Comet assay on one- and two-cell mouse embryos.

DNA damage quantified as the comet tail length was assessed using in vitro and in vivo comet assay on one- and two-cell mouse embryos obtained by natural mating. The use of a protocol with three layers of agarose reduces the embryo loss and makes it possible to study a small number of embryos. A significantly lower level of basal, but not induced DNA damage was found in embryos with cleaved zona pellucida compared to embryos with intact zona pellucida.

Induced Aneugenic Effects in Mouse Oocytes In Vivo.

Aneugenic effects of the chemicals with antitumor activity were studied in mouse oocytes in vivo by cytogenetic analysis. In control mice, no oocytes with numerical chromosome aberrations were found. Colchicine (0.

Investigation of genotoxic and cytotoxic effects of micro- and nanosized titanium dioxide in six organs of mice in vivo.

Titanium dioxide is manufactured worldwide in large quantities for use in a wide range of applications including as food additives, in cosmetics and pigments for coloring ingested and externally applied drugs. Although TiO(2) is chemically inert it can cause negative health effects, such as lung cancer in rats. However, the mechanisms involved in TiO(2)-induced genotoxicity and carcinogenicity have not been clearly defined and are poorly studied in vivo.

Evaluation of genotoxicity and reproductive toxicity of silicon nanocrystals.

Silicon crystal 2-5 nm nanoparticles in the form of 1-5-μ granules in water suspension were injected intraperitoneally in a single dose to male F(1)(CBA×C57Bl/6) mice or to outbred albino rats on days 1, 7, and 14 of gestation. Silicon crystal nanoparticles in doses of 5, 25, and 50 mg/kg exhibited no cytogenetic activity in mouse bone marrow cells after 24-h exposure and in doses of 5 and 25 mg/kg after 7 and 14-day exposure. A 24-h exposure to silicon nanoparticles in a dose of 5 mg/kg significantly increased DNA damage (detected by DNA comet assay) in bone marrow cells.

[Preclinical safety investigation of GB-115 dipeptide].

Preclinical safety investigations of newly synthesized dipeptide compound GB-115 (amide N-phenylhexanoyl-glycyl-L-tryptophan), an antagonist of cholecystokinin receptors, were performed. No animals were lost after GB-115 acute oral administration at a maximum dose of 6000 mg/kg in mice and at 3500 mg/kg in rats. GB-115 administered per os during 6 months in rabbits and rats (both males and females) at the doses of 0.

[Comutagen interaction of verapamil and ribavirin].

The chromosome aberration assay in the bone marrow cells of C57BL/6 mice was used to study the cytogenetic activity of ribavirin (10, 50, 100, 200, and 400 mg/kg, p.o.) alone and in combinations with verapamil (0.

[Preclinical study of noopept toxicity].

Within the framework of a preclinical investigation, the new nootrope drug noopept (N-phenyl-acetyl-L-propyl-glycine ethylate) was tested for chronic toxicity upon peroral administration in a dose of 10 or 100 mg/kg over 6 months in both male and female rabbits. The results of observations showed that noopept administered in this dose range induced no irreversible pathologic changes in the organs and systems studied and exhibited no allergenic, immunotoxic, and mutagen activity. The drug affected neither the generative function nor the antenatal or postnatal progeny development.

[Corpuscular mutagenesis and its prevention].

The carcinogenic and mutagenic activity of dust containing chrysotile-asbestos and zeolites, as well as the role of active oxygen species in their cytotoxic and mutagenic actions are discussed. Superoxide dismutase (50 mg/ml) was demonstrated to prevent the mutagenic effects of chrysotile-asbestos and latex, catalase (20 mg/ml) to prevent the same of zeolites in experiments on cultured human whole blood. The intraperitoneal administration of dusts of chrysotile-asbestos and zeolites in a dose of 50 mg/kg to C57B1/6 mice was found to elevate the count of cells with chromosomal aberrations in the peritoneal liquid and bone marrow cells of mice, which was dependent on dust exposure time.

Peculiarities of the clastogenic properties of chrysotile-asbestos fibers and zeolite particles.

It has been established that chrysotile-asbestos fibers and zeolite particles induce chromosome aberrations in human lymphocytes from whole blood cultures, peritoneal fluid cells and bone marrow cells of mice. It is shown that the level of cytogenetic response from the intraperitoneal administration of chrysotile-asbestos fibers and zeolite particles depends on the time of their exposure. Further, it is shown that SOD eliminates the cytogenetic effect of chrysotile-asbestos fibers, while catalase inhibits that of zeolite particles.

[Remote effects in the mutagenic action of chrysotile asbestos and zeolite dusts in vivo].

It was proposed that there are a generalized mutagenic actions of chrysotile-asbestos fibers and zeolite particles in vivo. Chrysotile-asbestos fibers and different species zeolite particles in doses 50 mg/kg, intraperitoneally, increased the levels of damaged chromosomes not only in peritoneal cells, but also in bone marrow of C57BL/6 mice. Cytogenetic effect of chrysotile-asbestos does not depends on the time exposure of animals with mutagenic factor.

Oxygen radical-mediated mutagenic effect of asbestos on human lymphocytes: suppression by oxygen radical scavengers.

The mutagenic effect of chrysotile asbestos fibers and zeolite and latex particles on human lymphocytes in whole blood has been studied. It was concluded that their mutagenic activities were mediated by oxygen radicals because they were inhibited by antioxidant enzymes (SOD and catalase) and oxygen radical scavengers (rutin, ascorbic acid, and bemitil). It was proposed that oxygen radicals were released by phagocytes activated upon exposure to mineral dusts and fibers.