Morphological Characteristics of the Action of Cationic Peptide Warnerin on Regeneration of the Connective Tissue around Implanted Teflon Catheters in Mice under Conditions of Immunosuppression.

Warnerin pretreatment of catheter segments subcutaneously implanted to mice under conditions of immunosuppression led to a significant increase in the number of neutrophils in the surrounding tissues on day 1; the number of fibroblasts tended to decrease by day 3. Immunohistochemical study showed the presence of T and B lymphocytes on day 3, but no positive reactions to vimentin and CD34 were observed during the first 2 days. These changes suggest that warnerin reduced the intensity of regeneration processes in tissues around the implant, which can be used for suppression of fibrosis.

Activation of the sorption of Staphylococcus epidermidis 33 on hydrophobic polystyrene surface by low-molecular-weight autogenous factors.

The results of studying the compounds secreted into the medium during the adhesion of Staphylococcus epidermidis to surfaces with different levels of hydrophobicity are presented. These compounds seem to be peptides with a molecular weight of 550-600 Da capable of stimulating the adhesion of the tested bacterial strain by performing, in essence, the function of Quorum sensing factors of bacterial adhesion.

[Physiological properties of the vancomycin-resistant strain Staphylococcus epidermidis 33 GISK VAN(R)].

Physiological properties of a selected Staphylococcus epidermidis strain 33 GISK VAN(R) with high resistance to vancomycin, multiple resistance to various antibiotics, as well as decreased sensitivity to lysozyme, lysostaphin, and the low-molecular mass peptide warnerin were studied. The strain was characterized by a thicker cell wall, resulting in considerably decreased rates of vancomycin penetration into the cells and in limited access of the antibiotic to its targets on the bacterial membrane.

[Effect of lantibiotic warnerin on lipid bilayer membranes].

The effect of the lantibiotic warnerin on the ionic permeability of artificial membranes has been studied. Membranes were composed of different lipid fractions, including lipids isolated from warnerin-sensitive cells of Staphylococcus epidermidis. It was shown that warnerin selectively interacts with artificial membranes of different lipid composition, which leads, in some cases, to the formation of ionic channels. A computer model of the spatial structure of warnerin has been coustructed, which supports a high probability of the membranotropic activity of this peptide.

[The dependence of the antibacterial effect of the polycationic peptide warnerin on the energy state of target cells].

The bactericidal effect of the polycationic peptide warnerin, produced by Staphylococcus warneri IEGM KL-1, was found to depend on the energy state of susceptible Staphylococcus epidermidis cells. The pre-treatment of these cells with compounds that diminish the proton-motive force of plasma membranes enhanced cell tolerance to warnerin. The components deltapsi and deltapH of the membrane proton potential influenced the antibacterial activity of warnerin in different ways. In particular, the antibacterial activity of warnerin decreased when the electric component of the proton-motive force of target membranes declined.

[Lysozyme of the mollusk Unio pictorum and the sensitivity of alkanotrophic rhodococci to its effect]. / Lizotsim molliuska Unio pictorum i chuvstvitel'nost' k nemu alkanotrofnykh rodokokkov.

A preparation of lysozyme from a freshwater bivalve, Unio pictorum, has been isolated by sorption to chitin, and its physicochemical properties have been studied. An assessment of the sensitivity of 48 strains of rhodococci, belonging to the species Rhodococcus rubber, R. luteus, and R. erythropolis (Specialized Collection of Alkanotrophic Microorganisms of the Institute of Ecology and Genetics of Microorganisms, Ural Division of the Russian Academy of Sciences), which were isolated from diverse natural waters, to lysozyme of the mollusk Unio pictorum demonstrated that the three species differ in their sensitivity to its effects. The high resistance of rhodococci to lysozyme is indicative of their considerable permanence in hydrobiocenoses (and, therefore, ability to maintain self-purification of microbiocenoses from hydrocarbons).

[Determination of gamma-aminobutyric acid concentration and activity of glutamate decarboxylase in blood serum of patients with multiple sclerosis]. / Issledovanie kontsentratsii gamma-aminomaslianoi kisloty i aktivnosti glutamatdekarboksilazy v syvorotke krovi bol'nykh rassleiannym sklerozom.

The pathology of neurotransmitters is of the key importance in the pathogenesis of multiple sclerosis. The developed method makes it possible to determine, with a high accuracy degree, the level of gamma-aminobutyric acid (GABA) and the activity of glutamate decarboxylase (GAD) in the blood serum of patients with multiple sclerosis. The study showed that the level of neurotransmitters and the GAD activity in the blood serum of patients was reduced as compared to the controls. The neuronal transmission pathology can have the key importance in the development, progressing and clinical course of the demyelization process.

[The efficient accumulation of cesium ions by Rhodococcus cells]. / Effektivnoe izvlechenie tseziia kletkami bakterii roda Rhodococcus.

Bacteria of the genus Rhodococcus were found to be able to accumulate cesium by means of active transport and nonspecific sorption on the cell surface structures. The maximum removal (up to 97%) of cesium from a medium with ammonium acetate was observed at 28 degrees C, pH 7.8-8.6, and an equimolar content (0.2 mM) of potassium and cesium ions in the medium. The most active cesium-accumulating Rhodococcus sp. strains can be used for purification of industrial wastewaters contaminated with radionuclides.

[Effect of peptide antibacterial factor and changes in Staphylococcus susceptibility to antibiotics]. / Izmenenie antibiotikochuvstvitel'nosti stafilokokkov v usloviakh realizatsii éffekta peptidnogo antibakterial'nogo faktora.

The susceptibility to antibiotics of the Staphylococcus epidermidis cells in the presence of low-molecular weight peptide factor was investigated. The factor was isolated from the Styaphylococcus warneri culture media. The factor enhanced the S. epidermidis susceptibility to ampicillin, chloramphenicol, lincomycin, rifampicin, tetracycline, cefalexine, erythromycin and fusidine. The same effect was demonstrated for the cells of S. epidermidis resistant to cadmium ions along with resistance to several antibiotics. However the cells reaction in this case was expressed to a lower extent. It was suggested that revealed alterations in staphylococci susceptibility to antibiotics was due to the peptide factor effect on cytoplasmic membrane permeability that resulted in nonspecific increase in accumulation of various compounds with low-molecular weight.

[Regulation of beta-galactosidase synthesis in Escherichia coli by exogenous cyclic 3',5'-adenosine monophosphate]. / Reguliatsiia sinteza beta-galaktozidazy Escherichia coli ékzogennym tsiklicheskim 3',5'-adenozinmonofosfatom.

The effect of cyclic 3',5'-adenosine monophosphate (cAMP) on the rate of beta-galactosidase biosynthesis was studied in the cells of Escherichia coli M-17 growing in MPB and mineral media with glucose and maltose, i.e. under the conditions of various catabolite repression, as well as upon lac-operon induction by isopropyl-beta-D-galactopyranoside (IPGP). The stimulating action of exogenous cAMP was found only in a medium with salts and glucose. The induction by IPGP was highest during the growth in a medium with glucose and maltose. When the medium contained IPGP, cAMP accelerated the enzyme synthesis in all media, but only at the early growth phases, while cAMP eliminated the effect of IPGP at the stationary phase of growth. The regulation of beta-galactosidase biosynthesis by cAMP demonstrated for the first time that this effect depended on the physiological state of E. coli: the expression of catabolite-sensitive E. coli genes was subject to both positive and negative regulation in one and the same inducible system. The effect exerted by cAMP depended on the nature of a carbon source in the growth medium.

[Partial purification and various characteristics of antibacterial factor in preparations of interferon]. / Chastichnaia ochistka i nekotorye kharakteristiki antibakterial'nogo faktora v preparatakh interferona.

A factor showing antibacterial activity was isolated from human alpha-interferon native preparations with affinity chromatography on immobilized cells of staphylococci. The antibacterial activity was found to be stable to the effect of nucleases and heating. Exposure to trypsin activated the antibacterial activity while exposure to pepsin somewhat destroyed it. Growth of the staphylococcal culture resistant to antibiotics was inhibited by the factor.

[Method of determining low-molecular weight oligoamines in various biological materials]. / Metod opredeleniia nizkomolekuliarnykh oligoaminov v razlichnom biologicheskom materiale.

A modified procedure is described for thin-layer chromatography of dansyl-spermine, -spermidine, -cadaverine and -putrescine. Distinct separation of the dansyl derivatives studied from dansyl-ammonium, which usually causes difficulties, was achieved. This procedure enabled to estimate the pyckomolar quantities of biogenic oligoamines. The method does not require radioactive compounds, enables to carry out the measurements without the use of spectrofluorimeter or fluorescent densitometer. The densitometry of the chromatogram photo-prints was successfully used for quantitative estimation of the oligoamines.

[Cyanide-resistant respiration of bacteria and its relation to metabolite oversynthesis]. / Tsianidrezistentnoe dykhanie bakterii i ego vzaimosviaz' s izbytochnym sintezom metabolitov.

The phenomenon of cyanide-resistant respiration was studied in bacteria as well as its relation to the oversynthesis of metabolites. Cyanide-resistant respiration was shown to be common of aerobic and facultative anaerobic bacteria. The resistance of respiration to cyanide was observed when the growth of a microbial culture was inhibited or ceased entirely, provided the culture lacked the oversynthesis of metabolites. When a culture was capable of metabolites oversynthesis under such conditions, cyanide-resistant respiration (if any) declined. Therefore, there is a competition between metabolites oversynthesis and cyanide-resistant respiration, which is typical of many microorganisms.

[Membrane potential of Pseudomonas aeruginosa spheroplasts having a cyanide-resistant respiration]. / Membrannyi potentsial sferoplastov Pseudomonas aeruginosa, obladaiushchikh tsianidresistentnym dykhaniem.

The membrane potential (delta psi) of Ps. aeruginosa spheroplasts was measured by a hydrophobic cation--tetraphenylphosphonium (TPP+) under conditions of simultaneous and separate action of the main respiratory chain and cyanide-resistant oxidase. In all cases, oxidation of endogenous substrates by spheroplasts was followed by generation of a membrane potential of the value of 127--156 mv. An addition of 1 mM cyanide did not practically affect the potential value. The discharge of the potential was attained by further addition of dicyclohexylcarbodiimide (DCCD) or valinomycin. The oxidation of the substrates added by the main respiratory chain was accompanied by an additional increase in the potential by 20--30 mv. In this case, an addition of cyanide decreased the potential by the same value. Oxidation of all substrates, except for TMPD+ ascorbate under conditions of functioning of cyanide-resistant oxidase also increased the potential by 15--50 mv. However, in this case cyanide did not practically affect the increase of the potential. The gain in the potential under TMPD + ascorbate oxidation by cyanide-resistant spheroplasts is prevented by cyanide. A question is discussed as to whether the transfer of reducing equivalents directly via cyanide-resistant oxidase is associated with the generation of a membrane potential or its functioning is not connected with the accumulation of energy in the form available for the cell.