[SUBSPECIES DIFFERENTIATION OF YERSINIA PESTIS STRAINS BY PCR WITH HYBRIDIZATION-FLUORESCENT DETECTION].

AIM: Develop a method of differentiation of Y.pestis strains of different subspecies based on PCR with hybridization-fluorescent detection in real-time. MATERIALS AND METHODS: DNA target search for differentiation of subspecies of plague causative agent was carried out by Mauve 2.3.1, Mega 5.0 and BLAST algorithm based on comparison of full-genome sequenc- es of Y.pestis strains. Primers and TAqMan probes were calculated for the DNA targets found, conditions of PCR with hybridization-fluorescent detection - optimized. RESULTS: DNA targets carrying marker mutations for the caucasus, altai, gissar, ulegei subspecies, strains from Talass alpine plague reservoir were detected. The effectiveness of the DNA targets found and the developed approach of subspecies differentiation is confirmed on 101 Ypestis strains of different subspecies, isolated from natural foci of Russia, near and far abroad. CONCLUSION: The developed approach based on PCR with real-time detection allows for a rapid and effective differentiation of Ypestis strains of various subspecies.

[The role of M-cholinoreceptors in the regulation of Th1 and Th2 lymphocyte functions].

Experiments on Wistar rats showed that the activation of m-cholinoreceptors by aceclidine (daily administration in a dose of 0.05 LD50, s.c., for 3 days) enhanced the function of Th1 lymphocytes to a greater extent in comparison to Th2 lymphocytes. The blockage of m-cholinoreceptors by the atropin led to a more pronounced suppression of Th2 lymphocytes function in comparison to Th1 cells.

[Changes in the toxicity and immunotoxity of tetrachloromethane and carbophos under the action of 2,4,6-triphenyl-4H-selenopyran and their connection with cytochrome P-450 dependent monooxygenase system].

It is established in experiments on noninbred rats that 2,4,6-triphenyl-4H-selenopyrane (peroral administration in a dose of 0.8 mg/kg during 3 days) induces cytochrome P450, thus increasing the toxicity and immunotoxicity of carbon tetrachloride (metabolized via "lethal synthesis"), and reduces the analogous effects of carbophos, the biotransformation of which proceeds via the formation of low-toxicity and nontoxic metabolites.

Inhibition of function of T cell subpopulations and decrease in cytokine production during subacute poisoning with various toxicants.

Experiments on outbred albino rats showed that subacute intoxication with organophosphorus compounds dimethyldichlorovinyl phosphate and malathion primarily decreased functional activity of Th1 lymphocytes, immune reactions associated with these cells, and interferon-g production compared to that of Th2 lymphocytes and interleukin-4 synthesis. Acrylic acid nitrile and methanol produced the opposite effect. Sulfur mustard and sodium arsenite were equally potent in reducing the function of Th1 and Th2 lymphocytes and production of cytokines.

Role of Th1 and Th2 lymphocytes and cytokines produced by these cells in suppression of immune reactions during subacute poisoning with anticholinesterase toxicants.

Experiments on Wistar rats showed that subacute poisoning with anticholinesterase toxicants zarin and agent VX (daily subcutaneous injections in 1/7 LD50 for 6 days) led to suppression of cellular and humoral immune reactions and to a decrease in blood concentrations of cytokines (IL-2, IL-4, IFN-gamma) with a reduction of the IFN-gamma/IL-4 and IL-2/IL-4 ratios, which attests to more pronounced decrease in Th1 lymphocyte function in comparison with Th2 cells.

[Immunostimulant properties of polyoxidon on the model of acute poisoning with anticholinesterase chemicals in rats].

Experiments on noninbred rats showed that, upon acute poisoning with toxic chemicals (sarin, VX agent; 1.0 LD50) and the treatment with atropine (10 mg/kg), the administration of polyoxidon in a daily dose of 100 mg/kg over 4 days partly reduces the degree of immune system suppression and the level of lipid peroxidation induced by toxic chemicals.

Inhibition of cytochrome P-450 with 2-diethylamino-ethyl-2,2-diphenylpropylacetate (SKF-525A) reduces immunotoxicity of chlorinated carbohydrates.

Experiments on outbred albino rats showed that single intraperitoneal injection of cytochrome P-450 inhibitor 2-diethylaminoethyl-2,2-diphenylpropylacetate (SKF-525A) in a dose of 50 mg/kg before acute poisoning with 1,2-dichloroethane and trichloroethane in a dose of 1.0 LD(50), metabolized in the body to compounds with higher toxicity (the phenomenon of "lethal synthesis") reduced their immunotoxicity by decreasing the formation of their biotransformation products.

[The influence of aminostigmine on the parameters of nonspecific resistance and immune system of the organism upon acute poisoning of benzyl 3-quinuclidylate].

The results of experiments on outbred rats weighing 180 -240 g showed that the acute poisoning with benzyl 3-quinuclidylate decreases the parameters of nonspecific resistance of the organism, reduces the antibody production mainly to T-dependent antigens (sheep red blood cells), decreases the activity of natural killers and the antibody-dependent cell-mediated cytotoxicity, and suppresses the formation of delayed-type hypersensitivity. Aminostigmine partly inhibits the immunotoxicity benzyl 3-quinuclidylate.

[The effect of immunofan on the immunity system characteristics and lipid peroxidation parameters upon acute chemical poisoning]. / Vliianie imunofana ha pokazateli sistemy immuniteta i perekisnogo okisleniia lipidov posle ostrykh otravlenii toksichnymi khimicheskimi veshchestvami.

The results of experiments on Wistar rats under conditions of acute poisoning with 0.75 LD50 of zarin (isopropylmethyl fluorophosphonate), luisite (beta-chlorovinyl dichloroarsine), arsenic chloride, and dichloroethane showed that a four-day treatment with immunofan in a dose of 10 microg/kg restored the immune status characteristics (antibody formation to T-dependent antigen, antibody-dependent cell-mediated cytotoxicity, natural killer cell activity, and delayed type hypersensitivity) and the related LPO parameters.

Effect of tetrachloromethane on the immune system.

Acute poisoning with tetrachloromethane in a dose of 0.75 LD(50) suppressed humoral and cell immune reactions in Wistar rats. Immunotoxicity of tetrachloromethane is realized via initiation of lipid peroxidation and inhibition of acetylcholine esterase in T lymphocytes and alpha-naphthyl AS-acetate esterase and alpha-naphthyl butyrate esterase in splenocytes.

Anticholinesterase mechanism as a factor of immunotoxicity of various chemical compounds.

Experiments on Wistar rats showed that acute poisoning with chemicals in a dose of 0.75 LD(50) (dimethyl dichlorovinyl phosphate, sarin, VX substance, sulfur yperite, lewisite, tetraethyl lead, dichloroethane) inhibiting platelet acetylcholine esterase, alpha-naphthyl-AS-acetate esterase, and alpha-naphthyl-butyrate esterase suppressed T cell-mediated immune reactions.

[Effect T-activin on the activity of the natural killer cells after acute intoxication by toxic chemical substances]. / Vliianie T-aktivina na aktivnost' estestvennykh kletok-killerov posle ostroi intoksikatsii toksichnymi khimicheskimi veshchestvami.

The results of experiments on male mongrel mice showed that a three-day treatment with T-activin in a dose of 2.5 micrograms/kg restored the activity of natural killer cells reduced by acute poisoning (1 LD50) with ethylene glycol (EG), methanol (MeOH), and ethanol (EtOH). In a dose of 5 micrograms/kg, T-activin produced the same action in the test animals upon acute poisoning with dimethyldichlorovinyl phosphate (DDVP), carbophos (CP), dichloroethane (DE), acrylonitrile (AN), Acetonitrile (AcN), atropine (AT). The degree of suppression of the native killer cell activity by the above chemicals increases in the following order: EtOH < EG < MeOH < CP < AT < AcN < DE < AN < DDVP.

Suppression of natural killer cells after acute intoxication with alcohols and cholinotropic preparations and their reactivation with T-activin.

Acute poisoning with alcohols and cholinotropic preparations carboxyphosphamide and atropine (0.8 LD(50)) was modeled on male outbred mice weighing 18-24 g. The decrease in activity of natural killer cells was most pronounced after injection of atropine, but insignificant after treatment with ethanol. The inhibitory effect of ethylene glycol, methanol, and methanol on functional activity of natural killer cells in vitro directly depended on their concentration. The effects of alcohols in equimolar concentrations of 10, 100, and 500 mM were similar. Therefore, immunotoxicity of alcohols was associated with the action of their metabolites. The ability of products formed after biotransformation of ethylene glycol, methanol, and ethanol in equimolar concentrations to cause damage to natural killer cells decreased in the following order: glyoxylic acid>formic acid>acetaldehyde>glycolaldehyde>glycolic acid. T-Activin injected subcutaneously in doses of 2.5 and 5.0 microg/kg for 3 days normalized activity of natural killer cells suppressed after acute poisoning with alcohols and cholinotropic preparations.

Combined effects of toxicants with various mechanisms of action and mechanical trauma on the immune system.

Experiments on Wistar rats showed that the combined action of mechanical trauma and organophosphorus compound dimethyl dichlorovinyl phosphate a dose of 0.8 LD50 was accompanied by summation of their immunosuppressive effects. We observed an additive effect in relation to stimulation of the adrenal cortex. Treatment with general chemical toxicants (acrylic acid nitrile and acetonitrile, 0.8 LD50) alone or in combination with mechanical trauma produced similar increase in plasma corticosterone concentration. This effect was short-lasting and less pronounced compared to the influence of dimethyl dichlorovinyl phosphate. The immunosuppressive effect of trauma and nitriles is primarily related to the influence of poisons.

[The effect of unithiol on the changes in immunotoxicity of 2-chloroethenylchloroarsine]. / Vliianie unitiola na izmenenie immunotoksichnosti 2-khlorétenildikhlorarsina.

The results of experiments on Wistar rats under conditions of acute intoxication with 2-chloroethenyldichloroarsine (beta-chlorovinyldichloroarsine) (0.75 LD50) showed that unithiol increases antiinfectious nonspecific resistance (NSR) of the organism. This is manifested by improved NSR characteristics: increased activity of the natural killer cells, predominant formation of antibodies to thymus-dependent antigen, and development of delayed-type hypersensitivity. However, no complete recovery of the NSR parameters impaired by 2-chloroethenyldichloroarsine is observed.

Role of anticholinesterase mechanism in suppression of antibody formation during acute poisoning with organophosphorus compounds.

Experiments on Wistar rats showed that acute poisoning with organophosphorus compound dimethyl dichlorovinyl phosphate (0.5 LD(50)) was accompanied by two opposite effects: inhibition of acetylcholinesterase in T lymphocytes leading to suppression of thymus-dependent antibody formation (predominant effect) and acetylcholine-induced stimulation of antibody production. Acetylcholine activated acetylcholinesterase in intact T cells.

[Effect of ethanol on methanol immunotoxicity]. / Vliianie étanola na izmenenie immunotoksichnosti metanola.

The results of experiments on Wistar rats under acute methanol poisoning conditions (1 LD 50) showed that ethanol serves as an antidote of methanol. Ethanol reduces nonspecific resistance of the organism and decreases activity of the native killer cells, antibody production mainly with respect to the T-dependent antigen, antibody-mediated cell cytotoxicity, and the formation of delayed type hypersensitivity.

Role of activation of the sympathoadrenal system in the realization of immune reactions during acute poisoning with organophosphorus compounds.

Experiments on Wistar rats showed that acute poisoning with organophosphorus compound dimethyldichlorovinylphosphate (0.2 and 0.8 LD50) was accompanied by suppression of the major immune reactions. Increasing the concentration of epinephrine and norepinephrine in the plasma produced less pronounced opposite effects, except for the influence on natural killer activity.

[Effect of the cholinesterase reactivator dipyroxime in various models of delayed hypersensitivity during acute intoxication by acrylonitrile]. / Vliianie reaktivatora kholinésterazy dipiroksima na formirovanie giperchuvstvitel'nosti zamedlennogo tipa.

Delayed type hypersensitivity (DTH) response with respect to sheep erythrocytes was studied on various models in CBA mice against the background of acute intoxication with nitrile acrylic acid (NAA). The effect of dipiroxime on the DTH response under these conditions was determined and the relationship of these reactions with the activity of alpha-naphthylbutyratesterase in splenic cells and popliteal lymph nodes was assessed. Dipiroxime partly recovered DTH in various experimental series (except for the reaction of suppressor cell transfer) by restoring the alpha-naphthylbutyratesterase activity in cells of the lymphoid organs studied.

Mechanisms of immunotoxic effects of acrylonitrile.

Cholinesterase reactivator dipyroxime and hydrogen cyanide antidote anticyan partially restore cell and humoral immune response in mice after acute acrylonitrile poisoning (0.5 LD(50)). When used in combination these drugs virtually completely prevented the suppression of immune reactions. The main mechanism of immunotoxic effect of acrylonitrile is mediated through inhibition of T lymphocyte esterases and a(3) component of cytochrome c oxidase of immunocyte mitochondrial respiration enzymes, which is important for prevention and treatment of immune disturbances caused by this toxin.