A dengue é hoje objeto da maior campanha de saúde pública do Brasil, que se concentra no controle do Ae aegypti, único vetor reconhecido como transmissor do vírus da dengue em nosso meio. Este mosquito está adaptado a se reproduzir nos ambientes doméstico e peridoméstico 21 ABSTRACT Dengue epidemics occur typically in the warmest months without qualitative differences for the Brazilian geographic regions. However, this disease has an important quantitative difference. We observe two clusters in the country regarding the number of case notifications: The first cluster is formed by the North-East and South-East regions, that sum about 86% of the all notifications; and the second is formed by the

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A febre dengue e suas formas graves (dengue hemorrágica e síndrome do choque da dengue) estão hoje presentes em quase todos os estados do Brasil, com os sorotipos Den-1, Den-2 e Den-3 circulando simultaneamente em 24 estados 10 . A persistência e a progressão desta virose estão condicionadas à sobrevivência e reprodução do seu vetor, a fêmea do mosquito Aedes aegypti, no ambiente. Dado que não existe ainda uma vacina para a dengue, o combate aos criadouros é tido ainda como a melhor estratégia.As ABSTRACTTemperatures in the City of Rio de Janeiro in the first quarter of the year over the period 1986-2003, especially the minimum, were significantly higher in the years in which dengue epidemics started in the city. There was no significant relationship with total rainfall for the same quarter of the year, but epidemics were more frequent in the years in which the volume of rain during the summer was small (less than 200mm).

Gluconacetobacter diazotrophicus, an endophyte isolated from sugarcane, is a strict aerobe that fixates N2. This process is catalyzed by nitrogenase and requires copious amounts of ATP. Nitrogenase activity is extremely sensitive to inhibition by oxygen and reactive oxygen species (ROS). However, the elevated oxidative metabolic rates required to sustain biological nitrogen fixation (BNF) may favor an increased production of ROS. Here, we explored this paradox and observed that ROS levels are, in fact, decreased in nitrogen-fixing cells due to the up-regulation of transcript levels of six ROS-detoxifying genes. A cluster analyses based on common expression patterns revealed the existence of a stable cluster with 99.8% similarity made up of the genes encoding the α-subunit of nitrogenase Mo–Fe protein (nifD), superoxide dismutase (sodA) and catalase type E (katE). Finally, nitrogenase activity was inhibited in a dose-dependent manner by paraquat, a redox cycler that increases cellular ROS levels. Our data revealed that ROS can strongly inhibit nitrogenase activity, and G. diazotrophicus alters its redox metabolism during BNF by increasing antioxidant transcript levels resulting in a lower ROS generation. We suggest that careful controlled ROS production during this critical phase is an adaptive mechanism to allow nitrogen fixation.

Influenzinum RC altered cellular and biochemical features of MDCK and J774G8 cells.

The aim of this study was to investigate and compare the frequency of BKV, JCV, WUV, and KIV in the saliva of healthy individuals. Samples were analyzed for the presence of polyomaviruses (BKV, JCV, WUV, and KIV) DNA by real-time PCR. Of the 291 samples tested, 71 (24.3%) were positive for at least one of the screened polyomaviruses. Specifically, 12.7% (37/291) were positive for WUV, 7.2% (21/291) positive for BKV, 2.4% (7/291) positive for KIV, and 0.3% (1/291) positive for JCV. BKV and WUV co-infections were detected in 1.7% (5/291) of individuals. No other co-infection combinations were found. The mean number of DNA copies was high, particularly for WUV and BKV, indicating active replication of these viruses. Polyomavirus detection was higher among individuals 15-19 years of age (46.0%; 23/50) and ≥50 years of age (33.3%; 9/27). However, the detection rate in the first group was almost 1.7× greater than the latter. WUV infections were more frequent in individuals between the ages of 15 and 19 years and the incidence decreased with age. By contrast, BKV excretion peaked and persisted during the third decade of life and KIV infections were detected more commonly in subjects ≥50 years old. These findings reinforced the previous hypotheses that saliva may be a route for BKV transmission, and that the oral cavity could be a site of virus replication. These data also demonstrated that JCV, WUV, and KIV may be transmitted in a similar fashion.

Five extracts from A . brasilianu, obtained through different procedures, showed anti-HSV activity. The best activity was detected in a fraction (B) that was obtained from the crude cold aqueous extract on Sephadex GIs. Fraction B showed low cellular toxicity and inhibition from 32.4% to 99.9% at concentrations from 6.2 to 50.0 pg/mL, exhibiting a therapeutic index of 32. Fractions obtained on Sephadex Glm and reversed-phase column also showed considerable inhibition. Fraction B did not show any virucidal activity, however, its inhibitory activity was revealed during the later stages of the virus replication cycle. This fraction showed activity on DNA synthesis of infected cells.

Introduction: Sylvatic yellow fever (SYF) is enzootic in Brazil, causing periodic outbreaks in humans living near forest borders or in rural areas. In this study, the cycling patterns of this arbovirosis were analyzed. Methods: Spectral Fourier analysis was used to capture the periodicity patterns of SYF in time series. Results: SYF outbreaks have not increased in frequency, only in the number of cases. There are two dominant cycles in SYF outbreaks, a seven year cycle for the central-western region and a 14 year cycle for the northern region.Most of the variance was concentrated in the central-western region and dominated the entire endemic region. Conclusions: The seven year cycle is predominant in the endemic region of the disease due the greater contribution of variance in the central-western region; however, it was possible identify a 14 cycle that governs SYF outbreaks in the northern region. No periodicities were identified for the remaining geographical regions.