Efeitos da deficiência de vitamina A na função pulmonar de crianças após infecção respiratória viral

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Produção e avaliação de nanoemulsão catiônica como possível vetor não-viral para pIRES2-EGFP

Gene therapy is based on the transfer of exogenous genetic material into cells or tissues in order to correct, supplement or silencing a particular gene. To achieve this goal, efficient vehicles, viral or non-viral, should be developed. The aim of this work was to produce and evaluate a nanoemulsion system as a possible carrier for no-viral gene therapy able to load a plasmid model (pIRES2-EGFP). The nanoemulsion was produced by the sonication method, after been choose in a pseudo-ternary phase diagram build with 5 % of Captex 355®, 1.2 % of Tween 80®, 0.8 % of Span 80®, 0.16% of stearylamine and water (to 100 %). Measurements of droplet size, polydispersity index (PI), zeta potential, pH and conductivity, were performed to characterize the system. Results showed droplets smaller than 200 nm (PI < 0.2) and zeta potential > 30 mV. The formulation pH was near to 7.0 and conductivity was that expected to oil in water systems (70 to 90 μS/s) A scale up study, the stability of the system and the best sterilization method were also evaluated. We found that the system may be scaled up considering the time of sonication according to the volume produced, filtration was the best sterilization process and nanoemulsions were stable by 180 days at 4 ºC. Once developed, the complexation efficiency of the plasmid (pDNA) by the system was tested by agarose gel electrophoresis retardation assay.. The complexation efficiency increases when stearylamine was incorporated into aqueous phase (from 46 to 115 ng/μL); regarding a contact period (nanoemulsion / pDNA) of at least 2 hours in an ice bath, for complete lipoplex formation. The nanoemulsion showed low toxicity in MRC-5 cells at the usual transfection concentration, 81.49 % of survival was found. So, it can be concluded that a nanoemulsion in which a plasmid model was loaded was achieved. However, further studies concerning transfectation efficiency should be performed to confirm the system as non-viral gene carrier

Detection of infectious bronchitis virus and specific anti-viral antibodies using a concanavalin A-Sandwich-ELISA

Concanavalin A-Sandwich ELISA (Con A-S-ELISA) was developed for the detection of infectious bronchitis virus (IBV) or chicken specific anti-viral antibodies. The antigen detection limit for the Con A-S-ELISA was 10(5,1) EID50/mL. Three homologous and four heterologous IBV strains were similarly detected. This assay was highly effective in detecting the virus after infected tissue homogenates were passed once in embryonated chicken eggs, showing a good agreement with virus isolation technique. The Con A-S-ELISA was also used to measure anti-IBV chicken antibodies and showed a high coefficient of correlation (r = 0.85) and an agreement of k = 0.80 with the commercially available Indirect-ELISA. The relative sensitivity and specificity between these two tests were, respectively, 92.86% and 95.65% with an accuracy of 93.39%. Thus, the Con A-S-ELISA proved to be able to detect alternatively homologous and heterologous IBV strains or specific chicken anti-IBV antibodies, using the Con A as capture reagent of this assay.

Comparação dos testes de virusneutralização contra os genótipos 1 e 2 do vírus da diarreia viral bovina (BVDV-1 e BVDV-2) em bovinos de rebanhos naturalmente infectados

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Adenosine deaminase activity as a biochemical marker of inflammatory response in goats infected by caprine arthritis-encephalitis virus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ocorrência de animais persistentemente infectados pelo vírus da diarréia viral bovina em rebanhos bovinos nos Estados de Minas Gerais e São Paulo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detecção de anticorpos contra o vírus da diarréia viral bovina no soro sangüíneo, no leite individual e no leite de conjunto em tanque de expansão de rebanhos não vacinados

Pela pesquisa de anticorpos contra o vírus da diarréia viral bovina (BVD), utilizando o teste de ELISA indireto, foi estudada a correlação existente entre a proporção de vacas lactantes e a presença de anticorpos no leite de conjunto do tanque de expansão. Para isso foram analisadas amostras de soro sangüíneo e de leite individual de 376 vacas lactantes não vacinadas, provenientes de 10 propriedades localizadas nas regiões Sul do Estado de Minas Gerais e Nordeste do Estado de São Paulo, assim como uma amostra do leite do tanque de expansão de cada rebanho. em todas as propriedades foram encontradas vacas reagentes no soro sangüíneo, cuja freqüência variou de 12,28 a 100,00%. Já a análise do leite individual não revelou animais reagentes em duas propriedades, e nas demais a freqüência variou de 5,26 a 70,83%. Foram detectados anticorpos no leite do tanque de expansão das propriedades cuja proporção de soros sangüíneos reagentes foi igual a ou maior que 82,86%, e cuja proporção de leites individuais reagentes foi igual a ou maior que 32,14%.

Ocorrência da diarréia viral bovina nas regiões sul do Estado de Minas Gerais e nordeste do Estado de São Paulo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental infection of Newcastle disease virus in pigeons (Columba livia): Humoral antibody response, contact transmission and viral genome shedding

The aim of this study was to evaluate the humoral antibody response, the genome viral excretion and the contact transmission of pathogenic chicken origin Newcastle disease virus (NDV) from experimentally infected pigeons (Columba livia) to in-contact pigeon. The antibody response to infection was assessed by the hemagglutination inhibition (HI) test and the genome viral excretion was detected by RT-PCR. Viral strain induced high antibody levels, both in inoculated and in sentinel birds. The pathogenic viral strain for chickens was unable to produce clinical signs of the disease in experimentally infected pigeons, although it induced the Immoral antibody response and produced NDV genome shedding. NDV genome was detected intermittently throughout the experimental period, from 5 days post-infection (dpi) to 24 dpi. Therefore, viral genome shedding occurred for 20 days. The viral genome was detected in all birds, between I I and 13 dpi. Furthermore, the high infectivity of the virus was confirmed, as all non-inoculated sentinel pigeons showed antibody levels as high as those of inoculated birds. (C) 2007 Elsevier B.V. All rights reserved.

Serological Evidence of Bovine Herpesvirus 5 (BoHV-5) in Cattle at the Colombia's Eastern Plains

Several diseases involve the nervous system of cattle, among which infections with Rabies Virus and Bovine Herpes Virus 5 (BoHV-5) are noteworthy. In order to detect seropositive animals to BoHV-5, 156 Brahman-Zebu bovines blood samples from Colombia's eastern plains were analyzed through seroneutralization assay; the area has a history of animals dying with nervous symptoms and which rule out the disease of rabies. All animals were over one year old and randomly selected from two different herds reporting no vaccination for infectious bovine rhinotracheitis in a period exceeding one year. Results indicated seropositivity for BoHV-5 in 91 cases (58.4%), of which 88 were also seropositive for bovine herpes virus 1 (BoHV-1), while 41 were seronegative for both agents. 22/64 seronegative cases for BoHV-5 were seropositive for BoHV-1 and 2/43 seronegative cases for BoHV-1 were seropositive for BoHV-5, and consequently, these animals could be only infected by encephalitis herpes virus. With these initial findings, emphasis its placed on the need establish the true impact of the disease in Colombia and proposes the epidemiological surveillance of cattle in the region studied in order to establish mechanisms for control of viral infection.

Algoritmo memético com infecção viral: uma aplicação ao problema do caixeiro viajante assimétrico

The Combinatorial Optimization is a basic area to companies who look for competitive advantages in the diverse productive sectors and the Assimetric Travelling Salesman Problem, which one classifies as one of the most important problems of this area, for being a problem of the NP-hard class and for possessing diverse practical applications, has increased interest of researchers in the development of metaheuristics each more efficient to assist in its resolution, as it is the case of Memetic Algorithms, which is a evolutionary algorithms that it is used of the genetic operation in combination with a local search procedure. This work explores the technique of Viral Infection in one Memetic Algorithms where the infection substitutes the mutation operator for obtaining a fast evolution or extinguishing of species (KANOH et al, 1996) providing a form of acceleration and improvement of the solution . For this it developed four variants of Viral Infection applied in the Memetic Algorithms for resolution of the Assimetric Travelling Salesman Problem where the agent and the virus pass for a symbiosis process which favored the attainment of a hybrid evolutionary algorithms and computational viable

Molecular mapping of the viral determinants of systemic wilting induced by a Lettuce mosaic virus (LMV) isolate in some lettuce cultivars

The isolate AF199 of Lettuce mosaic virus (LMV, genus Potyvirus) causes local lesions followed by systemic wilting and plant death in the lettuce cultivars Ithaca and Vanguard 75. Analysis of the phenotype of virus chimeras revealed that a region within the PI protein coding region (nucleotides 112-386 in the viral genome) and/or another one within the CI protein coding region (nucleoticles 5496-5855) are sufficient together to cause the lethal wilting in Ithaca, but not in Vanguard 75. This indicates that the determinants of this particular symptom are different in these two lettuce cultivars. The wilting phenotype was not directly correlated with differences in the deduced amino acid sequence of these two regions. Furthermore, transient expression of the LMV-AF 199 proteins, separately or in combination, did not induce local necrosis or any other visible reaction in the plants. Together, these results Suggest that the systemic wilting reaction might be Clue to RNA rather than protein sequences. (c) 2004 Elsevier B.V. All rights reserved.

First Identification of Culex flavivirus (Flaviviridae) in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estratégias de Produção in vitro de Bioinseticida Viral: influências do Isolado, da Cinética e do Modo de operação

Societal concerns about environmental sustainability has lead to the development of ecologically-friendly alternatives to chemical insecticides for crop protection. One such alternative is biological pest control. In particular, baculoviruses are well suited as insect biopesticides due to their narrow host specificity and relative ease of propagation. In Brazil, the baculovirus Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) is the main biological control agent employed for the soybean pest, Anticarsia gemmatalis. This baculovirus biopesticide is currently produced using caterpillars, but increasing market demand for the product has encouraged the development of an in vitro manufacturing process, which can be scaled up to much higher virus productivities. In this study, three wild-type AgMNPV isolates (AgMNPV-2D, AgMNPV-MP2 and AgMNPV-MP5) and a recombinant form (vAgEGT-LacZ) were characterised in terms of occlusion body (OB) production and infection kinetics, to enable future optimisation of the in vitro production process. These viruses were propagated using a Spodoptera frugiperda (IPLB-SF21) insect cell line grown in shaker-flask batch cultures. Among the virus isolates tested, AgMNPV-MP5 was found to be the best producer, yielding (5.3±0.85)x108 OB/mL after 8 days post infection. The characterisation of vAgEGT-LacZ propagation in suspension cell cultures has not been previously reported in the literature; hence it became the main focus for this thesis. In particular, it was carried out a study on the effect of the multiplicity of infection (MOI) on OB production. Five successive batches were performed getting a final production (8.9±1.42)x1014 occlusion bodies, considering that production is related for a bioreactor with final volume of 10m3. A low MOI associated with a fed-batch process for vAgEGT-LacZ production was found to support a 3-fold higher OB yield when compared to the default batch process (1.8x107 and 5.3x107 OB/mL, respectively). This yield is competitive with regards to the production process.