Navegando por Autor "CASSEB, Livia Medeiros Neves"

Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Comparação das técnicas de ELISA indireto e Imunofluorescência indireta na detecção de anticorpos anti-Neospora caninum em búfalas (Bubalus bubalis)
(2013-04) SILVA, Sandro Patroca da; MOTA, Rinaldo Aparecido; FARIA, Eduardo Bento de; CASSEB, Alexandre do Rosário; CASSEB, Livia Medeiros Neves; DIAS, Hilma Lúcia Tavares
To compare two serologic tests for detection of antibodies against Neospora caninum in sera from buffaloes, samples were collected from 288 buffaloes of 2 to 10 years of age. To identify the presence of IgG, anti-N. caninum was used for the indirect immunofluorescence assay (IFAT), with title 200 as the cutoff, and for the immunoenzymatic test (indirect ELISA), considering as positive samples with ratio S/P >0.5. There were 153 (53.12%) animals positive for N. caninum by IFAT, whilst 50 (17.36%) animals were reactive in ELISA. The presence of antibodies anti-N. caninum demonstrates that the parasite is circulating among buffaloes raised in Pará State, Brazil. ELISA and IFAT tests could be used to diagnose immunoglobulins against this agent. However there was a weak correlation (Kappa = 0.36) between both tests, considering the IFAT as the gold standard.
Acesso aberto (Open Access)
Estudo epidemiológico da raiva, caracterização antigênica de cepas do vírus da raiva isoladas na Amazônia brasileira
(Universidade Federal do Pará, 2009-10-27) CASSEB, Livia Medeiros Neves; ROSA, Elizabeth Salbé Travasos da; http://lattes.cnpq.br/2209576799096027; VASCONCELOS, Pedro Fernando da Costa; http://lattes.cnpq.br/0973550817356564
Aiming to evaluate the epidemiology of rabies, new diagnostic procedures – antigenic and genetic characterization - were included in this study to investigate the epidemiologic profile of animal rabies in the Brazilian Amazon region, between January 2000 and July 2009. A careful revision of information of Central Nervous System (CNS) samples received and examined at Rabies Laboratory of Instituto Evandro Chagas was performed. A total of 265 rabies virus strains isolated from CNS samples of humans (33) and domestic/sylvatic animals (232) were antigenically characterized by indirect immunofluorescent assay (IFA) using a panel of eight monoclonal antibodies against the rabies virus nucleoprotein produces by the CDC; moreover, from 21 of them the nucleoprotein (gene N) was partially characterized by nucleotide sequencing followed by phylogenetic analyzes. Obtained sequences were compared internally and with other rabies virus sequences from Brazil and other American countries, using the Bayesian and maximum likelihood methods. It was observed a lower transmission of rabies virus in urban areas; the detection of the rural cycle of rabies in almost all Amazonian states; the occurrence of aerial rabies cycle in Pará and Amapá states; identification of rabies virus variant 2 (AgV2) among domestic dogs and cats as the main viral transmission mechanism; detection of circulating antigenic variants AgV3, AgV4 and “Eptesicus” variant in sylvan animals; and finally, reduction of dog-to-man transmission of rabies virus which was replaced by an increasing of bat-to-man transmission cycle, especially in Pará state. In conclusion, the association of antigenic and molecular techniques resulted in a better understanding of rabies molecular epidemiology in the Amazon region.
Acesso aberto (Open Access)
Imunopatologia experimental do vírus da raiva, com as variantes antigênicas 2 e 3
(Universidade Federal do Pará, 2015-06-02) CASSEB, Livia Medeiros Neves; VASCONCELOS, Pedro Fernando da Costa; http://lattes.cnpq.br/0973550817356564
The rabies is considered a zoonosis due have as host, reservoirs and transmitters the domestic or wild mammals. It´s characterized in acute disease caused by rabies virus (RABV) that affects the central nervous system (CNS) characterized by encephalitis with fatal prognosis in almost all cases, in any mammalian species. The aim of this study was to describe pathological findings and immunopathology of different strains of rabies virus in the tissues of the central nervous system, checking cellular and humoral immune response during experimental infection of Mus musculus mice. The animals were inoculated with two antigenic variants of RABV (VAg2 and VAg3), by different routes of infection, and a control group. The animals were observed for development of clinical signs and symptoms, collected and euthanized following a kinetic. The tissues were fixed in formaldehyde 10%, embedded in paraffin, stained with hematoxylin-eosin for histopathological analysis and with specific antibodies for immunohistochemical to characterize and quantify in situ distribution of the antigen and the inflammatory response. RABV antigens were found in the CNS in a diffuse way, but mainly in neurons. It was observed suppression of CD4+ lymphocytes, with increase of CD8+ lymphocytes. It was observed significant apoptosis with glial cell death and an increase of proinflammatory cytokines (TNF-α, IFN-γ, IL-6, IL-1β and IL-8), anti-inflammatory (TGF-β and IL-4) and iNOS in both antigenic variants of RABV, but without observation of a TH17 profile. The analyses enable the characterization of rabies as meningoencephalitis, since it affects the meningeal, perivascular and intraparenchymal microenvironments. And the inflammatory process was observed even in the presence of inclusion bodies, but with less intensity.
Acesso aberto (Open Access)
Prevalência de anticorpos contra arbovírus da família Bunyaviridae em búfalos de água
(Universidade Federal do Pará, 2015-09) CASSEB, Alexandre Rosário; SILVA, Sandro Patroca da; CASSEB, Livia Medeiros Neves; CHIANG, Jannifer Oliveira; MARTINS, Lívia Carício; VASCONCELOS, Pedro Fernando da Costa
The State of Pará comprises 26% of Brazilian Amazon region where a large diversity of arboviruses has been described. This study sought to assess the prevalence and distribution of haemagglutination-inhibition antibodies against antigens of nine different types of arbovirus of the Bunyaviridae family, where eight were Orthobunyavirus: Guaroa virus, Maguari virus, Tacaiuma virus, Utinga virus, Belem virus, Caraparu virus, Oropouche virus and Catu virus, and one Phlebovirus: Icoaraci virus in sera samples of water buffaloes in Pará State, Brazil. For all Arboviruses investigated there were antibodies, with the exception of Belem virus. Antibodies to Maguari viruswere more prevalent (7.33%). The water buffaloes of the present study showed variable levels of antibodies in monotypic and heterotypic reactions that may indicate there are movements from most bunyavirus studied in domestic buffaloes in the state of Pará, and the Maguari virus presents the largest circulation. Therefore, further studies are needed to investigate the role of water buffalo in the maintenance and dispersal of arboviruses, as well as whether these viruses can cause disease in that species, especially in cases of birth defects and abortions.