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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

Estudo sobre a participa??o de roedores na cadeia de transmiss?o de Leishmania infantum (Protozoa: Trypanosomatidae) no Rio Grande do Norte

Barbosa, Patr?cia Batista Barra Medeiros 11 July 2005 (has links)
Made available in DSpace on 2014-12-17T14:03:26Z (GMT). No. of bitstreams: 1 PatriciaBBMB.pdf: 749567 bytes, checksum: e355ba98f4fd47889fd16327a3ca1f09 (MD5) Previous issue date: 2005-07-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / American visceral leishmaniasis is a zoonosis caused by Leishmania infantum and transmitted by the bite of the sand flies Lutzomia longipalpis.The main domestic reservoir is the dog, while foxes and opposums are the known wild reservoirs. However, identification of natural infections with L. infantum in rodents appears for need of investigating the participation of these rodents how source of infection of the parasite. In the present work the Leishmania infantum infection was investigated in rodents captured in Rio Grande do Norte, aiming at to offer subsidies to the understanding of the epidemic chains of LVA in the State. Thirteen Galea spixii were distributed in four groups, being G1 the group control with four animals and the others, G2, G3 and G4, with three animals each. Those animals were intraperitoneally inoculated with 107 promastigotas of L. infantum and accompanied for, respectively, 30, 90 and 180 days. Weekly the animals were monitored as for the corporal weight and rectal temperature. At the end of each stipulated period the animals were killed. Blood were used for determination of the parameters biochemical and haematological, PCR, ELISA, microscopic examination and cultivation in NNN medium. Liver, spleen and lymph node were used in Giemsa-stained impression and cultivation in NNN medium. Liver and spleen fragments were still used in PCR and histopathological, respectively. At the same time 79 rodents of the species Rattus rattus, Bolomys lasiurus, Oligoryzomys nigripis, Oryzomys subflavus and Trichomys apereoides were captured in the Municipal districts of Brejinho, Campo Grande, Coronel Ezequiel, Passa e Fica and V?zea for identification of natural infection with L. infantum. Evidence of infection was checked by direct examination of Giemsa-stained impression of liver, spleen and blood and culture of these tissues in NNN medium. Antibodies were researched by ELISA. They were not found differences among the weigh corporal final, rectal temperature and biochemical and haematological parameters of the Galea spixii controls and infected. The rectal temperature of the animals varied from 36OC to 40OC. For the first time values of the haematocrit (33,6% to 42,8%), hemoglobin (10,2 to 14,5g/dl), erythrocyts number (4,67x106 to 6,90x106/mm3), total leukocytes (0,9x103 to 9,2x103/mm3), platelets (49x103 to 509x103/mm3) total proteins (1,56 to 6,06 g/dl), albumin (1,34 to 3,05 g/dl) and globulins (0,20 to 3,01 g/dl) of the Galea spixii were determined. The lymphocytes were the most abundant leucocytes. Infection for L. infantum was diagnosed in two animals euthanasied 180 days after the infection. In one of the animals was also identified antibodies anti-Leishmania. The parasite was not found in none of the five other species of rodents captured. Galea spixii are resistant to the infection for L. infantum and they are not good models for the study for visceral leishmaniose, although they can act as infection sources. More studies are necessary to determine the paper of the rodents in the epidemic chain of transmission of the visceral leishmaniose in the State of Rio Grande do Norte / A leishmaniose visceral americana ? uma zoonose causada pelo parasita Leishmania infantum e transmitida pela picada do fleb?tomo Lutzomya longipalpis. O c?o ? o principal reservat?rio dom?stico, enquanto que raposas e gamb?s s?o os reservat?rios silvestres conhecidos. No entanto, a identifica??o de infec??es naturais com L. infantum em roedores aponta para a necessidade de se investigar a participa??o destes animais como fonte de infec??o do parasita para os insetos vetores. No presente trabalho investigou-se a infec??o com parasita Leishmania infantum em roedores capturados no Rio Grande do Norte, objetivando oferecer subs?dios ? compreens?o das cadeias epidemiol?gicas da LVA no Estado. Treze pre?s da esp?cie Galea spixii foram distribu?dos em quatro grupos, sendo G1 o grupo controle com quatro animais e os demais, G2, G3 e G4, com tr?s animais cada. Esses animais foram inoculados por via intraperitonial com 107 promastigotas de L. infantum e acompanhados por, respectivamente, 30, 90 e 180 dias. Semanalmente os animais foram monitorados quanto ao peso corporal e temperatura retal. Ao final de cada per?odo estipulado os animais foram eutanasiados. O sangue colhido foi utilizado na determina??o dos par?metros bioqu?micos e hematol?gicos, PCR, ELISA, confec??o de esfrega?o sangu?neo e cultivo em meio NNN. Fragmentos de f?gado, ba?o e linfonodos foram utilizados para confec??o de l?minas por aposi??o e cultivo em meio NNN. Fragmentos de f?gado e ba?o foram ainda utilizados para realiza??o de PCR e histopatol?gico, respectivamente. Concomitantemente 79 roedores das esp?cies Rattus rattus,Bolomys lasiurus, Oligoryzomys nigripis, Oryzomys subflavus e Trichomys apereoides foram capturados nos Munic?pios de Brejinho, Campo Grande, Coronel Ezequiel, Passa e Fica e V?rzea para identifica??o de infec??o natural por L. infantum. O diagn?stico da infec??o nos animais foi realizado pelo exame direto das impress?es coradas com Giemsa e cultura em meio NNN de f?gado, ba?o e sangue. N?o foram encontradas diferen?as no o ganho de peso total, temperatura retal e par?metros bioqu?micos e hematol?gicos dos pre?s controles e infectados. A temperatura retal variou entre 36OC e 40OC. Pela primeira vez foram determinados os valores do hemat?crito (33,6% a 42,8%), hemoglobina (10,2 a 14,5g/dl), n?mero de eritr?citos (4,67x106 a 6,90x106/mm3), leuc?citos totais (0,9x103 a 9,2x103/mm3), plaquetas (49x103 a 509x103/mm3), prote?nas totais (1,56 a 6,06 g/dl), albumina (1,34 a 3,05 g/dl) e globulinas (0,20 a 3,01 g/dl) nesta esp?cie. Os linf?citos foram os leuc?citos mais abundantes. Infec??o por L. infantum foi diagnosticada em dois animais eutanasiados aos 180 dias, sendo que em um desses tamb?m foram identificados anticorpos contra o parasita. N?o foi observada positividade em nenhuma das cinco outras esp?cies de roedores capturadas. A esp?cie Galea spixii ? resistente ? infec??o por L. infantum e, portanto, n?o ? bom modelo para o estudo da leishmaniose visceral, embora possam atuar como fontes de infec??o. Mais estudos s?o necess?rios para que se possa determinar o papel dos roedores na cadeia epidemiol?gica da leishmaniose visceral no Estado do Rio Grande do Norte
2

Etude d'un clade de rétrotransposons Copia : les GalEa, au sein des génomes eucaryotes / Study of a clade of retrotransposon Copia : The GalEa, in eukaryotic genomes

Donnart, Tifenn 02 February 2015 (has links)
Les éléments transposables jouent un rôle majeur dans l’évolution des génomes eucaryotes. La connaissance de la distribution des éléments transposables entre différentes espèces au sein d’un même taxon est une condition essentielle pour étudier leur dynamique et mieux comprendre leur rôle dans l'évolution des espèces. Compte tenu de leur abondance, de leur diversité spécifique et de milieu de vie, les crustacés sont un excellent modèle pour étudier la génomique comparative des rétrotransposons. C’est notamment chez les Galathées qu’a été défini le clade GalEa des éléments de la superfamille des Copia. Nous avons étudié la distribution de deux superfamilles de rétrotransposons à LTR bien connus: les Gypsy et les Copia, au sein des crustacés. En combinant des PCRs avec amorces dégénérées et des analyses in silico, nous avons identifié 35 familles de rétrotransposons Copia et 46 familles de rétrotransposons Gypsy dans respectivement 15 et 18 espèces de crustacés (principalement des malacostracés : crabes, crevettes, krill...). Ces éléments présentent une distribution et une diversité différentes au sein des crustacés. Les éléments Gypsy apparaissent relativement fréquents et diversifiés dans toutes les espèces. A l’inverse, les éléments Copia semblent rares, donc difficilement détectables, et sont largement dominés par les éléments du clade GalEa. Ces résultats suggèrent deux stratégies différentes de dynamique pour les rétrotransposons Gypsy (théorie de la Reine Rouge) et les rétrotransposons GalEa (‘domino days spreading’ branching process). De plus, les éléments GalEa présentent un grand succès évolutif en étant largement distribués dans de nombreuses branches de métazoaires. Ils sont aussi présents chez quelques algues rouges et nous en avons également détecté chez des Fungi. Profitant des nombreuses données génomiques disponibles, nous avons donc étudié la distribution des éléments GalEa de Fungi, dans le but de comparer celle-ci aux résultats obtenus chez les crustacés. En fait, ils n’apparaissent qu’au sein d’un grand embranchement d’ascomycètes, les Pezizomycotina, et ils forment un groupe monophylétique au sein des GalEa. Enfin, chez les Fungi, les éléments GalEa ne sont pas majoritaire parmi les rétrotransposons Copia. Nous avons donc initié une nouvelle étude chez les mollusques, afin de définir si les résultats obtenus chez les crustacés sont une caractéristique des éléments GalEa, des malacostracés ou des métazoaires. / Transposable elements play a major role in the evolution of eukaryotic genomes. Knowing the distribution of transposable elements between different species within the same taxon is essential to study their dynamics and to better understand their role in the evolution of species. Given their abundance, species diversity and living environment, crustaceans are an excellent model for studying comparative genomics of retrotransposons. It is notably in the squat lobsters that the GalEa clade of Superfamily Copia was defined. We studied the distribution of two well-known LTR retrotransposons superfamilies: Gypsy and Copia, in crustaceans. By combining PCRs with degenerate primers and in silico analysis, we identified 35 families of Copia retrotransposons and 46 families of Gypsy retrotransposons in 15 and 18 species of crustaceans (mainly Malacostraca: crabs, shrimp, krill ...). These elements have different distribution and diversity in crustaceans. Gypsy elements appear relatively commonly and diverse in all species. Conversely, the Copia elements seem rare, and consequently more difficult to detect, and are largely dominated by the elements of the clade GalEa. These results suggest two different dynamic strategies for retrotransposons Gypsy (the Red Queen theory) and retrotransposons GalEa (‘domino days spreading’ branching process). In addition, GalEa elements present a great evolutionary success being widely distributed in many branches of metazoans. They are also present in certain red algae and we have also detected them in Fungi. Taking advantage of the large amount of available genomic data, we have studied the distribution of GalEa elements of Fungi, in order to compare it with the results obtained in crustaceans. In fact, they appear only in a large phylum of Ascomycetes, in Pezizomycotina, and they form a monophyletic group within the GalEa. Finally, in the Fungi, the GalEa elements are not majority among Copia retrotransposons. We have therefore initiated a new study in molluscs, to define if the results obtained in crustaceans are a feature of GalEa elements, Malacostraca or metazoans.

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