Use of Corynebacterium pseudodiphtheriticum for elimination of Staphylococcus aureus from the nasal cavity in volunteers exposed to abnormal microclimate and altered gaseous environment

Effectiveness of saline suspension of Corynebacterium pseudodiphtheriticum containing spray was assessed in a 30-days chamber experiment modeling the effects of hyperthermia and polluted air on humans. Spray was targeted at eliminating Staphylococcus aureus from the nasal cavity of human subjects. Three of four volunteers became S. aureus carriers in the course of the experiment, and one was a chronic carrier of methicillin-resistant S. aureus (MRSA). Spray application eradicated S. aureus in three subjects and reduced its presence in the MRSA carrier. Results of the study suggest that C. pseudodiphtheriticum can be used for control of S. aureus in the nasal environment. However, further investigations are required.     

Biocatalytic synthesis of conducting polymers and prospects for its application

Enzymatic methods of synthesis of conducting polymers, physicochemical properties of the resulting products, and mechanisms of the reactions are considered. The enzymes involved in oxidative polymerization of monomers are briefly characterized. Examples of practical application of enzymatically synthesized conducting polymers are given.     

A protocol for isolation and visualization of yeast nuclei by scanning electron microscopy (SEM)

This protocol details methods for the isolation of yeast nuclei from budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe), immuno-gold labeling of proteins and visualization by field emission scanning electron microscopy (FESEM). This involves the removal of the yeast cell wall and isolation of the nucleus from within, followed by subsequent processing for high-resolution microscopy. The nuclear isolation step can be performed in two ways: enzymatic treatment of yeast cells to rupture the cell wall and generate spheroplasts (cells that have partially lost their cell wall and their characteristic shape), followed by isolation of the nuclei by centrifugation or homogenization; and whole cell freezing followed by manual cell rupture and centrifugation. This protocol has been optimized for the visualization of the yeast nuclear envelope (NE), nuclear pore complexes (NPCs) and associated cyto-skeletal structures. Samples once processed for FESEM can be stored under vacuum for weeks, allowing considerable time for image acquisition.     

Two phases of chromatin decondensation during dedifferentiation of plant cells: distinction between competence for cell fate switch and a commitment for S phase

Cellular dedifferentiation is the major process underlying totipotency, regeneration, and formation of new stem cell lineages in multicellular organisms. In animals it is often associated with carcinogenesis. Here, we used tobacco protoplasts (plant cells devoid of cell wall) to study changes in chromatin structure in the course of dedifferentiation of mesophyll cells. Using flow cytometry and micrococcal nuclease analyses, we identified two phases of chromatin decondensation prior to entry of cells into S phase. The first phase takes place in the course of protoplast isolation, following treatment with cell wall degrading enzymes, whereas the second occurs only after protoplasts are induced with phytohormones to re-enter the cell cycle. In the absence of hormonal application, protoplasts undergo cycles of chromatin condensation/decondensation and die. The ubiquitin proteolytic system was found indispensable for protoplast progression into S phase, being required for the second but not the first phase of chromatin decondensation. The emerging model suggests that cellular dedifferentiation proceeds by two functionally distinct phases of chromatin decondensation: the first is a transitory phase that confers competence for cell fate switch, which is followed, under appropriate conditions, by a second proteasome-dependent phase representing a commitment for the mitotic cycle. These findings might have implications for a wide range of dedifferentiation-driven cellular processes in higher eukaryotes.     

Effect of vitamin D3, arginine, and a biologically active complex from Serratula coronata on free radical oxidation of lipids in vitamin D deficiency

Lipid free-radical oxidation (LFRO) on the D-deficient model with the animal administration per os by vitamin D3 (cholecalciferol), specimen from Serratula coronata plant, containing low molecular weight biological sterol--20-hydroxyecdysone (ecdysterone) was investigated. As well influence of arginine as one of the amino acid components of the specimen from Serratula coronata was investigated. The LFRO in the blood serum, liver microsomal and mitochondrial fractions were characterize by measured of the chemiluminescence kinetic parameters. Vitamin D3, the specimen from Serratula coronata plant and arginine displayed some antioxidant (AO) properties as was established. On the basis of the received experimental data the series of their antioxidizing activity: vitamin D3 = drug from Serratula coronata > arginine were offered. The possible mechanism of the 20-hydroxyecdysone and arginine participation on LFRO maybe in free-radical reactions breaking via hydroxy and amino groups in structure of their molecules.     

Deficit of glucocorticoid production in rats aggravates ulcerogenic effects of stimuli of various modality and intensity

Effects of glucocorticoid deficiency and corticosterone replacement on gastric mucosal injury induced by various ulcerogenic stimuli have been evaluated in rats. Gastric erosions were induced in male rats by stimuli of different modalities and intensities. Glucocorticoid deficiency was induced by adrenalectomy or delayed inhibitory action after a single pharmacological dose of cortisol (300 mg/kg, i.p.) injected one week before the onset of ulcerogenic stimulus. Ulcerogenic stimuli induced both a plasma corticosterone rise and a gastric mucosal injury. The area of mucosal damages induced various stimuli ranging from a small to extensive those. Glucocorticoid deficiency significantly potentiated an ulcerogenic action of each ulcerogenic stimulus. Replacement by corticosterone (4 mg/kg, s.c., 15 min before the onset of ulcerogenic stimulus) prevented or significantly decreased the erosion--potentiating effect of glucocorticoid deficiency. These results show that endogenous glucocorticoids released during ulcerogenic influences help gastric mucous membrane to resist against a harmful action of both weak and strong ulcerogenic stimuli.     

Oxidative Modification of Proteins: Oxidation of Tryptophan and Production of Dityrosine in Purified Proteins Using Fenton's System

Specific features of metal-catalyzed oxidation (MCO) of purified proteins (human serum albumin and human erythrocyte superoxide dismutase) were analyzed by the oxidation level of tryptophan and tyrosine. The production of dityrosine cross-links and the oxidation of tryptophan residues were recorded by fluorescence. The degree of oxidative modification of the amino acid residues of the proteins depended on the concentration of the Fenton's medium components and on the incubation time. These changes were different in different proteins. By electrophoresis and gel-permeation chromatography, changes in the superoxide dismutase structure are shown to be caused by oxidative modification of the enzyme and to be accompanied by a decrease in its activity. Findings with OH^. scavengers (mannitol and ethanol) suggest that oxidative modification of the proteins in Fenton's medium should be associated not only with hydroxyl radical but also with ferryl and perferryl ions and with the radical PH₃.     

Plants in urbanized natural environment: florogenesis,coenogenesis and population structure

Published data on both flora and phytocoenosis genesis and plant population dynamics are reviewed. Urbanized environment is rated as a stress factor for single plants and their communities. The change of plant population structure in cities and towns is analysed as the important indicator of the environment quality. The problems of phytoindication of environment quality in cities and towns for its optimization are considered.     

A comparison of the immune response induced by DNA or by an inactivated vaccine against tick-borne encephalitis

BALB/c mice were immunized with recombinant plasmid DNA pSVK3-ENS1 and pcDNAI-NS3 containing, respectively, genes E-NS1 and NS3 of tick-borne encephalitis (TBE) virus. Antibodies to TBE virus proteins were detected in the blood sera of the immunized animals by the method of the enzyme immunoassay. Though the titers of virus-specific antibodies in the sera of mice immunized with protein vaccines exceeded those registered after immunization with DNA vaccines, essential protective immunity was observed after the use of both vaccines.