Structural transformations of arabinogalactan from the Siberian larch during mechanochemical processing and the biological properties of the products

It has been found by gel-penetrating chromatography and quantitative ¹³C NMR spectroscopy that mechanochemical processing of arabinogalactan isolated from the wood of the Siberian larch changes the molecular mass distribution, monosaccharide composition, and the degree of branching of its macromolecules. This is due to the partial destruction of polysaccharide macromolecules and subsequent recombination of resulting fragments. The intensity of these processes depends on the conditions of mechanochemical processing. Based on the data of IR and ¹³C NMR spectra, the conclusion has been drawn that no functionalization of arabinogalactan macromolecules occurs under these conditions. The toxicopharmacological properties of mechanically processed arabinogalactan have been studied. Its acute toxicity is >5000 mg/kg.     

Enzymatic System of Metabolism and Detoxication of Xenobiotics as a Basis of Metabolic Portraiting during Prognostication of Risk of Pathological Processes

We studied intraspecific features of the main enzymes of metabolism and detoxication of xenobiotics on mice (eight inbred lines) and rats (five lines) for estimation of possible variants of complete or incomplete metabolic equality. Significant genetically determined intraspecific differences for activities of the enzymes of metabolism and detoxication of xenobiotics were described. Generalized criteria for comparison of the metabolic status were proposed on the basis of activities of the main enzymes: cytochrome P-450 (hydroxylation and epoxidation), epoxyhydrolase, glutathione-S-transferase, UDP-glucuronosyl transferase, and sulfotransferase. The proposed criteria for estimation of the metabolic parameters of an individual can serve as a basis of metabolic portraiting.     

Effect of donor immunization with different influenza vaccines on the insulin level of the blood serum

Materials on the study of relationship between the activity of immunoreactive insulin and the degree of an increase in the level of anti-influenza antibodies, induced by vaccine strains, are presented. A short-term decrease in the activity of insulin, more pronounced in donors immunized with adsorbed chemical influenza vaccine, and an increase in the antibody level, mainly in the group of donors receiving killed influenza vaccine, have been noted.     

Quantitative characteristics of radiation injury of the spermatogenic epithelium and the rate of its recovery after exposure to fast neutrons and gamma-radiation

The paper submits the results of studies on the kinetics of spermatogenous epithelium cell number after exposure to fast neutrons (60-300 cGy) and gamma-radiation (200-600 cGy). It was shown that a relative decrease in the quantity of spermatocytes is determined by an exponential dose-response curve with D0 of 35 and 120 cGy for neutrons and gamma-radiation respectively. For spermatides and spermatozoa a single D0 value of 20 and 55 cGy was obtained for neutrons and gamma-radiation respectively. As the radiation dose increases the recovery process in the epithelium is substantially decelerated. The equation T1/2 = T1/2(0)e0.0009D well describes the dependence of the half-recovery period T1/2 upon the equivalent dose.     

Interaction of puromycin with acceptor site of human placenta 80 S ribosomes

The complex N-AcPhe-tRNA(Phe).poly(U).80 S ribosome from human placenta was treated with puromycin taken in various concentrations. Based on the kinetic data of N-acetylphenylalanyl-puromycin formation, the association constant of puromycin with the acceptor site of the ribosome was estimated to be (3.96 +/- 0.84) x 10(4) M-1 at 37 degrees C.     

Palladium(II)-coproporphyrin I as a photoactivable group in sequence-specific modification of nucleic acids by oligonucleotide derivatives

The 34-mer oligodeoxynucleotide was shown to be selectively modified at the G17 position upon photoirradiation in the presence of complementary 17-mer oligodeoxynucleotide bearing Pd(II)-coproporphyrin I covalently linked to the 5'-end phosphate group.     

The Thermodynamic Basis for Viral RNA Detection by the RIG-I Innate Immune Sensor

RIG-I is a cytoplasmic surveillance protein that contributes to the earliest stages of the vertebrate innate immune response. The protein specifically recognizes 5′-triphosphorylated RNA structures that are released into the cell by viruses, such as influenza and hepatitis C. To understand the energetic basis for viral RNA recognition by RIG-I, we studied the binding of RIG-I domain variants to a family of dsRNA ligands. Thermodynamic analysis revealed that the isolated RIG-I domains each make important contributions to affinity and that they interact using different strategies. Covalent linkage between the domains enhances RNA ligand specificity while reducing overall binding affinity, thereby providing a mechanism for discriminating virus from host RNA.