Navegando por Palavras-chave "parasites"

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    Chronic hepatosplenic schistosomiasis mansoni: magnetic resonance imaging and magnetic resonance angiography findings
    (Taylor & Francis Ltd, 2007-03-01) Bezerra, A. S. A.; D'Ippolito, Giuseppe [UNIFESP]; Caldana, R. P.; Cecin, A. O.; Ahmed, M.; Szejnfeld, Jacob [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Beth Israel Deaconess Med Ctr
    Purpose: To evaluate the hepatosplenic manifestations and the portal venous system in patients with chronic infection by Schistosoma mansoni.Material and Methods: A cross-sectional observational study was performed in 28 patients with chronic hepatosplenic schistosomiasis submitted to magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the abdomen. Images were interpreted independently by two radiologists to determine the reproducibility of image interpretation and who evaluated the presence of morphological alterations in the liver and spleen, such as hepatosplenomegaly, hepatic fissure widening, periportal fibrosis, and the presence of siderotic nodules. Interobserver and intra-observer agreement were measured with the kappa and intraclass correlation tests. Evaluation of venous collateral pathways and portal and splenic veins was done in consensus by both examiners.Results: Observers identified enlargement of the left lobe (78.5-92.8%) and caudate-to-right-lobe ratio (78.5-92.8%), irregularity of hepatic contours (89.2-96.4%), fissure widening (89.2-100%), and splenic siderotic nodules (84.2%). Splenomegaly, heterogeneity of hepatic parenchyma, peripheral hepatic vessels, and periportal fibrosis were observed in 100% of patients. MRI findings presented almost perfect interobserver (kappa = 0.65-1) and intra-observer (kappa = 0.73-1 for observer 1, and kappa = 0.65-1 for observer 2) agreement for the variables analyzed. MRA showed the presence of collateral pathways in the majority of patients (71.4%) along with widening of portal and splenic veins.Conclusion: Using MRI, hepatosplenic alterations in schistosomiasis are characterized by heterogeneity of hepatic parenchyma, presence of peripheral perihepatic vessels, periportal fibrosis, splenomegaly, siderotic nodules, and the presence of venous collateral pathways.
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    Importance of CD8 T cell-mediated immune response during intracellular parasitic infections and its implications for the development of effective vaccines
    (Academia Brasileira de Ciências, 2003-12-01) Rodrigues, Mauricio Martins [UNIFESP]; Boscardin, Silvia Beatriz [UNIFESP]; Vasconcelos, Jose Ronnie Carvalho de [UNIFESP]; Hiyane, Meire Ioshie [UNIFESP]; Salay, Gerson [UNIFESP]; Soares, Irene S.; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Obligatory intracellular parasites such as Plasmodium sp, Trypanosoma cruzi, Toxoplasma gondii and Leishmania sp are responsible for the infection of hundreds of millions of individuals every year. These parasites can deliver antigens to the host cell cytoplasm that are presented through MHC class I molecules to protective CD8 T cells. The in vivo priming conditions of specific CD8 T cells during natural infection are largely unknown and remain as an area that has been poorly explored. The antiparasitic mechanisms mediated by CD8 T cells include both interferon-g-dependent and -independent pathways. The fact that CD8 T cells are potent inhibitors of parasitic development prompted many investigators to explore whether induction of these T cells can be a feasible strategy for the development of effective subunit vaccines against these parasitic diseases. Studies performed on experimental models supported the hypothesis that CD8 T cells induced by recombinant viral vectors or DNA vaccines could serve as the basis for human vaccination. Regimens of immunization consisting of two different vectors (heterologous prime-boost) are much more efficient in terms of expansion of protective CD8 T lymphocytes than immunization with a single vector. The results obtained using experimental models have led to clinical vaccination trials that are currently underway.
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    Mites in clinical stool specimens: potential misidentification as helminth eggs
    (Elsevier B.V., 2007-11-01) Werneck, Jessica Sanchez; Carniato, Telma; Gabriel, Alexandre; Tufik, Sergio [UNIFESP]; Andrade, Soraya Sgambatti; AFIP Med Lab; Universidade Federal de São Paulo (UNIFESP)
    We report the finding of unexpected microscopic oval structures in clinical stool samples processed by AFIP/Medicina Laboratorial, a laboratory performing routine clinical analysis in São Paulo, Brazil. Surprisingly, these objects were identified as mite eggs, sometimes accompanied by adult mites. Because misidentification of mite eggs as helminth ova may lead to erroneous treatment with far-reaching consequences, we sought to verify the frequency of adult mites and mite eggs among a number of processed stool specimens. Given their similarity to some helminth eggs, it is important that clinical laboratories recognize these structures, especially in geographic regions where intestinal parasitosis is prevalent. (C) 2007 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier B.V. Alt rights reserved.
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    Observations on non-random distribution of spores of Henneguya spp. (Cnidaria: Myxosporea: Myxobolidae) within plasmodia
    (Folia Parasitologica, 2017) Eiras, Jorge C.; Cruz, Manuel; Cruz, Cristina; Saraiva, Aurelia; Adriano, Edson A. [UNIFESP]; Szekely, Csaba; Molnar, Kalman
    Species of the cnidarian genus Henneguya Thelohan, 1892 (Myxosporea: Myxobolidae) are histozoic parasites commonly found in freshwater and, more rarely, in marine fish. The development of these parasites in fish tissues includes the formation of plasmodia within which occurs the sporogony originating spores with two caudal processes, which are usually randomly distributed within the plasmodia. In this report the authors present some cases of non-random distribution of the spores of six species of Henneguya within their plasmodia. Two different patterns of non-random distribution were found based on a literature survey. These patterns and their origin are discussed. Apparently this non-random distribution of the spores is due to both internal and external factors.