59, P < 0.0001). This assay could be used in screening and monitoring individuals on therapy, showing no genotype-dependent GSI-IX differences in detection. (c) 2008
Elsevier Inc. All rights reserved.”
“The aim of the work is to study the mechanisms of the interaction of risperidone with human and bovine serum albumins using the fluorescence quenching technique. Risperidone is an atypical antipsychotic drug used to treat many psychiatric disorders. We selectively excited the fluorescence of tryptophan residues with a 290 nm wavelength light, and observed quenching by titrating human and bovine serum albumin solutions with risperidone. Emission spectra were recorded in the range from 300 to 450 nm for each quencher addition. Stern-Volmer Selleck VX-661 graphs were plotted and quenching constants were estimated. Results showed that the drug quenches the fluorescence of the human serum albumin by the formation of a complex risperidone-albumin. Association constants calculated from Stern-Volmer equation for low concentrations (lower than 1:10 ratio risperidone/albumin) were of 2.56 x 10(5) M-1, at 25 degrees C, and 1.43 x 10(5) M-1, at 37
degrees C. As the quenching intensity of bovine serum albumin, which contains two tryptophan residues, was found to be higher than that of human serum albumin, which contains only one tryptophan residue. Hence, we suggest that the primary binding site for risperidone in albumin should be located in sub domain IB. (C) 2011 Elsevier B.V. All rights reserved.”
“Light exerts a direct effect on sleep and wakefulness in nocturnal and diurnal animals, with a light pulse during the dark phase suppressing locomotor activity and promoting sleep in the former. In the present study, we investigated this direct effect of light on various sleep parameters by exposing mice to a broad range of illuminances (0.2-200W/cm2;
equivalent to 1-1000lux) for 1h during the dark phase https://www.selleckchem.com/products/AZD1480.html (zeitgeber time 13-14). Fitting the data with a three-parameter log model indicated that approximate to 0.1W/cm2 can generate half the sleep response observed at 200W/cm2. We observed decreases in total sleep time during the 1h following the end of the light pulse. Light reduced the latency to sleep from similar to 30min in darkness (baseline) to similar to 10min at the highest intensity, although this effect was invariant across the light intensities used. We then assessed the role of melanopsin during the rapid transition from wakefulness to sleep at the onset of a light pulse and the maintenance of sleep with a 6-h 20W/cm2 light pulse. Even though the melanopsin knockout mice had robust induction of sleep (similar to 35min) during the first hour of the pulse, it was not maintained. Total sleep decreased by almost 65% by the third hour in comparison with the first hour of the pulse in mice lacking melanopsin, whereas only an 8% decrease was observed in wild-type mice.