Effects of peroxynitrite and lipopolysaccharide on mitotic activity of C6 glioma cells

Peroxynitrite is one of the most potent neurotoxic agents with multiple targets in neurons and glial cells. This study addressed a question of whether peroxynitrite-mediated cytotoxicity can be prevented by Escherichia coli lypopolisaccharide (LPS) due to its mitogenic activity towards C6 glioma cells. A number of characteristic morphological changes (processes impairments, nuclei modifications, cytoplasm vacuolization) and apoptotic cells were observed in the cell culture after 24-h treatment with 3-morpholinosyndnonimine (SIN-1), a well-known donor of peroxynitrite. These morphological changes were clearly associated with a SIN-1 dose-dependent increase in the number of pathological mitoses as well as with SIN-1 inhibition of the menadione-induced, lucigenin-enhanced chemiluminescence of C6 glioma cells, an independent indicator of mitotic activity of these cells. The mitotic index of C6 glioma cells increased in response to LPS and underwent non-uniform changes depending on SIN-1 concentrations. At a mitogenic concentration of 100 ng/ml, LPS reduced significantly the toxicity of SIN-1 determined as the accumulation of pathological mitoses, thus acting as a protective agent. Taken together, our findings indicate that SIN-1 specifically impairs the mitotic process in C6 glioma cells, and provide the first evidence that antimitotic effects of peroxynitrite can be restored by LPS.     

Thermopulser with Channel for Assessment of Thermopulsing Session Efficiency

A single-crystal microcontroller thermopulser with a channel for thermopulsing session efficiency assessment is described. The real-time monitoring of respiratory arrhythmia represents the state of autonomic nervous system, thereby providing evaluation of thermopulsing session efficiency.     

The dynamics of monoamine metabolism in rat brain structures in the late period after exposure to accelerated carbon ions

We studied the effect of carbon ions (¹²C) with an energy of 500 MeV/nucleon at a dose of 1 Gy on monoamine metabolism in the brains of rats of different ages. Neurochemical parameters that characterize the distribution of noradrenaline (NA), dopamine (DA), serotonin (5-HT), and its metabolites were evaluated during 2 months on days 30 and 90 after the exposure to radiation. We studied the prefrontal cortex, hypothalamus, hippocampus, and striatum. The results showed changes in the activities of the NA, DA, and 5-HT systems in rats of different age groups after exposure to radiation. The most prominent differences in the exposed and control animals were observed in the prefrontal cortex and hypothalamus, which indicates the important role of these brain regions in long-term effects of exposure to radiation on the central nervous system. A comparison of animals from different age groups showed a decrease in the intensity of the temporal changes in all analyzed structures except the striatum in the exposed rats. Based on these findings, we assumed that the activation of compensatory and repairing mechanisms occurs in the late post-radiation period. At relatively low linear energy transfer of particles (10.6 keV/µm), it may lead to the partial recovery of brain functions that were impaired by radiation. At higher values of the linear energy transfer, the compensatory and recovery processes are activated to a lesser degree and functional impairment increases with time.     

Nitric oxide is necessary for labilization of a consolidated context memory during reconsolidation in terrestrial snails

Nitric oxide (NO) is known to be involved in associative memory formation. We investigated the influence of blocking NO function on the reconsolidation of context memory in terrestrial snails (Helix lucorum L.). After a 10 day session of electric shocks in one context only, context memory in snails was observed in test sessions as the significant difference of amplitudes of withdrawal responses to tactile stimuli in two different contexts. After a 1 day rest, a session of ‘reminding’ was performed, preceded by injection in different groups of the snails with either vehicle or combination of the protein synthesis blocker anisomycin (ANI) with one of the following drugs: the NO scavenger carboxy‐PTIO, the NO‐synthase inhibitors N‐omega‐nitro‐L‐arginin, nitroindazole and NG‐nitro‐L‐arginine methyl ester hydrochloride, or the NO donor S‐nitroso‐N‐acetyl‐DL‐penicillamine. Testing the context memory at different time intervals after the reminder under ANI injection showed that the context memory was impaired at 24 h and later, whereas the reminder under combined injection of ANI and each of the NO‐synthase inhibitors used or the NO scavenger showed no impairment of long‐term context memory. Injection of the NO donor S‐nitroso‐N‐acetyl‐DL‐penicillamine with or without reminder had no effect on context memory. The results obtained demonstrated that NO is necessary for labilization of a consolidated context memory.     

Cytogenetic effects in human blood lymphocytes in vitro after irradiation by protons with 1-GEV energy]

Cytogenetic disorders in peripheral blood lymphocytes of humans were studied in culture following single irradiation by protons with energy of 1 GeV. Doses ranged from 0.05 to 2.0 Gy. A large number of structural damages were observed. Nature of dependence of frequency of such irradiation markers as dicentrics and centric ring was established. Relative biological coefficient of relative energy protons was calculated as 1.2.     

Serotonin Precursor 5-Hydroxytryptophan Disturbs the Protective Effect of Low Doses of Antibodies to S100B Protein during the Formation of Long-Term Sensitization

We studied the effect of ultralow doses of antibodies to calcium-binding protein S-100B and 5-hydroxytryptophan, a metabolic precursor of serotonin, on the formation of long-term sensitization as a neurobiological model of anxiety and depression. Daily administration of antibodies to S-100B to edible snails before the formation of long-term sensitization prevents its development. 5-Hydroxytryptophan administered before the formation of long-term sensitization abolished the protective effect of antibodies to S-100B protein.     

Role of mutations identified in ORFs M56 (terminase), M70 (primase) and M98 (endonuclease) in the temperature-sensitive phenotype of murine cytomegalovirus mutant tsm5

Twenty-six non-synonymous and synonymous mutations have been identified in the temperature-sensitive (ts) mutant (tsm5) of the K181 (Birmingham) variant of murine cytomegalovirus that is deficient in DNA synthesis, processing and packaging at the non-permissive temperature and produces undetectable levels of infectious virus in mice. Non-synonymous mutations identified in the M70 (primase), M56 (terminase) and M98 (nuclease) ORFs were introduced individually and in combination into the K181 (Perth) variant using BAC technology to examine their role in the ts phenotype. The M56 (G439R) and M98 (P324S) mutations had no evident role in the ts phenotype. However, the C890Y M70 mutation alone and in combination with the M56 and/or M98 mutations rendered the virus ts, unable to replicate in mice and highly defective in DNA synthesis. Reversion of the tyrosine mutation to cysteine or introduction of C890M (experimentally) or C890S (naturally) restored the wt phenotype.     

Study of <Emphasis Type="Italic">Monarda Fistulosa</Emphasis> Essential Oil as a Prospective Antiseborrheic Agent

Monarda fistulosa essential oil characterized by pronounced therapeutic effects is proposed for the treatment of seborrhea. Studies of its antibacterial, antimycotic, and antiinflammatory activities showed that it inhibits microorganism growth and is superior to hydrocortisone in combination with vitamin B₆ by its antiinflammatory activity.     

Quantitative characterization of nuclear polymorphism of the epithelial cells in fibroadenomatosis and cancer of the breast

A method for quantitative analysis of epithelial cell nuclear polymorphism was suggested, viz. identification of general statistical population using Petunin's criterion. This criterion was employed to assess heterogeneity of visible surface of interphase epithelial cell nuclei and to assay nuclear DNA level in fibroadenomatous hyperplasia and cancer of the breast. Heterogeneity index (h), alongside with other parameters, appeared useful for quantitative assessment of the disease: heterogeneity index values ranging 0.1-0.4 point to pronounced heterogeneity of epithelial cell nucleus surface and DNA level, and are suggestive of malignant transformation of tissue, whereas benign proliferation of the epithelium is usually characterized by 0.4 less than h less than or equal to 0.9.