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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.
141

Períodos de convivência das plantas daninhas no feijoeiro inoculado com Rhizobium tropici ou com adubação nitrogenada

Franciscon, Hugo 17 February 2017 (has links)
Submitted by Helena Bejio (helena.bejio@unioeste.br) on 2017-11-23T22:23:29Z No. of bitstreams: 2 Hugo Franciscon 2017.pdf: 2487508 bytes, checksum: cc47f34aceca2ba9016d4c6bde853e92 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-11-23T22:23:29Z (GMT). No. of bitstreams: 2 Hugo Franciscon 2017.pdf: 2487508 bytes, checksum: cc47f34aceca2ba9016d4c6bde853e92 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Two researches were conducted, the first in order to solve a methodological problem and the second aimed to investigate the effects of inoculation and nitrogen fertilization on the period prior to interference (PPI) in bean crop. First research: In the literature there are different methodologies for the establishment of interference periods; however, none of them combined accuracy, practicality and the inclusion of economic factors. Therefore, a research was carried out aiming the development of a new methodology that includes economic factors, accuracy and practicality; proving their applicability and accuracy in the data obtained from the literature and test its practicality based on hypothetical data. The integral method was obtained as a result, which was tested on interference periods data from the literature and compared with other methods, proving to be efficient; however, it fell short in practicality. To make the method more practical, a equations bank was elaborated, which was tested by means of hypothetical data; the equations present in the bank, proved to be accurate and, thus, made it possible to make the integral method, besides being precise, practical. Therefore, it was concluded that the integral method combined the practicality, precision and the use of economic factors in the determination of interference periods, achieving the established objectives. Second research: The objective was to verify if the substitution of the broadcast nitrogen fertilization by the inoculation with R. tropici can increase the bean crop tolerance to the weed interference and, thus, to extend its PPI. Two experiments of coexistence periods were installed during the seasons of 2014 and 2015. The experimental design was a randomized block design, with 4 replications, in a 2x10 factorial scheme, 2 handlings and 10 coexistence periods. The periods, in days after emergence (DAE), were 0 (control), 14, 21, 28, 35, 42, 49, 56, 63 and 90 (until harvest). At the end of each period the floristic survey was performed, calculating the density and dry mass of each weed species. A curve of accumulation of dry mass of the aerial part of the crop was also elaborated and its phenological stages determined. At harvest was performed to count the population of bean plants and determined the thousand grain weight and productivity of the culture. The PPI was determined by the integral method, the criterion used to determine the tolerated loss was the economic criterion of the WEEPEL. The substitution of broadcast nitrogen fertilization by inoculation with Rhizobium tropici did not increase the crop ability to compete with weeds and did not lengthen the PPI, which was provided by the use of broadcast nitrogen fertilization. The PPI for the bean under handling without broadcast nitrogen fertilization and with inoculation (without N) was between 17.80 and 49.51 DAE in mean of seasons; While when under handlinf with broadcast nitrogen fertilization and without inoculation the PPI was between 26.38 and 57.06 DAE, in mean of seasons. / Foram realizados dois estudos, o primeiro com o intuito de solucionar um problema metodológico e o segundo visando investigar os efeitos da inoculação e da adubação nitrogenada sobre o período anterior à interferência (PAI) no feijoeiro. Primeiro estudo: Há na literatura diferentes metodologias para o estabelecimento de períodos de interferência; porém, nenhuma delas combinou precisão, praticidade e a inclusão de fatores econômicos. Diante disso, foi realizado um estudo com os objetivos de desenvolver uma nova metodologia que inclua critérios econômicos e seja precisa e prática, comprovar sua aplicabilidade e precisão em dados obtidos da literatura e testar sua praticidade com base em dados hipotéticos. Como resultado, obteve-se o método integral, o qual foi testado em dados de períodos de interferência retirados da literatura e comparado com outros métodos, demonstrando-se eficiente; porém, deixou a desejar na praticidade. Para tornar o método mais prático, foi elaborado um banco de equações, o qual foi testado por meio de dados hipotéticos; as equações presentes no banco, demonstraram-se exatas e, assim, permitiram tornar o método integral, além de preciso, prático. Portanto, concluiu-se que o método integral combinou a praticidade, precisão e o uso de fatores econômicos na determinação de períodos de interferência, logrando os objetivos estabelecidos. Segundo estudo: o objetivo foi verificar se a substituição da adubação nitrogenada em cobertura pela inoculação com R. tropici pode aumentar a tolerância do feijoeiro à matointerferência e, assim, alongar seu PAI. Foram instalados dois experimentos de período de convívio da cultura com as plantas daninhas, durante os anos de 2014 e 2015. O delineamento experimental adotado foi o de blocos casualizados, com 4 repetições, em esquema fatorial 2x10, 2 manejos e 10 períodos de convívio. Os períodos, em dias após a emergência (DAE), foram 0 (testemunha), 14, 21, 28, 35, 42, 49, 56, 63 e 90 (até a colheita). Ao final de cada período foi realizado o levantamento florístico, calculada a densidade e massa seca de cada espécie de planta daninha. Também foi elaborada uma curva de acúmulo de massa seca da parte aérea da cultura e determinados os seus estádios fenológicos. Na colheita foi realizada a contagem da população de plantas de feijoeiro e determinada a massa de mil grãos e a produtividade da cultura. O PAI foi determinado pelo método integral, o critério usado para se determinar a perda tolerada foi o critério econômico do PADRE. A substituição da adubação nitrogenada em cobertura pela inoculação com Rhizobium tropici não aumentou a capacidade da cultura em competir com as plantas daninhas e não alongou o PAI, o qual foi proporcionado pelo uso da adubação nitrogenada em cobertura. O PAI para o feijoeiro sob o manejo sem adubação nitrogenada em cobertura e com inoculação (sem N) ficou entre 17,80 e 49,51 DAE na média dos anos; enquanto que quando sob o manejo com adubação em cobertura e sem inoculação o PAI se situou entre 26,38 e 57,06 DAE, na média dos anos.
142

O luto em adolescentes pela morte do pai: risco e prevenção para a saúde mental / The bereavement of adolescents for the death of father: risk and prevention for mental health

Monica Maria de Angelis Mota 15 October 2008 (has links)
Este estudo explora, descreve e discute a vivência de luto de cinco adolescentes que perderam o pai biológico por morte de causas diversas. Para tanto, investigaram-se vivências e manifestações relacionadas a essas experiências de perda, suas repercussões para os jovens e para seu desenvolvimento emocional, as estratégias de que eles se valeram para enfrentar esse luto, sua resiliência frente à perda vivida (capacidade do jovem de resistir às adversidades geradas pela morte do pai, adaptar-se e manter-se psicologicamente saudável), identificando-se fatores de risco (vulnerabilidades) e de proteção para a elaboração desse luto e o desenvolvimento dos adolescentes, bem como a necessidade ou não de se proporem formas de cuidado específicas para os enlutados, entre as inúmeras possibilidades terapêuticas, mesmo que profiláticas. Como procedimento, usaram-se o Inventário de Auto-avaliação para jovens de 11 a 18 anos (YSR), para rastrear a eventual presença de problemas de saúde mental, e uma entrevista semi-estruturada com roteiro. A análise dos dados obtidos estabeleceu que o luto pela morte do pai biológico na adolescência tem características próprias, distinguindo-se do luto que essa perda acarreta em outras etapas do ciclo vital, em função dos desafios singulares do desenvolvimento nesse período. Embora a morte do pai biológico represente para o adolescente uma crise, também pode ser uma oportunidade para que, no enfrentamento dessa perda, ele amadureça. Constatou-se ainda a importância do suporte social de uma rede de apoio que compreenda e atenda as necessidades do enlutado, sobretudo pela presença de uma mãe funcional, para a ressignificação dessa perda, além de que, se o adolescente tem dificuldade para expressar seu luto, pode ficar entorpecido e negar as conseqüências dessa perda, comprometendo seu desenvolvimento emocional. / This study explores, describes and discuss the bereavement experience of five adolescents who had lost their biological father by death of several causes. Thus, it was sought to investigate the experiences and events related to these experiences of loss; its impact on young people and for their emotional development; the strategies that they used to cope with this mourning; the resilience to face the loss experienced (the adolescents ability to resist to the adversities generated by the death of the father, adapt to and remain psychologically healthy), identifying risk factors (vulnerabilities) and protection factors for the resolution of this bereavement and the development of adolescents, and if its necessary to propose ways of special care for the bereaved, among the many therapeutic possibilities, even if prophylactic. As procedure, were used the Inventory of Self-assessment for young people from 11 to 18 years-old (YSR), to trace the possible presence of mental health problems and a semistructured interview with a script. The analysis of data obtained established that the mourning for the death of biological father in adolescence presents its own characteristics, distinguishing itself from the grief that this loss brings at other times of the life cycle, according to the natural challenges of development in that period; the fact that, although the death of the biological father represents a crisis for the adolescent, can also be an opportunity for him or her, when facing this loss, matures; The importance of social support of a supportive network that understands and meets the needs of the bereaved, especially the presence of a functional mother, for the re-signification of this loss, as well as the fact that the teenagers difficulties to express themselves about the mourning that they experience can guide them to remain numb and deny the consequences of this loss, and impair their emotional development.
143

Changements phénotypiques des cellules endothéliales irradiées au cours du développement des lésions radiques pulmonaires / Phenotypic changes in irradiated endothelial cells and roles in lung injury following radiation therapy

Lavigne, Jérémy 16 October 2017 (has links)
La radiothérapie thoracique peut induire le développement de pneumopathies aiguës et de fibroses. La dysfonction du système vasculaire participe au développement de lésions radiques. Dans l'intestin, un KO endothélial de PAI-1 protège les souris de la fibrose radique. Le premier objectif de ce projet est d'explorer le rôle de PAI-1 dans l'apparition de la fibrose radique pulmonaire. L'irradiation thoracique de souris à 17 Gy altère sévèrement le parenchyme pulmonaire et l'analyse histologique révèle que l'invalidation de PAI-1 aggrave les lésions à 2 et 13 semaines. Cette invalidation ne protège donc pas les animaux des dommages radiques pulmonaires. L'organisation en parallèle du poumon permet d'envisager une tolérance à de fortes doses par fraction sur des petits volumes. Des irradiations en conditions stéréotaxiques ont donc été réalisées chez la souris. Les analyses histologiques montrent une déstructuration alvéolaire et un fort infiltrat inflammatoire au niveau de la zone cible. Un œdème est observable dans l'ensemble du poumon ipsilatéral deux semaines après irradiation. Le poumon ipsilatéral est également affecté par des altérations de structure, tel un épaississement des septa alvéolaires. Ces bouleversements se traduisent également au niveau transcriptomique. A la vue de l'ensemble de ces altérations, un test à l'effort a été réalisé pour évaluer l'impact potentiel sur la fonction pulmonaire. Les résultats mettent en évidence une diminution des performances des animaux. Les analyses sont à approfondir mais elles démontrent l'importance de s'intéresser aux tissus sains situés hors du volume cible mais recevant des fractions variables de la dose délivrée. / Radiation-induced endothelial dysfunction is known to participate to the development of normal tissue damage. PAI- is implicated in the phenotypic changes of irradiated endothelial cells and KOendo mice are protected from radiation damage to the gut. Whole thorax of PAI-1 KOendo and floxed mice were exposed to 17 Gy. Histological analyzes showed that PAI-1 KOendo induces a worsening of injuries at 2 and 13 weeks. Consequently, contrary to the gut no protection from radiation-induced lung damage is observed in PAI-1 KOendo mice. Our second aim was to study the effects of a single high dose stereotactic irradiation on pulmonary tissues. Histological analyzes and scanner imaging show important injuries on the targeted volume. An ipsilateral edema can also be observed 2 weeks after irradiation. Ipsilateral lung is moreover importantly damaged. A thickening of alveolar septa is notably observable. A transcriptomic analysis show important similarities between tissues from the ipsilateral lung and the focal lesion. As really highly damages have been observed in both scanner and histological analyzes, we decided to perform forced physical activity test on treadmill. A drastic decrease of maximal distance traveled has been observed from two weeks. These experiments highlighted a deficiency in respiratory function and all of these results show the importance of non-targeted irradiated pulmonary volume in the development of radiation-induced fibrosis. Effect of an endothelium-specific deletion of HIF-1α has been investigated in this model of stereotactic irradiation. Only few differences have been observed between KOendo and control mice. Experiments are still ongoing.
144

Conséquences de la délétion spécifique de PAI-1 dans l'endothélium sur la réponse radio-induite de l'intestin / Consequences of specific endothelial deletion of PAI-1 on gut's radiation-induced response

Rannou, Emilie 17 March 2015 (has links)
Les lésions radiques aux tissus sains représentent un réel problème de santé publique, puisqu’elles constituent l’un des principaux facteurs limitants des traitements radiothérapeutiques. Les concepts qui entourent leur pathogenèse ont progressivement évolués vers une vision intégrée de la pathogénèse, qui implique l’ensemble des compartiments qui composent le tissu cible. Parmi eux, l’endothélium semble tenir une place centrale dans la séquence d’évènements interdépendants qui conduisent au développement des lésions radiques. Grâce à l’utilisation de nouveaux modèles murins transgéniques, ce travail de thèse fournit la démonstration directe d’un continuum endothélium-dépendant dans l’évolution des lésions intestinales radiques. En effet, la modification du phénotype endothélial grâce à la délétion ciblée du gène SERPINE1, choisi du fait de son rôle clé dans le développement de l’entérite radique, influence différents paramètres du développement de la pathologie. Ainsi, les souris PAI-1 KOendo présentent une meilleure survie, ainsi que des atteintes tissulaires précoces et tardives moins sévères, après irradiation localisée du grêle. En outre, ces animaux présentent une diminution du nombre de cellules intestinales apoptotiques dans les heures qui suivent l’irradiation, de la densité de l’infiltrat de macrophages une semaine après irradiation, ainsi qu’une polarisation différentielle de ces macrophages tout au long du processus physiopathologique. Dans une volonté de protéger les tissus sains des effets secondaires de la radiothérapie sans entraver le traitement anti-cancéreux, l’intérêt de PAI-1 comme cible thérapeutique laisse peu de place aux doutes. / Radiation-induced injury to healthy tissues is a real public health problem, since they are one of the most limiting factors that restrict efficiency of radiation therapy. Concepts surrounding the development of radiation-induced damage have gradually evolved into a contemporary and integrated view of the pathogenesis, involving all compartments of target tissue. Among them, endothelium seems to be central in the sequence of interrelated events that lead to the development of radiation-induced damage, although there are rare concrete elements that support this concept. By using new transgenic mouse models, this PhD project provides a direct demonstration of an endothelium-dependent continuum in evolution of radiation-induced intestinal damage. Indeed, changes in the endothelial phenotype through targeted deletion of the gene SERPINE1, chosen because of its key role in the development of radiation enteritis, influences various parameters of the development of the disease. Thus, lack of PAI-1 secretion by endothelial cells significantly improves survival of the animals, and limits severity of early and late tissue damage after a localized small bowel irradiation. Furthermore, these mice partially KO for PAI-1 showed a decrease in the number of apoptotic intestinal stem cells in the hours following irradiation, a decrease in the macrophages infiltrate density one week after irradiation, and a change in the polarization of macrophages throughout the pathophysiological process. In an effort to protect healthy tissues from radiation therapy side effects, without hindering the cancer treatment, PAI-1 seems to be an obvious therapeutic target.
145

Rôle de l'inhibiteur de l'activateur tissulaire du plasminogène de type 1 (PAI-1) dans la dépression majeure chez la souris / The role of Plasminogen Activator Inhibitor type-1 (PAI-1) in major depressive disorders

Party, Helene 18 October 2017 (has links)
La dépression majeure représente l’une des affections les plus lourdes dans le monde, touchant plus de 350 millions depersonnes. La 5e édition du Diagnostic and Statistical Manual of Mental Disorders (DSM-V) est la référence mondiale utiliséepour poser le diagnostic de la pathologie chez l’humain. Bien que très nombreux, les antidépresseurs prescrits à ce jour restentencore malheureusement inefficaces pour 30% des patients. Dans ce contexte, il est fondamental de développer de nouvellesstratégies thérapeutiques pour soigner les patients. Des études récentes suggèrent, sans toutefois le démontrer véritablement,l’implication de l’axe « activateur tissulaire du plasminogène / inhibiteur de l’activateur tissulaire du plasminogène de type 1 »(axe tPA/PAI-1) dans la pathogenèse de la dépression majeure.La première partie de mes travaux a été consacrée à la mise au point d’un nouveau système d’évaluation comportementalede la dépression majeure chez la souris en modélisant de manière exhaustive et standardisée les symptômes cliniques du DSMV.La seconde partie de mes travaux a consisté à étudier les mécanismes d’action potentiels de l’axe tPA/PAI-1 dans ladépression majeure. Pour ce faire, j’ai tout d’abord caractérisé le phénotype comportemental de souris déficientes en tPA (souristPA-/-) et en PAI-1 (souris PAI-1-/-), ainsi que de leurs homologues de type sauvage, grâce au système fonctionnel d’évaluationinitialement mis en place. Par ailleurs, du fait de la forte comorbidité entre anxiété et dépression, les comportements de typeanxieux ont également été analysés chez ces animaux. Mes expériences ont révélé un phénotype de type dépressif, indépendantdu tPA, chez les souris déficientes en PAI-1, associé à des diminutions des concentrations de deux monoamines (sérotonine etdopamine) dans des structures cérébrales connues pour être impliquées dans la dépression majeure (hippocampe et noyau du litde la strie terminale). De surcroît, l’enrichissement modéré de l’environnement n’amenuise pas les symptômes de type dépressifdes souris PAI-1-/- mais conduit cependant à la disparition des troubles anxieux dépendants, quant à eux, de l’axe tPA/PAI-1.La troisième partie de ma thèse a été dédiée à des manipulations pharmacologiques visant à tester l’efficacitéd’antidépresseurs de type inhibiteurs de la recapture de la sérotonine. L’escitalopram produit un effet anxiolytique chez les sourisdéficientes en PAI-1, sans toutefois contrebalancer le phénotype dépressif chez ces mêmes sujets. Qui plus est, la fluoxétine, àla même dose que l’escitalopram, est toxique pour ces souris.Les résultats de ma thèse apportent ainsi la première démonstration de l’implication de PAI-1 dans la dépression majeurepar un mécanisme indépendant de son interaction avec le tPA. Ces travaux démontrent également que la souris PAI-1-/- constitueun outil essentiel et innovant pour étudier les mécanismes cellulaires et moléculaires sous-jacents à la dépression majeure, ainsique pour la recherche de cibles thérapeutiques visant à améliorer l’efficacité des traitements. / Major depressive disorder is one of the heaviest mental disorders in the world, affecting more than 350 people worldwide.It is in the fifth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-V) that the basis for an internationallyadmitted diagnosis was laid. Albeit diverse, existing antidepressants still remain ineffective for 30% of the patients. Under suchcircumstances, the necessity of developing new therapeutical strategies has arisen. Recent studies tend to suggest, withoutabsolute demonstration, the implication of the axis "Tissue Plasminogen Activator / Plasminogen Activator Inhibitor type-1"(tPA/PAI-1 axis) in the pathogenesis of major depressive disorders.The first section of my works has been devoted to the development of a new system of behavioural assessment in micefor depressive-like disorders, through a comprehensive and standardised modelling of clinical symptoms of DSM-V.The second section of my works has consisted in studying the potential action mechanisms of the tPA/PAI-1 axis in theemergence of depressive-like disorders. To do so, I first had to identify the behavioural phenotype of mice having from a tPA(tPA-/- mice) and PAI-1 (PAI-1-/-mice) deficiency as well as their wild-type counterparts through the system of assessment setup in the beginning of my research. In addition, due to the significant comorbidity between anxiety and depression, anxious-likebehaviours have been analysed as well. Among PAI-1-deficient mice, my experiments have disclosed a depressive-likephenotype, independent of tPA, and correlated with a decrease in the concentration of two monoamines (serotonin and dopamine)in brain structures known to be involved in major depressive disorder (hippocampus and bed nucleus of the stria terminalis).Besides, the moderate enrichment of the environment does not reduce the depressive-like symptoms of PAI-1-/- mice, yet inducesthe dissipation of dependent-tPA/PAI-1 axis anxious disorders.The third section of my PhD has been devoted to pharmacological experiments meant to assess the effectiveness ofantidepressants classified among selective serotonin reuptake inhibitors (SSRIs). Escitalopram produces anxiolytic falloutsamong PAI-1-deficient mice without for all that offsetting the depressive phenotype among these same mice. Moreover,fluoxetine administered in the same concentration as escitalopram has proven to be toxic for these mice.The results of these doctoral experiments have therefore demonstrated for the first time the implication of PAI-1 in theprocess of major depressive disorder through a mechanism independent from its interaction with tPA. These works have alsodemonstrated that PAI-1-/- mice make up a fundamental and cutting edge tool to study the cellular and molecular mechanismsunderlying major depressive disorder as well as to develop competent therapeutical targets intended to improve the efficiency oftreatments.
146

A presença do pai no processo de amadurecimento: um estudo sobre D. W. Winnicott

Fulgencio, Claudia Dias Rosa 29 June 2007 (has links)
Made available in DSpace on 2016-04-28T20:39:30Z (GMT). No. of bitstreams: 1 Claudia Dias Rosa Fulgencio.pdf: 424997 bytes, checksum: a557035c159523a923e47d2ba28ae34c (MD5) Previous issue date: 2007-06-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose aim of this paper is to explain Winnicott s concept of what is expected of a father, in terms of his presence and the many roles played by him in the bringing up of a child, during the process of personal maturation, from birth to the stage of Oedipus Complex, keeping in mind healthy up-bringing. Without intending to write a comparative paper that takes into account many psychoanalytic ways of approaching a same topic, I aim to identify aspects of Winnicott s theories, which referring to this theme, can characterize the most important differences between this author and the traditional psychoanalysis concepts. While the traditional psychoanalysis, due to the centerpiece of Oedipus and to the magnitude of the sexuality theory, the father s role was limited mostly overall to the role of an interventionist and a representative of the law, as for Winnicott, the presence of the father in involved implicated since the beginning of life, when questions concerning Oedipus Complex have no meaning whatsoever, and continues changing as the child matures. This paper confirms the thesis that the thoughts reasonings viewpoints thinkings of this author represents a new theoretical and practical foundation from which the human questions, in this case, the presence and role of the father, in the process of maturation, can be understood / Este estudo tem por objetivo explicitar a concepção de Winnicott acerca do que é requerido do pai, em termos de presença e dos diversos papéis que lhe estão reservados na criação de um filho, ao longo do processo de amadurecimento pessoal, do nascimento até o estágio do complexo de Édipo, tendo em vista um desenvolvimento saudável. Sem pretender fazer um estudo comparativo que leve em conta as várias abordagens psicanalíticas sobre essa mesma questão, viso identificar aspectos da teoria de Winnicott que, referidos a esse tema, podem caracterizar as diferenças marcantes da teoria desse autor com relação às formulações da psicanálise tradicional. Enquanto nesta última, devido à centralidade do Édipo e à primazia da teoria da sexualidade, o papel do pai ficou delimitado, sobretudo, ao de interventor e de representante da lei, em Winnicott, a presença do pai está implicada desde o início da vida, quando as questões relativas ao complexo edípico não fazem ainda nenhum sentido, e vai se alterando à medida em que o amadurecimento da criança avança. Este estudo corrobora a tese de que o pensamento desse autor representa um novo fundamento teórico e prático a partir do qual as questões humanas, no caso, a presença e a parte que cabe ao pai, no processo de amadurecimento, podem ser entendidas
147

Avaliação dos efeitos da sinvastatina via Inibidor do Ativador do Plasminogênio 1 (PAI-1) sobre a terapia celular com células estromais mesenquimais / Evaluation of the effects of simvastatin in mesenchymal stromal cell therapy through Plasminogen Activator inhibitor 1 (PAI-1)

Faria, Carolina Arruda de 08 August 2016 (has links)
A Doença Pulmonar Obstrutiva Crônica (DPOC) é caracterizada pela limitação persistente de trocas gasosas, usualmente progressiva e associada a uma resposta inflamatória crônica exacerbada das vias aéreas a partículas e gases nocivos. Apesar de prevenível e tratável, não se logrou até o presente uma terapêutica eficaz, que resulte na cura da doença. Neste cenário, a terapia celular apresenta-se como uma alternativa terapêutica potencialmente promissora em DPOC, bem como em outras doenças pulmonares degenerativas e de caráter inflamatório. Porém, vários aspectos da terapia celular carecem de um melhor entendimento. Um dos principais desafios ao sucesso da terapia celular são as baixas taxas de sobrevivência das células transplantadas. O Inibidor do Ativador de Plasminogênio 1 (Plasminogen Activator Inhibitor 1 - PAI-1) pode representar um potencial mediador da sobrevivência de células estromais mesenquimais (CTM) pós-transplante, pois tem sido proposto que anticorpos neutralizadores do PAI-1 auxiliam no aumento da sobrevivência de CTM no tecido-alvo da terapia celular. Desta forma, a diminuição dos níveis de PAI-1 possui um potencial terapêutico interessante, ao modular os principais processos envolvidos na criação de um ambiente pouco propício ao \"homing\" celular durante o processo de injúria. A diminuição dos níveis de PAI-1 é promovida, pela sinvastatina, fármaco da família das estatinas. Desta forma, objetivou-se com este trabalho analisar os efeitos da sinvastatina sobre a expressão do PAI-1, bem como sua influência na sobrevivência das células infundidas para terapia celular de enfisema pulmonar em modelo murino. Camundongos da linhagem FVB foram submetidos à instilação intranasal de elastase para indução de enfisema pulmonar e, posteriormente, tratados com CTM do tecido adiposo e sinvastatina. Os resultados mostraram que, quanto aos aspectos morfológicos e funcionais, considerando-se a análise conjunta de ambos os pulmões, não houve diferença estatisticamente significativa entre os grupos submetidos à instilação intranasal de elastase e submetidos à terapia celular com CTM tratados ou não com sinvastatina. Quando porém os pulmões foram analisados individualmente constatou-se que não houve diferença estatisticamente significativa entre os grupos controle e os resultados referentes ao lado direito do pulmão dos animais tratados com elastase e que receberam sinvastatina e infusão de CTM. Diferenças anatômicas entre os lados direito e esquerdo do pulmão, levaram a uma maior deposição de células no lado direito, como evidenciado pelos resultados obtidos nos ensaios de bioluminescência. Pode-se, portanto, inferir que a recuperação morfológica no lado direito do pulmão de animais com DPOC/enfisema poderia ser decorrente de um efeito regenerativo parácrino das CTM associadas à sinvastatina. / Chronic Obstructive Pulmonary Disease - COPD is characterized by the persistent limitation of gas exchange, is usually progressive, and associated to a chronic augmented inflammatory response of the airways to particles and noxious gases. Despite preventable e treatable, an effective, curative therapeutic approach is yet to be achieved. In this context, cell therapy presents itself as a promising therapeutic approach for COPD and other pulmonary inflammatory and degenerative diseases. However, many aspects of cell therapy with stem cells remain unclear. One of the major challenges to the success of cell therapy are the low survival rates of transplanted cells. The Plasminogen Activator Inhibitor 1 (PAI-1) is a potential mediator of the survival of mesenchymal stromal cells (MSC) after transplantation, since PAI-1 neutralizing antibodies have been shown to increase the survival rate of MSC in the target tissue of cell therapy. Thus, the decreased levels of PAI-1 has an interesting therapeutic potential to modulate key processes involved in creating an inhospitable environment, during the process of injury, to the homing of transplanted cells. Decreased levels of PAI-1 are promoted by simvastatin, a drug of the statins family. Thus, the goal of this work was to evaluate the effect of simvastatin in vivo on the expression of PAI-1, as well as its influence on the survival rate of infused cells in mice model of cell therapy for pulmonary COPD/emphysema. FVB mice were submitted pulmonary emphysema induction by means of intranasal instillation of elastase and than treated with adipose-derived mesenchymal stem cells and simvastatin. The results regarding morphological and functional aspects, when considering the analisys of both lungs, presented no statistically significant difference among the groups submitted to intranasal instillation of elastase and cell therapy with MSC, treated or not with simvastatin. However, when the lungs where analyzed individually, it was found that there was no statistically significant difference between the control group and the results regarding the right lung of animals treated with elastase and that received simvastatin and MSC infusion. Anatomical differences between the right and left sides of the lung lead to a higher deposition of cells in the right side, as observed in the bioluminescence assays. Thus, it is possible to infer that the morphological recovery in the right side of the lung of animals with DPOC/emphysema could be due to a regenerative paracrine effect of mesenchymal stem cells associated with simvastatin.
148

Transcriptional Regulation of human Plasminogen Activator Inhibitor-1 Gene Expression by Insulin-like Growth Factor-1, Insulin and Upstream Stimulatory Factor-2 / Transkriptionelle Regulation der Genexpression des humanen Plasminogen-Activator Inhibitor-1 durch Insulin-like Growth Factor-1, Insulin und Upstream Stimulatory Factor-2

Dimova, Elitsa Yosifova 26 April 2005 (has links)
No description available.
149

Atividade pró-trombótica da toxina ExoU de Pseudomonas aeruginosa detectada em modelos experimentais in vivo e in vitro / Prothrombotic activity of the toxin Pseudomonas aeruginosa toxin ExoU detected in experimental models in vivo and in vitro

Glória Beatriz da Silva Machado 29 June 2011 (has links)
Pseudomonas aeruginosa é um importante agente de pneumonia, particularmente em pacientes submetidos à ventilação mecânica, que pode evoluir para sepse, com elevadas taxas de letalidade. Na sepse, o processo inflamatório sistêmico exacerbado favorece o desequilíbrio entre as vias de coagulação e fibrinólise e a instalação de um estado pró-coagulante, com o aparecimento de trombose microvascular, coagulação intravascular disseminada e falência de múltiplos órgãos. Conhecendo a potente atividade pró-inflamatória da toxina ExoU produzida por P. aeruginosa, decorrente de sua atividade fosfolipásica A2, o objetivo desta tese foi investigar seu potencial de indução de alterações hemostáticas relacionadas à patogênese da sepse. Utilizando modelo de sepse em camundongos inoculados, por via intratraqueal, com suspensões de P. aeruginosa produtora de ExoU (PA103) ou de cepa com deleção do gene exoU, não produtora da toxina, foi mostrado que ExoU determinou maior gravidade da infecção, maior taxa de letalidade, leucopenia, trombocitose, hiperpermeabilidade vascular e transudação plasmática, evidenciadas, respectivamente, pela maior concentração de proteínas nos lavados broncoalveolares (LBAs) e acúmulo do corante Azul de Evans, previamente inoculado nos animais, por via endovenosa, no parênquima renal. ExoU favoreceu, também, a ativação plaquetária, confirmada pela maior concentração de plaquetas expressando P-selectina em sua superfície, maior número de micropartículas derivadas de plaquetas e maior concentração plasmática de tromboxano A2. A histopatologia dos pulmões e rins dos animais infectados com PA103 confirmou a formação de microtrombos, que não foram detectados nos animais controles ou infectados com a cepa mutante. Nos pulmões, a produção de ExoU determinou intensa resposta inflamatória com maior concentração de leucócitos totais e polimorfonucleados, interleucina-6 e fator de necrose tumoral-α nos LBAs. A análise imunohistoquímica mostrou intensa deposição de fibrina nos alvéolos e septos interalveolares. A atividade pró-coagulante dependente do fator tissular detectada nos LBAs dos camundongos infectados com PA103 foi independente da produção do inibidor da via de ativação do fator tissular (TFPI), mas associada ao aumento da produção do inibidor do ativador do plasminogênio-1 (PAI-1). Para investigar a participação do fator de ativação plaquetária (PAF) na liberação de PAI-1, foi pesquisada a atividade da enzima PAF-acetil-hidrolase (PAF-AH) nos LBAs dos camundongos. A atividade de PAF-AH apresentou-se significativamente elevada nos LBA dos camundongos infectados com PA103. O tratamento dos animais com um inibidor do PAF, antes da infecção, resultou na diminuição significativa das concentrações de PAI-1 e de leucócitos totais, bem como da atividade pró-coagulante dos LBAs. In vitro, ExoU induziu maior expressão do RNA mensageiro de PAI-1 e maior liberação da proteína PAI-1 nos sobrenadantes de células epiteliais respiratórias da linhagem A549. O tratamento das células A549 com um anticorpo anti-receptor de PAF, antes da infecção, reduziu significativamente a concentração de PAI-1 nos sobrenadantes de células infectadas com a cepa selvagem. Estes resultados demonstraram um novo mecanismo de virulência de P. aeruginosa através da atividade pró-trombótica de ExoU e a possibilidade de utilização da identificação de ExoU em isolados clínicos de pacientes graves como um marcador prognóstico para estes pacientes. / Pseudomonas aeruginosa is an important agent of pneumonia, mainly in patients undergoing mechanical ventilation, which can progress to sepsis with high mortality rates. In sepsis, the systemic inflammatory process favors exacerbated imbalance between the coagulation and fibrinolysis pathways and the installation of a procoagulant state, leading to microvascular thrombosis, disseminated intravascular coagulation and multiple organ failure. Knowing the powerful proinflammatory activity of the P. aeruginosa toxin ExoU, secondary to its phospholipase A2 activity, the goal of this study was to investigate the ExoU potential to induce hemostatic changes related to sepsis pathogenesis. By using a murine model of pneumosepsis, obtained by the intratracheal injection of suspensions of the ExoU-producing PA103 P. aeruginosa strain or of its isogenic mutant PA103ΔexoU, defective in the toxin synthesis, ExoU was shown to enhance the severity of the infection and to induce higher mice mortality rate as well as leukopenia, thrombocytosis, vascular hyperpermeability and plasma transudation, evidenced, respectively, by the higher protein concentration in the bronchoalveolar lavage fluids (BALF) and accumulation of Evans blue dye, previously intravenous injectioned, in mice renal parenchyma. ExoU also favored platelet activation, evidenced by the higher concentration of platelets expressing P-selectin on their surface, greater number of platelet-derived microparticles and increased plasma concentration of thromboxane A2. Histopathology of the lungs and kidneys of PA103-infected animals confirmed the formation of microthrombi, which were not detected in controls or in animals infected with the bacterial mutant. In lungs, ExoU induced an intense inflammatory response with high concentrations of total and polymorphonuclear leukocytes, interleukin-6 and tumor necrosis factor-α in mice BALF. Immunohistochemical analysis showed intense fibrin deposition in the alveoli and interalveolar septa. The tissue factor-dependent procoagulant activity detected in BALF from PA103-infected mice did not depend on decreased production of tissue factor pathway inhibitor (TFPI) production, but was associated with increased concentration of plasminogen activator inhibitor-1 (PAI-1). To investigate the role of platelet activating factor (PAF) in PAI-1 release, we compared the activity of the enzyme PAF-acetylhydrolase (PAF-AH) in BALF from control and infected mice, and we observed that PAF-AH activity was significantly elevated in BALF from PA103-infected animals. Mice treatment with a PAF inhibitor prior to infection resulted in a significant reduction of PAI-1 concentration, as well as of BALF total leukocytes and procoagulant activity. In vitro, ExoU induced higher expression of PAI-1 m RNA and increased release of PAI-1 protein in supernatants from A549 epithelial respiratory cell cultures. A549 cell treatment with an anti-PAF receptor prior to infection significantly reduced PAI-1 concentration in supernatants from cells infected with the wild type strain. These results show a novel mechanism by which a baterial product can favor a prothrombotic activity and ExoU production by infecting P. aeruginosa isolates may have prognostic implications for patients.
150

Atividade pró-trombótica da toxina ExoU de Pseudomonas aeruginosa detectada em modelos experimentais in vivo e in vitro / Prothrombotic activity of the toxin Pseudomonas aeruginosa toxin ExoU detected in experimental models in vivo and in vitro

Glória Beatriz da Silva Machado 29 June 2011 (has links)
Pseudomonas aeruginosa é um importante agente de pneumonia, particularmente em pacientes submetidos à ventilação mecânica, que pode evoluir para sepse, com elevadas taxas de letalidade. Na sepse, o processo inflamatório sistêmico exacerbado favorece o desequilíbrio entre as vias de coagulação e fibrinólise e a instalação de um estado pró-coagulante, com o aparecimento de trombose microvascular, coagulação intravascular disseminada e falência de múltiplos órgãos. Conhecendo a potente atividade pró-inflamatória da toxina ExoU produzida por P. aeruginosa, decorrente de sua atividade fosfolipásica A2, o objetivo desta tese foi investigar seu potencial de indução de alterações hemostáticas relacionadas à patogênese da sepse. Utilizando modelo de sepse em camundongos inoculados, por via intratraqueal, com suspensões de P. aeruginosa produtora de ExoU (PA103) ou de cepa com deleção do gene exoU, não produtora da toxina, foi mostrado que ExoU determinou maior gravidade da infecção, maior taxa de letalidade, leucopenia, trombocitose, hiperpermeabilidade vascular e transudação plasmática, evidenciadas, respectivamente, pela maior concentração de proteínas nos lavados broncoalveolares (LBAs) e acúmulo do corante Azul de Evans, previamente inoculado nos animais, por via endovenosa, no parênquima renal. ExoU favoreceu, também, a ativação plaquetária, confirmada pela maior concentração de plaquetas expressando P-selectina em sua superfície, maior número de micropartículas derivadas de plaquetas e maior concentração plasmática de tromboxano A2. A histopatologia dos pulmões e rins dos animais infectados com PA103 confirmou a formação de microtrombos, que não foram detectados nos animais controles ou infectados com a cepa mutante. Nos pulmões, a produção de ExoU determinou intensa resposta inflamatória com maior concentração de leucócitos totais e polimorfonucleados, interleucina-6 e fator de necrose tumoral-α nos LBAs. A análise imunohistoquímica mostrou intensa deposição de fibrina nos alvéolos e septos interalveolares. A atividade pró-coagulante dependente do fator tissular detectada nos LBAs dos camundongos infectados com PA103 foi independente da produção do inibidor da via de ativação do fator tissular (TFPI), mas associada ao aumento da produção do inibidor do ativador do plasminogênio-1 (PAI-1). Para investigar a participação do fator de ativação plaquetária (PAF) na liberação de PAI-1, foi pesquisada a atividade da enzima PAF-acetil-hidrolase (PAF-AH) nos LBAs dos camundongos. A atividade de PAF-AH apresentou-se significativamente elevada nos LBA dos camundongos infectados com PA103. O tratamento dos animais com um inibidor do PAF, antes da infecção, resultou na diminuição significativa das concentrações de PAI-1 e de leucócitos totais, bem como da atividade pró-coagulante dos LBAs. In vitro, ExoU induziu maior expressão do RNA mensageiro de PAI-1 e maior liberação da proteína PAI-1 nos sobrenadantes de células epiteliais respiratórias da linhagem A549. O tratamento das células A549 com um anticorpo anti-receptor de PAF, antes da infecção, reduziu significativamente a concentração de PAI-1 nos sobrenadantes de células infectadas com a cepa selvagem. Estes resultados demonstraram um novo mecanismo de virulência de P. aeruginosa através da atividade pró-trombótica de ExoU e a possibilidade de utilização da identificação de ExoU em isolados clínicos de pacientes graves como um marcador prognóstico para estes pacientes. / Pseudomonas aeruginosa is an important agent of pneumonia, mainly in patients undergoing mechanical ventilation, which can progress to sepsis with high mortality rates. In sepsis, the systemic inflammatory process favors exacerbated imbalance between the coagulation and fibrinolysis pathways and the installation of a procoagulant state, leading to microvascular thrombosis, disseminated intravascular coagulation and multiple organ failure. Knowing the powerful proinflammatory activity of the P. aeruginosa toxin ExoU, secondary to its phospholipase A2 activity, the goal of this study was to investigate the ExoU potential to induce hemostatic changes related to sepsis pathogenesis. By using a murine model of pneumosepsis, obtained by the intratracheal injection of suspensions of the ExoU-producing PA103 P. aeruginosa strain or of its isogenic mutant PA103ΔexoU, defective in the toxin synthesis, ExoU was shown to enhance the severity of the infection and to induce higher mice mortality rate as well as leukopenia, thrombocytosis, vascular hyperpermeability and plasma transudation, evidenced, respectively, by the higher protein concentration in the bronchoalveolar lavage fluids (BALF) and accumulation of Evans blue dye, previously intravenous injectioned, in mice renal parenchyma. ExoU also favored platelet activation, evidenced by the higher concentration of platelets expressing P-selectin on their surface, greater number of platelet-derived microparticles and increased plasma concentration of thromboxane A2. Histopathology of the lungs and kidneys of PA103-infected animals confirmed the formation of microthrombi, which were not detected in controls or in animals infected with the bacterial mutant. In lungs, ExoU induced an intense inflammatory response with high concentrations of total and polymorphonuclear leukocytes, interleukin-6 and tumor necrosis factor-α in mice BALF. Immunohistochemical analysis showed intense fibrin deposition in the alveoli and interalveolar septa. The tissue factor-dependent procoagulant activity detected in BALF from PA103-infected mice did not depend on decreased production of tissue factor pathway inhibitor (TFPI) production, but was associated with increased concentration of plasminogen activator inhibitor-1 (PAI-1). To investigate the role of platelet activating factor (PAF) in PAI-1 release, we compared the activity of the enzyme PAF-acetylhydrolase (PAF-AH) in BALF from control and infected mice, and we observed that PAF-AH activity was significantly elevated in BALF from PA103-infected animals. Mice treatment with a PAF inhibitor prior to infection resulted in a significant reduction of PAI-1 concentration, as well as of BALF total leukocytes and procoagulant activity. In vitro, ExoU induced higher expression of PAI-1 m RNA and increased release of PAI-1 protein in supernatants from A549 epithelial respiratory cell cultures. A549 cell treatment with an anti-PAF receptor prior to infection significantly reduced PAI-1 concentration in supernatants from cells infected with the wild type strain. These results show a novel mechanism by which a baterial product can favor a prothrombotic activity and ExoU production by infecting P. aeruginosa isolates may have prognostic implications for patients.

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