Navegando por Assunto "Picornaviridae"

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Acesso aberto (Open Access)
Estudo morfológico e imunológico da encefalite induzida pelo vírus juruaçá em modelo murino
(Universidade Federal do Pará, 2013-10-08) FERREIRA, Natalie Chaves; DINIZ JUNIOR, José Antônio Picanço; http://lattes.cnpq.br/1897655177251738
Many studies have been conducted to understand the neuropathogenesis of viral encephalitis from experimental work, however, no experimental studies have been devoted to understanding the neuropathogenesis of members of the Picornaviridae family isolated from bats in the Amazon region. The Juruaçá virus, one of these agents, partially characterized as a member of the Picornaviridae family by Araujo et al. (2006), caused lesions in the brain of neonatal mice with reactive gliosis presence, although not cause cytopathic effect (CPE) in primary cultures of central nervous system (CNS) cells, suggesting that this viral agent is responsible for the death of animals due to an intense immune response. The aim of this study was to investigate the immune response in the CNS and cellular changes caused by Juruaçá virus in newborn albino mice of strain BALB/c from histopathological analysis, microglial activation, and expression of cytokines, nitric oxide (NO) and reactive oxygen species (ROS). Thus, we performed sample processing for histopathology, immunosorbent assay, immunohistochemical and immunofluorescence assays, tests to quantify NO and superoxide radicals, and statistical analysis. Our results demonstrated that the Juruaçá virus induces lesions throughout the brain, with greater intensity in the cortical parenchyma. Immunohistochemical tests showed the presence of viral antigens and reactive microglias distributed throughout the brain and anterior spinal cord. Microglias with amoeboid shape, demonstrating intense activation, were observed in the cerebral cortex, olfactory bulb, anterior olfactory nucleus, midbrain and forebrain near the lateral ventricle. The production of anti-inflammatory cytokines (IL-10 and IL-4) decreased over time, whereas pro-inflammatory cytokines (IL -12, IL- 6, IL- 1β, TNF-α and IFN-γ) increased significantly from the 8th day. Assays for ROS detection showed great superoxide radicals production from the 4th day, as NO production was always lower in the infected animals. Probably, activation of glial cells, especially microglias, and subsequent production of proinflammatory cytokines and ROS promoted a devastating action on the cells of the CNS, which coincides with the intensification of clinical signs. In accordance with what has been explained above, became evident that our results indicate that the Juruaçá virus is responsible for a imprint inflammatory disease that leads to death 100% of infected neonates mice.
Acesso aberto (Open Access)
Pesquisa de enterovírus em casos de síndrome de meningite asséptica de Belém, PA
(Universidade Federal do Pará, 2005-10) LAMARÃO, Letícia Martins; GOMES, Maria de Lourdes Contente; FERREIRA, Lauze Lee Alves; PARACAMPOS, Cleide Mara Fonseca; ARAÚJO, Lia Crystina Bastos; CARNEIRO NETO, José Tavares; SANTANA, Marquete B.
With the objective of isolating and identifying enteroviral serotypes, which are the most frequent etiologic agents of aseptic meningitis syndrome, cerebrospinal fluid samples were studied from patients referred to the health unit in the City of Belém (State of Pará, Brazil), from March 2002 to March 2003. The samples were inoculated in RD and HEp-2 cells line, and the positive were identified by neutralization test or indirect immunofluorescence. Out of 249 samples, 33 (13.2%) were positive 57.6% (n = 19) in patients under 11 years of age (p <0.03) and predominantly (72.7%) in males (p <0.008). The serotypes isolated were: Echovirus 30 (n = 31), Coxsackievirus B5 (n = 1) and Echovirus 30 and 4. In conclusion, this type of study also serves to determine the national picture, which is still little defined, regarding the most prevalent viral agents in AMS cases.