Effects of long-term action of direct electric field on brain slices

An attempt of modeling of experimental paradigm of long-term transcranial direct current stimulation (ltDCS) ofa human brain by constant electric field was undertaken on rat hippocampal slices. At anodal or cathodal direction of electric field (14 min, 250 mV/mm) statistically significant changes of population spikes (pop-spikes) amplitude in the field CAl towards increase or decrease respectively occurred in reply to stimulation of Schaffer collaterals (1/30). Long-lasting aftereffects were not observed. NMDA receptors blockade by MK-801 removed field-generated effects and caused the gradual j reduction of pon-spikes throughout all time of registration. The assumption is come out that the phenomenon of reduction of pop-spikes can reflect synaptic transforming in a "silent" condition.     

Synthesis and Cytotoxic Activity of a Number of Functionalized 2,3-Allenoates

Russian Journal of Bioorganic Chemistry - A series of new functionalized allenoates has been synthesized, and their cytotoxic effect has been studied against the tumor cell line (HepG2 and Jurkat)...     

A taxonomic revision of Tyrini of the Oriental?region. V. Revision of the genus Lasinus Sharp, 1874 (Coleoptera,Staphylinidae, Pselaphinae)

The genus Lasinus Sharp, 1874 of the Pselaphodes complex of genera (Pselaphitae: Tyrini: Tyrina) is revised. The three so far known species, Lasinus mandarinus Raffray, 1890, Lasinus monticola Sawada, 1961 and Lasinus spinosus Sharp, 1874 are redescribed. Eight new species, Lasinus sinicus sp. n. from China, Lasinus mikado sp. n., Lasinus yamamotoi sp. n., Lasinus inexpectatus sp. n., Lasinus yakushimanus sp. n., Lasinus amamianus sp. n., Lasinus saoriae sp. n., and Lasinus okinawanus sp. n. from Japan, are described. And all species are illustrated. Lectotypes are designated for Lasinus mandarinus and Lasinus spinosus. An identification key to species of the genus Lasinus is provided.     

A kinetic model of the cleavage of permutational variants of the antigenomic HDV-ribozyme

The kinetic characteristics have been studied for noncircularly permuted variants of the human hepatitis delta virus (HDV) antigenomic ribozyme to find out the cause of the two-phase kinetics of the self-cleavage reaction. Different ways of reaction initiation, suboptimal conditions, and jumpwise changes of reaction conditions have been used, and the temperature dependences have been studied. A correlation has been shown between the apparent kinetic constant of the first reaction phase and the portion of the ribozyme molecules that self-cleaved during the first phase. Partial restoration of the initial reaction characteristics has been shown by the reinitiation of reaction being stopped after completing the first phase. On the basis of all the data obtained, a scheme of the self-cleavage reaction has been proposed including: (i) activation of the ribozyme with energy of 40-50 kcal/mol and a characteristic time of several deciminutes under optimal reaction conditions; (ii) fast and reversible reaction of the phosphodiester bond cleavage; (iii) reaction leading to isomerization of the 3',5'-phosphodiester bond to the 2',5' bond in the self-cleavage site with a characteristic activation time of tens of minutes; and (iv) practically irreversible conformational change leading to fixation of the cleavage by immobilization of the 5'-terminal nucleotide of the product in the center of the formed structure and displacement of the 3'-terminal nucleotide to the periphery. The latter process has a characteristic time of tens of minutes and a low activation energy.