Galloylated catechins and stilbene diglucosides in Vitis vinifera cell suspension cultures

Suspension cultures of Vitis vinifera were found to produce catechins and stilbenes. When cells were grown in a medium inducing polyphenol synthesis, (−)-epicatechin-3-O-gallate, dimeric procyanidin B-2 3′-O-gallate and two resveratrol diglucosides were isolated, together with a new natural compound that was identified as cis-resveratrol-3,4′-O-β-diglucoside by spectroscopical methods.     

On the Modularity of the Intrinsic Flexibility of the μ Opioid Receptor: A Computational Study

The µ opioid receptor (µOR), the principal target to control pain, belongs to the G protein-coupled receptors (GPCRs) family, one of the most highlighted protein families due to their importance as therapeutic targets. The conformational flexibility of GPCRs is one of their essential characteristics as they take part in ligand recognition and subsequent activation or inactivation mechanisms. It is assessed that the intrinsic mechanical properties of the µOR, more specifically its particular flexibility behavior, would facilitate the accomplishment of specific biological functions, at least in their first steps, even in the absence of a ligand or any chemical species usually present in its biological environment. The study of the mechanical properties of the µOR would thus bring some indications regarding the highly efficient ability of the µOR to transduce cellular message. We therefore investigate the intrinsic flexibility of the µOR in its apo-form using all-atom Molecular Dynamics simulations at the sub-microsecond time scale. We particularly consider the µOR embedded in a simplified membrane model without specific ions, particular lipids, such as cholesterol moieties, or any other chemical species that could affect the flexibility of the µOR. Our analyses highlighted an important local effect due to the various bendability of the helices resulting in a diversity of shape and volume sizes adopted by the µOR binding site. Such property explains why the µOR can interact with ligands presenting highly diverse structural geometry. By investigating the topology of the µOR binding site, a conformational global effect is depicted: the correlation between the motional modes of the extra- and intracellular parts of µOR on one hand, along with a clear rigidity of the central µOR domain on the other hand. Our results show how the modularity of the µOR flexibility is related to its pre-ability to activate and to present a basal activity.     

Statistical evaluation of sister chromatid exchanges

Summary Log-linear models are fitted to sister chromatid exchange (SCE) scores in order to test the significance of the differences in SCE scores observed between individuals or between experimental treatments. The analysis is performed at the level of chromosome groups. In each single test all measurements from all chromosome groups, both from the control and from the experimental sets, are utilized. By proceeding in this way full use is made of all the available information on the SCE scores at the level of chromosome groups and the shortcomings of the classical Student-t and chi-square tests are avoided.This work was supported by a grant Geconcerteerde Acties from the Belgian Government.     

Characterization of the efficiency of a cell separation process by the extent of elimination of a contaminating cell type

A stepwise approach to the selection of an appropriate technique for a cell separation problem is presented in which the preparative purification of cells is linked to their analytical separation. We have introduced the extent of elimination of a contaminating cell type from the cell type which one chooses to purify, as a separation parameter that characterizes the efficiency of a separation process independently of the relative cell composition of the starting material. In order to compare different separation techniques, a preparative fraction boundary needs to be chosen between the cell types. We defined this boundary in terms of the physical property on which the separation is based such that yield and purity of the isolated cell suspension are optimized simultaneously. With this analytical approach, it was found that a similar elutriation technique separated human and equine mononuclear cells equally well and that the separability of human monocytes and lymphocytes improved when the cells were separated by increasing the limiting sedimentation coefficient value of the elutriation chamber in small increments.     

Interaction of K+ ion with the solvated gramicidin A transmembrane channel.

Using Urry's gramicidin A (GA) atomic coordinates and ab into calculations, the interaction energies of a K+ ion with GA are examined. From these energies the values of the fitting parameters are obtained for 6-12-1 atom-atom pair potentials. The potential of the GA channel as experienced by the ion is analyzed in detail. An energy profile of the K+ ion in the GA channel is obtained by analyzing iso-energy maps. Using Monte Carlo simulations, the energy profiles of the K+ ion with the solvated GA channel are analyzed and the hydration structures in the presence of the K+ ion are studied.     

Soluble Factors from Lactobacillus reuteri CRL1098 Have Anti-Inflammatory Effects in Acute Lung Injury Induced by Lipopolysaccharide in Mice

We have previously demonstrated that Lactobacillus reuteri CRL1098 soluble factors were able to reduce TNF-α production by human peripheral blood mononuclear cells. The aims of this study were to determine whether L. reuteri CRL1098 soluble factors were able to modulate in vitro the inflammatory response triggered by LPS in murine macrophages, to gain insight into the molecular mechanisms involved in the immunoregulatory effect, and to evaluate in vivo its capacity to exert anti-inflammatory actions in acute lung injury induced by LPS in mice. In vitro assays demonstrated that L. reuteri CRL1098 soluble factors significantly reduced the production of pro-inflammatory mediators (NO, COX-2, and Hsp70) and pro-inflammatory cytokines (TNF-α, and IL-6) caused by the stimulation of macrophages with LPS. NF-kB and PI3K inhibition by L. reuteri CRL1098 soluble factors contributed to these inhibitory effects. Inhibition of PI3K/Akt pathway and the diminished expression of CD14 could be involved in the immunoregulatory effect. In addition, our in vivo data proved that the LPS-induced secretion of the pro-inflammatory cytokines, inflammatory cells recruitment to the airways and inflammatory lung tissue damage were reduced in L. reuteri CRL1098 soluble factors treated mice, providing a new way to reduce excessive pulmonary inflammation.