Mineral Oil Inhibits Movement of Potato Virus Y in Potato Plants in an Age-Dependent Manner

Potato Virus Y (PVY) is one of the most devastating pathogens threatening potato production worldwide. It is a RNA virus that is disseminated by aphids in a non-persistent manner. Regular application of mineral oil on potato fields is known to reduce the number of PVY-positive tubers in post-harvest testing. The mechanism of this phenomenon is not well understood, but it is hypothesized to influence the virus-vector-plant relationships. Here, we present data from greenhouse and field trials that shed light on the effect of mineral oil on local and systemic accumulation of PVY^O in susceptible Shepody and Russet Burbank. The data suggests that mineral oil did not influence PVY^O levels in mechanically-inoculated leaves nor tubers of plants with a secondary infection. However, a reduction in systemic PVY^O levels was observed in mineral oil-treated older plants but not in younger plants, suggesting that mineral oil inhibits PVY^O movement in an age-dependent manner.     

Dual activation of the Drosophila toll pathway by two pattern recognition receptors

The Toll-dependent defense against Gram-positive bacterial infections in Drosophila is mediated through the peptidoglycan recognition protein SA (PGRP-SA). A mutation termed osiris disrupts the Gram-negative binding protein 1 (GNBP1) gene and leads to compromised survival of mutant flies after Gram-positive infections, but not after fungal or Gram-negative bacterial challenge. Our results demonstrate that GNBP1 and PGRP-SA can jointly activate the Toll pathway. The potential for a combination of distinct proteins to mediate detection of infectious nonself in the fly will refine the concept of pattern recognition in insects.     

Supernova shock breakout from a red supergiant

Massive stars undergo a violent death when the supply of nuclear fuel in their cores is exhausted, resulting in a catastrophic "core-collapse" supernova. Such events are usually only detected at least a few days after the star has exploded. Observations of the supernova SNLS-04D2dc with the Galaxy Evolution Explorer space telescope reveal a radiative precursor from the supernova shock before the shock reached the surface of the star and show the initial expansion of the star at the beginning of the explosion. Theoretical models of the ultraviolet light curve confirm that the progenitor was a red supergiant, as expected for this type of supernova. These observations provide a way to probe the physics of core-collapse supernovae and the internal structures of their progenitor stars.     

Tubulin polyglutamylase enzymes are members of the TTL domain protein family

Polyglutamylation of tubulin has been implicated in several functions of microtubules, but the identification of the responsible enzyme(s) has been challenging. We found that the neuronal tubulin polyglutamylase is a protein complex containing a tubulin tyrosine ligase-like (TTLL) protein, TTLL1. TTLL1 is a member of a large family of proteins with a TTL homology domain, whose members could catalyze ligations of diverse amino acids to tubulins or other substrates. In the model protist Tetrahymena thermophila, two conserved types of polyglutamylases were characterized that differ in substrate preference and subcellular localization.     

Marine polysaccharides: a source of bioactive molecules for cell therapy and tissue engineering

The therapeutic potential of natural bioactive compounds such as polysaccharides, especially glycosaminoglycans, is now well documented, and this activity combined with natural biodiversity will allow the development of a new generation of therapeutics. Advances in our understanding of the biosynthesis, structure and function of complex glycans from mammalian origin have shown the crucial role of this class of molecules to modulate disease processes and the importance of a deeper knowledge of structure-activity relationships. Marine environment offers a tremendous biodiversity and original polysaccharides have been discovered presenting a great chemical diversity that is largely species specific. The study of the biological properties of the polysaccharides from marine eukaryotes and marine prokaryotes revealed that the polysaccharides from the marine environment could provide a valid alternative to traditional polysaccharides such as glycosaminoglycans. Marine polysaccharides present a real potential for natural product drug discovery and for the delivery of new marine derived products for therapeutic applications.     

Gastropexy with an automatic stapling instrument for the treatment of gastric dilatation and volvulus in 20 dogs

Surgical stapling equipment was used to create a gastropexy in 20 dogs undergoing emergency surgery for gastric dilatation and volvulus (GDV). The technique involved creation of a tunnel between the seromuscular layer and the submucosa of the pyloric antrum, and a matching tunnel beneath the right m. transversus abdominis. The arms of a gastrointestinal anastomosis stapling device were introduced into the tunnels, and the device was fired to create the gastropexy. One dog died of systemic sequelae of GDV during the early postoperative period. None of the remaining 19 dogs developed a recurrence of GDV during follow-up periods ranging from 5 to 43 months. In 11 dogs, the integrity of the gastropexy was evaluated by abdominal ultrasonography and either negative contrast gastrography or double contrast gastrography; in these dogs, the radiographic and/or the ultrasonographic findings were suggestive of an intact gastropexy. There were no complications involving the gastropexy staple line. The results of this study indicate that an effective and consistent permanent gastropexy can be created, using surgical stapling equipment.     

Recombinant proteins and peptides as tools for studying IgE reactivity with low-molecular-weight glutenin subunits in some wheat allergies

Two genes of wheat low-molecular-weight glutenin subunits (LMW-GS), B16 and P73, were cloned and expressed in E. coli. They were homologous to proteins encoded respectively at Glu-B3 and Glu-D3 loci. The N-terminal and C-terminal halves of B16 (NB16 and B16C) and the two chimeras combining the halves of the two genes (B16-P73 and P73- B16) were also expressed. All these constructs were compared for their reactivity with IgE from 24 patients suffering from different forms of wheat allergies. The results confirmed that LMW-GSs bound IgE in all adult allergies tested. Strong differences in reactivity between all the constructs were observed. They were disease-dependent. In wheat-dependent exercise-induced anaphylaxis (WDEIA), the reactivity of the constructs depended partly on common epitopes with omega-5 gliadins but also on differences in molecule conformation. The presence of NB16 in the constructs greatly influenced their IgE reactivity.     

Light-scattering study of the structure of aggregates and gels formed by heat-denatured whey protein isolate and beta-lactoglobulin at neutral pH

The structure of aggregates and gels formed by heat-denatured whey protein isolate (WPI) has been studied at pH 7 and different ionic strengths using light scattering and turbidimetry. The results were compared with those obtained for pure beta-lactoglobulin (beta-Lg). WPI aggregates were found to have the same self-similar structure as pure beta-Lg aggregates. WPI formed gels above a critical concentration that varied from close to 100 g/L in the absence of added salt to about 10 g/L at 0.2 M NaCl. At low ionic strength (<0.05 M NaCl) homogeneous transparent gels were formed, while at higher ionic strength the gels became turbid but had the same self-similar structure as reported earlier for pure beta-Lg. The length scale characterizing the heterogeneity of the gels increased exponentially with increasing NaCl concentration for both WPI and pure beta-Lg, but the increase was steeper for the former.