[Toxicological and sanitary characterization of bentonite nanoclay].

Intragastric administration of nanoclay to rats during 28 days led to reductions in the relative weight of the liver, the activity of its conjugating enzymes, the antagonistic activity of bifidoflora, and the hyperproduction of colonic yeast microflora. The findings lead to the conclusion that nanoclays that may be present in foods must be the object of sanitary regulation.

[Characterization of silver nanoparticles migration from package materials destined for contact with foods].

There was studied migration of artificial silver nanoparticles from polyethylene films destined for package of such foods as bread and poultry into model media reproducing physico-chemical properties and composition of said products. Modification of films was performed by 5- or 10-fold spraying of silver nanoparticles on the surface of package material. Model media were composed from water, alcohol and plant oil according to US FDA and Russian Federal Service for Surveillance of Consumer Rights Protection and Human Well-Being official recommendation. Nanoparticles were detected in model media by means of transmission electron and atomic force microscopy. Quantification of silver in nanoparticles migrating from films was performed by mass-spectrometry with inductively coupled plasma. The results obtained showed that silver migrated from films into test media in form of nanoparticles with mean diameter close to 10-20 nm. Migrated particles were partially aggregated to complexes with dimension about 50 nm with degree of aggregation depending on media composition. Quantification showed that amounts of silver nanoparticles migrating in foods did not exceed save level of this nanomaterial consumption even in aggravated conditions when almost all volume of product was consumed in form packaged in films modified with nanosilver.

Effects of titanium dioxide nanoparticles on small intestinal mucosa in rats.

Penetration of titanium dioxide nanoparticles into enterocytes after their administration into isolated loop of rat small intestine was shown in vivo by transmission electron microscopy. Using electron diffraction, titanium dioxide nanoparticles were identified in the apical regions of the cells under plasma membranes and in deeper parts of the cytoplasm as solitary objects or small aggregations. Water dispersions of nanoparticles (3-h exposure to high concentrations) caused no appreciable morphological changes in enterocyte ultrastructure. A 28-day subacute intragastric administration of water dispersion of nanoparticles to rats led to titanium accumulation in the liver, their level was significantly higher than in the control group, which was shown by mass spectrometry with inductive-bound plasma. These data indicated the possibility of penetration of titanium dioxide nanoparticles through the gastrointestinal barrier under near-physiological conditions.

[Toxicological sanitary characterization of silver nanoparticles introduced in gastrointestinal tract of rats].

Water suspensions of silver nanoparticles were introduced intragastrically to growing male Wistar rats daily for 28 days. There were studied animals mass gain, relative masses of viscera, intestinal barrier resistance against protein macromolecules, DNA oxidative damage, tissue non-protein thiol levels, first and second phase of xenobiotic detoxication system activity, lysosomal membranes stability in liver together with routine blood biochemical and hematological indices and caecal's microbiocenose state. The data testifying to possible toxic risks, connected with reaction of silver's nanoparticles is obtained.

[Toxicological sanitary characterization of titanium dioxide nanoparticles introduced in gastrointestinal tract of rats. Communication 2. Intestinal microbiocenosis condition and allergic sensitivity].

Intestinal microbiocenosis condition, cytokine IL-6, IL-10 and TNF-alpha levels and allergic sensitivity in experimental systemic anaphylaxis test were studied in rats that received intragastrically nanoparticles of titanium dioxide. The results obtained were discussed from the standpoint of possible health risks related to nanodimensional titanium dioxide exposure.

Mercaptoethanol and dithiothreitol decrease the difference of electrochemical proton potentials across the yeast plasma and vacuolar membranes and activate their H(+)-ATPases.

Mercaptoethanol and dithiothreitol (DTT) inhibited the acidification of external medium by Saccharomyces carlsbergensis cells and protoplasts during glucose oxidation. The inhibition was also observed when cells were incubated with mercaptoethanol or when mercaptoethanol and DTT were used to prepare protoplasts. Experiments with S. carlsbergensis plasma membrane vesicles and vacuoles showed these thiol reagents to inhibit ATP-dependent generation of delta pH and Em across plasma membrane vesicles and vacuoles but to activate their H(+)-ATPases. Mercaptoethanol and DTT are suggested to de-energize plasmalemma as well as tonoplast by increasing their H(+)-permeability and to disturb the cell ion homeostasis.

[The pharmacological correction of recurrent immediate-type allergic reactions]. / Farmakologicheskaia korrektsiia povtornykh allergicheskikh reaktsii nemedlennogo tipa.

The effect of drugs on the early and late phases of repeated allergic reactions (RAR) was studied in experiments on rabbits. The action of the drugs was estimated by the number of challenge doses of antigen, endured by survived and dead rabbits, percentage of the animals' death, and by the place of each group on the lethality scale. Diphenhydramine, ouabain and their combinations, silver nitrate (20 mg/kg) and DOCA enhanced whereas histamine, unithiol, cholesterol, and silver nitrate (20 and 0.2 mg/kg) decreased allergization in the period of RAR. The characteristic features of the action of the drugs on RAR were revealed and compared to the first allergic reaction. Qualitative and quantitative differences were shown in the action of different drug doses and combinations on RAR. The authors provide evidence for the possibility of treating allergic diseases by drug administration in a quiet period.

[The effect of sulfur-containing preparations on the development of immediate allergization]. / Vliianie serosoderzhashchikh preparatov na razvitie allergizatsii nemedlennogo tipa.

The effects of sulfur-containing drugs and an inhibitor of sulfhydryl groups on the development of allergization of immediate type were studied. In experiments on rabbits and guinea pigs it was shown that the effects of sulfur-containing drugs depend on the dose, the stage of the allergic process. The donors of sulfhydryl groups significantly reduce anaphylactic shock and repeated allergic reactions of immediate type. The inhibitor of sulfhydryl groups produces the dose-dependent increase or decrease of the allergic reaction. The studied drugs change the dynamics of the content of sulfhydryl groups during sensitization.

[Treatment efficacy in destructive forms of pulmonary tuberculosis in relation to the methods of administering rifadin and isoniazid]. / Effektivnost' lecheniia destruktivnykh form tuberkuleza legkikh v zavisimosti ot sposobov vvedeniia rifadina i izoniazida.

The efficacy was studied of 130 patients with freshly detected destructive forms of pulmonary tuberculosis depending on the method of administration of rifadin and isoniazid. Treatment of pulmonary tuberculosis was realized with rifadin, isoniazid and streptomycin. Three groups of patients were distinguished. In group I rifadin and isoniazide was taken orally, in group II--rifadin was administered orally and intrabronchially, isoniazid--orally. In group III rifadin was orally and intrabronchially, isoniazid--intravenously. The treatment was more effective with combined administration of rifadin and intravenous administration of isoniazid.

[The activity of growth-regulating substances isolated from the spleen and thymus of healthy cows and of those with hemoblastoses]. / Issledovanie aktivnosti rostreguliruiushchikh veshchestv, vydelennykh iz selezenki i timusa zdorovykh i bol'nykh gemoblastozami korov.

Certain agents of the proteoglycan nature possessing organ-specific rather than the species-specific antimitotic chalone activity have been obtained from the normal bovine spleen and thymus. The preparations obtained by the same method from the spleen and the thymus of animals affected by lympholeukemia and lymphosarcoma did not reveal the antimitotic activity; moreover, they were of high mitogenic organ-specific character. A connection between the mitogenic factor produced by lymphocytic cells and the bovine leukemia virus is possible.

[Effect of some steroidal compounds on the development of an immediate allergic reaction]. / Vliianie nekotorykh steroidnykh soedinenii na razvitie nemedlennoi allergicheskoi reaktsii.

In experiments on rabbits various effects of steroidal agents (hydrocortisone, deoxycorticosterone, beta-lipoproteids, cholesterol, saponins, digitoxin, strophanthin) on the development of sensitization and allergization at their administration during sensitization and before the resolving dose of the antigen were shown.