Synergistic Interactions between the NS3hel and E Proteins Contribute to the Virulence of Dengue Virus Type 1

Dengue virus constitutes a significant public health problem in tropical regions of the world. Despite the high morbidity and mortality of this infection, no effective antiviral drugs or vaccines are available for the treatment or prevention of dengue infections. The profile of clinical signs associated with dengue infection has changed in recent years with an increase in the number of episodes displaying unusual signs. We use reverse genetics technology to engineer DENV-1 viruses with subsets of mutations previously identified in highly neurovirulent strains to provide insights into the molecular mechanisms underlying dengue neuropathogenesis. We found that single mutations affecting the E and NS3hel proteins, introduced in a different genetic context, had a synergistic effect increasing DENV replication capacity in human and mosquito derived cells in vitro. We also demonstrated correlations between the presence of these mutations and viral replication efficiency, viral loads, the induction of innate immune response genes and pathogenesis in a mouse model. These results should improve our understanding of the DENV-host cell interaction and contribute to the development of effective antiviral strategies

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

Consistent patterns of common species across tropical tree communities

Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1-6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

Estudo de confiabilidade do SINAN a partir das Campanhas para a Eliminação da Sífilis Congênita no Município do Rio de Janeiro Reliability of the National Disease Surveillance Data System using Campaigns for the elimination of congenital syphilis in the City of Rio de Janeiro

A partir da construção da base de dados das Campanhas para a Eliminação da Sífilis Congênita, realizadas no Município do Rio de Janeiro em 1999 e 2000, estabeleceu-se a confiabilidade dos dados informados ao Sistema Nacional de Agravos de Notificação (SINAN). Procedeu-se também a um estudo da qualidade do preenchimento das variáveis, que são as informações solicitadas para a notificação do caso. O percentual de concordância simples para a variável número de consultas de pré-natal foi de 91% e 92,1% e para a variável sífilis na gravidez foi de 62,7% e 76,3%, para os anos de 1999 e 2000, respectivamente. A concordância para as variáveis idade da mãe, data do tratamento e tipo de tratamento foi estabelecida pelo coeficiente kappa. A variável idade apresentou excelente concordância. Contudo, as outras duas resultaram em baixa concordância para os dois anos estudados. Em relação à qualidade, variáveis importantes como realização do primeiro VDRL, do segundo VDRL e a idade gestacional no tratamento, apresentaram percentuais de caselas vazias/ignoradas superiores a 20%. O estudo da confiabilidade entre a base primária das campanhas e o SINAN-SC corrobora a necessidade de desenvolver estratégias para aprimorar a qualidade do último nos vários níveis dos sistemas de saúde. A mudança da definição de caso de sífilis congênita, realizada em 2004, e a introdução do Curso Básico de Vigilância Epidemiológica para sífilis na gestação e sífilis congênita devem contribuir para o aprimoramento do sistema.<br>Using the database obtained from the Campaigns for the elimination of congenital syphilis in the City of Rio de Janeiro in 1999 and 2000, we performed a reliability study on the National Disease Surveillance Data System (SINAN). We also evaluated the quality of the data provided. The percentage of agreement for the variable number of consultations in prenatal care was 91.0% in 1999 and 92.1% in 2000, and for syphilis during pregnancy was 62.7% in 1999 and 76.3% in 2000. Kappa statistics for the variables age of mother, date of treatment and therapy regimen provided an almost perfect agreement for age, in both years, but a slight to fair agreement for the other two. Looking at the quality of data, important variables as first VDRL during pregnancy, second VDRL and gestational age at syphilis treatment had more than 20% of blank or unknown answers. The reliability study of the SINAN using the campaigns' primary databases corroborates the need of establishing strategies to increase the quality of the SINAN at the various levels of the health systems. The 2004 change in case definition and the implementation of the Basic Course in Epidemiological Surveillance on syphilis in pregnancy and congenital syphilis will contribute to the improvement of the system