Mutagenic activity of luminal and pyrazidol

The mutagenic activity of two psychotropic preparations luminal and pyrazidol was studied. It was shown that luminal is capable of indicing chromosomal aberrations in bone marrow cells of mice as well as dominant lethal mutations in postmeiotic stages of spermiogenesis. This allows one to consider it as genetically dangerous. Pyrazidol did not show any mutagenic activity in the studied test objects. These data must be taken into account when treating individuals who are still in the reproductive period of life.     

New site-specific endonucleases from strains of Bacillus

In a search for new restriction endonucleases type II, among forty bacterial strains of the Bacillus genus two strains producing site-specific endonucleases have been found. Endonucleases BbvAIII and BspFI, isolated from B. brevis BLM B-677 and B. species F, are shown to be true isoschisomers of BspMII (Kpn2I) and Sau3AI, respectively.     

Free radicals and antioxidants

The data obtained from the author's laboratory were used to make this review. The author's classification of free radicals, approaches, the origin and metabolism of primary radicals, the contribution of iron ions to the production of secondary radicals and the mechanisms of antioxidative protection of cells and tissues from damage are considered. According to the classification proposed, the radicals may be divided into primary (superoxide, semiquinones and nitric oxide), secondary (hydroxyl and lipid radicals) and tertiary (radicals of antioxidants). The primary radicals are formed by enzymatic systems and perform biologically important functions. The secondary radicals are formed from hydroperoxides in the reactions of divalent iron ions and damage to cell structures. In the cells and blood plasma, there is a complicated system of antioxidants that prevent the production of secondary radicals. All antioxidants may be arbitrarily divided into water-soluble and hydrophobic. The first group involves the enzymes catalase and glutathione peroxidase, iron ion chelators (such as ceruloplasmin and transferrin in the blood and carnosine in other tissues), and, probably, hydroxyl radical traps, such as uric acid and ascorbate. The hydrophobic antioxidants include primarily the free radical traps alpha-tocopherol, flavonoids, and carotenes. Studies of lipid peroxidation kinetics in the membranous structures, carried out by chemiluminescence and mathematical modeling of the reactions have shown that the radicals of antioxidants (such as alpha-tocopherol) enter the further reactions in the lipid phase, including those with lipid hydroperoxides.     

Use of kinetics of Fe+2-induced chemiluminescence in a tris-buffer liposome suspension for studying the antioxidant activity of blood plasma

In order to evaluate antioxidant activity (AOA) of different preparations in respect to Fe(2+)-induced lipid peroxidation (LPO) chemiluminescence (CL) kinetics in tris-buffer liposome suspension was proposed. For studying AOA stages of fast flash, latent period and slow flash related to LPO reaction development were used. The measurement of CL kinetic parameters along with malondialdehyde accumulation makes it possible to determine also the mechanism of antioxidant effect on the preparations under consideration. The mechanism of AOA of the blood plasma is mainly due to transferrin, ceruloplasmin and HCO3- interaction with Fe2+ leading to abstraction of some part of ferrous ions participated in LPO reactions. In the case of albumin the change of CL kinetic parameters was proposed to be conditioned by the competition with ferrous ions for binding sites on liposomes. The effect of a-tocopherol at physiological concentrations compared with other blood plasma components in this system was negligibly small.     

Analysis of the primary structure of the supplementary regulatory region of the riboflavin operon in Bacillus subtilis

The sequencing of a 3.5 kb EcoRI-BamHI fragment located in the 236 degrees region of the Bacillus subtilis chromosome revealed a 690-bp long open reading frame, partly similar in amino acid composition to flavokinases/FAD synthases from several microorganisms. The discovered sequence can be identified with the gene ribR, an auxiliary regulatory gene of the riboflavin operon of Bacillus subtilis.     

Cerebrospinal fluid sorption in the system of complex treatment of chronic cerebral ischemia

Those people living in industrial regions have increased incidence of chronic disorders of the hepatobiliary system. In postpartum female patients presenting with the above extragenital pathology, there occur with a greater than usual frequency such abnormalities as uterus hypotony, its subinvolution, hypogalactia, with the postpartum septic complications running a graver course. Immune inadequacies and microcirculatory disorders detected in women presenting with chronic disorders of the hepatobiliary system result in the pathological course of the postpartum period.