Potential Flood-Related Daily Urban Mobility problems in Rio de Janeiro (Brazil)

Unplanned urban expansion merges mobility and flood problems, creating a new challenge to be faced by big cities stakeholders. It is known that transport and mobility activities cause impacts on urban environment. Nevertheless, natural phenomena may also cause impacts on urban mobility. The estimate of the flow of people among traffic regions, together with hydrographic information, support the computation of people affected during flood episodes. Rio de Janeiro State registers the highest urbanization rate in Brazil. Based on origin and destination data, a Google Maps based script was developed to get each travel path. All regions intercepted by local rivers were considered to compute the amount of people directly affected in their mobility. The total number of indirectly affected people is calculated through the routes that intersect each river. The results suggest that Pavuna and Guandu Mirim Rivers should be highly considered by stakeholders to mitigate flood effects on urban mobility in the MRRJ.A estimativa de pessoas que passam por zonas de tráfego, juntamente com informações hidrográficas, serve como base para o estudo de relações entre mobilidade e inundações. A partir de dados de origem e destino, foi desenvolvido um script baseado no Google Maps para obter os caminhos feitos em cada viagem. Para computar a quantidade de pessoas diretamente afetadas na mobilidade, foram selecionadas todas as regiões interceptadas pelos rios. O número total de pessoas indiretamente afetadas foi calculado através da análise de rotas que interceptam os rios, e, com base nesta informação, foram estimadas quantas pessoas têm sua mobilidade potencialmente afetada por inundações em cada rio. Os resultados sugerem que os rios Pavuna e Guandu Mirim devem receber atenção prioritária por tomadores de decisão para mitigar os efeitos de inundações sobre a mobilidade urbana na região metropolitana do Rio de Janeiro

Quantificação e seqüênciamento do gene da transcriptase reversa em gatos naturalmente infectados com vírus da imunodeficiência felina tratado com AZT

O Vírus da Imunodeficiência Felina (FIV) é um lentivírus que causa uma síndrome de imunodeficiência em gatos domésticos. O FIV tem sido particularmente utilizado em estudos de resistência viral aos análogos de nucleosídeos devido a Transcriptase Reversa (TR) apresentar propriedades físicas, catalíticas e sensibilidade às drogas semelhantes à TR do HIV. Os objetivos desse trabalho foram tratar com AZT gatos naturalmente infectados com o FIV, fazer o monitoramento da carga viral e DNA proviral por PCR em tempo real e monitoramento genético por seqüenciamento. Dos 12 animais infectados, 6 receberam o AZT na dose de 10mg/kg/dia e 6 receberam placebo. Durante 96 dias de tratamento, o plasma e sangue destes animais foram analisado com relação à carga viral e concentração relativa de DNA proviral utilizando-se a técnica de quantificação relativa por PCR em tempo real com SYBR Green, desenvolvida por nossa equipe. Além disso, foi realizado o sequenciamento genético da região que codifica a TR de 3 dos animais. Foi realizada com sucesso a padronização da PCR em tempo real para quantificação relativa do FIV. Não houve diferença estatisticamente significativa da carga viral ou do DNA proviral entre os grupos tratado e controle. O seqüenciamento genético revelou a presença de lisina na posição 41 do sítio ativo da TR. A presença deste aminoácido confere até 4 vezes menor sensibilidade ao AZT em mutantes do HIV. Por possuir alta estabilidade genética, supomos que os vírus dos demais animais não sequenciados possuem também a 41-lisina A presença da 41-lisina pode ser uma das possíveis explicações para a falha do tratamento com AZT. Outra hipótese é a de que a dose fornecida não foi adequada.Feline Immunodeficiency Virus (FIV) is a lentivirus which causes a progressive disruption of the host's immune functions. FIV has been particularly used as a model for studies in retroviral resistance to nucleoside analogs because its similarities in physical properties, catalytic and sensitivity in comparison with HIV/RT. The aims of this work were to treat cats naturally infected with FIV, quantify viral load and proviral DNA by real time quantitative PCR with SYBR Green and analyze the viral nucleotide sequence. From 12 animals naturally infected, 6 received AZT at a dose of 10mg/kg/day and 6 received placebo. During 96 days of treatment, viral load and concentration of proviral DNA were measured by relative quantitative real time PCR developed by our staff. The nucleotide sequence of the RT encoding region was also achieved for 3 animals. The real time PCR relative quantification was successfully standardized for FIV. There was no significant statistical difference between treated and control groups. The nucleotide sequence revealed a lysine at position 41 on the enzyme active site. This lysine confers 4-fold decreased sensitivity to AZT in HIV RT-mutants. FIV subtype B has high genetic stability and we purposed that the other virus not sequenced have the same amino acid and hypothesized that this mutations can be one of the reasons determining the failure of the treatment. The other hypothesis is that the dose was not adequate.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Clonagem e expressão de fragmentos de anticorpos (scFV) contra o vírus da leucemia felina (FeLV) por phage display

O vírus da leucemia felina (FeLV) é um retrovírus que infecta principalmente gatos jovens. Em aglomerados de animais, a infecção pelo FeLV é a que mais contribui para a mortalidade. O emprego de técnicas moleculares de detecção viral permitiu avanços no que diz respeito à caracterização da patogenia e resposta à vacinação. Baseando-se nesses novos resultados, o diagnóstico da infecção deve ser realizado, primeiramente, com um teste de triagem de detecção da proteína de capsídeo p27, e, posteriormente, a confirmação com teste de detecção de DNA proviral. O diagnóstico e separação de animais positivos constituem o mecanismo primordial para conter a disseminação do FeLV. Diante disso, é de grande importância facilitar o acesso e baratear o diagnóstico. A construção de um teste de detecção da p27 baseia-se na produção de anticorpos monoclonais. A técnica de hibridomas é menos prática e demanda mais tempo para a obtenção de resultados satisfatórios quando comparada à técnica de Phage Display. Esta está em franco desenvolvimento e tem ganhado grande aplicabilidade na medicina veterinária. Empregamos o sistema de Phage Display desenvolvido por Krebber e colaboradores (1997). Primeiramente, foi construída uma biblioteca imune em camundongos, em seguida, foram amplificadas as regiões gênicas variáveis das cadeias leve (VL) e pesada (VH) e ligadas com um Linker de (Gli4Ser)4. Esses fragmentos geneticamente construídos derivados de anticorpos são denominados de single chain variable fragment ou scFv. Os scFvs foram fusionados à pIII e apresentados na superfície de fagos filamentos. Após três ciclos de seleção e enriquecimento contra a p27 recombinante produzida no laboratório, onze scFvs foram selecionados e caracterizados com relação à constituição nucleotídica e de aminoácidos. Dentre eles, o scFv 9 e scFv 70 foram escolhidos...The feline leukemia virus (FeLV) is a retrovirus that infects primarily young cats. In animal clusters, FeLV infection is the largest contributor to mortality. The use of molecular techniques for viral detection has allowed advances with regard to the pathogenicity and response to vaccination. Based on these new findings, the diagnosis of infection should be performed first, with a screening test for detection of p27 capsid protein, and subsequently confirmed with testing for proviral DNA. The diagnosis and segregation of positive animals is the primary mechanism to contain the FeLV spread. Therefore, it is of great importance to facilitate access and lower the diagnosis. The construction of a test for p27 detection relies on monoclonal antibody development. The hybridoma technique is less practical and more time consuming to obtain satisfactory results when compared to Phage Display technology. The latter has been improved rapidly and has gained wide application in veterinary medicine. We employed the Phage Display system developed by Krebber et al. (1997). First, an immune library was built in mice and the variable region of the light and the heavy genes were amplified and connected by a linker of (Gly4Ser)4. This genetically engineered antibody fragments are called single chain variable fragments or scFv. The scFvs were fused to the pIII protein and displayed on the surface of filamentous phages. After three rounds of selection and enrichment against recombinant p27 (produced in the laboratory), eleven scFvs were selected and characterized with respect to nucleotide and aminoacid composition. Among them, scFv 9 and scFv 70 were chosen for subcloning and expression in prokaryotic system for production of heterologous proteins. The scFvs in soluble forms were evaluated for their binding capacity to p27. The scFvs will be employed to the development of an immunoassay for FeLV detect... (Complete abstract click electronic access below)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Virus-host interaction in feline immunodeficiency virus (FIV) infection

Feline immunodeficiency virus (FIV) infection has been the focus of several studies because this virus exhibits genetic and pathogenic characteristics that are similar to those of the human immunodeficiency virus (HIV). FIV causes acquired immunodeficiency syndrome (AIDS) in cats, nevertheless, a large fraction of infected cats remain asymptomatic throughout life despite of persistent chronic infection. This slow disease progression may be due to the presence of factors that are involved in the natural resistance to infection and the immune response that is mounted by the animals, as well as due to the adaptation of the virus to the host. Therefore, the study of virus-host interaction is essential to the understanding of the different patterns of disease course and the virus persistence in the host, and to help with the development of effective vaccines and perhaps the cure of FIV and HIV infections. © 2013 Elsevier Ltd. All rights reserved

Cynomolgus monkeys (Macaca fascicularis) experimentally and naturally infected with hepatitis E virus: The bone marrow as a possible new viral target.

Hepatitis E virus (HEV) transmission through infected blood and blood products has already been described. However, little is known about the bone marrow (BM) as source of HEV infection. Our study aimed to investigate the presence of HEV antigen (Ag) and histological changes in BM of cynomolgus monkeys (Macaca fascicularis) experimentally and naturally infected with HEV. Four cynomolgus monkeys with acute, and two with chronic hepatitis E ─ after immunosuppressive therapy with tacrolimus ─ were compared with one colony-bred animal naturally infected. Both, natural and experimental infections were characterized by anti-HEV IgG seroconversion detected by ELISA, and viral RNA isolation confirmed by RT-qPCR and qualitative nested RT-PCR. BM biopsies were collected from all animals, submitted to histology and indirect immunofluorescence techniques and observed, respectively, by light and confocal microscopy. The HEV Ag-fluorescent-labeled cells were detected from BM biopsies obtained from three monkeys with acute and one with chronic hepatitis E, and also from the naturally infected monkey. In the experimentally infected animals with acute hepatitis, HEV Ag detection occurred at 160 days post-infection, even after viral clearance in serum, feces, and liver. Double-stranded RNA, a replicative marker, was detected in BM cells from both acute and chronically infected animals. Major histological findings included vacuolization in mononuclear and endosteal cells, an absence of organized inflammatory infiltrates, and also some fields suggesting displasic focal BM disease. These findings support the hypothesis of BM cells as secondary target sites of HEV persistence. Further experimental studies should be carried out to confirm the assumption of HEV transmission through BM transplantation

Serological Evidence of Hepatitis E Virus Infection in Brazilian Equines

Hepatitis E virus (HEV) infection has been demonstrated in various animal species; those recognized as potential zoonotic reservoirs pose a considerable risk to public health. In Brazil, HEV-3 is the only genotype identified in humans and swine nationwide, in a colony-breeding cynomolgus monkey and, recently, in bovines and capybara. There is no information regarding HEV exposure in the equine population in Brazil. This study aimed to investigate anti-HEV antibodies and viral RNA in serum samples from horses slaughtered for meat export and those bred for sport/reproduction purposes. We used a commercially available ELISA kit modified to detect species-specific anti-HEV, using an anti-horse IgG-peroxidase conjugate and evaluating different cutoff formulas and assay precision. Serum samples (n = 257) were tested for anti-HEV IgG and HEV RNA by nested RT-PCR and RT-qPCR. The overall anti-HEV seroprevalence was 26.5% (68/257) without the detection of HEV RNA. Most municipalities (53.3%) and farms (58.8%) had positive horses. Animals slaughtered for human consumption had higher risk of HEV exposure (45.5%) than those bred for sports or reproduction (6.4%) (p < 0.0001). The statistical analysis revealed sex and breeding system as possible risk-associated factors. The first serological evidence of HEV circulation in Brazilian equines reinforces the need for the surveillance of HEV host expansion in a one-health approach

Vírus da leucemia felina: análise da classificação da infecção, das técnicas de diagnóstico e da eficácia da vacinação com o emprego de técnicas sensíveis de detecção viral Feline leukemia virus: infection outcomes, diagnostic techniques and vaccine efficacy analysis employing sensitive techniques of virus detection

O Vírus da leucemia felina (FeLV) pertence à família Retroviridae, gênero Gammaretrovirus. Diferentemente de outras retroviroses, uma parcela dos gatos jovens e adultos exposta ao FeLV não apresenta antigenemia/viremia, de acordo com as técnicas convencionais de detecção viral, como isolamento em cultivo celular, imunofluorescência direta e ELISA. O emprego de técnicas de maior sensibilidade para detecção e quantificação viral, como o PCR quantitativo, permitiu a identificação de animais positivos para a presença de DNA proviral e RNA na ausência de antigenemia/viremia e, com isso, um refinamento da análise das diferentes evoluções da infecção. Assim, reclassificou-se a patogenia do FeLV em 4 categorias: infecção abortiva, regressiva, latente e progressiva. Foi possível também detectar DNA proviral e RNA em animais considerados imunes ao FeLV após vacinação. Diante disso, os objetivos desta revisão de literatura foram demonstrar as implicações da utilização de técnicas sensíveis de detecção viral na interpretação e classificação da infecção do FeLV e rever as técnicas de detecção do vírus para fins de diagnóstico. Além disso, apresentar os resultados referentes à eficácia da vacinação contra o FeLV com a utilização dessas técnicas.<br>Feline leukemia virus (FeLV) belongs to the Retroviridae family, genus Gammaretrovirus. Unlike other retroviruses, a portion of FeLV exposed animals eliminates antigenemia/viremia, according to convectional techniques of virus detection, such as isolation in cell culture, direct fluorescent antibody test and ELISA. The use of more sensitive techniques to detect and quantify viruses enabled the detection of proviral DNA and RNA in cats with undetectable antigenemia/viremia, and thus the refinement of the different infection outcomes analysis. As a result, FeLV pathogenesis was reclassified in 4 categories: abortive, regressive, latent and progressive infections. It was also demonstrated the detection of proviral DNA and RNA in cats believed to be immune to infection after vaccination. Therefore, the objectives of this review were to demonstrate the implications of the use of sensitive techniques for viral detection in the interpretation and classification of FeLV infection and reconsider the techniques for FeLV diagnostic purposes. In addition, it was presented the results concerning the effectiveness of FeLV vaccination with the use of these techniques