To investigate the

role of pH in dissociation of dimeric protein, we have performed a concise learn more study of hydrogen bonding and other interactions between units of dimer at low and normal pH. The Generalized Born calculation connotes that dimeric unit was relatively less stable and less proned for dimerisation at low pH. Our results provide a theoretical verification for previous assumptions of pH triggering mechanism of dengue envelope protein. During the pH alteration, we found a large decrement in salt bridges which were observed at normal pH. We also compared the flexibility of each unit and found that they exhibit different fluctuations during molecular dynamics simulations. (C) 2011 Elsevier B.V. All rights reserved.”
“Methadone is a long-acting opioid used in the treatment of various pain states and substitution therapy in heroin addiction. Extensive behavioral characterization has been carried out using the racemate, but limited investigation has selleck screening library been performed with the individual isomers. The

L-isomer is a potent opioid agonist, whereas the D-isomer has weak mu-opioid activity and has also been shown to possess N-methyl-D-aspartate antagonist properties in vitro. The acute antinociceptive effects of the isomers were evaluated in rats using a warm-water, tail-withdrawal procedure at two stimulus intensities (50 degrees and 55 degrees C). Increasing dose ratios of D-methadone to L-methadone were administered chronically to determine the ability of the D-isomer to modulate antinociceptive tolerance to the L-isomer. Acutely, both L-methadone (0.1-5.6 mg/kg, subcutaneously) and D-methadone (3.0-56.0 mg/kg, subcutaneously) produced antinociception, although the efficacy of the D-isomer was limited at 55 degrees C. These effects were dose dependently blocked by naltrexone (0.01-1.0 mg/kg, subcutaneously). Administered chronically, D-methadone (1.7-10 mg/kg, subcutaneously) dose dependently blocked tolerance development

to the L-isomer (1.7 mg/kg, subcutaneously). These findings support the antinociceptive effects of the isomers being opioid receptor mediated with the L-isomer functioning as a full-efficacy Selleck SBC-115076 agonist, whereas the D-isomer seems to have lower efficacy. The ability of nonracemic doses of the D-isomer to prevent tolerance development to the L-isomer may be attributed to partial l-agonist activity; however, N-methyl-D-aspartate antagonist activity cannot be discounted. Behavioural Pharmacology 22:548-557 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.”
“We studied the effects of two bifidobacteria strains isolated from healthy centenarians on intestinal function in mice. Bifidobacterium adolescentis BBMN23 and Bifidobacterium longum BBMN68 were orally administrated to specific pathogen-free BALB/c mice at different doses (2 x 10(11), 2 x 10(9), or 2 x 10(7) CFU/kg body weight) each day for 4 weeks. Villus height, crypt depth, villus width, and villus/crypt ratio (V/C) were determined.