125 resultados para Fiji disease virus


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The aim of this study was to evaluate the importance of vaccination against Newcastle Disease (ND) in lovebirds (Agapornis roseicollis) and to investigate the state of carrier of the virus (NDV) in this species. There were used 48 lovebirds, distributed at random into 4 experimental groups: GI (Ulster 2C strain), Gil (B1 strain), Gill (LaSota strain) and GIV (non-vaccinated group). At 12 months of age, all groups were challenged with a pathogenic virus (NDV) suspension (ElD50 = 1081510.1 mL) and a group of Specific-Pathogen-Free (SPF) chicks were used as control of the virus. Cloaca) swabs from each bird were collected after 9, 14 and 21 days post-challenge for detection of genome viral excretion by Reverse Transcription Polymerase Chain Reaction RT-PCR. Lovebirds of GI, Gil and Gill did not demonstrate any signs of ND. They were refractory to the clinical disease. In lovebirds from the control group, NDV genome was detected 9 and 21 days after challenge. Therefore it was demonstrated the state of carrier of NDV by lovebirds. In birds from the vaccinated groups, genome viral excretion was not detected by RT-PCR. It was also demonstrated the importance of the vaccination in the suppression of the state of virus carrier of ND in lovebirds.

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A 30-basepair (bp) deletion in the Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) gene has been reported in nasopharyngeal carcinoma and EBV-associated malignant lymphomas. Prior studies have found the deletion in about 10% to 28% of cases of Hodgkin's disease (HD), particularly in cases with aggressive histology. We studied the prevalence of 30-bp LMP1 gene deletion in EBV-positive HD in the United States (US) (12 cases) and Brazil (26 cases) with comparison to reactive lymphoid tissues (21 cases) and HD without EBV-positive Reed-Sternberg cells (15 cases). We studied the status of the LMP1 gene by Southern blot hybridization of polymerase chain reaction (PCR) products obtained after amplification with primers spanning the site of the deletion. We also performed EBV typing, EBER1 in situ hybridization, and LMP1 protein immunohistochemistry. EBV was detected in 12/26 (46%) cases of HD from the US and 26/27 (96%) cases of Brazilian HD. The 30-bp LMP1 gene deletion was observed in 4/12 (33%) cases of EBV-positive HD from US, and 12/26 (46%) cases of Brazilian EBV-positive HD, including 3 cases of type B EBV, as compared with 12/21 (57%) reactive lymphoid tissues and 9/15 (60%) cases of EBV-negative HD. US and Brazilian HD showed a higher prevalence of the 30-bp LMP1 gene deletion, compared with studies of others. The unexpected finding of high incidence of 30-bp deletion in LMP1 gene in reactive lymphoid tissue and HD without EBV-positive Reed-Sternberg cells suggests that this deletion may not be relevant to HD pathogenesis in most cases. Copyright (C) 1997 by W.B. Saunders Company.

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We analyzed clinicopathologic data, immunophenotype, and Epstein-Barr virus (EBV) status in 96 cases of Hodgkin disease (HD) in juveniles (younger than 20 years) and adults (20 years or older) from 2 distinctive states in Brazil. We studied 34 juvenile (group 1) and 16 adult (group 2) cases from Ceara and 31 juvenile (group 3) and 15 adult (group 4) cases from São Paulo. Ceara has a socioeconomic profile similar to a developing country; São Paulo is in better economic condition. Mixed cellularity (MC) was the major histologic subtype among groups 1 (22 [65%]), 3 (21 [68%]), and 4 (7 [47%]); nodular sclerosis (NS) was more frequent in group 2 (8 [50%]). EBV infection was observed in 61 cases (64%), including the following (among others): group 1, MC, 22 (65%) and NS, 4 (12%); group 2, NS, 3 (19%) and MC, 2 (12%); group 3, MC, 16 (52%) and NS, 1 (3%); and group 4, MC, 7 (47%). There was predominance of EBV+ HD cases in group 1 compared with group 3. HD in Brazilian patients is highly associated with EBV infection, but geographic differences reflect histologic subtypes and age distribution.

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

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Hepatitis C virus (HCV) infection represents an important public health problem worldwide. Reduction of HCV morbidity and mortality is a current challenge owned to several viral and host factors. Virus molecular evolution plays an important role in HCV transmission, disease progression and therapy outcome. The high degree of genetic heterogeneity characteristic of HCV is a key element for the rapid adaptation of the intrahost viral population to different selection pressures (e.g., host immune responses and antiviral therapy). HCV molecular evolution is shaped by different mechanisms including a high mutation rate, genetic bottlenecks, genetic drift, recombination, temporal variations and compartmentalization. These evolutionary processes constantly rearrange the composition of the HCV intrahost population in a staging manner. Remarkable advances in the understanding of the molecular mechanism controlling HCV replication have facilitated the development of a plethora of direct-acting antiviral agents against HCV. As a result, superior sustained viral responses have been attained. The rapidly evolving field of anti-HCV therapy is expected to broad its landscape even further with newer, more potent antivirals, bringing us one step closer to the interferon-free era. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

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

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The thermostability (TS) and efficacy offered by live vaccines against Newcastle disease strains B 1, La Sota, VG-GA and Ulster, produced or imported by four Brazilian laboratories, were evaluated during their validity period. Kinetic profiles were obtained from samples conserved in refrigerators during 0, 4, 8, 12, 16, 20 and 24 months after their manufacturing. The statistical analysis of the vaccine titre effect obtained by the fresh air (FA) method showed that the vaccine profiles were parallel and coincident, presenting a significant descending trend. The vaccine titres and efficiency proofs at the end of the validity period were above the level of legislation requirements and showed an average loss in titre of 0.40 and 0.66 log(10), within the first and second validity years, respectively. The titre obtained by TS, within the month after manufacturing, had no significant difference from the titre obtained by FA within 24 months after manufacturing, being their pairs of observations positively correlated (r = 0,49, p = 0.0003), showing that the TS method, which anticipates the vaccines' performance at the end of the validity period, can substitute the FA method 24 months after manufacturing. (C) 2009 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A total of 120 Pekin ducks were distributed at random into four experimental groups, vaccinated or not against Newcastle disease (ND): G1 (Ulster 2C strain), G2 (B1 strain), G3 (LaSota strain), and G4 (nonvaccinated group). At 60 days of age, all groups were challenged with a pathogenic ND virus (NDV) suspension, and a group of specific pathogen free (SPF) chicks (G5) was also inoculated. Cloacal and tracheal swabs from all birds were collected after six, 14, 20, and 30 days post-challenge for virus isolation. NDV was isolated in 100% of SPF chicks. Pekin ducks from all groups, vaccinated or not, did not show any ND clinical signs, demonstrating that these birds are not susceptible to ND clinical disease. In the control group (G4), the virus was isolated 20 to 30 days after challenge, suggesting their possible NDV carrier state. In the vaccinated groups, no virus was isolated. This demonstrates that vaccination of white Pekin ducks against NDV is important to reduce NDV shedding in the field.

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Lettuce mosaic virus (LMV) causes an economically important seedborne and aphid-transmitted disease of lettuce and ornamental crops worldwide. The genetic diversity among 73 LMV isolates was examined based on a 216-nucleotide sequence at the variable region encoding the NIb-coat protein junction, Three clusters of LMV isolates were distinguished: LMV-Yar, LMV-Greck, and LMV-RoW. In the latter cluster, two subgroups of isolates, LMV-Common and LMV-Most, accounted for a large proportion of the LMV isolates analyzed. These two subgroups included the seedborne isolates, consistent with this property contributing a selective advantage and resulting in widespread distribution. In addition to being seedborne, LMV-Most isolates overcome the two resistance genes commonly used in lettuce, mol(1) and mol(2), and thus represent a potential threat to lettuce cultivation. The complete sequence of an LMV-Most isolate (LMV-AF199) was determined, allowing a better definition of the genetic relationships among LMV-Most, LMV-Common, and an additional isolate of the LMV-RoW cluster.

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Chronic hepatitis C virus (HCV) infection is a worldwide health problem that may evolve to cirrhosis and hepatocellular carcinoma. Incompletely understood immune system mechanisms have been associated with impaired viral clearance. The nonclassical class I human leukocyte antigen G (HLA-G) molecule may downregulate immune system cell functions exhibiting well-recognized tolerogenic properties. HCV genotype was analyzed in chronic HCV-infected patients. Because HLA-G expression may be induced by certain viruses, we evaluated the presence of HLA-G in the liver microenvironment obtained from 89 biopsies of patients harboring chronic HCV infection and stratified according to clinical and histopathological features. Overall, data indicated that HCV genotype 1 was predominant, especially subgenotype 1a, with a prevalence of 87%. HLA-G expression was observed in 45(51%) liver specimens, and it was more frequent in milder stages of chronic hepatitis (67.4%) than in moderate (27.8%; p = 0.009) and severe (36.0%; p = 0.021) stages of the disease. Altogether, these results suggest that the expression of HLA-G in the context of HCV is a complex process modulated by many factors, which may contribute to an immunologic environment favoring viral persistence. However, because the milder forms predominantly expressed HLA-G, a protective role of this molecule may not be excluded. (C) 2012 American Society for Histocompatibility and Immunogenetics. Published by Elsevier B.V. All rights reserved.

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Recent advances have accelerated the development of biosensors for the analysis of specific gene sequences. In this kind of biosensor, a DNA probe is immobilized on a transducer and the hybridization with the target DNA is monitored by suitable methodology. In the present work, the streptavidin (STA) was encapsulated in thin films siloxane-poly(propylene oxide) hybrids prepared by sol-gel method and deposited on the graphite electrode surface by dip-coating process. Biotinylated 18-mer probes were immobilized through STA and a novel amperometric DNA biosensor for the detection and genotyping of the hepatitis C virus (genotypes 1, 2A/C, 2B and 3) is described. The HCV RNA from serum was submitted to reverse transcriptase-linked polymerase chain reaction (RT-PCR) and biotin-labeled cDNA was obtained. Thus, the cDNA was hybridized to the target-specific oligonucleotide probe immobilized on the graphite electrode surface and following the avidin-peroxidase conjugate was added. The enzymatic response was investigated by constant potential amperometry at -0.45 V versus Ag/AgCl using H2O2 and KI solutions. HCV RNA negative and positive controls and positive samples of sera patients were analyzed and the results were compared to commercial kit. The proposed methodology appeared to be suitable and convenient tool for streptavidin immobilization and diagnose of HCV disease. (c) 2006 Elsevier B.V. All rights reserved.

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Several yeast species of Candida genus can colonize the skin as well as the mucous membrane of the vagina and the digestive tract for short or long periods. Depending on the host's immunological state and the yeast's virulence, colonization can become an infection, invading the colonized tissues and also disseminating. AIDS is characterized by the host's intensive and progressive immunodepression which manifests as diverse symptoms, mainly lesions in the mouth. Oral candidiasis is the most prevalent opportunistic infection in individuals infected with human immunodeficiency virus (HIV) and is an important indicator of the disease progress and the immunosuppression increase. The factors involved in the equilibrium between Candida spp. and HIV-infected subjects are sometimes contradictory and were evaluated in the present study specially for colonization.

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We examined the types of Epstein-Barr virus-associated nuclear antigen-1 (EBNA-1) gene carboxy (C)-terminal mutations occurring in Hodgkin's disease (HD) and reactive tissues from two different geographic regions. Previously reported EBNA-1 C-terminal region amino acid sequence variants, based on the amino acid at codon 487, include Prototype (P)-ala, which is found in the B95.8-derived prototype virus, P-thr, Variant (V)-leu, V-val, and V-pro. Using polymerase chain reaction (PCR) to amplify portions of the EBNA-1 gene, followed by DNA sequencing, we found a single EBNA-1 gene sequence variant in each tissue, whether reactive or neoplastic and whether from Brazil or the United States. Variant EBNA-1 gene sequences were more common in both neoplastic and non-neoplastic tissues from different geographic areas than the so-called prototype sequence. In the 17 Brazilian HD cases, 4 cases had P-thr variants and 13 had V-leu variants. In the six reactive tissues from Brazil, one had a P-ala variant, two had P-thr variants, and three had V-leu variants. In the 12 American HD cases, 2 had P-ala variants, 6 had P-thr variants, and 4 had V-leu variants. The 11 American reactive tissues included 2 P ala variants, 5 P-thr variants, and 4 V-leu variants. In both countries, there were similar variant EBNA-1 sequences present in normal tissues and HD cases. Compared with the P ala and P-thr cases, the V-leu cases were more likely to have the 30-bp latent membrane protein 1 (LMP1) gene deletion (P = 0.0075). In addition, cases of HD with the V-leu were statistically associated with a substitution of asparagine for glutamine at codon 322 of the C-terminal portion of the LMP1 gene. Our results suggest that any variation in EBNA-1 gene sequence is caused by a polymorphism present in pre-existing viral strains in the underlying population, and not a mutation occurring during oncogenesis. (C) 1999 by the American Society of Hematology.