• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 132
  • 69
  • 11
  • 9
  • 9
  • 9
  • 9
  • 9
  • 9
  • 9
  • 8
  • 7
  • 6
  • 2
  • 1
  • Tagged with
  • 282
  • 58
  • 32
  • 22
  • 21
  • 21
  • 21
  • 21
  • 20
  • 20
  • 18
  • 17
  • 17
  • 17
  • 17
  • 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.
261

Fatores associados com a conduta visual em recém-nascidos

Bernardi, Fernanda Rombaldi January 2017 (has links)
Objetivo: Descrever características biológicas e ambientais associadas a habilidades motoras finas, medidas por diferentes níveis de conduta visual em lactentes de 1 e 3 meses. Desenho de estudo: 82 díades mãe-bebê foram recrutadas durante consultas pré-natais ou imediatamente após o nascimento e visitadas duas vezes para a coleta de dados (25-40 e 85-100 dias após o nascimento). Durante as visitas foram coletados fatores maternos (idade materna, escolaridade, tipo de parto, número de consultas pré-natais, tipo de amamentação e tabagismo), características biológicas do bebê (gênero, idade gestacional, nascimento, peso, circunferência da cabeça, Apgar), testes motores infantis (através da Escala de Avaliação do Comportamento Visuomotor Infantil e Alberta Infant Motor Scale/AIMS), perfil psicológico materno (através da Escala de Depressão Pós-natal de Edimburgo/EPDS e Escala de Ansiedade de Hamilton), variáveis ambientais (medidas pelo Affordance in the home environment for development scale/AHEMD), cuidados maternos (avaliado através do Coding Interacting Behavior/CIB), bem como a coleta de leite (medição de ácidos graxos totais, proteínas e cortisol) e sangue materno (medição de hormônios séricos e interleucinas). Resultados: 51 crianças foram testadas em tarefas de conduta visual e outras medidas. As mães das crianças com baixos escores de fixação visual apresentaram maiores níveis de proteína no leite materno aos 3 meses. Quanto ao perfil metabólico materno, as mães das crianças que apresentaram melhores escores de fixação visual apresentaram melhores níveis séricos de T4 (no primeiro mês) e prolactina (no terceiro mês). Conclusão: O desenvolvimento neuromotor precoce do bebê, especialmente as habilidades visuais e de motricidade fina, estão intimamente associados aos fatores biológicos maternos (fatores metabólicos maternos e composição do leite materno). / Objective: To describe biological and environmental characteristics associated with fine motor skills measured by different levels of visual tracking in infants of 1 and 3 months. Study design: 82 mother-infant dyads were recruited during prenatal consultations or immediately after birth and visited at two times for data collection (25-40 and 85-100 days after birth). During the visits were collected maternal factors (maternal age, education level, type of delivery, number of antenatal consultations, type of breastfeeding and smoking), biological characteristics of the baby (gender, gestational age, birth, weight, head circumference, Apgar), infant motor tests (through the Child Visuomotor Behavior Rating Scales and Alberta Infant Motor Scale/AIMS), maternal psychological profile (through the Edinburgh Postnatal Depression Scale/EPDS and Hamilton Anxiety Scale), environmental variables (measured by the Affordance in the home environment for development scale/AHEMD), maternal care (evaluated through Coding Interacting Behavior/CIB), as well as milk collection (measurement of total fatty acids, proteins and cortisol) and maternal blood (measurement of serum hormones and interleukins). Results: 51 children were tested on visual tracking tasks and other measures. The mothers of children with low visual fixation scores presented higher levels of protein in breastmilk at 3 months. Regarding the maternal metabolic profile, the mothers of the children who presented better visual conduct scores had better serum levels of T4 (in the first month) and prolactin (in the third month). Conclusion: Early neuromotor development of the baby, especially the visual and fine motor skills, are closely associated with maternal biological characteristics (metabolic factors and composition of breast milk).
262

Hypotalamo-hypofýzo-gonádová osa a epilepsie: vzájemné vztahy / The hypothalamic-pituitary-gonadal axis and epilepsy: mutual relationships

Čuchalová, Marcela January 2018 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Science Author: Marcela Čuchalová Supervisor: doc. MUDr. Josef Herink, DrSc. Title of diploma thesis: The hypothalamic - pituitary - gonadal axis and epilepsy: mutual relationships The content of the diploma thesis is an overview of the anatomy and physiology of the hypothalamic-pituitary-gonadal axis (HHG). Further chapters are devoted to the influence of epilepsy on HHG function, the effect of HHG hormones on epileptic activity itself. The effect of anti-epileptics on HHG functions will also be elucidated. The second part of the diploma thesis deals with separate chapters - catamenial epilepsy and epilepsy during pregnancy. Keywords: antiepileptic drugs, gonadotropin, hypothalamic-pituitary-gonadal axis, prolactin, sex hormones, temporal lobe epilepsy.
263

Fatores associados com a conduta visual em recém-nascidos

Bernardi, Fernanda Rombaldi January 2017 (has links)
Objetivo: Descrever características biológicas e ambientais associadas a habilidades motoras finas, medidas por diferentes níveis de conduta visual em lactentes de 1 e 3 meses. Desenho de estudo: 82 díades mãe-bebê foram recrutadas durante consultas pré-natais ou imediatamente após o nascimento e visitadas duas vezes para a coleta de dados (25-40 e 85-100 dias após o nascimento). Durante as visitas foram coletados fatores maternos (idade materna, escolaridade, tipo de parto, número de consultas pré-natais, tipo de amamentação e tabagismo), características biológicas do bebê (gênero, idade gestacional, nascimento, peso, circunferência da cabeça, Apgar), testes motores infantis (através da Escala de Avaliação do Comportamento Visuomotor Infantil e Alberta Infant Motor Scale/AIMS), perfil psicológico materno (através da Escala de Depressão Pós-natal de Edimburgo/EPDS e Escala de Ansiedade de Hamilton), variáveis ambientais (medidas pelo Affordance in the home environment for development scale/AHEMD), cuidados maternos (avaliado através do Coding Interacting Behavior/CIB), bem como a coleta de leite (medição de ácidos graxos totais, proteínas e cortisol) e sangue materno (medição de hormônios séricos e interleucinas). Resultados: 51 crianças foram testadas em tarefas de conduta visual e outras medidas. As mães das crianças com baixos escores de fixação visual apresentaram maiores níveis de proteína no leite materno aos 3 meses. Quanto ao perfil metabólico materno, as mães das crianças que apresentaram melhores escores de fixação visual apresentaram melhores níveis séricos de T4 (no primeiro mês) e prolactina (no terceiro mês). Conclusão: O desenvolvimento neuromotor precoce do bebê, especialmente as habilidades visuais e de motricidade fina, estão intimamente associados aos fatores biológicos maternos (fatores metabólicos maternos e composição do leite materno). / Objective: To describe biological and environmental characteristics associated with fine motor skills measured by different levels of visual tracking in infants of 1 and 3 months. Study design: 82 mother-infant dyads were recruited during prenatal consultations or immediately after birth and visited at two times for data collection (25-40 and 85-100 days after birth). During the visits were collected maternal factors (maternal age, education level, type of delivery, number of antenatal consultations, type of breastfeeding and smoking), biological characteristics of the baby (gender, gestational age, birth, weight, head circumference, Apgar), infant motor tests (through the Child Visuomotor Behavior Rating Scales and Alberta Infant Motor Scale/AIMS), maternal psychological profile (through the Edinburgh Postnatal Depression Scale/EPDS and Hamilton Anxiety Scale), environmental variables (measured by the Affordance in the home environment for development scale/AHEMD), maternal care (evaluated through Coding Interacting Behavior/CIB), as well as milk collection (measurement of total fatty acids, proteins and cortisol) and maternal blood (measurement of serum hormones and interleukins). Results: 51 children were tested on visual tracking tasks and other measures. The mothers of children with low visual fixation scores presented higher levels of protein in breastmilk at 3 months. Regarding the maternal metabolic profile, the mothers of the children who presented better visual conduct scores had better serum levels of T4 (in the first month) and prolactin (in the third month). Conclusion: Early neuromotor development of the baby, especially the visual and fine motor skills, are closely associated with maternal biological characteristics (metabolic factors and composition of breast milk).
264

Provocação social na díade mãe-filhote: efeitos da ontogenia no comportamento social da prole

Henriques, Thiago Pereira January 2014 (has links)
As duas primeiras semanas de vida em ratos são críticas para o desenvolvimento, pois os animais são suscetíveis a influências ambientais. Diversos parâmetros neuroendócrinos e comportamentais podem ser influenciados, a curto e a longo prazo, pelas interações com a mãe, assim como por estressores. Entre esses estressores, um ambiente precoce socialmente aversivo pode alterar os comportamentos sociais, a ansiedade e as respostas neuroendócrinas ao estresse em adultos. O foco deste trabalho foi investigar o impacto do paradigma de provocação social na díade mãe-filhote sobre os comportamentos sociais e as respostas hormonais da prole em três idades. A provocação social foi realizada nos dias pós-natais (PP) 2 e 5. O comportamento maternal das lactantes foi registrado em PP3, 4, e 6. Os filhotes foram submetidos ao teste de preferência olfatória em PP7, o comportamento de brincadeira em juvenis foi registrado em PP30 e os ratos adultos (a partir de PP80) foram submetidos aos testes de campo aberto, labirinto em cruz elevado e interação social. Os adultos também foram expostos ao estresse por contenção (PP90). Os resultados mostraram que a intervenção aumentou a presença das mães no ninho. A intervenção reduziu o tempo gasto pelos filhotes no lado da maravalha do ninho, reduziu os níveis plasmáticos de ocitocina e prolactina, porém, aumentou os níveis de arginina-vasopressina. Nos juvenis, a intervenção reduziu a brincadeira de luta e os níveis plasmáticos de arginina-vasopressina. Nos adultos, a intervenção não levou a alterações na ansiedade e nas respostas hormonais ao estresse, porém, reduziu a latência para os comportamentos agressivos e os níveis plasmáticos basais de ocitocina. Conforme observado nas lactantes e nos neonatos, a provocação social levou a uma alteração da relação mãe-filhote, afetando, também, hormônios relacionados ao comportamento afiliativo em neonatos. Da mesma forma, a redução da brincadeira de luta em juvenis expostos à intervenção neonatal pode ter ocorrido devido à alteração da argininavasopressina, hormônio envolvido nesse comportamento. Apesar da intervenção não ter alterado a ansiedade e as respostas hormonais ao estresse em adultos, afetou de maneira específica o comportamento agressivo, reduzindo a sua latência. Este achado pode ser relacionado à ocitocina diminuída, conhecida por ter efeitos antiagressivos. Logo, sugerimos que a provocação social altere, tanto de forma precoce quanto duradoura, os comportamentos sociais, assim como os hormônios responsáveis pela modulação desses parâmetros. / The first two weeks of life in rats are critical for development because the animals are susceptible to environmental influences. A variety of neuroendocrine and behavioral parameters may be influenced in a short or long lasting way by the interactions with the mother as well as by stressors. Among these stressors, a socially aversive environment may alter social behaviors, anxiety and neuroendocrine responses to stress in adult subjects. The focus of this work was to investigate the impact of the social instigation paradigm on motherlitter dyad over social behaviors and hormonal responses in rats at 3 ages. Social instigation was carried out at postpartum days (PP) 2 and 5. Maternal behavior from lactating rats was registered at PP3, 4 and 6. Pups were submitted to the nest odor preference test at PP7, play behavior was registered in juveniles at PP30, and adult rats (starting at PP80) were submitted to the open field, elevated plus maze and social interaction tests. Adult rats were also submitted to restraint stress. Results show that the intervention increased presence in nest of lactating rats. The intervention reduced time spent on nest bedding side in pups, decreased oxytocin and prolactin plasma levels, however, increased arginine-vasopressin levels. Juveniles submitted to the neonatal intervention had reduced play-fighting frequencies and arginine-vasopressin levels. In adults, the intervention has not altered anxiety and hormonal responses to stress, however, it decreased the latency for aggressive behaviors, as well as oxytocin basal levels. According to the outcomes observed in lactating rats and pups, social instigation altered mother-infant relationship, as well as levels of hormones involved in affiliative behavior in neonatal rats. Similarly, the reduced play-fighting in juveniles exposed to the intervention may be related to the decreased arginine-vasopressin levels, which is a hormone involved in such behavior. In spite of the intervention having not altered the anxiety and hormonal responses to stress in adult rats, it altered in a specific manner the aggressive behavior, reducing its latency. This finding may be related to the decreased oxytocin levels, which is a hormone known to have antiaggressive effects. Thus, we suggest that social instigation impairs early to late social behaviors, as well as the hormones responsible for the modulation of such parameters.
265

Estudo da atividade biológica e da expressão do gene da prolactina linfocitária e avaliação do nível de prolactina sérica em pacientes com lúpus eritematoso sistêmico / Study of biological activity and lymphocytic prolactin gene expression and evaluation of serum prolactin level in patients with systemic lupus erythematosus

Diane Belchior Paraiba 21 August 2008 (has links)
INTRODUÇÃO: Estudos indicam uma prevalência de 20 a 30% de hiperprolactinemia discreta em pacientes com lúpus eritematoso sistêmico (LES), sugerindo um possível papel da prolactina (PRL) na sua etiopatogenia. Como a expressão do gene da PRL é encontrada na maioria das células do sistema imunológico, onde atua como citocina, de forma parácrina e autócrina, a origem linfocitária desta PRL tem sido aventada. OBJETIVOS: estudar a expressão do gene da PRL linfocitária de pacientes com LES em atividade e inatividade de doença e de controles normais, e sua atividade biológica em bioensaios com células Nb2 e Ba/F-LLP; Determinar o nível sérico de PRL e a prevalência de macroprolactinemia numa população nossa com LES. MÉTODOS: grupo 1, composto de 73 pacientes (66 mulheres e 7 homens), sendo 28 pacientes com LES em atividade e 45 em inatividade de doença, onde foi avaliado o nível de PRL sérica e a prevalência da macroprolactinemia; grupo 2, derivado do grupo 1, com 30 pacientes: 18 com LES em atividade e 12 em inatividade e um grupo controle com 10 indivíduos normais, dos quais foram extraídos linfócitos do sangue periférico e colocados em cultura por 72 horas. Em seguida, o sobrenadante da cultura foi utilizado como amostra de PRL linfocitária em ensaios com células Nb2 (heterólogo) e Ba/F-LLP (homólogo) para avaliação da bioatividade. Os RNAs totais destes linfócitos foram extraídos e usados na RT-PCR em tempo real (método quantitativo), para comparar a expressão do gene da PRL em linfócitos de pacientes com LES em atividade e inatividade, utilizando pool de indivíduos normais como calibrador. RESULTADOS: hiperprolactinemia discreta foi encontrada em 21,9% (16 de 73 pacientes do grupo 1): 7 de 28 pacientes com LES em atividade (25%), e 9 de 45 em inatividade (20%). A presença de macroprolactinemia foi encontrada em 3 pacientes, todos com LES em inatividade. O nível de PRL sérica: grupo 1 (LES em atividade) teve mediana de 10,8 (4,9 38,9) ng/mL e o grupo 1 (LES em inatividade) mediana de 7,6 (1,9 49,6) ng/mL, não havendo diferença significante entre os dois subgrupos (p=0,123). No entanto, quando consideramos apenas o nível sérico da PRL monomérica, a mediana da PRL do grupo 1 (LES em inatividade) caiu para 7,3 ng/mL (1,9 20,6) ng/mL e assim, quando comparado novamente ao grupo 1 (LES em atividade), observamos que além de uma porcentagem maior dos casos em atividade apresentarem hiperprolactinemia, a mediana da PRL monomérica nesses pacientes é significantemente maior que nos pacientes em inatividade de doença (p= 0,016). Os bioensaios foram realizados com as amostras do grupo 2 (subgrupo do grupo 1): no ensaio com células Nb2, a bioatividade da PRL linfocitária foi semelhante, não havendo diferença significante entre os pacientes com LES em atividade e inatividade e desses com o grupo controle. Já o bioensaio com a Ba/F-LLP não mostrou sensibilidade adequada, portanto não sendo confiável para avaliação da PRL linfocitária. O RT-PCR em tempo real apresentou expressão gênica também semelhante entre os pacientes avaliados (grupo 2). CONCLUSÕES: A expressão do gene da PRL linfocitária e a sua bioatividade foram semelhantes nos pacientes com LES em atividade e inatividade. A prevalência de hiperprolactinemia nos nossos pacientes com LES foi de 21,9%, sendo maior nos pacientes com atividade de doença. A macroprolactinemia só foi encontrada em pacientes com LES inativo, sugerindo um possível efeito protetor deste achado. / INTRODUCTION: Studies point to a prevalence of 20-30% of discrete hyperprolactinemia in patients with systemic lupus erythematosus (SLE), suggesting a possible implication of prolactin (PRL) in the pathogenesis of this disorder. As the lymphocytic PRL gene expression is found in the majority of the immune cells, where it acts as citokine, by paracrine and autocrine regulation, the lymphocytic source of this PRL has been suggested. OBJECTIVES: 1) to study the lymphocytic PRL gene expression of patients with active and inactive SLE and normal controls, as well as its biological activity in bioassays using Nb2 (heterologous) and Ba/F-LLP cells (homologous); 2) To assess serum PRL level and the prevalence of macroprolactinemia in our population with SLE. METHODS: group 1, composed of 73 patients (66 women and 7 men), 28 patients with active and 45 with inactive SLE, where the serum PRL level and prevalence of macroprolactinemia were evaluated; group 2, a subset of group 1, with 30 patients: 18 with active and 12 with inactive SLE and 10 normal individuals as control group, from whom lymphocytes were extracted from peripheral blood and were set on culture for 72 hours. After that, the supernatant was taken as lymphocytic PRL samples in bioassays with Nb2 cells (heterologous) and Ba/FLLP (homologous) in order to assess its bioactivity. Total RNA from these lymphocytes was extracted and a comparison was made between lymphocytic PRL gene expression of patients with active and inactive SLE by real time RT-PCR, using normal pool as calibrator. RESULTS: mild hyperprolactinemia was found in 21.9% (16 of 73 patients of group 1), 7 of 28 patients in activity (25%), and 9 of 45 in inactivity (20%). Macroprolactinemia was found in 3 patients, all with inactive SLE. Regarding serum PRL levels group 1 (active SLE) had median of 10.8 (4.9 38.9) ng/mL and the group 1 (inactive SLE) median of 7.6 (1.9 49.6) ng/mL, without significant difference between the two sub-groups (p=0.123). However, when only monomeric PRL level was considered, the median of group 1 (inactive SLE) dropped to 7.3 ng/mL (1.9 20.6) ng/mL and, when compared again with group 1 (active SLE), we observed that beyond a bigger percentage of the cases in activity to present hyperprolactinemia, the medium of serum PRL level in patients with active SLE is significantly greater of that in the ones in inactivity (p= 0.016). The bioassays with the samples of group 2 (sub-group of group 1): The assays with Nb2 cells showed similar lymphocytic PRL bioactivity. They did not have significant difference between patients with SLE active and inactive and these with normal control group. The assays with Ba/F-LLP cells did not show adequate sensitivity, so not trustworthy for lymphocytic PRL evaluation. The real time RT-PCR also presented similar gene expression between patients (group 2). CONCLUSIONS: The gene lymphocytic PRL expression and its bioactivity were similar in patients with SLE in activity and inactivity of illness and the normal controls. The prevalence of hyperprolactinemia in our population of patients with SLE was of 21.9%, being greater in patients with active SLE. The macroprolactinemia was found only in patients with inactive SLE, suggesting a possible protective effect of this finding.
266

Provocação social na díade mãe-filhote: efeitos da ontogenia no comportamento social da prole

Henriques, Thiago Pereira January 2014 (has links)
As duas primeiras semanas de vida em ratos são críticas para o desenvolvimento, pois os animais são suscetíveis a influências ambientais. Diversos parâmetros neuroendócrinos e comportamentais podem ser influenciados, a curto e a longo prazo, pelas interações com a mãe, assim como por estressores. Entre esses estressores, um ambiente precoce socialmente aversivo pode alterar os comportamentos sociais, a ansiedade e as respostas neuroendócrinas ao estresse em adultos. O foco deste trabalho foi investigar o impacto do paradigma de provocação social na díade mãe-filhote sobre os comportamentos sociais e as respostas hormonais da prole em três idades. A provocação social foi realizada nos dias pós-natais (PP) 2 e 5. O comportamento maternal das lactantes foi registrado em PP3, 4, e 6. Os filhotes foram submetidos ao teste de preferência olfatória em PP7, o comportamento de brincadeira em juvenis foi registrado em PP30 e os ratos adultos (a partir de PP80) foram submetidos aos testes de campo aberto, labirinto em cruz elevado e interação social. Os adultos também foram expostos ao estresse por contenção (PP90). Os resultados mostraram que a intervenção aumentou a presença das mães no ninho. A intervenção reduziu o tempo gasto pelos filhotes no lado da maravalha do ninho, reduziu os níveis plasmáticos de ocitocina e prolactina, porém, aumentou os níveis de arginina-vasopressina. Nos juvenis, a intervenção reduziu a brincadeira de luta e os níveis plasmáticos de arginina-vasopressina. Nos adultos, a intervenção não levou a alterações na ansiedade e nas respostas hormonais ao estresse, porém, reduziu a latência para os comportamentos agressivos e os níveis plasmáticos basais de ocitocina. Conforme observado nas lactantes e nos neonatos, a provocação social levou a uma alteração da relação mãe-filhote, afetando, também, hormônios relacionados ao comportamento afiliativo em neonatos. Da mesma forma, a redução da brincadeira de luta em juvenis expostos à intervenção neonatal pode ter ocorrido devido à alteração da argininavasopressina, hormônio envolvido nesse comportamento. Apesar da intervenção não ter alterado a ansiedade e as respostas hormonais ao estresse em adultos, afetou de maneira específica o comportamento agressivo, reduzindo a sua latência. Este achado pode ser relacionado à ocitocina diminuída, conhecida por ter efeitos antiagressivos. Logo, sugerimos que a provocação social altere, tanto de forma precoce quanto duradoura, os comportamentos sociais, assim como os hormônios responsáveis pela modulação desses parâmetros. / The first two weeks of life in rats are critical for development because the animals are susceptible to environmental influences. A variety of neuroendocrine and behavioral parameters may be influenced in a short or long lasting way by the interactions with the mother as well as by stressors. Among these stressors, a socially aversive environment may alter social behaviors, anxiety and neuroendocrine responses to stress in adult subjects. The focus of this work was to investigate the impact of the social instigation paradigm on motherlitter dyad over social behaviors and hormonal responses in rats at 3 ages. Social instigation was carried out at postpartum days (PP) 2 and 5. Maternal behavior from lactating rats was registered at PP3, 4 and 6. Pups were submitted to the nest odor preference test at PP7, play behavior was registered in juveniles at PP30, and adult rats (starting at PP80) were submitted to the open field, elevated plus maze and social interaction tests. Adult rats were also submitted to restraint stress. Results show that the intervention increased presence in nest of lactating rats. The intervention reduced time spent on nest bedding side in pups, decreased oxytocin and prolactin plasma levels, however, increased arginine-vasopressin levels. Juveniles submitted to the neonatal intervention had reduced play-fighting frequencies and arginine-vasopressin levels. In adults, the intervention has not altered anxiety and hormonal responses to stress, however, it decreased the latency for aggressive behaviors, as well as oxytocin basal levels. According to the outcomes observed in lactating rats and pups, social instigation altered mother-infant relationship, as well as levels of hormones involved in affiliative behavior in neonatal rats. Similarly, the reduced play-fighting in juveniles exposed to the intervention may be related to the decreased arginine-vasopressin levels, which is a hormone involved in such behavior. In spite of the intervention having not altered the anxiety and hormonal responses to stress in adult rats, it altered in a specific manner the aggressive behavior, reducing its latency. This finding may be related to the decreased oxytocin levels, which is a hormone known to have antiaggressive effects. Thus, we suggest that social instigation impairs early to late social behaviors, as well as the hormones responsible for the modulation of such parameters.
267

Characterization of signaling mechanisms regulating cardiac contractility

Kubin, A.-M. (Anna-Maria) 17 May 2011 (has links)
Abstract The heart adapts to hemodynamic overload with cardiac hypertrophy. Initially the increase in heart mass normalizes wall stress and permits normal cardiac function. In the long term pathological growth is associated with increased heart size, loss of functional myocytes and fibrotic replacement, heart dilatation and cardiac dysfunction, which can ultimately lead to heart failure. Vasoactive peptides participate in the regulation of cardiac contractility in an auto/paracrine way, but the peptidergic signaling pathways are largely unknown. The present study aimed to characterize the signaling mechanisms mediating the positive inotropic effect of endothelin-1 (ET-1) and the effects of prolactin releasing peptide (PrRP) on cardiac contractility in the isolated perfused rat heart preparation. The study demonstrated that mitogen-activated protein kinases (MAPK) have opposing roles in the regulation of cardiac contractility stimulated by ET-1. Extracellular signal-regulated kinase 1/2 (ERK1/2) mediated positive inotropic response to ET-1 was found to be counterbalanced by p38-MAPK. In addition, the effect of ET-1 was partly dependent on enhanced NADPH oxidase reactive oxygen species (ROS) generation, which activated the ERK1/2 pathway. In contrast, β-adrenergic inotropic effect was limited by stimulation of ROS production via negating phospholamban phosphorylation. The positive inotropic effect of ET-1 was counterbalanced by guanylyl cyclase (GC)-cGMP-protein kinase G (PKG) pathway and neuronal nitric oxide synthase (nNOS). PrRP was found to exert a direct positive inotropic effect which was independent of cAMP and was suppressed by concurrent activation of protein kinase Cα (PKCα) and protein phosphatase 1 (PP1), and dephosphorylation of phospholamban. In conclusion, in the present study signaling pathways in the acute regulation of cardiac contractility stimulated by ET-1 were characterized. The results suggest that the positive inotropic effect of ET-1 is mediated by ROS and ERK1/2 while p38-MAPK counterbalances the effect of ET-1. In addition, GC-cGMP-PKG pathway and nNOS modulate the response to ET-1. The study also established the previously unknown cardiac effects of PrRP. The findings provide a better understanding of molecular mechanisms involved in the regulation of cardiac contractility, and may indicate potential targets for novel therapeutic interventions. / Tiivistelmä Sydänlihaksen lisääntynyt mekaaninen kuormitus esimerkiksi verenpainetaudin tai sydäninfarktin yhteydessä voi johtaa sydämen kammion seinämän paksuuntumiseen eli hypertrofiaan. Hypertrofia auttaa sydäntä sopeutumaan lisääntyneeseen työmäärään, mutta se on myös sydän- ja verisuonitautitapahtumien riskitekijä. Pitkään jatkuva kuormitus johtaa usein sydämen pumppausvoiman heikkenemiseen ja sydämen vajaatoimintaan. Sydän tuottaa useita paikallisesti vaikuttavia vasoaktiivisia tekijöitä, jotka osallistuvat sydämen supistuvuuden säätelyyn. Väitöskirjatutkimuksessa tutkittiin signaalinvälitysjärjestelmiä, jotka osallistuvat endoteliini-1:n (ET-1) sydämen supistusvoimaa lisäävän eli positiivisen inotrooppisen vaikutuksen muodostumiseen sekä selvitettiin prolaktiinia vapauttavan peptidin (PrRP) vaikutuksia sydämen supistusvoimaan käyttämällä koemallina eristettyä, perfusoitua rotan sydäntä. Väitöskirjatyön tutkimustulokset osoittivat, että mitogeeni-aktivoituvat proteiinikinaasit (MAPK) ERK1/2 ja p38-MAPK osallistuvat ET-1:n inotrooppisen vaikutuksen säätelyyn. ERK1/2 välitti, ja p38-MAPK rajoitti ET-1:n lisäämää supistusvoiman kasvua. NADPH-oksidaasin tuottamat reaktiiviset happiradikaalit välittivät sydämessä ET-1:n inotrooppista vaikutusta ja ERK1/2 fosforylaatiota. Toisaalta NADPH-oksidaasin tuottamat happiradikaalit rajoittivat β-adrenergisen agonistin inotrooppista vaikutusta. Guanylaattisyklaasi (GC)-cGMP-proteiinikinaasi G (PKG) -järjestelmä ja neuronaalinen typpioksidisyntaasi (nNOS) vaimensivat ET-1:n lisäämää sydämen supistusvoiman kasvua. PrRP lisäsi sydämen inotropiaa syklisestä AMP:stä riippumattomalla tavalla, mutta vasteen säätelyyn havaittiin osallistuvan proteiinikinaasi C ja proteiinifosfataasi 1. Väitöskirjatutkimuksessa saatiin uutta tietoa solunsisäisistä viestinvälitysjärjestelmistä, jotka osallistuvat sydämen supistusvoimaan säätelyyn. Havaintojen perusteella ET-1:n positiivisen inotrooppisen vaikutuksen muodostumista välittävät reaktiiviset happiradikaalit ja ERK1/2, kun taas p38-MAPK rajoittaa vastetta. Lisäksi GC-cGMP-PKG -järjestelmä ja nNOS osallistuvat ET-1:n vaikutusten säätelyyn. Tutkimuksessa havaittiin myös, että PrRP vaikuttaa sydämen supistuvuuteen. Solutason mekanismien yksityiskohtien tunteminen voi mahdollistaa tulevaisuudessa sydän- ja verisuonisairauksien, kuten sydämen hypertrofian ja vajaatoiminnan, hoitomenetelmien tehostumisen ja mahdollisesti uudentyyppisten hoitomenetelmien kehittämisen.
268

Troubles hormonaux et leur implication dans la progression de la maladie de Huntington

Saleh, Nadine 29 September 2009 (has links)
Les processus physiopathologiques qui mènent à la dégénérescence neuronale ainsi qu’aux symptômes de la maladie de Huntington (MH) demeurent non identifiés et les hypothèses actuelles ne permettent pas d’expliquer l’hétérogénéité intra et interindividuelle de l’évolution de ces symptômes. Ainsi, la progression de la maladie reste donc difficile voire impossible à prédire. Dans ce contexte, il est important d’explorer d’autres facteurs qui semblent être impliqués dans le processus pathogène de la maladie mais qui pourraient également influencer l’évolution de ces symptômes et ainsi prédire la progression de la maladie. Plusieurs éléments de preuve renforcent l’hypothèse de l’existence de troubles hormonaux dans la MH tels que l’atteinte de l’hypothalamus et la perte de poids. Cependant, en raison du peu d’études, de leur qualité et de la discordance de leurs résultats, l’existence des modifications hormonales dans la maladie de Huntington et plus particulièrement leur lien avec la progression de la maladie reste controversée. L’objectif de ce travail est de décrire le profil hormonal de l’axe hypothalamohypophysaire dans la MH afin de mieux comprendre le rôle de ces hormones sur la progression et éventuellement sur la physiopathologie de la maladie. Dans notre étude transversale, nous avons mis en évidence une activation de l’axe somatotrope (Growth Hormone/Insulin Growth Factor 1), une inhibition en fonction de la sévérité de la maladie de deux axes : gonadotrope (Testostérone) et thyréotrope (Thyroid Stimulating Hormone et triiodothyronine) mais aucune modification des hormones de l’axe corticotrope ni de la prolactine. De plus, la modification hormonale de l’axe somatotrope était non pathologique et précoce alors qu’elle était tardive pour les deux autres axes. Pour expliquer le lien entre ces modifications et la progression de la maladie une étude longitudinale a été mise en place. Les résultats de cette étude montre que seule l’élévation plasmatique d’IGF1 était prédictive de la détérioration cognitive. L’ensemble de nos résultats apporte une meilleure description et compréhension du profil de l’axe hypothalamo-hypophysaire dans la maladie de Huntington. Les axes pituitaires ne sont pas tous atteints et leur atteinte n’est pas dans le même sens. La relation inverse entre l’activation de l’axe somatotrope et la détérioration cognitive renforce l’hypothèse d’une résistance à l’effet de l’IGF1 dans la maladie de Huntington comme pour la maladie d’alzheimer. En conclusion, compte tenu de l’implication de l’IGF1 dans la prédiction de la progression cognitive dans la maladie de Huntington, il serait intéressant de détecter si les modifications biologiques de l’IGF1 existent dès la phase asymptomatique cognitive afin d’envisager d’utiliser l’IGF1 comme biomarqueur de l’apparition ou de l’évolution des symptômes cognitives. D’un autre côté, il serait important d’étendre les recherches sur les mécanismes responsables des modifications hormonales dans la maladie de Huntington afin de mieux comprendre l’effet de cause à effet s’il existe entre ces modifications et les symptômes de la maladie / The pathophysiological processes leading to neurodegeneration and the symptoms of Huntington's disease (HD) remain unidentified and current hypothesis do not explain the intra and interindividual heterogeneity of the evolution of these symptoms. Thus, the progression of the disease remains difficult or impossible to predict. In this context, it is important to explore other factors that appear to be involved in the pathogenic process of the disease but could also influence the evolution of these symptoms and predict disease progression. Several evidences reinforce the hypothesis of the existence of hormonal disorders in HD such as the atrophy of the hypothalamus and weight loss. Because of few studies, their quality and the discrepancies of their results, the existence of hormonal changes in Huntington's disease and particularly their relationship to disease progression remains controversial. The objective of this work is to describe the hormonal profile of the hypothalamicpituitary axis in HD in order to better understand the role of these hormones on the progression and on the pathophysiology of the disease. In our cross-sectional study, we identified an activation of the somatotropic axis (Growth Hormone / Insulin Growth Factor 1), an inhibition according to the severity of the disease in two axes: gonadotrope (Testosterone) and thyréotrope (Thyroid Stimulating hormone and triiodothyronine) but no change in hormones of corticotropic axis and prolactin. In addition, the somatotropic axis is overactive even in patients with early disease. To explain the link between these changes and the progression of the disease, a longitudinal study was done. The results of this study showed that only the elevated plasma IGF1 was predictive of cognitive impairment. All of our results provide a better description and understanding of the profile of the hypothalamic-pituitary axis in Huntington's disease. Pituitary axes are not all disturbed. The inverse relationship between activation of the somatotropic axis and cognitive impairment strengthens the hypothesis of a resistance to the effect of IGF1 in Huntington's disease like in Alzheimer's disease. In conclusion, given the involvement of IGF1 in the prediction of cognitive progression in Huntington's disease, it would be interesting to detect whether the biological changes of IGF1 are already present at the asymptomatic cognitive stage in order to use IGF1 as a biomarker of the onset or changes in cognitive symptoms. On the other hand, , it would be important to extend research on the mechanisms responsible for hormonal changes in Huntington's disease to better understand the link between these changes and symptoms of the disease
269

O efeito da prolactina na migração de células de câncer de mama pela remodelação da actina no citoesqueleto / Prolactin effects on breast cancer cell migration through actin cytoskeleton remodeling

Priscilla Ludovico da Silva 14 October 2016 (has links)
INTRODUÇÃO: A prolactina é um hormônio polipeptídico que possui reconhecida ação sistêmica, principalmente no sistema reprodutor. O papel desse hormônio no desenvolvimento e na extensão do câncer da mama ainda é muito debatido. A progressão do câncer de mama em grande parte depende do movimento celular e da capacidade da célula em remodelar seu citoesqueleto de actina. Nesse processo, proteínas envolvidas na migração celular, como moesina, FAK e c-Src, são influenciadas por vários hormônios, incluindo a prolactina. O presente estudo teve por objetivo avaliar os efeitos da PRL na migração de células T47D, MCF-7 e ZR75-1 de câncer de mama, bem como os mecanismos envolvidos. MÉTODOS: As células foram cultivadas em placas de cultura com meio suplementado e divididas em oito grupos diferentes de tratamento: Grupo I (veículo); Grupo II (PRL na concentração de 25 ng/mL); Grupo III (PRL na concentração de 50 ng/mL), Grupo IV (PRL na concentração de 100 ng / mL), Grupo V (RNAi + veículo); Grupo VI (RNAi + PRL na concentração de 25 ng/mL); Grupo VII (RNAi + PRL na concentração de 50 ng/mL) e Grupo VIII (RNAi + PRL na concentração de 100 ng / mL). Nos Grupos de I a IV, a reorganização da actina do citoesqueleto foi analisada por imunofluorescência após 30 minutos do tratamento. Em todos os grupos estudados foram realizadas análise da migração horizontal com auxílio de microscopia de luz e avaliadas as expressões de Moesina, p-Moesina, FAK, p-FAK, c-Src e p-c-Src por Western Blot após 48 horas do tratamento. RESULTADOS: As células de câncer de mama expostas à prolactina apresentaram um aumento da expressão de Moesina, p-Moesina, FAK, p-FAK, c-Src e p-c-Src. Essas alterações moleculares estão associadas à reorganização da actina do citoesqueleto e ao aumento da mobilidade das células. CONCLUSÕES: Nossos dados sugerem que a prolactina aumenta a migração das células T47D, MFC-7 e ZR75-1 de câncer de mama e remodela a actina do citoesqueleto pela via de sinalização intracelular das proteínas c-Src, FAK e moesina / INTRODUCTION: Prolactin is a polypeptide hormone with a recognized systemic action mainly on reproductive physiology. The role of this hormone on breast cancer development and progression has been debated a lot yet. Breast cancer invasion largely depends on cell movement and on the ability to remodel the actin cytoskeleton. In this process, proteins involved in cell migration, such as moesin, FAK and c-Src, are influenced by a large number of hormones, such as prolactin. The present study was aimed for evaluating the effects of PRL on migration of T47D, MCF-7 and ZR75-1 breast cancer cells as well as the molecular mechanisms in this process. METHODS: The cells were cultured in dishes with supplemented medium and were divided in eight different assays: Group I (control); Group II (25ng/ml of prolactin); Group III (50ng/ml of prolactin); Group IV (100ng/ml of prolactin); Group V (RNAi + control); Group VI (RNAi + 25ng/ml of prolactin); Group VII (RNAi + 50ng/ml of prolactin); Group VIII (RNAi + 100ng/ml of prolactin). In Groups I to IV, the actin cytoskeletal reorganization was analyzed by immunofluorescence 30 minutes after the treatment. In all groups, were performed the horizontal migration analysis with light microscopy and evaluated the expression of moesin, p-moesin, FAK, p-FAK, c-Src and p-c-Src by Western blot after 48 hours of treatment. RESULTS: Breast cancer cells exposed to prolactin display an elevated moesin, p-moesin, FAK, p-FAK, c-Src and p-c-Src expression. These molecular changes are associated with the reorganization of actin cytoskeleton and increased mobility of cells. CONCLUSION: Our data suggest that prolactin enhances the migration of T47D, MFC-7 and ZR75-1 breast cancer cells through the actin cytoskeleton remodeling by intracellular signaling pathway of c-Src, FAK and moesin proteins
270

Úloha stabilních analogů peptidu uvolňujícího prolaktin při obezitě a hypertenzi. / The role of stable analogs of prolactin-releasing peptide in obesity and hypertension.

Neprašová, Barbora January 2018 (has links)
Anorexigenic neuropeptides have the potential to decrease food intake and ameliorate obesity and its complications such as high blood glucose or high blood pressure. However, they are not able to cross the blood-brain barrier after peripheral application. Recently, we have designed and synthesized lipidized analogs of prolactin-releasing peptide (PrRP), which resulted in stabilization of the molecule and allowed us to apply the peptide to the periphery to achieve its central biological effect, as it was demonstrated by increased neuronal activity shown by c-Fos in particular hypothalamus nuclei. The aim of this study was to choose the effective dose in acute food intake experiments and then to characterize the subchronic effect of palmitoylated PrRP analogs in mouse and rat models of obesity and diabetes. Several animal models were used: diet-induced obese (DIO) mice (C57Bl/6J), DIO Sprague-Dawley rats, and two rat models with leptin receptor-deficiency: Zucker diabetic (ZDF) rats and spontaneously hypertensive (SHROB) rats. Consumption of a high-fat diet in DIO mice and rats increased their body weight and blood pressure. Two-week intraperitoneal treatment with palmitoylated PrRP31 lowered the food intake, body weight, and returned the blood pressure to normal levels. This treatment also improved...

Page generated in 0.0642 seconds