Combate ao Aedes Aegypti e investigação epidemiológica de dengue na área de abrangência da unidade de atenção primária à saúde Sebastião Amorim II / Combating Aedes Aegypti and epidemiological investigation of dengue in the area of coverage of the primary health care unit Sebastião Amorim II

Dengue, Zika e Chikungunya são doenças virais que têm se tornado um grande problema de saúde pública no Brasil. Segundo o Ministério da Defesa (2015), 80% dos focos de criadores do mosquito encontram-se no interior e ao redor das residências. De acordo com os registros no Sistema de Informação de Agravos de Notificação, em 2012 notificou-se 77 casos em Patos de Minas, hoje este número até o mês de maio de 2016 já se encontra em torno de 233 casos. Dada a gravidade da situação, este trabalho objetivou a busca ativa de focos de proliferação e medidas de conscientização da população em especial da Unidade Básica de Saúde Sebastião Amorim II no intuito de reduzir a incidência do número de casos e direcionar o problema para os órgãos públicos responsáveis com embasamento teórico e prático.

Measuring the strength of interaction between the Ebola fusion peptide and lipid rafts: implications for membrane fusion and virus infection.

The Ebola fusion peptide (EBO₁₆) is a hydrophobic domain that belongs to the GP2 membrane fusion protein of the Ebola virus. It adopts a helical structure in the presence of mimetic membranes that is stabilized by the presence of an aromatic-aromatic interaction established by Trp8 and Phe12. In spite of its infectious cycle becoming better understood recently, several steps still remain unclear, a lacuna that makes it difficult to develop strategies to block infection. In order to gain insight into the mechanism of membrane fusion, we probed the structure, function and energetics of EBO₁₆ and its mutant W8A, in the absence or presence of different lipid membranes, including isolated domain-resistant membranes (DRM), a good experimental model for lipid rafts. The depletion of cholesterol from living mammalian cells reduced the ability of EBO₁₆ to induce lipid mixing. On the other hand, EBO₁₆ was structurally sensitive to interaction with lipid rafts (DRMs), but the same was not observed for W8A mutant. In agreement with these data, W8A showed a poor ability to promote membrane aggregation in comparison to EBO₁₆. Single molecule AFM experiments showed a high affinity force pattern for the interaction of EBO₁₆ and DRM, which seems to be a complex energetic event as observed by the calorimetric profile. Our study is the first to show a strong correlation between the initial step of Ebola virus infection and cholesterol, thus providing a rationale for Ebola virus proteins being co-localized with lipid-raft domains. In all, the results show how small fusion peptide sequences have evolved to adopt highly specific and strong interactions with membrane domains. Such features suggest these processes are excellent targets for therapeutic and vaccine approaches to viral diseases

Measuring the Strength of Interaction between the Ebola Fusion Peptide and Lipid Rafts: Implications for Membrane Fusion and Virus Infection

The Ebola fusion peptide (EBO16) is a hydrophobic domain that belongs to the GP2 membrane fusion protein of the Ebola virus. It adopts a helical structure in the presence of mimetic membranes that is stabilized by the presence of an aromaticaromatic interaction established by Trp8 and Phe12. In spite of its infectious cycle becoming better understood recently, several steps still remain unclear, a lacuna that makes it difficult to develop strategies to block infection. In order to gain insight into the mechanism of membrane fusion, we probed the structure, function and energetics of EBO16 and its mutant W8A, in the absence or presence of different lipid membranes, including isolated domain-resistant membranes (DRM), a good experimental model for lipid rafts. The depletion of cholesterol from living mammalian cells reduced the ability of EBO16 to induce lipid mixing. On the other hand, EBO16 was structurally sensitive to interaction with lipid rafts (DRMs), but the same was not observed for W8A mutant. In agreement with these data, W8A showed a poor ability to promote membrane aggregation in comparison to EBO16. Single molecule AFM experiments showed a high affinity force pattern for the interaction of EBO16 and DRM, which seems to be a complex energetic event as observed by the calorimetric profile. Our study is the first to show a strong correlation between the initial step of Ebola virus infection and cholesterol, thus providin

Measuring the strength of interaction between the ebola fusion peptide and lipid rafts: implications for membrane fusion and virus infection

9 p. : il., tab.The Ebola fusion peptide (EBO16) is a hydrophobic domain that belongs to the GP2 membrane fusion protein of the Ebola virus. It adopts a helical structure in the presence of mimetic membranes that is stabilized by the presence of an aromaticaromatic interaction established by Trp8 and Phe12. In spite of its infectious cycle becoming better understood recently, several steps still remain unclear, a lacuna that makes it difficult to develop strategies to block infection. In order to gain insight into the mechanism of membrane fusion, we probed the structure, function and energetics of EBO16 and its mutant W8A, in the absence or presence of different lipid membranes, including isolated domain-resistant membranes (DRM), a good experimental model for lipid rafts. The depletion of cholesterol from living mammalian cells reduced the ability of EBO16 to induce lipid mixing. On the other hand, EBO16 was structurally sensitive to interaction with lipid rafts (DRMs), but the same was not observed for W8A mutant. In agreement with these data, W8A showed a poor ability to promote membrane aggregation in comparison to EBO16. Single molecule AFM experiments showed a high affinity force pattern for the interaction of EBO16 and DRM, which seems to be a complex energetic event as observed by the calorimetric profile. Our study is the first to show a strong correlation between the initial step of Ebola virus infection and cholesterol, thus providing a rationale for Ebola virus proteins being co-localized with lipid-raft domains. In all, the results show how small fusion peptide sequences have evolved to adopt highly specific and strong interactions with membrane domains. Such features suggest these processes are excellent targets for therapeutic and vaccine approaches to viral diseases

Dynamic light scattering of vesicles incubated with Ebola fusion peptide.

<p>(A) PC LUVs, (B) PC∶PE∶PI∶Cho LUVs, (C) PC∶PE∶SPM∶Cho LUVs, (D) lipid rafts from BHK-21 cells and (E) lipid rafts from Vero cells. All experiments were done in phosphate buffer pH 7 at 37°C. The peptide concentration was 100 µM, and the liposome concentration was 1 mM.</p

Transparent thermally stable poly (etherimide) film as flexible substrate for OLEDs

5 p. : il.In this work, ITO thin films were deposited onto poly(etherimide) (PEI) substrates at room temperature using r.f. magnetron sputtering and successively they were annealed in the 423–523 K (150–250 °C) temperature range. PEI/ITO substrates were structurally, optically and electrically characterized in order to verify the quality of the deposited ITO films and the PEI thermal stability during the ITO annealing process. A transmittance of about 80% was measured in the visible range. The best electrical properties achieved were: 3.04×10−4 Ω cm, 12.07×1021cm2/V.s, 16.8 × 1021 cm−3, for resistivity, carrier concentration and mobility, respectively. Small molecule Flexible Organic Light Emitting Diodes (FOLED) were then fabricated and characterized onto ITO functionalized PEI substrates. These preliminary results show clearly that PEI can be successfully used as substrate in flexible optoelectronic devices either operating in high temperature or when the process needs high temperatures

Binding of wtEBO₁₆ and W8A to lipid membranes by isothermal titration calorimetry.

<p>Each peak corresponds to a 5 µL injection of vesicles into the sample cell containing a 100 µM solution of wtEBO₁₆ (a) or W8A (b) peptide. (A) PC LUVs, (C) PC∶PE∶PI∶Cho LUVs (2∶1∶0.5∶1), (E) PC∶PE∶SPM∶Cho LUVs (1∶1∶1∶1.5) LUVs, (G) lipid rafts from BHK-21 cells and (I) lipid rafts from VERO cells. (B), (D), (F), (H) and (J) are enlarged views of selected heat peak of titration experiments shown in (A, b), (C, b), (E, b), (G, b) and (I, b) curves, respectively. All measurements were conducted at 37°C in phosphate buffer pH 7. The peaks were obtained after subtraction of the heat of dilution of the vesicles into buffer from the raw data obtained with the peptides.</p

Peptide membrane interaction.

<p>(A) Living Vero cells were incubated with wtEBO₁₆ at 25 (circles) or 37°C (square). Membrane mixing was followed by the decrease in the pyrene excimer/monomer fluorescence ratio for 30 min. (B) Living Vero cells in the absence (square) or in the presence (circle) of MβCD were incubated with wtEBO₁₆ at 37°C. Membrane mixing was followed by the decrease in the pyrene excimer/monomer ratio for 30 min. The peptide concentration was 100 µM in all experiments. The MβCD concentration was 20 mM. The percentage of lipid mixing was obtained by the relation described in Freitas et al <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0015756#pone.0015756-Freitas1" target="_blank">[12]</a>.</p

Schematic view of Ebola virus entry and fusion promoted by the fusion domain (EBO₁₆).

<p>The interaction between Trp8 and Phe12 is emphasized with the tridimensional structure of EBO₁₆ immersed in the lipid membrane (from PDB entry 2RLJ, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0015756#pone.0015756-Freitas1" target="_blank">[12]</a>).</p

Effect of MβCD on cell viability.

<p>(A) Cholesterol depletion. Cells were pre-treated with MβCD for 30 min at 37°C, and cholesterol content was quantified as described in Experimental Procedures. (B) Cell viability. Cells were incubated with MβCD for 30 min at 37°C. Then MTT reagent was added and incubated for 4 h. The cells were incubated overnight with the solubilization buffer. Absorbance was measured at 570 nm. The bars represent BHK-21, VERO and C636, respectively from left to right.</p