noradrenaline and adrenaline synthesis and acts as a neurotransmitter in the central nervous system. The three main nuclei, named the retrorubral field (A8 group), the substantia nigra pars compacta (A9 group) and the ventral tegmental area (A10 group), are arranged in the die-mesencephalic portion and are involved in three complexes circuitries - the mesostriatal, mesolimbic and mesocortical pathways. These pathways are related to behavioral manifestations, motricity, learning, reward and pathologies such as Parkinson?s Disease and Schizophrenia. Thus, the aim of this study was to perform de morphological analysis of the A8, A9 and A10 nuclei of the common marmoset (Callithrix jacchus). The marmoset is a neotropical primate, whose morphological and functional characteristics supports the suitability of use of this animal in biomedical research. Coronal sections of the marmoset brain were submitted to cytoarchitectonic characterization and TH-immunohistochemistry. Based on the morphology of the neurons, it was possible to subdivide the A10 group in seven regions: interfascicular nucleus, raphe rostral linear nucleus and raphe caudal linear nucleus, in the middle line; paranigral and parainterfascicular nucleus, in the middle zone; rostral portion of the ventral tegmental area nucleus and parabrachial pigmented nucleus, located in the dorsolateral portion of the mesencephalic tegmentum. A9 group was divided into four regions: substantia nigra compacta dorsal and ventral tiers; substantia nigra compacta lateral and medial clusters. No subdivisions were founded into A8 group. These results revealed that A8, A9 and A10 are phylogenetically conserved between species, but it?s necessary to expand the studies about this compartmentalization, investigating its occurrence in other primate species or investigating its functional relevance.
177

Inibição da atividade das enzimas 5-alfa redutase e aromatase na prostata do gerbilo da Mongolia / 5-alpha reductase and aromatase enzymatic activies inhibition in the Mongolian gerbil prostate

Corradi, Lara Silvia 24 January 2008 (has links)
Orientador: Sebastião Roberto Taboga / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-10T18:00:13Z (GMT). No. of bitstreams: 1 Corradi_LaraSilvia_D.pdf: 6064748 bytes, checksum: 6595f8861a86f33fa6761af9a8f6b0a8 (MD5) Previous issue date: 2008 / Resumo: Os andrógenos têm papel central na biologia da próstata, mas os estrógenos também podem afetar o crescimento e a diferenciação desta glândula. Em tecidos específicos do corpo, a proporção entre andrógenos e estrógenos pode diferir significativamente daquela encontrada no plasma sanguíneo. As concentrações intracelulares desses esteróides nos tecidos alvos são reguladas pelo metabolismo local de hormônios, altamente dependente de enzimas específicas metabolizadoras de esteróides, como a 5a-redutase (5a-r) e a Aromatase (aro). Na próstata, a ação androgênica é acentuada devido à conversão de testosterona em dihidrotestosterona por ação da enzima 5a-r, enquanto que a aro é responsável pela aromatização da testosterona em estrógenos. Assim, a síntese local destes esteróides assume grande importância em doenças que acometem tecidos glandulares, como o câncer de próstata, onde níveis anormais de hormônios promovem o desenvolvimento e o aumento de ocorrência de malignidades. Desse modo, os papéis dos andrógenos e estrógenos ativados podem ainda ser melhor compreendidos na manutenção das interações homeostáticas epitélio-estromais prostáticas. Estudos com inibidores específicos destas enzimas vêm sendo desenvolvidos a fim de se tentar esclarecer os reais papéis enzimáticos na manutenção da fisiologia prostática, assim como no surgimento e desenvolvimento de doenças. De modo geral, após 30 dias consecutivos de inibição, simultânea ou não, das enzimas 5a-r e aro, respectivamente por ação da Finasterida e do Letrozol, a próstata de gerbilos jovens, adultos e velhos mostrou-se com o compartimento epitelial e o estromal alterados e reorganizados na tentativa de adaptar-se à nova condição hormonal induzida. Imediatamente após o término de administração das drogas, na fase inicial do período de pós-tratamentos, as concentrações de testosterona e estrógenos modificaram-se, as células epiteliais tiveram o padrão de atividade secretora alterada e, no estroma, a matriz extracelular ficou totalmente remodelada, além das células musculares lisas e dos fibroblastos fenotipicamente alterados. Na fase final do período de pós-tratamento, ficou evidente a tentativa da próstata em se normalizar morfologica e fisiologicamente, porém, em nenhuma das idades isso aconteceu de modo efetivo. O bloqueio da metabolização de hormônios esteróides na próstata pode ser uma ferramenta importante para o estudo da interação epitélio-estroma tanto na fisiologia normal, quanto nas doenças da próstata. Sugere-se portanto, que o desbalanço entre as concentrações de andrógenos e estrógenos provocados pela Finasterida e de Letrozol, juntos ou separados, alterou significativamente a interação epitélio-estroma. Todos os resultados obtidos parecem ser indicativos de importantes sinais do novo cenário hormonal intraprostático. A recuperação do equilíbrio entre as concentrações hormonais da próstata fica comprometida após o bloqueio enzimático, dando, portanto, às enzimas em estudo, status de crucial importância para o desenvolvimento e manutenção da próstata. O estabelecimento de modelos experimentais para o estudo das relações entre epitélio e estroma e o conhecimento dos componentes celulares e macromoleculares da próstata tornam-se instrumentos muito importantes para o entendimento do desenvolvimento, da estrutura e da fisiologia desta glândula / Abstract: Androgens have substantial role in the biology of the prostate, but estrogens also can affect the growth and differentiation of this gland. In specific tissues of the body, the ratio between androgens and estrogens can differ significantly from that found into plasma. The intracellular concentrations of these steroids in target tissues are mediated by a local hormone metabolism, by specifcs steroid-metabolizing enzymes, as the 5a-redutase (5a -r) and the aromatase (aro). In the prostate, the androgenic action is accented due to the conversion of testosterone in dihydrotestosterone by the activity of the 5a -r, while aro enzyme is an alternative pathway for the aromatization of testosterone into estrogens. These locally syntheses of steroids hormones assume thus, a great importance to the prostate cancer, where abnormal hormone levels can promote development and proliferation of malignancy to this gland. The activated functions of androgens and estrogens may be better understood focusing the maintenance of homeostatic prostatic epithelial-stromal interactions. Studies conducted with inhibitors of these specific enzymes have been carried out in an effort to clarify the real role of steroid-metabolizing enzymes in the maintenance of prostatic physiology, as well as into malignant progression prostatic cancer. After 30 consecutive days of inhibition, simultaneous or not, of the enzymes 5a -r and aro, respectively by Finasterida and Letrozol, the prostate of young, adult and old gerbils revealed that epithelial and estromal compartments were totally modified and reorganized in the attempt to adapt it to the new induced hormonal condition. Immediately after the end of drugs administration, in the early phase of the post-treatments period, the concentrations of testosterone and estrogens had been altered, the epithelial cells had their secretore activity pattern modified and, in the stromal compartment, the extracellular matrix was totally remodeled. The smooth muscle cells and fibroblasts became fenotipically modified. In the late phase of the post-treatments period, it was evident the attempt of the prostate gland in became morphologically and physiologically as a normal gland, however, this was not achieved in any analyzed gerbil. These steroids hormone metabolization blockade seems to be a good tool for the study of the epithelium-stroma interaction both in normal and abnormal prostate gland. Based on this data, it is suggested that the unbalance between androgens and estrogens intraprostatic concentrations provoked by Finasteride and Letrozol, together or not, interfered into the prostatic compartments interactions significantly. The results seem to be indicative of important signals of the new locally hormonal scene within the prostate gland. The recovery of balance hormonal concentrations of the prostate is damaged after the enzymatic blockade what gives, therefore, to this to 5a -r and aro enzymes, a status of crucial key for the normal and abnormal prostate gland. The establishment of experimental models for this kind of study and the knowledge of the cellular and macromolecular components of the prostate are also fundamental for the agreement of development, structure and physiology of prostate / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural
178

Optimization of PCR protocols used for genotyping transgenic mice & Evaluation of a method for co-detecting mRNA and protein / Optimering av PCR-protokoll som används för genotypning av transgena möss och utvärdering av en metod för att detektera mRNA och protein

Isaksson, Amanda January 2017 (has links)
The aim of the current study was divided into two separate goals, (i) optimization of a number of PCR-based protocols employed for genotyping transgenic mouse lines and (ii) evaluating a protocol for co-detection of mRNA and its correlated protein in the mouse midbrain. The optimization was performed on PCR protocols for genotyping the following transgenic mouse lines; Dat-Cre, Vglut2-Lox, Vglut2-Cre and Vmat2-Lox. Also, two different polymerases were evaluated parallel to each other – KAPA and Maxima Hot Start. One of the main findings from the PCR optimizations were that for the Vglut2-Lox protocol. By decreasing the annealing temp and increasing the MgCl2 the bands appeared brighter.  For the second part of the project, in-situ hybridization (ISH) was used to detect the mRNA expression with a `non-radioactive in situ hybridization´ protocol, using digoxigenin or fluorescein labelled riboprobes (mRNA probes). To detect the correlated protein a basic immunohistochemistry (IHC) protocol with the use of primary and secondary antibodies was implemented. The combined protocol was tested with Nd6 and Grp markers. Before testing to combined the protocols the ISH protocol was performed alone with riboprobes for Girk2, Lpl and Fst. The combined protocol detected mRNA and protein for both the control marker Th and the Nd6 marker. In conclusions, the optimized PCR protocols were optimal when used with the Maxima Hot Start polymerase and the new combined ISH and IHC protocol worked for markers Th and Nd6.
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Temporalité de l'initiation des fleurs et contrôle de l'architecture de l'inflorescence / Temporality of Flower Initiation and Control of Inflorescence Architecture

Chaumeret, Anaïs 27 October 2017 (has links)
La phyllotaxie, arrangement d’éléments botaniques autour de l’axe primaire de la plante, suit unpatron spatio-temporel robuste. Elle est établie au niveau du Méristème Apical Caulinaire (MAC),qui est la niche de cellules souches post-embryonnaires des parties aériennes de la plante.L’accumulation locale de la phytohormone auxine déclenche la formation des organes latéraux auniveau du MAC. En même temps, la déplétion d’auxine dans les cellules environnantes crée unchamp inhibiteur, où toute nouvelle organogenèse est impossible. La croissance permet auxanciens organes de constamment s’éloigner du MAC, ce qui libère l’espace nécessaire auxnouvelles organogenèses. C’est un exemple frappant de processus biologique auto-organisé etitératif. Des mécanismes moléculaires et génétiques régulant la phyllotaxie ont été identifiés,majoritairement dans le contexte d’une phyllotaxie commune, qu’est la spirale de Fibonacci. Iln’est pas actuellement démontré que ces mécanismes expliquent aussi d’autres types dephyllotaxies. Nous avons identifié DRB27, un mutant d’Arabidopsis thaliana présentant une fortetendance à générer des pseudo-verticilles. Cela rappelle la phyllotaxie observée chez presquetoutes les fleurs et quelques tiges d’espèces non parentes. La quantification de la phyllotaxie deDRB27 ainsi que des expériences d’imagerie in vivo, ont révélé que ces groupes d’organes ne sontpas des verticilles, mais correspondent à des éruptions d’organogenèses se produisant en croissantà la périphérie du MAC quand, à l’inverse, de larges domaines restent inactifs. Ces observationsvont à l’encontre des règles classiques de positionnement d’organes lors de la mise en place de laphyllotaxie. De façon surprenante, nous avons identifié deux mutations candidates affectant lesrégulateurs abaxiaux FILAMENTOUS FLOWER et MIR166A, potentiellement toutes deuximpliquées dans le phénotype phyllotactique de DRB27. Alors que ces gènes sont exprimés dansles organes en développement, cela suggère des retours d’information sur la phyllotaxie, de façonnon autonome. Nous avons identifié des séries d’anomalies dans le MAC de DRB27, incluant despatrons de signalisation d’auxine anormaux, la perturbation des frontières entre les organes et leméristème, la modification des domaines WUS-CLV3 et de la géométrie du MAC, ainsi qu’unemodification de la dureté de la surface du méristème. Toutes ces données suggèrent que l’identitéet le développement des organes latéraux agissent sur l’homéostasie du MAC et l’établissement dupatron phyllotactique. / Phyllotaxis, the arrangement of botanical elements around plant axis,conforms to a robust spacial-temporal pattern. It is primarily established atthe shoot apical meristem (SAM), the post-embryonic aerial stem-cellniche. Local accumulation of the phytohormone auxin locally triggersorgan formation at the SAM, while depletion of auxin in the surroundingcells creates an inhibitory field, where no new organ can be initiated.Growth constantly moves older organs away from the SAM, clearingspace for new organogenesis. This is a striking example of an iterative and self-organized process driven by inhibitory fields. Molecular and geneticmechanisms regulating phyllotaxis are now being identified, but mostly inthe context of the most common Fibonacci spiral. Whether or not thesame mechanisms explain other types of phyllotaxis remains to beexplored. We identified DRB27, an Arabidopsis thaliana mutant with astrong tendency to generate clusters of organs. This is reminiscent of thewhorled phyllotaxis, observed in almost all angiosperm flowers and insome shoots of unrelated species. Quantification of DRB27 phyllotaxisand live imaging revealed that clusters are not whorls but correspond toburst of organs initiating in crescent domains at the periphery of the SAM.Conversely, large crescent domains remain devoid of organ initiation.Organogenesis in these clusters violates classical rules of organ spacing inphyllotactic systems. Surprisingly, we identified two candidate mutationsaffecting the two abaxial regulators FILAMENTOUS FLOWER andMIR166A, which likely combines to produce DRB27 peculiar phyllotaxis.Since these genes are expressed in developing organs, it suggests non-cellautonomous feedbacks on phyllotaxis. We identify a series of anomaliesin DRB27 SAM, including abnormal patterns of auxin signalling,perturbation of organ boundary formation, modification of CLV3/WUSdomains and SAM geometry and increase in cell wall stiffness. Takentogether our data questions how lateral organ identity and developmentfeedbacks on SAM homeostasis and phyllotaxis patterning.
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Real-time PCR analysis of age-dependent alterations in the RVLM neurotransmitter gene expression profile of F344 rats

Craig, Robin Ann January 1900 (has links)
Doctor of Philosophy / Department of Anatomy and Physiology / Michael J. Kenney / It is well established that normal aging is associated with progressive increases in efferent sympathetic nerve discharge (SND). Type II diabetes, obesity, heart failure, and hypertension are pathologies that have been attributed to both the processes of aging and sympathetic dysfunction, exemplifying the importance of understanding central regulation of SND during aging. However, the central mechanisms mediating altered SND with advancing age remain unclear. The rostral ventral lateral medulla (RVLM) is a brainstem region critically involved in setting the basal level of sympathetic outflow and cardiovascular function. Indeed, the RVLM is the only presympathetic region that when bilaterally inactivated results in profound reductions in both SND and arterial pressure. Glutamatergic influences in RVLM activity are powerfully inhibited by tonic GABAergic neural inputs originating from the caudal ventral lateral medulla (CVLM); effects that are mediated by GABAA receptors located on presympathetic neuronal cell bodies within the RVLM. In the present study we proposed that reductions in GABA[subscript A] receptor subunit gene expression may reflect withdrawal of GABAergic tone in the RVLM thereby contributing to the basal sympathetic activation that occurs with advancing age. Therefore, the objective of the current study was to identify age-related changes in the constitutive expression of genes related to GABAergic and muscarinic, nicotinic and dopaminergic receptor systems due to their reported involvement in modulating GABA[subscript A] receptor function, in the RVLM of adult young (3-5 mo. old), middle-aged (12 mo. old), weight stable presenescent (24-25 mo. old) and senescent (>24 mo. old) Fischer 344 (F344) rats using a commercially available real-time PCR array. Real-time analysis revealed nonuniform and age-associated changes in the RVLM GABA, muscarinic, nicotinic and dopaminergic neurotransmitter gene expression profile between young and middle-aged F344 rats. Heterogeneous expression of genes related to these neurotransmitters was also observed between presenescent and senescent F344 rats. Our results suggest that potential changes in neurotransmitter synthesis and degradation, uptake, transport, signaling and receptor subunit composition may account for the sympathoexcitatory state that is commonly observed in the aged.

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