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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

Avaliação de neuropeptídeos e aminoácidos para elucidação da neurobiologia das doenças psiquiátricas / Evaluation of neuropeptides and amino acids to elucidate the neurobiology of psychiatric diseases

Fonseca, Marina Salviato Balbão Santiago 04 September 2012 (has links)
Os transtornos neuropsiquiátricos incluem-se entre as patologias de alta incidência, difícil identificação e prognósticos variados. Dentre eles se destaca a esquizofrenia, uma doença funcional do cérebro caracterizada essencialmente por uma fragmentação da estrutura básica dos processos de pensamento, acompanhada pela dificuldade em estabelecer a distinção entre experiências internas e externas. O presente estudo visa à investigação do risco cardíaco decorrente do ganho de peso causado pelo uso do antipsicótico olanzapina em pacientes esquizofrênicos, bem como a avaliação dos níveis dos neuropeptídeos relacionados ao balanço energético, a fim de estabelecer o mecanismo de ação responsável por este ganho de peso. Como a identificação conclusiva dos fatores etiológicos ou patogênicos dos transtornos neuropsiquiátricos permanece desconhecida, o trabalho visa ainda à avaliação dos níveis plasmáticos de alguns aminoácidos neurotransmissores, correlacionando-os a estes transtornos. Para a avaliação do risco cardíaco e do possível mecanismo do ganho de peso, um grupo de 30 pacientes com diagnóstico de esquizofrenia em início de terapia com a olanzapina foi submetido a avaliações antropométricas, bioquímicas e determinação plasmática de grelina, leptina, neuropeptídeo NPY e polipeptídeo YY durante 12 meses. A investigação da correlação entre transtornos neuropsiquiátricos e aminoácidos, foi realizada em outros 150 indivíduos subdivididos em cinco grupos de 30 pessoas, pacientes com diagnóstico de esquizofrenia, epilepsia, depressão e transtorno afetivo bipolar, os quais foram comparados a um grupo controle. Os resultados obtidos referentes ao estudo do risco cardíaco foram demonstrados através do aumento significativo do peso, índice de massa corporal e circunferências de cintura e quadril. Em relação aos parâmetros bioquímicos, verificaram-se alterações clinicamente significativas nos níveis de colesterol, triglicérides, LDL-colesterol, glicose, insulina e cortisol. Quanto aos neuropeptídeos, observou-se aumento significativo na grelina e neuropeptídeo NPY. Os níveis plasmáticos dos aminoácidos não essenciais, glutamato, aspartato, serina, glicina e arginina, por sua vez, mostraram-se significativamente alterados nas patologias neuropsiquiátricas quando comparados ao grupo controle, sendo que o glutamato apresentou incremento altamente significante em todas as patologias neuropsiquiátricas estudadas, evidenciando a íntima correlação entre este aminoácido e os transtornos supracitados, bem como a hipótese da hiperfunção glutamatérgica em nível periférico, isto é, valores plasmáticos. Neste contexto, evidenciou-se que a terapia com a olanzapina aumenta o risco cardíaco em decorrência da maior liberação dos hormônios orexígenos, podendo comprometer a qualidade de vida destes pacientes por favorecer a síndrome metabólica. Dessa forma, o estudo contribui para elucidação deste marcante efeito adverso da olanzapina que é o ganho de peso. Evidenciou-se, ainda, que a determinação dos aminoácidos plasmáticos, aliada a outras técnicas de avaliação em desenvolvimento e pesquisa, poderão servir como marcadores biológicos para os trantornos neuropsiquiátricos, bem como de medidas preventivas e no estabelecimento de uma nova perspectiva para alvos de futuros fármacos adjuvantes à terapia neuropsiquiátrica. / Neuropsychiatric disorders are among diseases with high incidence, difficult to identify and with varied predictions. Among them stands out schizophrenia, a brain functional disease essentially characterized by fragmentation of the basic structure of thinking processes, accompanied by difficulty to distinguish between internal and external experiences. The present study aims to investigate cardiac risk in schizophrenic patients due to weight gain caused by the use of antipsychotic olanzapine, as well as evaluating the levels of neuropeptides related to energy balance in order to establish the mechanism of action responsible for such weight gain. As the conclusive identification of etiological or pathogenic factors of neuropsychiatric disorders remains unknown, the work also aims to assess the plasma levels of some neurotransmitter amino acids, correlating them with these disorders. For the evaluation of cardiac risk and the possible mechanism of weight gain, a group of 30 patients diagnosed with schizophrenia and at the start of olanzapine therapy underwent anthropometric evaluations and biochemical quantification of serum ghrelin, leptin, and neuropeptide NPY polypeptide YY 12 months. The investigation of the correlation between neuropsychiatric disorders and amino acids was performed in other 150 individuals divided into five groups of 30 persons, patients with schizophrenia, epilepsy, depression and bipolar disorder, which were compared to a control group. The results obtained for the study of cardiac risk were demonstrated by the significant increase in weight, body mass index and waist and hip circumferences. Regarding biochemical parameters, there were no clinically significant changes in cholesterol, triglycerides, LDL-cholesterol, glucose, insulin and cortisol. Concerning neuropeptides, we could observe a significant increase in ghrelin and neuropeptide NPY. Plasma levels of nonessential amino acids, glutamate, aspartate, serine, glycine and arginine, in turn, were significantly altered in neuropsychiatric disorders. Glutamate showed a highly significant increase in all studied neuropsychiatric disorders, showing the close correlation between this amino acid and the aforementioned disorders, as well as the glutamatergic hyperfunction hypothesis at peripheral level, that is, plasma levels. In this context, it was observed that therapy with olanzapine increases cardiac risk due to augmented release of orexigenic hormones, which can compromise the quality of life of patients by promoting metabolic syndrome. Thus, it contributes to elucidation of this striking side effect of olanzapine which is the weight gain. It was also clear that the determination of plasma amino acids, combined with other evaluation techniques in research and development, may serve as biomarkers for neuropsychiatric disorders, as well as preventive measures and the establishment of a new perspective for future targets adjuvant therapy for neuropsychiatric drugs.
172

Genomic and Peptidomic Characterization of the Developing Avian Brain

Scholz, Birger January 2008 (has links)
<p>Chicken and Japanese quail are commonly used models in developmental and sex specific neuroendocrine research. There is relatively little known about the mechanisms behind their sex specific brain development, especially regarding the impact of the sex chromosomes (male: ZZ, female ZW) in relation to gonadal hormones. This thesis explores several aspects of these processes. Gene expression analysis with cDNA and Affymetrix arrays on brain tissue from both pre-gonadal embryos and embryos with differentiated gonads indicate a strong sex chromosomal presence in sexual dimorphic somatic tissue development in both chicken and Japanese quail. This sex chromosome pattern seems to remain in adult brain tissue. The data demonstrates that chicken males exhibit a significant level of Z-gene dosage compared to females in both somatic and germ line derived embryonic tissues. Several avian sex determination gene candidates (MHM non-coding RNA, DMRT1, HINTW, and HINTZ) were analyzed by real-time PCR. DMRT1 is dosage compensated in male brain tissue, in contrast to its reported gene dosage in male gonads. Early embryonic ethinylestradiol (EE2) exposure did not affect male or female neural gene expression patterns during later development. A peptidomics analysis on quail embryonic day 12 (ed12) and ed17 diencephalon by LC-MS identified over 60 endogenous peptides and analyzed the expression patterns for 38 of them with regard to age, sex and early EE2 exposure. There was a general upregulation between ed12 and ed17, but no clear sex effects were detected. Multivariate analysis indicates that EE2 exposed individuals differ from control individuals in a gender independent manner, and that Gonadotropin-inhibiting hormone related peptide 2 (GnIH-RP2) is a candidate for EE2 induced peptidomic alterations in male embryonic brain.</p>
173

Genomic and Peptidomic Characterization of the Developing Avian Brain

Scholz, Birger January 2008 (has links)
Chicken and Japanese quail are commonly used models in developmental and sex specific neuroendocrine research. There is relatively little known about the mechanisms behind their sex specific brain development, especially regarding the impact of the sex chromosomes (male: ZZ, female ZW) in relation to gonadal hormones. This thesis explores several aspects of these processes. Gene expression analysis with cDNA and Affymetrix arrays on brain tissue from both pre-gonadal embryos and embryos with differentiated gonads indicate a strong sex chromosomal presence in sexual dimorphic somatic tissue development in both chicken and Japanese quail. This sex chromosome pattern seems to remain in adult brain tissue. The data demonstrates that chicken males exhibit a significant level of Z-gene dosage compared to females in both somatic and germ line derived embryonic tissues. Several avian sex determination gene candidates (MHM non-coding RNA, DMRT1, HINTW, and HINTZ) were analyzed by real-time PCR. DMRT1 is dosage compensated in male brain tissue, in contrast to its reported gene dosage in male gonads. Early embryonic ethinylestradiol (EE2) exposure did not affect male or female neural gene expression patterns during later development. A peptidomics analysis on quail embryonic day 12 (ed12) and ed17 diencephalon by LC-MS identified over 60 endogenous peptides and analyzed the expression patterns for 38 of them with regard to age, sex and early EE2 exposure. There was a general upregulation between ed12 and ed17, but no clear sex effects were detected. Multivariate analysis indicates that EE2 exposed individuals differ from control individuals in a gender independent manner, and that Gonadotropin-inhibiting hormone related peptide 2 (GnIH-RP2) is a candidate for EE2 induced peptidomic alterations in male embryonic brain.
174

Neuropeptides and neurotrophins in arthritis : studies on the human and mouse knee joint

Grimsholm, Ola January 2008 (has links)
Neuropeptides, such as substance P (SP) and bombesin/gastrin-releasing peptide (BN/GRP), and neurotrophins are involved in neuro-immunomodulatory processes and have marked trophic, growth-promoting and inflammation-modulating properties. The impact of these modulators in rheumatoid arthritis (RA) is, however, unclear. An involvement of the innervation, including the peptidergic innervation, is frequently proposed as an important factor for arthritic disease. Many patients with RA, but not all, benefit from treatment with anti-TNF medications. The studies presented here aimed to investigate the roles of neuropeptides, with an emphasis on BN/GRP and SP, and neurotrophins, especially with attention to brain-derived neurotrophic factor (BDNF), in human and murine knee joint tissue. The expression patterns of these substances and their receptors in synovial tissue from patients with either RA or osteoarthritis (OA) were studied in parallel with the levels of these factors in blood and synovial fluid from patients with RA and from healthy controls. Correlation studies were also performed comparing the levels of neuropeptides with those of pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6)]. Furthermore, the impact of anti-TNF treatment on the levels of BDNF in blood was investigated. In a murine model of RA, the expression of these substances on articular chondrocytes along with their expression in synovial tissue was investigated. The expression of BN/GRP in human synovial tissue was confined to fibroblast-like and mononuclear-like cells whereas SP was detected in nerve-related structures. Receptors for these neuropeptides (GRP-R and NK-1R) were frequently present in blood vessel walls, and on fibroblast-like and mononuclear-like cells. The expression of BDNF and its receptors, p75 neurotrophin receptor and TrkB, was mainly confined to nerve structures. The levels of SP, and particularly those of BN/GRP, in synovial fluid and peripheral blood correlated with the levels of pro-inflammatory cytokines. There were clearly more correlations between SP-BN/GRP and inflammatory parameters than between BDNF and these factors. Plasma levels of BDNF were decreased following anti-TNF-treatment. In the joints of the murine model, there was a marked expression of neurotrophins, neurotrophin receptors and NK-1R/GRP-R in the articular chondrocytes. The expression was down-regulated in the arthritic animals. A neurotrophin system was found to develop in the inflammatory infiltrates of the synovium in the arthritic mice. The results presented suggest that there is a local, and not nerve-related, supply of BN/GRP in the human synovial tissue. Furthermore, BN/GRP and SP have marked effects in the synovial tissue of patients with RA, i.e., there were abundant receptor expressions, and these neuropeptides are, together with cytokines, likely to be involved in the neuro-immunomodulation that occurs in arthritis. The observations do on the whole suggest that the neuropeptides, rather than BDNF, are related to inflammatory processes in the human knee joint. A new effect of anti-TNF treatment; i.e., lowering plasma levels of BDNF, was observed. Severe arthritis, as in the murine model, lead to a decrease in the levels of neurotrophin, and neurotrophin and neuropeptide receptor expressions in the articular cartilage. This fact might be a drawback for the function of the chondrocytes. Certain differences between the expression patterns in the synovial tissue of the murine model and those of human arthritic synovial tissue were noted. It is obvious that local productions in the synovial tissue, nerve-related supply in this tissue and productions in chondrocytes to different extents occur for the investigated substances.
175

Study of PACAP and NGF signal transduction pathways in regulating serpin gene expression in PC12 cells

Au, Yuen-kwan., 區箢筠. January 2004 (has links)
published_or_final_version / abstract / toc / Zoology / Master / Master of Philosophy
176

Recherche de nouvelles hormones peptidiques codées par le génome humain

Mirabeau, Olivier 30 January 2008 (has links) (PDF)
Cette thèse porte sur la découverte de gènes humains non caractérisés codant pour des précurseurs à hormones peptidiques. Les hormones peptidiques (PH) ont un rôle important dans la plupart des processus physiologiques du corps humain. Ce sont de petites protéines sécrétées générées après clivage de précurseurs plus larges codés par le génome. Dans la première partie de la thèse, l'on introduit des algorithmes, basés sur les chaînes de Markov cachées (HMM), qui vont nous permettent de modéliser les séquences protéiques des précurseurs à hormones peptidiques. On montre que l'on peut dégager des caractéristiques particulières au niveau de la séquence chez ce groupe de protéines et l'on s'attarde en particulier sur la modélisation de deux signaux toujours présents chez ces protéines, les peptides signaux et les sites de clivage par les prohormones convertases. On présente ensuite des algorithmes qui prennent en compte le degré de conservation des résidus le long d'alignements de protéines orthologues. On montre que ces nouveaux algorithmes améliorent de manière significative les résultats obtenus à l'aide des algorithmes classiques. Enfin, après lancement de l'algorithme sur des données de protéomes, l'on dégage une liste de candidats dont certains ont pu être étudiés au laboratoire. La deuxième et la troisième partie de la thèse présentent les conclusions que l'on peut tirer des données de Western blot relatives aux profils de sécrétion et de découpage (processing) de chacun des deux candidats les plus prometteurs, " spexine " et " augurine ". On présente des données d'expression sur la souris (hybridation in situ, immunohistochimie,...) que l'on a récemment obtenues sur ces nouvelles hormones peptidiques potentielles ainsi que des données fonctionnelles sur la " spexine ". En conclusion, l'on avance des hypothèses quant aux fonctions de ces deux protéines. Si les fonctions de ces nouveaux peptides nous sont encore inconnues, leur expression chez la souris, tant au niveau de l'ARN messager que de la protéine, révèle des pistes qui devraient soulever un intérêt certain chez les spécialistes du domaine des peptides. Enfin, dans la quatrième et dernière partie de la thèse, l'on présente pour quatre autres candidats (dont on n'a pu mener une étude approfondie) des données préliminaires d'expression de gène et de sécrétion in vitro après transfection de l'ADN codant pour ces protéines dans des cellules issues de lignées cellulaires pancréatiques.
177

Insights into the molecular interactions of the neurogenic basic helix-loop-helix transcription factor, neuroD2, and the mechanism of regulation of a key target, RE-1 silencing transcription factor /

Ravanpay, Ali Cyrus, January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 61-63).
178

In vitro studies on intestinal epithelial cell proliferation : effects of cytokines, Helicobacter pylori, serotonin and neuroendocrine peptides /

Zachrisson, Kristina, January 1900 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.
179

Lessons from sleepy mice : narcolepsy and the Orexin neuropeptide system

Willie, Jon Timothy January 2005 (has links) (PDF)
Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2005. / Vita. Bibliography: 255-274.
180

Estudo do envolvimento da neurotransmissão CRFérgica do Núcleo Leito da Estria Terminal (NLET) nas respostas autonômicas desencadeadas pelo estresse por restrição agudo em ratos

Oliveira, Leandro Augusto de 10 April 2015 (has links)
Submitted by Daniele Amaral (daniee_ni@hotmail.com) on 2016-09-13T18:42:57Z No. of bitstreams: 1 DissLAO.pdf: 6690751 bytes, checksum: ad771d53381565a9c810eb4f7a21c348 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-15T13:32:59Z (GMT) No. of bitstreams: 1 DissLAO.pdf: 6690751 bytes, checksum: ad771d53381565a9c810eb4f7a21c348 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-15T13:33:08Z (GMT) No. of bitstreams: 1 DissLAO.pdf: 6690751 bytes, checksum: ad771d53381565a9c810eb4f7a21c348 (MD5) / Made available in DSpace on 2016-09-15T13:33:28Z (GMT). No. of bitstreams: 1 DissLAO.pdf: 6690751 bytes, checksum: ad771d53381565a9c810eb4f7a21c348 (MD5) Previous issue date: 2015-04-10 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / The corticotropin-releasing factor (CRF) is involved in behavioral and physiological responses to emotional stress through its action in several limbic structures, including the bed nucleus of the stria terminalis (BNST). Nevertheless, the role of CRF1 and CRF2 receptors in the BNST in autonomic adjustments during aversive threat is unknown. Therefore, in the present study we investigated the involvement of CRF receptors within the BNST in autonomic responses evoked by the acute restraint stress in rats. For this, we evaluated the effects of bilateral treatment of the BNST with selective agonists and antagonists of either CRF1 or CRF2 receptors in the arterial pressure and heart rate increase and the decrease in tail skin temperature induced by restraint stress. Microinjection of the selective CRF1 receptor antagonist CP376395 into the BNST reduced the pressor and tachycardiac responses caused by restraint. Conversely, BNST treatment with the selective CRF1 receptor agonist CRF increased restraint-evoked arterial pressure and HR responses and reduced the fall in tail skin temperature response. All effects of CRF were inhibited by local BNST pretreatment with CP376395. The selective CRF2 receptor antagonist antisauvagine-30 reduced the arterial pressure increase and the fall in tail skin temperature. The selective CRF2 receptor agonist urocortin-3 increased restraint-evoked pressor and tachycardiac responses and reduced the drop in cutaneous temperature. All effects of urocortin-3 were abolished by local BNST pretreatment with antisauvagine-30. These findings indicate an involvement of both CRF1 and CRF2 receptors in the BNST in autonomic adjustments during emotional stress. / O fator liberador de corticotropina (CRF) está envolvido em respostas comportamentais e fisiológicas ao estresse emocional por meio de sua ação em várias estruturas límbicas, incluindo o núcleo leito da estria terminal (NLET). No entanto, o papel dos receptores CRF1 e CRF2 no NLET nas respostas autonômicas durante situações aversivas é desconhecido. Portanto, no presente estudo nós investigamos o envolvimento de receptores de CRF do NLET nas respostas autonômicas evocadas pelo estresse de restrição agudo em ratos. Para isso, foram avaliados os efeitos do tratamento bilateral do NLET com agonistas e antagonistas seletivos dos receptores CRF1 ou CRF2 nas respostas de aumento da pressão arterial e frequência cardíaca e de diminuição da temperatura cutânea da cauda induzidas pelo estresse por restrição agudo. Microinjeção do antagonista seletivo do receptor CRF1, CP376395, no NLET reduziu as respostas de aumento da pressão arterial e frequência cardíaca evocadas pelo estresse por restrição. Por outro lado, o tratamento do NLET com o agonista seletivo do receptor CRF1, CRF, causou um aumento das respostas pressora e taquicárdica e reduziu a resposta de queda de temperatura cutânea da cauda. Os efeitos do CRF foram inibidos pelo pré-tratamento do NLET com CP376395. O antagonista seletivo do receptor CRF2, antisauvagine-30, reduziu o aumento da pressão arterial e a queda da temperatura cutânea da cauda induzidas pelo estresse por restrição. O agonista seletivo do receptor CRF2, urocortina-3, potenciou as respostas pressora e taquicárdica e reduziu a queda na temperatura cutânea da cauda. Todos os efeitos da urocortina-3 foram abolidos pelo pré-tratamento local no NLET com antisauvagine-30. Esses resultados indicam um envolvimento de ambos os receptores CRF1 e CRF2 no NLET nos ajustes autonômicos durante o estresse emocional.

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