Navegando por Assunto "Plasmodium gallinaceum"

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Alterações hematológicas, bioquímicas e histopatológicas no modelo de malária aviária Gallus gallus por Plasmodium gallinaceum: papel do óxido nítrico
(Universidade Federal do Pará, 2011-07-29) MACCHI, Barbarella de Matos; DAMATTA, Renato Augusto; http://lattes.cnpq.br/6212140983414786; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978
Malaria causes major losses to human populations in the world. Experimental models are needed for a better understanding of the pathological mechanisms of the diseases and the development of new treatments. Chickens infected with Plasmodium gallinaceum constitute an adequate malaria model due to the phylogenetic proximity of this parasite to human Plasmodium as well as similarities in disease manifestation, as cerebral malaria. The aim of the present study was to investigate the role of nitric oxide in avian malaria development in chickens experimentally infected with P. gallinaceum, treated or not with aminoguanidine (AG - nitric oxide synthase inhibitor). Survival, classical hematology, serum biochemistry and pathology was assayed during the development of the disease. The greatest survival was observed in animals treated with AG that also presented higher parasitemia. Decrease in hematological parameters and Mean Corspucular Volume of erythrocytes increase was showed, indicating bone marrow response to anemia. Lymphopenia and thrombocytopenia were detected in infected animals, but not at the same proportion in treated animals. Monocytes, lymphocytes and heterophils showed an increase in size and changes that indicated activation. Thrombocytes were also higher with the infection and with atypical morphology. Treated animals showed fewer lesions in histological sections of brain, liver and spleen, and NO production decreased, principally during high parasitemia, compared to untreated animals. These results characterize the participation of the chemistry mediator nitric oxide in the pathogenesis of malaria in the avian model.
Acesso aberto (Open Access)
Papel do óxido nítrico na infecção malárica por P. gallinaceum
(Universidade Federal do Pará, 2013-10-08) OLIVEIRA, Karla Caroline Marques de; MACCHI, Barbarella de Matos; http://lattes.cnpq.br/5330351659478942; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978
Malaria is a severe infectious disease caused by parasites of the genus Plasmodium that infect different types of vertebrate’s hosts and is responsible for a huge number of deaths. The severe Malaria can lead to death and involves different pathophysiological signs as well as anemia and inflammation. Experimental models are necessary to improve the knowledge about mechanisms involved at the pathogenesis of the disease and the developing new protocols of treatment. Chickens infected with P. gallinaceum are a good model of malaria due to phylogenetic relatedness with human Plasmodium and because both species presents common clinical signs as cerebral malaria. The Nitric Oxide (NO) is an important effector molecule, but little is known about their role in malaria on chickens, meanly due to the lack of specific markers to evidence the NO production in this model. It is known that chickens infected with P. gallinaceum has a high mortality and causes an overproduction of nitrite by macrophages. The animals, when treated with aminoguanidine (AG), an inhibitor of inducible oxide nitric synthase (iNOS), showed a higher level of parasitemia. However, the rate of survivor was superior, beyond the clinical manifestations, as milder anemia. It is necessary to achieve a better comprehension about physiological aspects of avian malaria with the inhibition of NO’s production by the AG. In the context , the present study aims to investigate NOS activity and the role of NO during the avian malaria infection, with in vivo models, using P. gallinaceum as pathological agent , and in vitro with chicken’s macrophage of HD11 strain. This research will give a better understanding of avian malaria in chickens, including cerebral, and the involvement of nitrergic system in infected chickens.