Interaction between the NS4B amphipathic helix, AH2, and charged lipid headgroups alters membrane morphology and AH2 oligomeric state — Implications for the Hepatitis C virus life cycle

AbstractThe non-structural protein 4B (NS4B) from Hepatitis C virus (HCV) plays a pivotal role in the remodelling of the host cell's membranes, required for the formation of the viral replication complex where genome synthesis occurs. NS4B is an integral membrane protein that possesses a number of domains vital for viral replication. Structural and biophysical studies have revealed that one of these, the second amphipathic N-terminal helix (AH2), plays a key role in these remodelling events. However, there is still limited understanding of the mechanism through which AH2 promotes these changes. Here we report on solid-state NMR and molecular dynamics studies that demonstrate that AH2 promotes the clustering of negatively charged lipids within the bilayer, a process that reduces the strain within the bilayer facilitating the remodelling of the lipid bilayer. Furthermore, the presence of negatively charged lipids within the bilayer appears to promote the disassociation of AH2 oligomers, highlighting a potential role for lipid recruitment in regulating NS protein interactions

Tratamento hidrotérmico na manutenção da qualidade pós-colheita de maracujá-amarelo Hydrothermal treatment on the maintenance of postharvest quality of passion fruit

Objetivando avaliar o efeito da temperatura de imersão na manutenção da qualidade pós-colheita de frutos de maracujá-amarelo, instalou-se na FCA/UNESP este experimento, composto pelos seguintes tratamentos: T1 (testemunha); T2 (35&deg;C por 2 horas); T3 (35&deg;C por 4 horas); T4 (43&deg;C por 2 horas); T5 (43&deg;C por 4 horas); T6 (53&deg;C por 2 horas); T7 (53&deg;C por 4 horas), sendo os frutos mantidos em câmaras BOD a 12 &plusmn; 1 &deg;C e 80-90% UR. A cada três dias, foram retiradas amostras dos tratamentos para as seguintes análises: Grupo destrutivo - pH, firmeza, sólidos solúveis (SS), acidez titulável (AT), relação (SS/AT), rendimento de polpa e vitamina C; e para o grupo-controle determinaram-se perda de massa e coloração da casca. Com base nos resultados obtidos, os tratamentos hidrotérmicos dos frutos, com temperaturas menores, como é o caso do T2 e T3, apresentaram frutos com menor perda de massa, melhor manutenção da coloração, boa manutenção da firmeza da casca e teores razoáveis de vitamina C, enquanto as temperaturas mais elevadas causaram danos à aparência dos frutos (queima da casca) e reduziram os teores de vitamina C na polpa.<br>To assess the effects of immersion temperature on the maintenance of postharvest quality of passion fruit, an experiment was installed in FCA/UNESP. It was composed of seven treatments: T1 (control), T2 (35&deg;C for 2 hours), T3 (35&deg;C for 4 hours), T4 (43&deg;C for 2 hours), T5 (43&deg;C for 4 hours), T6 (53&deg;C for 2 hours), T7 (53&deg;C for 4 hours). The fruits were maintained in BOD chambers at 12 &plusmn; 1&deg;C and 80-90% RH. Samples of each treatment were collected every other three days. It was analyzed: Destructive group - pH, firmness, soluble solids (SS), titratable acidity (TA), ratio (SS/TA), pulp yield and vitamin C, as well as mass loss and peel color were determined for the control group. According to the results, lower temperatures treatments, such as T2 and T3, showed fruit with less mass loss, best color maintenance, good firmness maintenance and reasonable vitamin C content. Whereas higher temperatures caused damages to the appearance of the fruit (burned peels) and reduced vitamin C content in the pulp

Enraizamento de estacas lenhosas de pereira tratadas com AIB e mantidas em ambiente de estufa tipo B.O.D. e de telado Rooting of hardwood cuttings of pear tree with IBA under B.O.D. chamber and greenhouse environment

Pesquisou-se o enraizamento da pereira em ambiente controlado de estufa tipo B.O.D. e em telado simples. Utilizou-se a cultivar híbrida 'Limeira', destinada exclusivamente para fins culinários e para porta-enxerto. Estacas lenhosas sem folhas, medindo 25 cm de comprimento, foram tratadas com ácido indolbutírico (AIB) nas concentrações de 0; 2.000; 4.000 e 6.000 mg.L-1 por 10 segundos. Como substrato, utilizou-se da mistura de vermiculita e areia grossa (2:1 v/v), sendo a mesma umedecida com meio contendo solução salina MS e sacarose 1%. As estacas permaneceram por 42 dias dentro de estufas tipo B.O.D. (temperatura de 25ºC, umidade relativa do ar de 90% e fotoperíodo de 8 horas) e de telado com irrigação por microaspersão, sem controle ambiental. Em ambiente controlado de estufa, as estacas não-tratadas com AIB iniciaram intensa brotação das gemas e formação de calo após sete dias do plantio. Já em ambiente de telado, essas estacas demoraram 21 dias para o início de brotação das gemas, mostrando menor desenvolvimento de calo. Nas estacas tratadas com AIB, os calos surgiram nas regiões dos cortes após o terceiro dia de incubação na estufa B.O.D. As raízes desenvolveram-se a partir dos tecidos da base e dos calos, tornando-se mais nítidas a partir de 14 e 28 dias, respectivamente, para os ambientes de estufa e de telado. Após 42 dias, o melhor percentual de enraizamento (83%) foi verificado no tratamento com AIB a 2.000 mg.L-1, em ambiente de estufa B.O.D. O emprego dessa estufa, com temperatura, luz e umidade relativa controladas, mostrou-se viável em relação ao telado, no processo de enraizamento das estacas lenhosas da pereira 'Limeira', podendo favorecer o sistema de propagação vegetativa da pereira e encurtar o período da formação de mudas.<br>The rooting of cuttings pear under controlled environment of chamber (B.O.D. type) and greenhouse was searched. Hardwood cuttings of 'Limeira' pear, without leaves, measuring 25 cm of length, were treated with 0, 2000, 4000 and 6000 mg.L-1 of indolbutyric acid (IBA), for 10 seconds. The vermiculite and sand mixture substrate (2:1 v/v) was used and humidified with half contends MS saline solution and sucrose 1%. The cutting stayed per 42 days inside both B.O.D. chamber (temperature of 25ºC, relative humidity of 90% and photoperiod of 8 hours) and greenhouse with irrigation for aspersion, without environmental control. In B.O.D chamber, the cuttings not treated with IBA began an intense sprouting of the buds and callus formation after seven days of planting. On the other hand in greenhouse atmosphere, those cuttings delayed 21 days for the beginning of the bud sprouting, showing smaller callus development. In the cuttings treated with IBA, the callus appeared in the areas of the cuts after the third day of incubation in the stove B.O.D. The roots were developed starting from the tissues of the base and of the callus, becoming clearer from the 14th and 28th day, respectively, for the stove atmosphere and of greenhouse. After 42 days, the best rooting percentage (83%) was verified in the treatment with IBA at 2000 mg.L-1, in B.O.D chamber atmosphere. The utilization of B.O.D chamber, with controlled temperature, light and relative humidity, showed to be more advantageous than the process of greenhouse in the rooting of woody cutting of the 'Limeira' pear tree, that could favor the system of vegetative propagation of the pear tree and to shorten the period of formation of young plants

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used