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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.
1

Avalia??o dos efeitos t?xicos in vitro e in vivo do extrato hidroetan?lico dos frutos de Genipa americana L. (Rubiaceae) em camundongos Swiss

Assis, Cinthya Saraiva de 27 October 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-23T20:55:01Z No. of bitstreams: 1 CinthyaSaraivaDeAssis_DISSERT.pdf: 1209351 bytes, checksum: 5bb50037084ea9c40b94cff6abdaf523 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-28T17:58:44Z (GMT) No. of bitstreams: 1 CinthyaSaraivaDeAssis_DISSERT.pdf: 1209351 bytes, checksum: 5bb50037084ea9c40b94cff6abdaf523 (MD5) / Made available in DSpace on 2016-06-28T17:58:44Z (GMT). No. of bitstreams: 1 CinthyaSaraivaDeAssis_DISSERT.pdf: 1209351 bytes, checksum: 5bb50037084ea9c40b94cff6abdaf523 (MD5) Previous issue date: 2015-10-27 / O uso terap?utico de plantas medicinais tem contribu?do desde a antiguidade de forma ben?fica para a sa?de. No entanto, muitas esp?cies carecem de evid?ncias cient?ficas que forne?am embasamento para a sua utiliza??o na pr?tica terap?utica. Neste contexto, encontra-se a esp?cie Genipa americana L. (Rubiaceae), conhecida popularmente como jenipapo e utilizada como antissifil?tica, antiulcerosa e anti-hemorr?gica, contra hematomas, como t?nico, afrodis?aco, etc. Visto que, essa esp?cie carece de estudos toxicol?gicos, o objetivo deste trabalho foi avaliar a toxicidade in vivo (toxicidade aguda e subcr?nica) e in vitro (citotoxicidade) do extrato dos frutos da G. americana. O extrato hidroetan?lico dos frutos de G. americana foi preparado por macera??o. Foi realizada uma an?lise fitoqu?mica preliminar para avaliar a presen?a de metab?litos secund?rios no extrato. No estudo da citotoxicidade do extrato (0,1; 1,0; 10; 100 e 1000 ?g/100?L) foram utilizadas linhagens de c?lulas normais (3T3) e tumorais (786-0, HepG2 e B16), analisados pelo ensaio do MTT. Para a avalia??o da toxicidade aguda (dose ?nica de 2000 mg/Kg) e subcr?nica (100, 500 e 1000 mg/Kg por 30 dias) foram utilizados camundongos Swiss de ambos os sexos. Ao final dos experimentos, amostras de sangue e ?rg?os foram coletados para an?lise. Os dados entre os grupos foram comparados pelo test T ou por ANOVA com p?s-teste de Dunnett com n?vel de signific?ncia de 5%. O estudo fitoqu?mico do extrato indicou principalmente a presen?a de irid?ides. Os ensaios de citotoxicidade apresentaram resultados de at? 70% de inibi??o celular frente ? linhagem de B16, na dose de 1000 ?g/100?L, e at? 29% frente ? linhagem 786-0, na dose de 10 ?g/100?L. O extrato n?o promoveu morte nas c?lulas 3T3 e HepG2. Durante as avalia??es in vivo, n?o houve mortes de animais. A an?lise das amostras de sangue revelou que os animais submetidos ? avalia??o da toxicidade aguda apresentaram leves altera??es hep?ticas, e que os animais submetidos ? avalia??o da toxicidade subcr?nica apresentaram altera??es no peso relativo do rim esquerdo e na concentra??o plasm?tica de ur?ia. N?o foram observadas diferen?as entre grupos testes e controles na avalia??o histopatol?gica dos ?rg?os coletados. Apesar das altera??es encontradas nos ensaios de toxicidade in vivo, segundo os crit?rios descritos pelos Guias OECD, sugere-se que o extrato hidroetan?lico dos frutos da G. americana seja classificado como de baixa toxicidade. A citotoxicidade do extrato sugere que omesmo possui potencial contra as linhagens de melanoma (B16) e carcinoma renal (786-0). / The therapeutic use of medicinal plants has contributed since antiquity in a beneficial way for health. However, many species lacks of scientific evidence which provide basis for their use in therapeutic practice. In this context is the Genipa americana L. species (Rubiaceae), popularly known as jenipapo and used to treat syfilis, ulcer and hemorrhagic disturbs. It's also used against bruising, as tonic and as aphrodisiac. Due this species lacks toxicological studies, the aim of this study was to evaluate the toxicity in vivo (acute and sub-chronic toxicity) and in vitro (cytotoxicity) of the hydroethanolic extract from G. americana fruits. The hydroethanolic extract of G. americana fruits was prepared by maceration. A preliminary phytochemical analysis was performed to assess the presence of secondary metabolites in the extract. The cytotoxicity study of the extract (0.1, 1.0, 10, 100 and 1000 mg / 100 ul) were performed against normal cells (3T3) and tumor (786-0, HepG2 and B16), analyzed by the MTT assay. To evaluate the acute (single dose of 2000 mg / Kg) and subchronic (100, 500 and 1000 mg / kg for 30 days) toxicity Swiss mice of both sexes were used. At the end of the experiment, blood samples and organs were collected for analysis. Data between groups were compared by t test or ANOVA with Dunnett's post-test with 5% significance level. The phytochemical study of the extracts mainly indicated the presence of iridoids. Results for cytotoxicity tests showed up to 70% inhibition of B16 cell line at a dose of 1000 mg / 100 ul, and up to 29% inhibition of 786-0 at a dose of 10 ug / 100 ul. The extract did not cause death in 3T3 and HepG2 cells. During the in vivo assays, there were no animal deaths. Analysis of blood samples revealed that the animals submitted to the evaluation of acute toxicity had changes in AST and ALT, and that the animals evaluated for subchronic toxicity showed changes in the relative wet weight of the kidney and plasma urea concentration. No differences were observed between groups on histopathological evaluation of the collected organs. Despite the changes found in the in vivo toxicity tests, using the criteria described by the OECD Guidelines, it is suggested that the hydroethanolic extract of the fruits of the G. americana is classified as low toxicity. The cytotoxicity of the extract suggests that they have potential against melanoma cell lines (B16).
2

Electoral campaigning in Latin America's new democracies: The Southern Cone

Espindola, Roberto January 2007 (has links)
No / This book examines how political communication and the mass media have played a central role in the consolidation of emerging democracies around the world. Covering a broad range of political and cultural contexts, including Eastern and Southern Europe, Latin America, Asia and Africa, this new volume investigates the problems and conflicts arising in the process of establishing an independent media and competitive politics in post-autocratic societies. Considering the changing dynamic in the relationship between political actors, the media and their audience, the authors of this volume address the following issues: Changing journalistic role perceptions and journalistic quality The reasons and consequences of persisting instrumentalization of the media by political actors The role of the media in election campaigns The way in which the citizens interpret political messages and the extent to which the media influence political attitudes and electoral behaviour The role of the Internet in building a democratic public sphere.
3

High resolution sedimentological studies of lacustrine series, search for annual climatic proxies and interhemispheric comparison (examples of Lake Baikal, Siberia, 50 °N and Lake District, Chile, 40°S)/Etude sédimentologique à haute résolution de séries lacustres. Recherche de traceurs paléoclimatiques annuels et comparaison des réponses de lhémisphère Nord (Lac Baïkal, Sibérie) et de lhémisphère Sud (Lake District, Chili).

Boës, Xavier 02 December 2005 (has links)
Lobjectif de cette thèse est la reconstitution des changements climatiques quaternaires à partir de critères sédimentologiques en milieu lacustre. Il sagit entre autre dutiliser les sédiments saisonniers comme un outil de datation précis pour calibrer les reconstitutions paléoclimatiques. Cette démarche permet de mieux comprendre lorigine et/ou la propagation dévénements chauds ou froids générés soit dans lhémisphère Nord, soit dans lhémisphère Sud. Le Lac Baïkal (Sibérie) et le Lac Puyehue (Sud du Chili) contribuent à établir des nouvelles connexions climatiques. Un volet important de la thèse concerne le développement dune méthode nouvelle pour détecter les sédiments laminés saisonniers dans les carottages. La méthode consiste à imprégner les sédiments argileux avec des polymères après avoir préalablement lyophilisé le matériel. Ce travail permet de montrer : (i) que la résolution des reconstitutions paléoclimatiques réalisées à partir des sédiments du Lac Baïkal peut être augmentée, à condition de calibrer le signal sédimentaire ainsi que la chronologie du 14C ; (ii) quil est possible de reconstituer lévolution des précipitations et des réponses de type El Niño à partir des sédiments lacustres du Sud du Chili ; (iii) que la chronologie des événements climatiques de la transition Pléistocène/Holocène est plus complexe, et les épisodes chauds/froids plus nombreux que précédemment décrits ; (iv) que les archives lacustres permettent de compléter les connexions climatiques entre les deux hémisphères.

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