[Colonization activity of conditionally pathogenic microorganisms and features of biofilm formation on the surface of thermoplastic polymer material]. / Kolonizatsionnaya aktivnost' uslovno-patogennykh mikroorganizmov i osobennosti obrazovaniya bioplenki na poverkhnosti stomatologicheskogo termoplastichnogo polimernogo materiala.

THE PURPOSE OF THE STUDY: Was to assess the microbial colonization and biofilm-forming activity of conditionally pathogenic microorganisms in vitro to samples of acrylic-free thermoplastic polymer material and to assess the possibility of its use for the manufacture of removable tooth splinting structures by injection method. MATERIALS AND METHODS: The reference strains S. aureus, S. epidermidis, S. pyogenes, E. faecalis, E. coli, and C. albicans. Biofilm-forming activity was assessed by the level of ethanol extraction of a 0.1% aqueous solution of gentian violet by measuring on a PowerWave X microplate reader (USA). RESULTS: A low degree of severity of microbial colonization and sufficient colonization resistance to the formation of a microbial biofilm of E. coli (0.374±0.056 cu opt. Pl.), S. aureus (0.272±0.039 cu. Opt. Pl.), S. epidermdis (0.299±0.028 cu opt. Pl.), S. ryogenes (0.399±0.069 cu opt. Pl.), E. faecalis (0.401±0.089 cu opt. Pl.). Moreover, C. albicans strains form a more pronounced biofilm (0.425±0.104 cu opt. Pl.) in comparison with other strains studied in the experiment. CONCLUSION: Samples from a thermoplastic polymer based on polyoxymethylene have satisfactory biomedical characteristics and can be used at the stages of dental orthopedic treatment of patients without oral candidiasis.

[The medical social work with individuals of elderly and senile age with total loss of teeth].

The article substantiates the necessity in applying the complex approach to handle medical social problems of patients in elderly and senile age suffering of complete absence of teeth conditions the relevance of developing medical and social work with this contingent. In the complex management of patients receiving dental orthopedic care, professional social workers apply medical, psychological, pedagogical and social measures targeted to maintain their actual health. It is demonstrated that such activities can be implemented within the framework of wide network of social service organizations in cooperation with dentists.

[Possible mechanism of antioxidant action of dinitrosyl iron complexes]. / Vozmozhnyi mekhanizm antioksidantnogo deistviia dinitrozil'nykh kompleksov zheleza.

The antioxidant effect of dinitrosyl iron complexes (DNICs) was studied in various model systems. DNICs with glutathione ligands effectively inhibited Cu2+-induced peroxidation of low density lipoproteins (LDL). The antioxidant effect of DNICs with phosphate ligands and free reduced glutathione (GSH) was less pronounced. In addition, DNICs with glutathione suppressed the formation of reactive oxygen species during co-oxidation of lecithin liposomes and glucose. Free radical oxidation in this system was induced with a lipophilic azo initiator and evaluated by luminol-dependent chemiluminescence. NO sharply stimulated chemiluminescence during co-oxidation of glucose and liposomes, thus suggesting the formation of potent oxidants under these conditions. Glutathione DNICs scavenge the superoxide radical anion generated in the xanthine-xanthine oxidase system. Superoxide production was assessed by lucigenin-dependent chemiluminescence and electron paramagnetic resonance (EPR) spectroscopy. Chemiluminescence revealed the dose-dependent character of antiradical effect of glutathione DNICs; moreover, these complexes turned out to be more efficient than GSH. EPR spectra of the adducts of the DEPMPO spin trap with free radicals suggest that the interaction of glutathione DNICs and superoxide does not result in the formation of the thiyl radical of glutathione. Here we propose a mechanism of the antioxidant action of glutathione DNICs, suggesting that unstable intermediate complexes are formed upon their interaction with superoxide or lipid radicals. Further, as a result of intramolecular rearrangement, these intermediates decompose without the free radical as the by-products.

Combined effect of G3139 and TSPO ligands on Ca(2+)-induced permeability transition in rat brain mitochondria.

Permeability of the mitochondrial outer membrane is determined by the activity of voltage-dependent anion channels (VDAC) which are regulated by many factors and proteins. One of the main partner-regulator of VDAC is the 18 kDa translocator protein (TSPO), whose role in the regulation of membrane permeability is not completely understood. We show that TSPO ligands, 1 µM PPIX and PK11195 at concentrations of 50 µM, accelerate opening of permeability transition pores (mPTP) in Ca(2+)-overloaded rat brain mitochondria (RBM). By contrast, PK11195 at 100 nM and anti-TSPO antibodies suppressed pore opening. Participation of VDAC in these processes was demonstrated by blocking VDAC with G3139, an 18-mer phosphorothioate oligonucleotides, which sensitized mitochondria to Ca(2+)-induced mPTP opening. Despite the inhibitory effect of 100 nM PK11195 and anti-TSPO antibodies alone, their combination with G3139 considerably stimulated the mPTP opening. Thus, 100 nM PK11195 and anti-TSPO antibody can modify permeability of the VDAC channel and mPTP. When VDAC channels are closed and TSPO is blocked, permeability of the VDAC for calcium seems to be the highest, which leads to accelerated pore opening.

Effect of peripheral benzodiazepine receptor (PBR/TSPO) ligands on opening of Ca2+-induced pore and phosphorylation of 3.5-kDa polypeptide in rat brain mitochondria.

The effect of nanomolar concentrations of PBR/TSPO ligands--Ro 5-4864, PK11195, and PPIX--on Ca2+-induced permeability transition pore (PTP) opening in isolated rat brain mitochondria was investigated. PBR/TSPO agonist Ro 5-4864 (100 nM) and endogenous ligand PPIX (1 microM) were shown to stimulate PTP opening, while antagonist PK11195 (100 nM) suppressed this process. Correlation between PBR ligand action on PTP opening and phosphorylation of a 3.5 kDa polypeptide was investigated. In intact brain mitochondria, incorporation of [gamma-(32)P]ATP into 3.5 kDa peptide was decreased in the presence of Ro 5-4864 and PPIX and increased in the presence of PK11195. At threshold Ca2+ concentrations leading to PTP opening, PBR/TSPO ligands were found to stimulate dephosphorylation of the 3.5 kDa peptide. Specific anti-PBR/TSPO antibody prevented both PTP opening and dephosphorylation of the 3.5-kDa peptide. The peptide was identified as subunit c of F(o)F(1)-ATPase by Western blot using specific anti-subunit c antibody. The results suggest that subunit c of F(o)F(1)-ATPase could be an additional target for PBR/TSPO ligands action, is subjected to Ca2+- and TSPO-dependent phosphorylation/dephosphorylation, and is involved in PTP operation in mitochondria.