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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.
111

Estudo dos genes reguladores do desenvolvimento oocitário e crescimento folicular (LH, AMH, BMP15, GDF9 e receptores do FSH, LH E AMH) em mulheres submetidas à fertilização in vitro

Meireles, Arivaldo José Conceição January 2014 (has links)
Introdução: Considerando a prevalência, a importância social dos tratamentos de alta complexidade de mulheres inférteis e o contexto atual da literatura que atribui relevância aos polimorfismos dos genes reguladores do desenvolvimento inicial e crescimento folicular, entre eles o FSHR, LH, LHR, AMH, AMHR, BMP15 e GDF9; torna-se imprescindível o melhor conhecimento e a quantificação desses fatores. Com isso poderemos individualizar e abordar de forma mais racional a investigação e o tratamento destas mulheres submetidas à fertilização in vitro (FIV). Objetivos: Avaliar se os polimorfismos dos genes do LH (Trp8Arg e Ile15Thr), AMH (Ile49Ser), BMP15 (673C/T, 9C/G, IVSI+905A/G), GDF9 (546G>A, 398C>G, 447C>T e 646G>A), e dos receptores do FSH (Ser680Asn), do LH (18isnILQ) e do AMH (Ile49Ser), estão relacionados a diferentes desfechos reprodutivos em pacientes submetidas à fertilização in vitro. Métodos: Realizamos dois estudos em mulheres submetidas à indução ovulatória para FIV: (1) um estudo caso-controle entre pacientes normo respondedoras e má respondedoras, (2) um estudo transversal em pacientes jovens submetidas à indução ovulatória para fertilização in vitro (FIV). Foi extraído DNA das pacientes submetidas à indução ovulatória para FIV a partir do sangue periférico para realização de polymerase chain reaction, com o objetivo de detectar os polimorfismos dos referidos genes e as respectivas relações com os resultados obtidos na estimulação ovariana, no Laboratório de Terapia Gênica do HCPA/UFRGS. Resultados: Foi evidenciado que a presença do polimorfismo 398C>G no gene GDF9 está associada à má resposta em pacientes inférteis submetidas à estimulação ovariana para fertilização in vitro (68% em má respondedoras versus 23% normo respondedoras, OR: 4.01, 95% IC:1.52-10.60). Além disso, o genótipo mutante para o polimorfismo G447C>T no gene do GDF9 foi encontrado em 50% nas pacientes má respondedoras versus 19% nas pacientes normo respondedoras (OR: 2.88, 95% IC:1.19-6.04), evidenciando uma forte associação destes polimorfismos com a má resposta ovariana à estimulação. Encontramos, também, que as mulheres portadoras do alelo mutante do gene 447C>T do GDF9 tiveram um número menor de folículos entre 12-14 mm no dia do hCG (1,62 versus 2,46, P = 0,007). As mulheres com o alelo mutante do gene do GDF9 398C>G tiveram um menor número de folículos maiores que 17 mm no dia do hCG (4,33 versus 6,49, P = 0,001), menor número de folículos entre 12 e 14 milímetros no dia do hCG (1,42 versus 2,25, P= 0,017), um menor número de folículos no dia do hCG (7,33 versus 10,11 versus, P = 0,007), e redução total de oócitos MII coletados (5,38 versus 8,84 P = 0,017). Conclusão: Concluímos que polimorfismos no gene do GDF9 têm uma influência significativa no desenvolvimento do oócito, uma vez que a presença dos alelos mutantes 447C>T e 398C>G diminui o número total de folículos maduros e o número total de oócitos coletados de tais pacientes, além deste último estar associado à má resposta ovariana em pacientes submetidas à indução da ovulação para fertilização in vitro. Isso mostra que este membro da família TGFβ além de atuar nas fases iniciais da foliculogênese também tem influência importante sobre a fase final do desenvolvimento do oócito. / Introduction: Given the prevalence, the social importance of high complexity treatments of infertile women and the current context of the literature assigns relevance to polymorphisms of genes regulating early follicle growth and development, including LH, AMH, BMP15, GDF9, FSHR, LHR and AMHR; become essential to better understanding and quantification of these factors. With this we can individualize and address more rationally research and treatment of these women undergoing IVF. Objectives: Evaluate the relationship of polymorphisms of LH (Trp8Arg andIle15Thr), AMH (Ile49Ser), BMP15 ( 673C/T, 9C/ G, IVSI+905A/ G) and GDF9 (546G>A, 398C>G, 447C>Tand646G>A) genes, and FSH (Ser680Asn), LH (18isnILQ) and AMH (Ile49Ser) receptors genes, related to different reproductive outcomes in patients undergoing IVF. Methods: Our study consisted of two phases: the first conducted a case-control study among patients with normal responders and poor responders, and the second a cross-sectional study in young patients undergoing ovulation induction for in vitro fertilization. DNA was extracted from peripheral blood for performing polymerase chain reaction (PCR) and analyzed at the Laboratory of Gene Therapy HCPA/UFRGS, with the objective of detecting polymorphisms of these genes and their relationships to the results obtained in ovarian stimulation. Results: It was shown that the presence of polymorphism 398C>G in GDF9 gene is associated with poor response in infertile patients undergoing controlled ovarian stimulation for in vitro fertilization (68% in poor responders versus 23% in normal responders). Furthermore, the genotype GDF9 447C>T mutant polymorphism was found in 50% and 19%, respectively, in poor and normal responders patients, showing a strong association with this polymorphism and a poor response in ovarian stimulation. Women carrying the GDF9 398C>G mutant allele had a smaller number of follicles between 12-14 mm on the day of r-hCG (1.62 vs. 2.46, respectively P=0.007). Women with GDF9 398C>G mutant allele had a smaller number of follicles larger than 17 mm on the r-hCG day (4.33 vs. 6.49, P=0.001), a smaller number of follicles between 12 and 14mm on the r-hCG day (1.42 vs. 2.25, P=0.017), a smaller number of follicles on the r-hCG day (7.33 vs. 10.11, P=0,007), and a reduced overall number of MII oocytes collected (5.38 vs. 8.84 ,P=0.017). Conclusion: We conclude that GDF9 polymorphisms in the gene have a significant influence on the development of the oocytes, since the presence of the mutant alleles 447C>T and 398C>G decreases the total number of mature follicles, total number of oocytes collected, and are associated a poor ovarian response in patients undergoing ovulation induction for in vitro fertilization. This shows that this member of the TGFβ family besides acting in the early stages of folliculogenesis also has important influence on the final stage of oocytes development.
112

Aspects of Online Learning

Harrington, Edward, edwardharrington@homemail.com.au January 2004 (has links)
Online learning algorithms have several key advantages compared to their batch learning algorithm counterparts: they are generally more memory efficient, and computationally mor efficient; they are simpler to implement; and they are able to adapt to changes where the learning model is time varying. Online algorithms because of their simplicity are very appealing to practitioners. his thesis investigates several online learning algorithms and their application. The thesis has an underlying theme of the idea of combining several simple algorithms to give better performance. In this thesis we investigate: combining weights, combining hypothesis, and (sort of) hierarchical combining.¶ Firstly, we propose a new online variant of the Bayes point machine (BPM), called the online Bayes point machine (OBPM). We study the theoretical and empirical performance of the OBPm algorithm. We show that the empirical performance of the OBPM algorithm is comparable with other large margin classifier methods such as the approximately large margin algorithm (ALMA) and methods which maximise the margin explicitly, like the support vector machine (SVM). The OBPM algorithm when used with a parallel architecture offers potential computational savings compared to ALMA. We compare the test error performance of the OBPM algorithm with other online algorithms: the Perceptron, the voted-Perceptron, and Bagging. We demonstrate that the combinationof the voted-Perceptron algorithm and the OBPM algorithm, called voted-OBPM algorithm has better test error performance than the voted-Perceptron and Bagging algorithms. We investigate the use of various online voting methods against the problem of ranking, and the problem of collaborative filtering of instances. We look at the application of online Bagging and OBPM algorithms to the telecommunications problem of channel equalization. We show that both online methods were successful at reducing the effect on the test error of label flipping and additive noise.¶ Secondly, we introduce a new mixture of experts algorithm, the fixed-share hierarchy (FSH) algorithm. The FSH algorithm is able to track the mixture of experts when the switching rate between the best experts may not be constant. We study the theoretical aspects of the FSH and the practical application of it to adaptive equalization. Using simulations we show that the FSH algorithm is able to track the best expert, or mixture of experts, in both the case where the switching rate is constant and the case where the switching rate is time varying.
113

Ovarian Reserve and Assisted Reproduction

Brodin, Thomas January 2013 (has links)
Treatment success in IVF-ICSI is mainly limited by female age, but differences in ovarian reserve (OR; the remaining pool of oocytes and their quality) between individuals modify treatment prerequisites among women of similar age. OR may be assessed by OR tests (ORTs). The main aims of this work were to study menstrual cycle length (MCL), basal levels of circulating gonadotrophins, antral follicle count (AFC) and serum Anti-Müllerian hormone (AMH) levels and their associations with and prognostic capacities regarding IVF-ICSI outcome in large cohorts of unselected women. Age-adjusted MCL was positively and linearly associated with pregnancy rates (PRs), live-birth rates (LBRs) and ovarian response to controlled ovarian hyperstimulation. An MCL of >34 days almost doubled the LBR compared with an MCL of <26 days. The grouped variable ‘combined FSH and LH levels’ was superior to both individual gonadotrophin levels and the LH:FSH ratio. The highest mean PR was seen in connection with a combination of FSH <6.7 U/l with LH >4.9 U/l; PRs were lowest when FSH-LH levels were opposite to this (high-low) and intermediate when FSH-LH levels were low-low or high-high. Associations with LBR and ovarian response were similar as those for PR. AFCs and serum AMH levels were positively and log-linearly associated with PR, LBR and ovarian response. Success rates levelled out above AFC 30 or AMH 5 ng/ml. Treatment outcome was superior among women with polycystic ovaries. Among the studied ORTs, logAFC and logAMH concentration correlated most strongly. After multivariate testing, entering all studied ORTs, AMH and female age remained independently associated with LBR. AMH + AFC + age predicted both poor and excessive ovarian responses with high accuracy. Adjusting for age and oocyte yield, all ORTs remained significant for LBR, implying that ORTs also capture information on oocyte quality. In conclusion, measures of OR are strongly associated with PR, LBR and ovarian response in a log-linear fashion, and partly reflect oocyte quality. The OR spectrum is continuous, from small ‘oligofollicular’ ovaries (the low extreme) to polycystic ovaries (the high extreme). Among the studied ORTs, AMH together with age provide the most powerful basal estimate for IVF/ICSI outcome.
114

Estudo dos genes reguladores do desenvolvimento oocitário e crescimento folicular (LH, AMH, BMP15, GDF9 e receptores do FSH, LH E AMH) em mulheres submetidas à fertilização in vitro

Meireles, Arivaldo José Conceição January 2014 (has links)
Introdução: Considerando a prevalência, a importância social dos tratamentos de alta complexidade de mulheres inférteis e o contexto atual da literatura que atribui relevância aos polimorfismos dos genes reguladores do desenvolvimento inicial e crescimento folicular, entre eles o FSHR, LH, LHR, AMH, AMHR, BMP15 e GDF9; torna-se imprescindível o melhor conhecimento e a quantificação desses fatores. Com isso poderemos individualizar e abordar de forma mais racional a investigação e o tratamento destas mulheres submetidas à fertilização in vitro (FIV). Objetivos: Avaliar se os polimorfismos dos genes do LH (Trp8Arg e Ile15Thr), AMH (Ile49Ser), BMP15 (673C/T, 9C/G, IVSI+905A/G), GDF9 (546G>A, 398C>G, 447C>T e 646G>A), e dos receptores do FSH (Ser680Asn), do LH (18isnILQ) e do AMH (Ile49Ser), estão relacionados a diferentes desfechos reprodutivos em pacientes submetidas à fertilização in vitro. Métodos: Realizamos dois estudos em mulheres submetidas à indução ovulatória para FIV: (1) um estudo caso-controle entre pacientes normo respondedoras e má respondedoras, (2) um estudo transversal em pacientes jovens submetidas à indução ovulatória para fertilização in vitro (FIV). Foi extraído DNA das pacientes submetidas à indução ovulatória para FIV a partir do sangue periférico para realização de polymerase chain reaction, com o objetivo de detectar os polimorfismos dos referidos genes e as respectivas relações com os resultados obtidos na estimulação ovariana, no Laboratório de Terapia Gênica do HCPA/UFRGS. Resultados: Foi evidenciado que a presença do polimorfismo 398C>G no gene GDF9 está associada à má resposta em pacientes inférteis submetidas à estimulação ovariana para fertilização in vitro (68% em má respondedoras versus 23% normo respondedoras, OR: 4.01, 95% IC:1.52-10.60). Além disso, o genótipo mutante para o polimorfismo G447C>T no gene do GDF9 foi encontrado em 50% nas pacientes má respondedoras versus 19% nas pacientes normo respondedoras (OR: 2.88, 95% IC:1.19-6.04), evidenciando uma forte associação destes polimorfismos com a má resposta ovariana à estimulação. Encontramos, também, que as mulheres portadoras do alelo mutante do gene 447C>T do GDF9 tiveram um número menor de folículos entre 12-14 mm no dia do hCG (1,62 versus 2,46, P = 0,007). As mulheres com o alelo mutante do gene do GDF9 398C>G tiveram um menor número de folículos maiores que 17 mm no dia do hCG (4,33 versus 6,49, P = 0,001), menor número de folículos entre 12 e 14 milímetros no dia do hCG (1,42 versus 2,25, P= 0,017), um menor número de folículos no dia do hCG (7,33 versus 10,11 versus, P = 0,007), e redução total de oócitos MII coletados (5,38 versus 8,84 P = 0,017). Conclusão: Concluímos que polimorfismos no gene do GDF9 têm uma influência significativa no desenvolvimento do oócito, uma vez que a presença dos alelos mutantes 447C>T e 398C>G diminui o número total de folículos maduros e o número total de oócitos coletados de tais pacientes, além deste último estar associado à má resposta ovariana em pacientes submetidas à indução da ovulação para fertilização in vitro. Isso mostra que este membro da família TGFβ além de atuar nas fases iniciais da foliculogênese também tem influência importante sobre a fase final do desenvolvimento do oócito. / Introduction: Given the prevalence, the social importance of high complexity treatments of infertile women and the current context of the literature assigns relevance to polymorphisms of genes regulating early follicle growth and development, including LH, AMH, BMP15, GDF9, FSHR, LHR and AMHR; become essential to better understanding and quantification of these factors. With this we can individualize and address more rationally research and treatment of these women undergoing IVF. Objectives: Evaluate the relationship of polymorphisms of LH (Trp8Arg andIle15Thr), AMH (Ile49Ser), BMP15 ( 673C/T, 9C/ G, IVSI+905A/ G) and GDF9 (546G>A, 398C>G, 447C>Tand646G>A) genes, and FSH (Ser680Asn), LH (18isnILQ) and AMH (Ile49Ser) receptors genes, related to different reproductive outcomes in patients undergoing IVF. Methods: Our study consisted of two phases: the first conducted a case-control study among patients with normal responders and poor responders, and the second a cross-sectional study in young patients undergoing ovulation induction for in vitro fertilization. DNA was extracted from peripheral blood for performing polymerase chain reaction (PCR) and analyzed at the Laboratory of Gene Therapy HCPA/UFRGS, with the objective of detecting polymorphisms of these genes and their relationships to the results obtained in ovarian stimulation. Results: It was shown that the presence of polymorphism 398C>G in GDF9 gene is associated with poor response in infertile patients undergoing controlled ovarian stimulation for in vitro fertilization (68% in poor responders versus 23% in normal responders). Furthermore, the genotype GDF9 447C>T mutant polymorphism was found in 50% and 19%, respectively, in poor and normal responders patients, showing a strong association with this polymorphism and a poor response in ovarian stimulation. Women carrying the GDF9 398C>G mutant allele had a smaller number of follicles between 12-14 mm on the day of r-hCG (1.62 vs. 2.46, respectively P=0.007). Women with GDF9 398C>G mutant allele had a smaller number of follicles larger than 17 mm on the r-hCG day (4.33 vs. 6.49, P=0.001), a smaller number of follicles between 12 and 14mm on the r-hCG day (1.42 vs. 2.25, P=0.017), a smaller number of follicles on the r-hCG day (7.33 vs. 10.11, P=0,007), and a reduced overall number of MII oocytes collected (5.38 vs. 8.84 ,P=0.017). Conclusion: We conclude that GDF9 polymorphisms in the gene have a significant influence on the development of the oocytes, since the presence of the mutant alleles 447C>T and 398C>G decreases the total number of mature follicles, total number of oocytes collected, and are associated a poor ovarian response in patients undergoing ovulation induction for in vitro fertilization. This shows that this member of the TGFβ family besides acting in the early stages of folliculogenesis also has important influence on the final stage of oocytes development.
115

Estudo dos genes reguladores do desenvolvimento oocitário e crescimento folicular (LH, AMH, BMP15, GDF9 e receptores do FSH, LH E AMH) em mulheres submetidas à fertilização in vitro

Meireles, Arivaldo José Conceição January 2014 (has links)
Introdução: Considerando a prevalência, a importância social dos tratamentos de alta complexidade de mulheres inférteis e o contexto atual da literatura que atribui relevância aos polimorfismos dos genes reguladores do desenvolvimento inicial e crescimento folicular, entre eles o FSHR, LH, LHR, AMH, AMHR, BMP15 e GDF9; torna-se imprescindível o melhor conhecimento e a quantificação desses fatores. Com isso poderemos individualizar e abordar de forma mais racional a investigação e o tratamento destas mulheres submetidas à fertilização in vitro (FIV). Objetivos: Avaliar se os polimorfismos dos genes do LH (Trp8Arg e Ile15Thr), AMH (Ile49Ser), BMP15 (673C/T, 9C/G, IVSI+905A/G), GDF9 (546G>A, 398C>G, 447C>T e 646G>A), e dos receptores do FSH (Ser680Asn), do LH (18isnILQ) e do AMH (Ile49Ser), estão relacionados a diferentes desfechos reprodutivos em pacientes submetidas à fertilização in vitro. Métodos: Realizamos dois estudos em mulheres submetidas à indução ovulatória para FIV: (1) um estudo caso-controle entre pacientes normo respondedoras e má respondedoras, (2) um estudo transversal em pacientes jovens submetidas à indução ovulatória para fertilização in vitro (FIV). Foi extraído DNA das pacientes submetidas à indução ovulatória para FIV a partir do sangue periférico para realização de polymerase chain reaction, com o objetivo de detectar os polimorfismos dos referidos genes e as respectivas relações com os resultados obtidos na estimulação ovariana, no Laboratório de Terapia Gênica do HCPA/UFRGS. Resultados: Foi evidenciado que a presença do polimorfismo 398C>G no gene GDF9 está associada à má resposta em pacientes inférteis submetidas à estimulação ovariana para fertilização in vitro (68% em má respondedoras versus 23% normo respondedoras, OR: 4.01, 95% IC:1.52-10.60). Além disso, o genótipo mutante para o polimorfismo G447C>T no gene do GDF9 foi encontrado em 50% nas pacientes má respondedoras versus 19% nas pacientes normo respondedoras (OR: 2.88, 95% IC:1.19-6.04), evidenciando uma forte associação destes polimorfismos com a má resposta ovariana à estimulação. Encontramos, também, que as mulheres portadoras do alelo mutante do gene 447C>T do GDF9 tiveram um número menor de folículos entre 12-14 mm no dia do hCG (1,62 versus 2,46, P = 0,007). As mulheres com o alelo mutante do gene do GDF9 398C>G tiveram um menor número de folículos maiores que 17 mm no dia do hCG (4,33 versus 6,49, P = 0,001), menor número de folículos entre 12 e 14 milímetros no dia do hCG (1,42 versus 2,25, P= 0,017), um menor número de folículos no dia do hCG (7,33 versus 10,11 versus, P = 0,007), e redução total de oócitos MII coletados (5,38 versus 8,84 P = 0,017). Conclusão: Concluímos que polimorfismos no gene do GDF9 têm uma influência significativa no desenvolvimento do oócito, uma vez que a presença dos alelos mutantes 447C>T e 398C>G diminui o número total de folículos maduros e o número total de oócitos coletados de tais pacientes, além deste último estar associado à má resposta ovariana em pacientes submetidas à indução da ovulação para fertilização in vitro. Isso mostra que este membro da família TGFβ além de atuar nas fases iniciais da foliculogênese também tem influência importante sobre a fase final do desenvolvimento do oócito. / Introduction: Given the prevalence, the social importance of high complexity treatments of infertile women and the current context of the literature assigns relevance to polymorphisms of genes regulating early follicle growth and development, including LH, AMH, BMP15, GDF9, FSHR, LHR and AMHR; become essential to better understanding and quantification of these factors. With this we can individualize and address more rationally research and treatment of these women undergoing IVF. Objectives: Evaluate the relationship of polymorphisms of LH (Trp8Arg andIle15Thr), AMH (Ile49Ser), BMP15 ( 673C/T, 9C/ G, IVSI+905A/ G) and GDF9 (546G>A, 398C>G, 447C>Tand646G>A) genes, and FSH (Ser680Asn), LH (18isnILQ) and AMH (Ile49Ser) receptors genes, related to different reproductive outcomes in patients undergoing IVF. Methods: Our study consisted of two phases: the first conducted a case-control study among patients with normal responders and poor responders, and the second a cross-sectional study in young patients undergoing ovulation induction for in vitro fertilization. DNA was extracted from peripheral blood for performing polymerase chain reaction (PCR) and analyzed at the Laboratory of Gene Therapy HCPA/UFRGS, with the objective of detecting polymorphisms of these genes and their relationships to the results obtained in ovarian stimulation. Results: It was shown that the presence of polymorphism 398C>G in GDF9 gene is associated with poor response in infertile patients undergoing controlled ovarian stimulation for in vitro fertilization (68% in poor responders versus 23% in normal responders). Furthermore, the genotype GDF9 447C>T mutant polymorphism was found in 50% and 19%, respectively, in poor and normal responders patients, showing a strong association with this polymorphism and a poor response in ovarian stimulation. Women carrying the GDF9 398C>G mutant allele had a smaller number of follicles between 12-14 mm on the day of r-hCG (1.62 vs. 2.46, respectively P=0.007). Women with GDF9 398C>G mutant allele had a smaller number of follicles larger than 17 mm on the r-hCG day (4.33 vs. 6.49, P=0.001), a smaller number of follicles between 12 and 14mm on the r-hCG day (1.42 vs. 2.25, P=0.017), a smaller number of follicles on the r-hCG day (7.33 vs. 10.11, P=0,007), and a reduced overall number of MII oocytes collected (5.38 vs. 8.84 ,P=0.017). Conclusion: We conclude that GDF9 polymorphisms in the gene have a significant influence on the development of the oocytes, since the presence of the mutant alleles 447C>T and 398C>G decreases the total number of mature follicles, total number of oocytes collected, and are associated a poor ovarian response in patients undergoing ovulation induction for in vitro fertilization. This shows that this member of the TGFβ family besides acting in the early stages of folliculogenesis also has important influence on the final stage of oocytes development.
116

Relation entre l’exposition aux parabènes et les hormones de la reproduction : une étude chez les jeunes filles canadiennes

Guth, Margot 05 1900 (has links)
Contexte : Les parabènes sont des substances antibactériennes et antifongiques utilisées comme conservateurs dans de nombreux produits d’usage courant (cosmétiques, soins personnels, pharmaceutiques et alimentaires). Des études in vitro et in vivo ont signalé les effets de perturbation endocrinienne des parabènes, soulevant des inquiétudes quant à leurs risques potentiels pour la santé humaine. Objectif : Évaluer l’association entre les concentrations urinaires de parabènes et les concentrations sériques d’hormones de la reproduction (estradiol, progestérone, hormone folliculostimulante et hormone lutéinisante) chez les jeunes filles de la population générale canadienne. Méthodes: Les données de l'Enquête canadienne sur les mesures de la santé (2014 – 2015) concernant les filles âgées entre 6 et 17 ans ont été utilisées pour cette étude. L’association entre les concentrations urinaires de parabènes et des hormones a été analysée par régression linéaire multivariée, en ajustant pour les covariables suivantes : âge, indice de masse corporelle, ethnicité, revenu, et saison lors de la collecte des échantillons urinaires et sanguins. Résultats : Les 382 participantes incluses dans cette étude étaient majoritairement blanches (76%), avaient un indice de masse corporelle normal (73%) et des niveaux détectables d’au moins un parabène (92 %). Des concentrations de parabènes plus élevées étaient associées à des concentrations d'hormones de la reproduction significativement inférieures pour l’estradiol, et les hormones folliculostimulante et lutéinisante; il n’y avait pas d’association pour la progestérone. Un doublement des concentrations des parabènes urinaires était associé à des concentrations inférieures d'estradiol de 5,8% (IC à 95% -9,3; -2,1), d’hormone folliculostimulante inférieure de 4,2% (IC à 95% -7,9; -0,3) et d’hormone lutéinisante inférieure de 10,8% (IC à 95% -17,4; -3,7). Discussion : Cette étude montre que l'exposition aux parabènes était associée à des concentrations circulantes plus faibles d'hormones de la reproduction chez des jeunes filles de la population générale. Le devis transversal ne permet pas de réaliser d’inférences causales. Néanmoins, ces résultats concordent avec les études animales et suggèrent que l’exposition aux parabènes pendant le développement puisse altérer le fonctionnement du système reproducteur. Des études longitudinales permettraient de confirmer, ou non, ces résultats. / Background: Parabens are chemical substances used as preservatives for their antibacterial and antifungal properties in many everyday products (personal care, cosmetics, pharmaceutical and food). Several in vitro and in vivo studies have shown their endocrine disrupting potential, raising some concerns for potential adverse human health effects. Objective: To assess the cross-sectional association between urinary concentration of parabens and serum reproductive hormones (estradiol, progesterone, follicle stimulating hormone and luteinizing hormone) in girls in the general Canadian population. Methods: Data from the Canadian Health Measures Survey (2014 – 2015) on girls aged 6-17 were used for this study. Associations between hormones and parabens were analyzed with multivariable linear regressions, adjusting for potential confounders (i.e., age, body mass index, ethnicity, household income, and sampling season). Results: The girls and teens included in the study (n=382) were mostly white (76%), had a normal body mass index (73%), and detectable levels of at least one paraben (92%). We observed significantly lower concentrations of reproductive hormones with higher paraben concentrations; there was no association with progesterone concentrations. A doubling in urinary parabens was associated with lower estradiol by 5.8% (95% CI -9.3, -2.1), lower FSH by 4.2% (95% CI -7.9, -0.3), and lower LH by 10.8% (95% CI -17.4, -3.7). Discussion: This study shows that exposure to parabens is associated with lower circulating levels of reproductive hormones in young girls in the general population. The cross-sectional design does not allow to make causal inferences. However, these results are consistent with animal studies and suggest that exposure to parabens during development may affect the functioning of the reproductive system. Future studies should employ a longitudinal design verify these results.
117

Tribbles pseudokinase 2 (TRIB2) dans le contrôle moléculaire de la fonction ovarienne bovine

Warma, Aly 11 1900 (has links)
Au cours des processus de croissance folliculaire et d'ovulation, les cellules stéroïdogéniques, y compris les cellules de granulosa (CG), jouent un rôle crucial dans la maturation et la libération de l'ovocyte. Notre laboratoire a identifié et caractérisé pour la première fois tribbles pseudokinase 2 (TRIB2) dans les CG de follicules ovariens. Des études ont démontré que TRIB2 joue un rôle dans la coordination de la mitose et la morphogenèse chez la drosophile alors que chez la souris, son expression dans les cellules du cumulus serait liée à la maturation ovocytaire. Cependant, le rôle exact de TRIB2 dans la fonction des CG et ses effets sur les voies de signalisation impliquées dans la croissance folliculaire restait à être défini. La présente étude de doctorat avait donc pour but d’étudier la fonction et les partenaires de liaison de TRIB2 dans les CG de follicules ovariens bovins. À l’aide d’un modèle d’étude in vivo consistant en des CG obtenues à partir de follicules à différents stades de développement, nous avons démontré une régulation à la baisse de TRIB2 par l’hormone lutéinisante (LH) et la gonadotrophine chorionique humaine (hCG) aussi bien au niveau du messager que de la protéine. De plus, les analyses utilisant un modèle in vitro de CG en culture ont montré que la FSH stimule l'expression de TRIB2 tandis que l'inhibition de TRIB2 via CRISPR/Cas9 entraîne une réduction significative de la prolifération des CG (P<0,05). Les analyses Western blot ont montré une augmentation des niveaux de phosphorylation d’ERK1/2 (MAPK3/1) et p38MAPK (MAPK14) suite à la surexpression de TRIB2. Ces résultats suggèrent un rôle de TRIB2 dans la croissance folliculaire et la modulation des voies MAPK. Avec l’approche double hybride chez la levure, nous avons identifié CALM1, INHBA, INPPL1, NT5E, SCD, SDHB et RAB14 comme partenaires de liaison de TRIB2. Les analyses RT-PCR ont montré que ces partenaires sont régulés différemment au cours du développement folliculaire et les manipulations de l’expression de TRIB2 (inhibition ou surexpression) résulte en une régulation différente (augmentation ou diminution) de l’expression des partenaires dans les CG. Ces résultats suggèrent un rôle de TRIB2 dans la régulation de cibles effectrices en lien avec la fonction des CG et le développement folliculaire. Enfin, un modèle de CG provenant de vaches en période post-partum a été utilisé pour mieux comprendre le contrôle de l’activité des CG. Des analyses complémentaires avec ce modèle ont révélé une réduction significative de TRIB2 chez les vaches ayant un taux élevé de BHB (>1.4mmol/L) comparé à celles ayant un faible taux de BHB (<1.2mmol/L). Cette réduction était concomitante à une augmentation d’interleukines pro-inflammatoires et une réduction d’interleukines anti-inflammatoires dans les CG. L’ensemble de ces résultats supporte un rôle de TRIB2 dans la modulation de la signalisation MAPK dans les CG, apporte une preuve solide que TRIB2 pourrait agir comme un régulateur de la prolifération et de la fonction des CG et de l’expression de gènes cibles, et suggère que TRIB2 pourrait affecter la stéroïdogenèse au cours du développement folliculaire et lors de la période post-partum. / During the processes of follicular growth and ovulation, steroidogenic cells, including granulosa cells, play a crucial role in the maturation and release of the oocyte. Our lab identified and characterized for the first time tribble pseudokinase 2 (TRIB2) in GC of ovarian follicles. Previous studies have shown that TRIB2 plays a role in the coordination of mitosis and morphogenesis in Drosophila while in mice its expression in cumulus cells is linked to oocyte maturation. However, the exact mechanism of action of TRIB2 as well as its function and effects on signaling pathways in GC during follicular growth remained to be defined. This study aimed therefore to further investigate TRIB2 function and identify its binding partners in GC. TRIB2 inhibition and overexpression experiments were conducted using, respectively, CRISPR/Cas9 technology and the pQE1 system. Using an in vivo model consisting of GC obtained from follicles at different stages of development, we demonstrated a downregulation of TRIB2 by the endogenous luteinizing hormone (LH) and human Chorionic Gonadotropin (hCG) at both the messenger and protein levels. In addition, analyzes using an in vitro model of cultured GC, we showed that FSH stimulates the expression of TRIB2 while inhibition of TRIB2 via CRISPR-Cas9 resulted in a significant reduction in GC proliferation (P<0.05). Western blot analyzes showed an increase in the phosphorylation levels of ERK1/2 (MAPK3/1) and p38MAPK (MAPK14) following TRIB2 overexpression. These results suggested a role of TRIB2 in follicular growth and modulation of MAPK pathways. In the second part of the thesis, we identified CALM1, INHBA, INPPL1, NT5E, SCD, SDHB and RAB14 as binding partners of TRIB2 in GC using the yeast two-hybrid approach. RT-qPCR analyzes showed that all of these partners are present in the dominant follicles but are differently regulated during follicular development. Moreover, TRIB2 manipulation (inhibition or overexpression) results in a different regulation (up- or down-regulation) of these partners expression in GC. These results suggest a role of TRIB2 in the regulation of effector targets genes related to follicular development and GC activity. In the third part of the thesis, a GC model from postpartum cows was also used to better understand the control of GC activity. Further analyses using this model revealed a significant decrease of TRIB2 in cows with high level of BHB (>1.4 mmol/L) as compared to those with a low BHB levels (<1.2 mmol/L). This reduction of TRIB2 was concomitant with an increase in pro-inflammatory interleukins and a reduction in anti-inflammatory interleukins in GC. Overall, these results support a role of TRIB2 in the modulation of MAPK signaling in GC, provide strong evidence that TRIB2 could act as a regulator of GC proliferation and function as well as expression of target genes in GC, and suggests that TRIB2 might affect steroidogenesis during follicular development and during the post-partum period.
118

Studies on Premenstrual Dysphoria

Eriksson, Olle January 2005 (has links)
<p>Premenstrual dysphoria, so severe that it affects the lives of the women afflicted, is the condition studied in this thesis. Physiological and pharmacological mechanisms of pathogenetic relevance were investigated. </p><p>Women with premenstrual dysphoria showed a stronger and less dampened response of LH to an estradiol challenge than asymptomatic women, indicating an altered neuroendocrine regulation. In women with premenstrual dysphoria, the LH response was correlated to the severity of irritability and bloating, and the early FSH response was correlated to the severity of depressed mood. </p><p>The positron-emission study showed strong, consistent correlations between worsening of mood symptoms and a decrease in brain trapping of the immediate serotonin precursor, from the mid-follicular to the late luteal phase in women with premenstrual dysphoria. The strongest correlations were seen for the cardinal mood symptoms of premenstrual dysphoria, and for their opposites. Physical symptoms showed weaker or no correlations with the exception of nociceptive symptoms from erogenous body regions which showed positive correlations to serotonin precursor trapping in the right caudate nucleus. The findings are consistent with the serotonin hypothesis of premenstrual dysphoria, and might possibly explain the observed effects of serotonin-augmenting drugs in this condition.</p><p>The partial 5-HT<sub>1A</sub> receptor agonist buspirone was superior to placebo in the treatment of premenstrual dysphoria. The weak SRI and 5-HT<sub>2</sub> receptor antagonist nefazodone was not superior to placebo. For women with premenstrual dysphoria in need of medication and who do not tolerate SRIs because of the sexual sideeffects, buspirone may be an alternative drug, since it had no adverse effects on sexual function. </p><p>The prevalence of polycystic ovaries and serum levels of androgens were not higher in women with premenstrual dysphoria than in their asymptomatic counterparts. The findings are not consistent with the hypothesis that irritability in women with premenstrual dysphoria is induced by elevated testosterone levels. </p><p>Thesis results, which are in line with the serotonin hypothesis of premenstrual dysphoria, may imply that increased brain sensitivity is one of the factors underlying severe premenstrual mood symptoms, thereby further supporting a common serotonergic dysregulation in this condition.</p>
119

Studies on Premenstrual Dysphoria

Eriksson, Olle January 2005 (has links)
Premenstrual dysphoria, so severe that it affects the lives of the women afflicted, is the condition studied in this thesis. Physiological and pharmacological mechanisms of pathogenetic relevance were investigated. Women with premenstrual dysphoria showed a stronger and less dampened response of LH to an estradiol challenge than asymptomatic women, indicating an altered neuroendocrine regulation. In women with premenstrual dysphoria, the LH response was correlated to the severity of irritability and bloating, and the early FSH response was correlated to the severity of depressed mood. The positron-emission study showed strong, consistent correlations between worsening of mood symptoms and a decrease in brain trapping of the immediate serotonin precursor, from the mid-follicular to the late luteal phase in women with premenstrual dysphoria. The strongest correlations were seen for the cardinal mood symptoms of premenstrual dysphoria, and for their opposites. Physical symptoms showed weaker or no correlations with the exception of nociceptive symptoms from erogenous body regions which showed positive correlations to serotonin precursor trapping in the right caudate nucleus. The findings are consistent with the serotonin hypothesis of premenstrual dysphoria, and might possibly explain the observed effects of serotonin-augmenting drugs in this condition. The partial 5-HT1A receptor agonist buspirone was superior to placebo in the treatment of premenstrual dysphoria. The weak SRI and 5-HT2 receptor antagonist nefazodone was not superior to placebo. For women with premenstrual dysphoria in need of medication and who do not tolerate SRIs because of the sexual sideeffects, buspirone may be an alternative drug, since it had no adverse effects on sexual function. The prevalence of polycystic ovaries and serum levels of androgens were not higher in women with premenstrual dysphoria than in their asymptomatic counterparts. The findings are not consistent with the hypothesis that irritability in women with premenstrual dysphoria is induced by elevated testosterone levels. Thesis results, which are in line with the serotonin hypothesis of premenstrual dysphoria, may imply that increased brain sensitivity is one of the factors underlying severe premenstrual mood symptoms, thereby further supporting a common serotonergic dysregulation in this condition.
120

Engineering the N-Glycosylation Pathway in Pichia Pastoris for the Expression of Glycoprotein Hormones

Manoharan, Simna January 2016 (has links) (PDF)
Proteins, participating in a myriad of biological function, are at the core of all cellular activities occurring within living organisms. Therapeutic proteins, hence constitute a major part of the pharmaceutical industry. The glycoprotein hormones follicle stimulating hormone (FSH), luteinizing hormone (LH), thyroid stimulating hormone (TSH) and human chorionic gonadotropin (CG) regulate various reproductive and metabolic functions in humans and hence have high therapeutic potentials. The increasing demand of recombinant proteins for therapeutic uses drives the development of better expression systems. The methylotrophic yeast Pichia pastoris, has been termed as an industrial workhorse for heterologous protein expression. However, the N-glycosylation in yeast is of the high mannose type, resulting in a reduced serum half-life of the recombinant proteins. In the current work, we have re-engineered the Pichia N-glycosylation pathway to mimic the human type of N-glycosylation. Towards this end, we abolished the yeast native N-glycosylation and introduced enzymes from various eukaryotic sources into the system. These modifications resulted in the conversion of the yeast Man9-20GlcNAc2 glycan structure to a more human like GlcNAc2Man3GlcNAc2 form on over 70 % of the heterologous expressed proteins. In order to demonstrate the application of these strains as efficient protein expression hosts, the glycoengineerd Pichia was used for large scale expression of the glycoprotein hormones, hCG and FSH. The purified recombinant hormones were found to have binding affinities and structure similar to that of the natural hormones. These recombinant hormones were also able to elicit over two fold responses in animal models compared to buffer controls and the activity was comparable to the natural counterparts. Thus, we report the generation of a glycoengineered Pichia pastoris, which can be considered as a serious contender for the expression of glycosylated proteins of therapeutic importance.

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