The full-length clone of cucumber green mottle mosaic virus and its application as an expression system for Hepatitis B surface antigen

A cucumber green mosaic mottle virus (CGMMV) full-length clone was developed for the expression of Hepatitis B surface antigen (HBsAg). The expression of the surface displayed HBsAg by the chimeric virus was confirmed through a double antibody sandwich ELISA. Assessment of the coat protein composition of the chimeric virus particles by SDS-PAGE analysis showed that 50% of the coat proteins were fused to the HBsAg. Biological activity of the expressed HBsAg was assessed through the stimulation of in vitro antibody production by cultured peripheral blood mononuclear cells (PBMC). PBMC that were cultured in the presence of the chimeric virus showed up to an approximately three-fold increase in the level of anti HBsAg immunoglobulin thus suggesting the possible use of this new chimeric virus as an effective Hepatitis B vaccine.     

4-(2-pyridyl)piperazine-1-carboxamides: potent vanilloid receptor 1 antagonists

A series of 4-(2-pyridyl)piperazine-1-carboxamide analogues based on the lead compound 1 was synthesized and evaluated for VR1 antagonist activity in capsaicin-induced (CAP) and pH (5.5)-induced (pH) FLIPR assays in a rat VR1-expressing HEK293 cell line. Potent VR1 antagonists were identified through SAR studies. From these studies, 18 was found to be very potent in the in vitro assay [IC(50)=4.8 nM (pH) and 35 nM (CAP)] and orally available in rat (F%=15.1).     

Effect of meteorological parameters on Poaceae pollen in the atmosphere of Tetouan (NW Morocco)

Poaceae pollen is one of the most prevalent aeroallergens causing allergenic reactions. The aim of this study was to characterise the grass pollen season in Tetouan during the years 2008–2010, to analyse the effect of some meteorological parameters on the incidence of the airborne Poaceae pollen, and to establish forecasting variables for daily pollen concentrations. Aerobiological sampling was undertaken over three seasons using the volumetric method. The pollen season started in April and showed the highest pollen index in May and June, when the maximum temperature ranged from 23 to 27 °C, respectively. The annual pollen score recorded varied from year to year between 2,588 and 5,404. The main pollen season lasted 114–173 days, with peak days occurring mainly in May; the highest concentration reached 308 pollen grains/m³. Air temperature was the most important meteorological parameter and correlated positively to daily pollen concentration increase. An increase in relative humidity and precipitation was usually related to a decrease in airborne pollen content. External validation of the models performed using data from 2011 showed that Poaceae pollen concentration can be highly predicted (64.2–78.6 %) from the maximum temperature, its mean concentration for the same day in other years, and its concentration recorded on the previous day. Sensitive patients suffering allergy to Poaceae pollen are at moderate to highest risk of manifesting allergic symptoms to grass pollen over 33–42 days. The results obtained provide new information on the quantitative contribution of the Poaceae pollen to the airborne pollen of Tetouan and on its temporal distribution. Airborne pollen can be surveyed and forecast in order to warn the atopic population.     

Synthesis of 2',3'-dideoxy-2'-fluoro-3'-thioarabinothymidine and its 3'-phosphoramidite derivative

An efficient method for the synthesis of 5'-O-monomethoxytrityl-2',3'-dideoxy-2'-fluoro-3'-thioarabinothymidine [(5'MMT)araF-T(3'SH), (5)] and its 3'-phosphoramidite derivative (6) suitable for automated incorporation into oligonucleotides, is demonstrated. A key step in the synthesis involves reaction of 5'-O-MMT-2,3'-O-anhydrothymidine (4) (Eleuteri, A.; Reese, C.B.; Song, Q. J. Chem. Soc. Perkin Trans. 1 1996, 2237 pp.) with sodium thioacetate to give (5'-MMT)araF-T(3'SAc) (5) (Elzagheid, M.I.; Mattila, K.; Oivanen, M.; Jones, B.C.N.M.; Cosstick, L?nnberg, H. Eur. J. Org. Chem. 2000, 1987-1991). This nucleoside was then converted to its corresponding phosphoramidite derivative, 6, as described previously ((a) Sun, S.; Yoshida, A.; Piccirilli, J.A. RNA, 1997, 3, 1352-1363; (b) Matulic-Adamic, J.; Beigelman, L. Helvetica Chemica Acta 1999, 82, 2141-2150: (c) Fettes, K.J.; O'Neil, I.; Roberts, S.M.; Cosstick, R. Nucleosides, Nucleotides and Nucl. Acids 2001, 20, 1351-1354).     

Reprint of "Structural and mechanistic aspects of Amt/Rh proteins" [J. Struct. Biol. 158 (2007) 472-481

Amt/Rh proteins, which mediate movement of ammonium across cell membranes, are spread throughout the three kingdoms of life. Most functional studies on various members of the family have been performed using cellular assays in heterologous expression systems, which are, however, not very well suited for detailed mechanistic studies. Although now generally considered to be ammonia conducting channels, based on a number of experimental studies and structural insights, the possibility remains that some plant Amts facilitate net ammonium ion transport. The Escherichia coli channel AmtB has become the model system of choice for analysis of the mechanism of ammonia conductance, increasingly also through molecular dynamics simulations. Further progress in a more detailed mechanistic understanding of these proteins requires a reliable in vitro assay using purified protein, allowing quantitative kinetic measurements under a variety of experimental conditions for different Amt/Rh proteins, including mutants. Here, we critically review the existing functional data in the context of the most interesting and unresolved mechanistic questions and we present our results, obtained using an in vitro assay set up with the purified E. coli channel AmtB.     

High-resolution habitat and bathymetry maps for 65,000 sq. km of Earth’s remotest coral reefs

Coral Reefs - With compelling evidence that half the world’s coral reefs have been lost over the last four decades, there is urgent motivation to understand where reefs are located and their...