39 resultados para trade protection


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Culture filtrate proteins (CFP) are potential targets for tuberculosis vaccine development. We previously showed that despite the high level of gamma interferon (IFN-gamma) production elicited by homologous immunization with CFP plus CpG oligodeoxynucleotides (CFP/CpG), we did not observe protection when these mice were challenged with Mycobacterium tuberculosis. In order to use the IFN-gamma-inducing ability of CFP antigens, in this study we evaluated a prime-boost heterologous immunization based on CFP/CpG to boost Mycobacterium bovis BCG vaccination in order to find an immunization schedule that could induce protection. Heterologous BCG-CFP/CpG immunization provided significant protection against experimental tuberculosis, and this protection was sustained during the late phase of infection and was even better than that conferred by a single BCG immunization. The protection was associated with high levels of antigen-specific IFN-gamma and interleukin-17 (IL-17) and low IL-4 production. The deleterious role of IL-4 was confirmed when IL-4 knockout mice vaccinated with CFP/CpG showed consistent protection similar to that elicited by BCG-CFP/CpG heterologous immunization. These findings show that a single dose of CFP/CpG can represent a new strategy to boost the protection conferred by BCG vaccination. Moreover, different immunological parameters, such as IFN-gamma and IL-17 and tightly regulated IL-4 secretion, seem to contribute to the efficacy of this tuberculosis vaccine.

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CpG oligodeoxynucleotides (ODN) have shown to be potent immunoadjuvants for several pathogens, but there is limited information concerning their use in immunization protocols against neosporosis. This study aimed to evaluate the potential of CpG-ODN combined with Neosporar lysate antigen (NLA) or excreted-secreted antigen (NcESA) to induce protective immune response against Neospora caninum infection in mice. C57BL/6 mice were vaccinated subcutaneously three times at 2-week intervals with NLA, NLA+CpG, NcESA, NcESA+CpG, CpG (adjuvant control) or PBS (infection control). Serological assays showed an increased specific IgG2a response in animals immunized with either antigen plus adjuvant and elevated levels of the IgG1 isotype in those vaccinated with antigens alone. Splenocyte proliferative responses upon antigen stimulation were higher in groups immunized with NLA OF NcESA combined with CpG, showing increased IL-12 levels. Also, mice vaccinated with NcESA or NcESA+CpG demonstrated higher IFN-gamma levels and IFN-gamma/IL-10 ratio. After lethal challenge, mice immunized with NLA+CpG or NLA had lower Morbidity score and body weight changes in comparison to other groups, and animals did not succumb during acute infection. In contrast, NcESA+CpG or NcESA groups exhibited the highest morbidity scores, body weight impairment and mortality rates, associated with greatest brain parasite burden and inflammation. In conclusion, CpG-ODN was able to induce a Th1-type humoral immune response with predominant IgG2a levels for either NLA or NcESA, but resulting in an effective Th1-driven cellular immune response and total Protection only when combined with NLA. Vaccination with NcESA alone or combined with CpG resulted in a strong cellular immune response associated with high levels of IFN-gamma and inflammation, rendering mice more susceptible to parasite challenge. (C) 2009 Elsevier Ltd. All rights reserved.

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The present study aimed to experimentally evaluate the protection role of glycerin preserved bovine peritoneum (BP) against intestinal adhesions to a vascular graft. Experiments were performed on 24 adult rabbits, randomly dived into two groups. All animals were submitted to a vascular graft over the infra-renal aorta and vena cava. Group I (12 animals) was submitted to a BP patch on the retroperitoneal opening, between the vascular prosthetic graft and the intestinal loops. Group II (12 animals) had the retroperitoneal opening sutured. After 7, 14, 28 and 60 days, 3 animals of each group were randomly killed and the retro peritoneum, with or without the BP patch, was removed for histological analysis. The histological analysis showed that the BP stimulated a moderate to intense inflammatory reaction at the beginning of the experiments and on the 60-day evaluation, the inflammatory reaction was mild, limited to the BP border with its histological structure preserved. In conclusion, the BP is a safe and cheap interposition material to be used between vascular grafts and intestinal loops, presenting a protection role against adhesions between them.

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Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system that causes neurological disorders in young adults. Previous studies in various populations highlighted an association between the HLA-DRB1*1.5 allele and MS. This study investigated the association between HLA-DRB1*15 and other HLA-DRB1 alleles and MS in a Brazilian Caucasian population sample from Londrina, Southern Brazil. HLA-DRB1 alleles were analyzed by polymerase chain reaction with specific sequence oligonucleotide primers in 119 MS patients and in 305 healthy blood donors as a control. Among the MS patients, 89 (75.0%) presented with relapsing remitting MS, 24 (20.0%) with secondary progressive MS and 6 (5.0%) with primary progressive MS. The frequency of the HLA-DRB1*15 allele observed in the MS Brazilian patients was similar to findings reported in previous studies carried out in populations worldwide. However, the results showed a higher frequency of the HLA-DRB1*15 allele in the MS patients compared to the controls, with a relative frequency of 0.1050 (10.50%) and 0.0443 (4.4%), respectively (OR=2.53; 95% CI 1.43-4.46; p=0.0009). A protector allele was also detected. The frequency of the HLA-DRB1*11 allele was reduced in the MS patients compared to the controls, with a relative frequency of 0.1345 (13.4%) and 0.1869 (18.7%), respectively (OR=0.67; 95% CI 0.44-1.03; p=0.0692). The results demonstrated that the HLA-DRB1*15 allele in heterozygosity is positively associated with MS (p=0.0079), and may be considered a genetic marker of susceptibility to the disease. A negative association between the HLA-DRB1*11 allele in homozygosity and MS was also verified (p=0.0418); this allele may be considered a genetic marker of resistance to MS in the Brazilian population.

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P>The aim of this study was to evaluate the frequency of TNFa-e microsatellites and the promoter region (TNF-308 and TNF-238) in HIV/AIDS-infected patients presenting or not lipodystrophy syndrome (LS). The design is the genetic case-control association study. Microsatellite and the TNF promoter region polymorphisms were amplified by PCR and submitted to polyacrylamide gel electrophoresis. The genotypes and allele frequencies for 67 HIV-positive patients with lipodystrophy were compared with 50 HIV-positive patients with no evidence of lipodystrophy and with 131 healthy HIV-negative individuals. The presence of the TNFa5 allele could provide HIV/AIDS patients with protection against developing LS. The presence of TNF-308G allele, as well as of its homozygote TNF-308GG, were associated with susceptibility to developing LS. In addition, the presence of the haplotype TNFe3-d3-238G-308A-c1-a5-b7 suggests protection against developing that syndrome. This study highlights that polymorphic sites spanning the region nearby the TNF locus are associated with LS development in HIV/AIDS patients.

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Aminoglycoside antibiotics cause considerable toxicity to the inner ear. A progressive hearing loss at high frequencies resulted from the loss of hair cells in the base of the cochlea and a constant preoccupation with finding a treatment that protects against their toxic effects. A self-protection phenomenon to high ototoxic doses of gentamicin is proposed in this paper. Thirty-eight adult guinea pigs with normal hearing were tested using Preyer`s reflex and the distortion product otoacoustic emission (DPOAE) test, and their cochleae were analyzed by scanning electron microscopy. To the four groups investigated, group I (control) and group II (low dose, 10 mg/kg/day for 30 days) showed a normal DPOEA and normal outer hair cells; group III (high dose, 160 mg/kg/day for 10 days) showed the absence of DPOEA and damage to the outer hair cells; and group IV (low dose, 10 mg/kg/day for 30 days followed by a high dose of 160 mg/kg/day for 10 days) showed a normal DPOEA and normal outer hair cells. These results demonstrate that there was a considerable self-protection phenomenon by gentamicin.

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The order Passeriformes comprises the largest number of families and species of birds of any avian order. Brazil is rich in passerine birds, which are a common victim of wildlife trafficking in Brazil. Annually, many birds die as a consequence of illegal trade. To investigate the occurrence of the principle diseases and to identify the main causes of death in smuggled passerine birds, the cause of death was evaluated in 360 passerine birds confiscated within the city of Sao Paulo, Brazil. Causes of death were determined by anatomopathologic and microbiologic studies. Infectious diseases were the cause of death of most birds, which corresponded to 78.6% of cases. The most common infectious diseases were poxvirus infection, aspergillosis, and coccidiosis. Although the etiologic agents of these diseases can coexist asymptomatically within hosts, once the host`s immunity is compromised, the pathogen multiplies quickly and causes disease. The results of this study may help to improve the care of passerine birds in captivity and increase the survival rate of confiscated birds. Results may also be useful for in situ conservation programs that investigate the reintroduction of confiscated species or captive birds.

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The purposes of this study were to model a vaccination regimen for Newcastle disease virus (NDV) in pigeons, and to evaluate the susceptibility and behavior of vaccinated birds against a highly pathogenic NDV Brazilian strain. Antibody response was assessed by means of hemagglutination inhibition test (HI), and viral genome excretion by means of RT-PCR. Vaccinal strains (La Sota and Ulster) induced high antibody titers without any adverse effects, both in inoculated and in sentinel birds. A viral strain pathogenic for chickens did not produce clinical signs of the disease in experimentally infected pigeons. Only 4 out of 10 vaccinated pigeons shed NDV genome, and just for two days. Results confirmed the high infectivity of the vaccinal strains used, as all nonvaccinated pigeons showed antibody titers as high as those of vaccinated birds.

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The presence of domestic animals in protected areas has been a growing world concern, including in the Brazilian Amazon. Introduced domestic carnivores can put the conservation of carnivores and other wild mammals at risk in protected areas. These risks can be associated with direct factors, such as the dogs` hunting habit, and indirect factors, such as the domestic carnivores` potential for transmitting infectious agents to wild populations. The objective of this study was to analyze the potential implications of humans and domestic animals staying in fragmented and altered areas such as the Wildlife Protection Areas (WPA) in the Tucuruf Lake Environmental Protection Area (Para, Brazil), created for the full protection of its fauna and flora. This evaluation was made through interviews conducted with riparian inhabitants living in the WPA and surrounding area, involving issues related to the presence of dogs (number of animals per domicile, birth rate, mortality rate, vaccination status, hunting habit) and wild carnivores (occurrence and location) in the study area. The results indicated risks mainly due to the presence of on average three dogs per domicile, as well as the high canine birth rate, their hunting habits, low vaccination rates and evidence of direct and indirect contact with the human, canine and wild carnivore populations. These factors represent risks to the health and conservation of Tucurui EPA wild carnivores since they provide favorable conditions for the transmission of pathogens from domestic fauna to wild fauna, as well as the risks brought about by hunting.