Thesis (M.A.)--Bowling Green State University, 2006. / Document formatted into pages; contains v, 83 p. Includes bibliographical references.

L’objectif de la thèse a été d’apporter des éléments sur la réaction acrosomique (RA) aviaire afin de mieux comprendre les processus menant à la fécondation et de mieux maîtriser la capacité des spermatozoïdes à être conservés. Nos résultats ont conforté l’hypothèse de l’absence de capacitation chez les oiseaux. De plus, il n’y a pas d’hyperactivation de la mobilité lors de la RA. Seul le Ca2+ s’avère être l’élément indispensable au déclenchement de la RA. L’évaluation de la RA avec des spermatozoïdes conservés à l’état liquide ou après cryoconservation a révélé une évolution différente en fonction du type de conservation. L’étude des voies de signalisation susceptibles d’être impliquées dans le déclenchement de la RA a suggéré l’activation de 3voies, PKA, PI3K et MAPK ERK. Ce travail ouvre de nombreuses perspectives scientifiques vers l’approfondissement des connaissances de la RA chez les oiseaux et sur l’utilisation qui peut en être faite pour mieux maîtriser la qualité des gamètes. / The aim of this work was to provide new information on chicken acrosome reaction (AR) for a better comprehension of the mechanisms leading to this reaction and a better control of the fertilizing potential of spermatozoa after in vitro storage. Our results showed that calcium is the factor absolutely necessary to initiate the AR and supported the hypothesis that chicken spermatozoa do not need to be capacitated. Moreover, motility hyperactivation was not found at the time of AR. Then, we showed that chicken sperm ability to undergo the AR may differ depending on the type of semen storage. Indeed, this ability was dramatically affected by liquid storage, but was submitted to contrasted effect after cryopreservation. Finally, we investigated the potential involvement of several signaling pathways in initiation of the chicken AR and the results showed that the AR could be mediated by activation of the PKA, PI3K and ERK MAPK pathways.

Dissertation--Universität Bielefeld, 2006. / Bibliogr. p. 267-285.

Ph.D.

Ulm, Univ., Diss., 2008.

Programa de Pós-Graduação em Ciências Biológicas. Núcleo de Pesquisas em Ciências Biológicas, Pró-Reitoria de Pesquisa e Pós Graduação, Universidade Federal de Ouro Preto. / Submitted by Oliveira Flávia (flavia@sisbin.ufop.br) on 2014-12-17T19:50:58Z No. of bitstreams: 1 DISSERTAÇÃO_CaracterizaçãoAvaliaçãoAtividades.pdf: 30857020 bytes, checksum: c062ec96efd13b67e7d301b2974f228d (MD5) / Approved for entry into archive by Gracilene Carvalho (gracilene@sisbin.ufop.br) on 2015-01-15T17:19:40Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO_CaracterizaçãoAvaliaçãoAtividades.pdf: 30857020 bytes, checksum: c062ec96efd13b67e7d301b2974f228d (MD5) / Made available in DSpace on 2015-01-15T17:19:40Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO_CaracterizaçãoAvaliaçãoAtividades.pdf: 30857020 bytes, checksum: c062ec96efd13b67e7d301b2974f228d (MD5) Previous issue date: 2008 / Neste trabalho foi avaliada a participação de ecto-nucleotidases, especialmente da família ENTPDase, na infecção in vitro pelo Trypanosoma cruzi. Foi demonstrado que diferentes cepas/clone apresentam atividade ecto-nucleotídásica diversa, porém, as formas tripomastigotas mantém maior hidrólise de ATP. Adicionalmente, utilizando a cepa Y, que apresentou a maior polaridade entre hidrólise de ATP e ADP, definimos uma cinética de atividade ecto-nucleotidásica sobre nucleotídeos de adenina durante a manutenção do ciclo celular (passagens) em células VERO. Nas passagens celulares as formas tripomastigotas apresentaram as maiores atividades ecto-ATPásicas e uma tendência à diminuição da relação de hidrólise ATP/ADP com o aumento do número de passagens. Na terceira passagem poucos parasitos foram capazes de internalizar, originando parasitos de P4, com perfil de hidrólise similar aos parasitos das passagens anteriores. A maioria dos parasitos que não internalizaram se diferenciaram em formas arredondadas do tipo amastigotas e apresentaram uma reduzida razão de hidrólise ATP/ADP, semelhante aos amastigotas derivados de tripomastigotas de P1 e P3. Estes dados sugerem que a diminuição da relação ATPase/ADPase seja um fator que de algum modo impede a internalização dos parasitos, induzindo à sua diferenciação e diminuição da infectividade. O uso dos inibidores de apirases como, Suramina, ARL67156 e GdCl3 levou ao bloqueio parcial da atividade ecto-ATPásica e ecto-ADPásica, nos parasitos vivos e na NTPDase-I recombinante purificada, e foram capazes de inibir a infecção em células VERO até o máximo de 78%. A infectividade in vitro também foi inibida pelo tratamento com antisoro anti-NTPDase-I, entretanto, este não se mostrou capaz de bloquear significativamente a hidrólise de ATP e ADP, sugerindo que esta proteína possa ter outras funções que afetam a infectividade além da regulação da concentração de nucleotídeos extracelulares, como, por exemplo, participação na adesão celular. Nossos dados, de maneira geral, indicam a participação das E-NTPDases e da NTPDase-I no processo infectivo e sugerem fortemente que o bloqueio da sinalização dependente destes parece ser realmente um bom alvo para a quimioterapia e possivelmente para imunização. Assim, a inibição do metabolismo extracelular de nucleotídeos de adenina surge agora efetivamente como um novo alvo para o bloqueio da infecção pelo T. cruzi. ______________________________________________________________________________________________ / ABSTRACT: In this work we evaluated the role of ecto-nucleotidases (E-NTPDases) in VERO cells Trypanosoma cruzi infection. It was demonstrated that different strains/clone of T. cruzi shows diverse ecto-nucleotidase activities, although all infective forms trypomastigotes presented higher levels of ATP hydrolysis. In addition, using Y strain, that presented highest polarity in ATP x ADP hydrolysis we performed a continuous in vitro infection of T. cruzi in VERO cells culture and evaluated the ectonucleotidase activities using adenine nucleotides. The results showed clearly that ATP/ADP ratio decreases with increase of the cellular passages. In the 3ª to 4ª passage parasites could not penetrate in VERO cells and differentiated to amastigote-like. Analysis of ecto-nucleotidase activities from infective P4 parasites showed higher ATP hydrolysis and ATPase/ADPase ratio. On the other hand the P4 amastigote-like parasites showed low levels of ATPase activity and lower ATPase/ADPase ratio. These data suggested that lower ATPase/ADPase ratio could be related with the decreasing in infectivity and induction of amastigote-like differentiation. Using apyrase inhibitors (Suramin, GdCl3, ARL67156) we observed significant levels of inhibition of ecto-apyrase activities in live trypomastigotes and in the recombinant purified T. cruzi NTPDase-I. The VERO cells infection using these parasites leaded to the block of in vitro infection achieving the maximum inhibition of 78% with 0.1 mM of Suramin. VERO cells infection were inhibited to when trypomastigotes were treated with anti-apyrase anti-serum (T. cruzi anti NTPDase-I), but this antiserum was not able to inhibit the T. cruzi ecto-apyrase and NTPDase-I activities. These data suggested that the NTPDase-I could have any other function that modulates the penetration of parasites in the host cells, maybe a role in adhesion events. Our data strongly supports the effective participation of E-NTPDases and the NTPDase-I in the T. cruzi in vitro infective processes. Additionally the partial blockage of this enzyme and related signalizations could really be a new good target to chemotherapy and immunization of Chagas Disease. Finishing, the inhibition of extra cellular adenine metabolism is now reveled as a new target to block T. cruzi infection.

Orientadores : Luis Bahamondes, Anibal Faundes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-07-18T20:17:18Z (GMT). No. of bitstreams: 1 Hardy_DanielGustavoFaundes_M.pdf: 1217623 bytes, checksum: e4c51c5b5e91f3268c4fcd0503d092d4 (MD5) Previous issue date: 1993 / Resumo: Um dos primeiros passos da Fertilização In Vitro (FIV) é o hiperestímulo ovariano para desenvolvimento folicular. A decisão sobre a escolha de um dos diversos protocolos é difícil, porque os resultados apresentados na literatura são controversos. Considerando obrigação da Universidade avaliar os procedimentos propedêuticos e terapêuticos realizados em suas dependências, foi natural incluir uma análise do custo/benefício no programa de FIV. Para isto foi desenvolvido um estudo descritivo, retrospectivo e comparativo da efetividade e relação custo/benefício de dois protocolos de desenvolvimento folicular, utilizados no Setor de Esterilidade do Departamento de Tocoginecologia da Universidade Estadual de Campinas (DTG/UNICAMP). O primeiro (protocolo 1) utilizou citrato de clomifeno, Gonadotrofina de Mulher Menopausada (hMG) e Gonadotrofina Coriônica Humana (hCG) e o segundo (protocolo 2) usou análogo de Hormônio Liberador de Gonadotrofinas (aGnRH), hMG e hCG. Para esta avaliação utilizaram-se como indicadores o nú-mero de folículos maiores ou iguais a 15mm, oócitos recuperados, embriões obtidos, embriôes transferidos e ciclos com transferência. Para a relação custo/benefício utilizou-se o custo dos medicamentos e três hipóteses para o valor estimado das ecografias, dosagens hormonais, coleta de oócitos, laboratório de FIV e transferência de embriões: 500, 2000 e 5000 dólares americanos (US$). O protocolo 2 foi mais eficaz na obtenção de todos os indicadores por ciclo e teve um custo médio menor para os indicadores avaliados quando considerado o valor dos procedimentos. Com a hipótese de US$ 500 para estes procedimentos, os ciclos com transferência tiveram um custo médio menor no protocolo 1. Porém, este teve uma média de embriões transferidos de 1,5 por ciclo, enquanto que no protocolo 2 a média foi de 3,9. visto que um maior número de embriões transferidos aumenta até mais de três vezes a probabilidade de gravidez, concluimos que o protocolo 2 apresentou uma relação custo/beneficio melhor que o protocolo 1. / Abstract: In vitro Fertilization (IVF) is a modern technique used for The treatment of infertile couples. Ovarian follicle hyperstimulation, which can be achieved by different protocols, is one of the steps in this technique. Which protocol to use is a difficult decision because the results published on these protocols are controversial. It is considered an obligation of the University to evaluate the different propedeutic and therapeutic procedures used in its facilities and it was natural to do so with the IVF program, including acostjeffective analysis. Adescriptive, retrospective and comparative study was developed to compare effectiveness and costjeffectiveness of two ovulation induction protocols, used in the IVF cases treated at the Infertility Clinic of the Department of Obstetrics and Gynecology of the State University of Campinas, in the period of May 1991 through April 1993. Protocol 1 used Clomiphene citrate (CC), Human Menopausal Gonadotropin (hMG) and Human Chorionic Gonadotropin (hCG) 'and protocol 2 used Gonadotropin Releasing Hormone analogue (aGnRH), hMG and hCG. For the evaluations we used as indicators follicles measuring 15mm or more, oocytes recovered, embryos obtained, embryos transferred and cycles with embryo transfere The effectiveness was evaluated by the mean frequency that these indicators presented in each protocol per cycle. The cost-effective relationship was initially evaluated using only the cost of the drugs, later adding to the initial numbers one of three hypothetical values for the additional costs, 500, 2,000 and 5,000 American dollars (US$). These costs were related to the sum of the individual cost of the ultrasound examination, hormonal dosage, oocyte retrieval, IVF laboratory and embryo transfere The study groups were similar regarding the age of the women and their partners, time of infertility, type of infertility, and statistically different in that tubal factor was more frequent in protocol 2 and male factor in protocol 1. The male factor is considered important for the fertilization rate and was similar for both protocols. Protocol 2 showed higher efficacy for alI the indicators by cycle. For the initial evaluation, using only the drugs cost, protocol 1 presented a lower mean cost for alI the indicators, but protocols 2 presented a lower mean cost for the same indicators when the additional cost was added to the evaluation. Using the hypothetical value of US$ 500 for the additional costs, cycles with embryo transfer presented a lower mean cost in protocol 1. On the other hand, the number of transferred embryos was 1.5 and 3.9 for protocol 1 and 2 respecti vely. As a greater number of embryos per transfer enhances the probability of pregnancy, we concluded that protocol 2 presented a better costjeffective rate than protocol 1. / Mestrado / Mestre em Ciências Médicas

No description available.

Thèse d'exercice : Médecine : Nancy 1 : 2009. / Titre provenant de l'écran-titre.

10 ABSTRACT The subject of this study was to evaluate the efect of abiotc elicitor on rutn producton in callus and suspension cultures of buckwheat. The cultvar of buckwheat used for this research was Fagopyrum esculentum Moench var. Bambi, cultvated in Murashige and Skoog nutrient medium with the additon of growth regulator 2,4-dichlorfenoxyacetc acid (2,4-D) in concentraton of 1 mg/l. The elicitor used in this study was a soluton of methylviologen, 1 ml of it was added to the cultures in three diferent concentratons: c1 = 100.0 mg/100 ml, c2 = 10.0 mg/100 ml and c3 = 1.0 mg/100 ml. The elicitor was afectng the cultures for 6, 12, 24, 48, 72 or 168 hours. Afer the defned period of tme, cultures were collected, dried out and stored for further analysis of rutn content. To control samples (without elicitor treatment) 1 ml of ethanol 96% was added and they were collected afer 6, 24, 72 or 168 hours. Releasing of rutn into the nutrient medium was also investgated. Rutn content in each sample of cultures and in each sample of nutrient medium was later determined by HPLC. Any signifcant increase in the producton of rutn was not observed in this study. The maximum amount of rutn detected was 0.1 mg/g DW, thus the lowest quantty detectable, and was found in suspension cultures in three cases, afer the additon of...