Controlling complexity: the clinical relevance of mouse complex genetics.

Experimental animal models are essential to obtain basic knowledge of the underlying biological mechanisms in human diseases. Here, we review major contributions to biomedical research and discoveries that were obtained in the mouse model by using forward genetics approaches and that provided key insights into the biology of human diseases and paved the way for the development of novel therapeutic approaches

Prevalência de Isospora em cães de diferentes áreas da cidade do Rio de Janeiro

Foi examinado um total de 222 cães, sendo que 197 eram cães de rua apreendidos nas áreas suburbanas e rurais do Rio de Janeiro e 25 eram animais de estimação, mantidos em residências (apartamentos) nas zonas Centro e Sul da cidade. Do total de 197 cães de rua, foram encontrados 49 (24,87%) parasitados por coccidios do gênero Isospora, sendo que 6 deles (3,04%) eram parasitados por I. canis e 43 (21,83%) por I. rivolta. Nos 43 casos de parasitismo por I. rivolta foi encontrada nas fezes uma alta percentagem de esporocistos livres com 4 esporozoitos (35 casos, representando 81,4%). As fezes foram coletadas diretamente do reto e a técnica empregada para o exame do material foi a centrífugo-flutuação em sulfato de zinco. Entre os 25 cães de estimação não foi encontrado nenhum caso de parasitismo por Isospora sp. Os valores médios para os diâmetros maior e menor das formas de Isospora sp. encontradas foram de 38,63&#956; x 31,93&#956;. para oocistos de I. canis; 23&#956; x 18,94&#956;. para oocistos de I. rivolta e, 19,94&#956; x 10,05&#956; para os esporocistos de I. rivolta, encontrados livres nas fezes. Não foi diagnosticado nenhum caso de I. bigemina. Entre todos os casos positivos foram encontrados apenas 3 casos de infecção maciça nos animais. Nos 3 casos, tratavam-se de animais jovens parasitados por I. rivolta. O teste estatístico de diferença de proporções demonstrou que o sexo e a idade dos animais não tiveram influência na maior ou menor percentagem de cães positivos para Isospora sp, na presente casuística.<br>A survey was carried out in order to determine the prevalence of coccidia of the genus Isospora in dogs in Rio de Janeiro. The collection of faecal samples was performed directly in the rectum. Stools were prepared for examination using the zinc sulphate centrifuge flotation technique. Out of 222 animais examined, 25 were pet dogs kept in apartments in the central and southem areas of the city. None of them was found to be infected by Isosipora sp. The remaining 197 dogs were strays, of which 49 (24,87%) were infected by coccidia of the genus Isospora; of these 6 (3,04%) were identified as I. canis and 43 (21,83%) as I. rivolta. No case of I. bigemina was detected. Among the I. rivolta cases, there was a high proportion of free sporocysts (35 cases, representing 81,4%). The average size of the largest and smallest diameters of the cysts found were 38,63&#956; 31,93&#956; for the oocysts of I. canis, and 23&#956; x 18,94&#956; for the oocysts of I. rivolta. Sporocysts of I. rivolta were found to measure an average 14,94&#956; x 10,05&#956;. Among all positive cases, three had massive infection, which were young dogs parasitized by I. rivolta. In the present study neither sex nor age were shown to have a statistical influence of the parasitism by Isospora sp

Trans-sialidase and sialidase activities discriminate between morphologically indistinguishable trypanosomatids.

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2014-09-09T17:58:05Z No. of bitstreams: 1 Medina-Acosta E Trans-sialidase....pdf: 806326 bytes, checksum: 6de64d4d093dee46c5513925f2f8d3e6 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2014-09-09T17:58:18Z (GMT) No. of bitstreams: 1 Medina-Acosta E Trans-sialidase....pdf: 806326 bytes, checksum: 6de64d4d093dee46c5513925f2f8d3e6 (MD5)Made available in DSpace on 2014-09-09T18:08:39Z (GMT). No. of bitstreams: 1 Medina-Acosta E Trans-sialidase....pdf: 806326 bytes, checksum: 6de64d4d093dee46c5513925f2f8d3e6 (MD5) Previous issue date: 1994New York University Medical Center. Michael Heidelberger Division of Immunology. New York, USAFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, BrasilNew York University Medical Center. Michael Heidelberger Division of Immunology. New York, USA / Universidade Federal da Bahia. Instituto de Ciências da Saúde. Salvador, BA, BrasilFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, BrasilNew York University Medical Center. Michael Heidelberger Division of Immunology. New York, USA / Universidade Federal da Bahia. Instituto de Ciências da Saúde. Salvador, BA, BrasilNew York University Medical Center. Michael Heidelberger Division of Immunology. New York, USA / Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, BrasilNew York University Medical Center. Michael Heidelberger Division of Immunology. New York, USAThe expression of trans-sialidase and sialidase activities in the kinetoplastid protozoa was explored as a potential marker to discriminate between the morphologically indistinguishable flagellates isolated from human, insects and vertebrate reservoir hosts. By virtue of the differences observed in the ratios of these enzyme activities, a collection of 52 species and strains comprising the major taxa of these parasites could be separated into four expression types. Type-I parasites express comparable levels of both trans-sialidase and sialidase activities (Endotrypanum species and Trypanosoma lewisi). Type-I1 parasites express predominantly trans-sialidase activity (Trypanosoma cruzi and Trypanosoma conorhini).Type-I11 parasites express sialidase activity exclusively (Trypanosoma rangeli and Trypanosoma leeuwenhoeki). Type-IV parasites do not express either activity (Leishmania species and Trypanoplasma borreli). The measurement of trans-sialidase and sialidase activities thus permits the differentiation of parasites frequently found in the same insect vectors that are difficult to distinguish, such as T. cruzi and 7: rangeli, or in the same sylvatic vertebrate and invertebrate hosts, such as Leishmania and Endotrypanum