Eksperimental'naia onkologiia最新文献

The genotoxic activity of exhausts from one-shaft gas-turbine GTE-5 engine (30 kW) and a standard D-54A diesel (40 kW) have been studied. Thus, the extracts of soot from GTE-5 and D-54A induced reversions in Salmonella typhimurium both with and without metabolic activation: furthermore, extracts of soot from GTE-5 demonstrated a higher mutagenic activity. The direct mutagenic effect of the exhausts depended neither on the presence of BP nor on the other polycyclic aromatic hydrocarbons (PAHs). Most probably, it was connected with the presence of nitro-PAHs. The need for studying the PAH content in vehicle engines' exhausts and for taking into account their effect in the control and standardization is established.

Four monoclonal antibodies (MAbs) from series IGR to human peripheral blood neutrophilic granulocyte cell surface antigens were obtained by the conventional hybridoma technique. Specificity of MAbs AGR was determined to various leukemic cell lines and human peripheral blood cells. Overlapping in characteristics of antigens (molecular weight, localization, expression on induced leukemic cell line HL-60) to MAbs IGR-1 4C7, IGR-1 5B6 and IGR-2 IA6 suggests their identity. These, apparently, cannot be analogous to the well known granulocyte cell surface glycoproteins LFA-1, CR-3, p150, 95 or GP 130. The characteristics of MAbs IGR-1 and IGR-2 permit concluding that the antibodies should be useful in normal and leukemic myelomonocytic cell linear differentiation studies.

The action of 15 chemicals, being tumor-promoters and/or inhibitors of cell-to-cell communications in vitro upon electric relations between giant cells of salivary gland of the Chironomus tentans larvae are studied. It is shown that out of 11 compounds disturbing the intercellular contacts in this model, 10 chemicals are tumour-promoters (Aroclor 1254, butylated hydroxytoluene, di(ethylhexyl)phthalate, DDT, deoxycholic acid, lithocholic acid, oleic acid, anthralin, iodine-acetate, tween-80) and 1 compound (oleoyl-acetyl-glycerol) is not studied for the promoting activity. At the same time, two other tumor-promoters (phenobarbital and TPA) as well as two nontumor-promoters (phorbol and chlorpromazine) do not influence the electric relations. The possibilities of using the developed test-system for the screening of the tumour-promoters are discussed.

The ribosome content (84 patients), DNA alkaline-labile sites or strand breaks (21 patients) and unscheduled DNA synthesis in lymphocytes under normal and B-cell chronic lymphocytic leukemia (B-CLL) were studied. It has been shown that the alkaline-labile DNA damages increased about 3-5 fold while the ribosome content was normal at an early (corresponding to Rai's O-I stages) and an advanced (II-III stages by Rai) stages of B-CLL. In the course of B-CLL, the DNA strand breaks and number of ribosomes per cell decreased with the correlation coefficient r = 0.72. The slowing down of the unscheduled DNA synthesis at the advanced and terminal (IV stage by Rai) B-CLL stages does not correlate with the DNA strand breaks. In the advanced stage with its established clinical variability of forms, when an adequate treatment was necessary, the lymphocyte ribosome levels drop following the expansion of main compartments involved by the leukemic spread.

It has been shown that hyperthermia (45 degrees C, 20-120 min) produces a number of changes in HeLa cells at the plasma membrane level: shedding of membrane glycoproteins; changes in the lectin-induced cell agglutination; the outflux from cells of substances with the nonspecific esterase activity.

The properties of glucose-6-phosphate dehydrogenase (G6PDH; glucose-6-phosphate-NADP-oxidoreductase, EC 1.1.1.49) in the liver tissue of intact rats and those with ascites Zaidel hepatoma were compared. The specific activity of the enzyme from hepatoma was 7 times as high as that of the enzyme from the normal liver. The G6PDH preparations with the specific activity of 1.5 U/mg of protein were obtained by the three-stage purification. No differences in kinetic properties, coenzyme specificity and electrophoretic mobility of the enzymes from hepatoma and normal liver were observed.

The individual response to chemotherapy was investigated in 17 heterotransplants of human lung tumours of different histogenesis by the subcapsule test. It is established that the subcapsule test is of high informativity only when testing the individual resistance of lung tumours, especially adenocarcinomas, to cytostatics.

The current literature data on mutagenicity of human carcinogens of natural origin are reviewed. The high correlation is established between carcinogenicity and mutagenicity of this group of agents, all 10 agents are active in the Ames assay or in the cytogenetic tests, 7 of them are mutagenic in the Ames test and 8 in cytogenetic assays.

Rabbits with the Brown-Pierce carcinoma have been studied in chronic experiments for dynamics of the permanent potential reflecting bioelectrochemical processes in different structures of the hypothalamic and limbic system: medial preoptic area, ventromedial nucleus, posterior hypothalamic area, basal and lateral amygdalas, hippocampus, nucleus coeruleus as well as in central nucleus of the suture. The space-temporal pattern of neurodynamic changes in the subcortical brain structures has been found. These changes correlated with developmental characteristics of the Brown-Pierce carcinoma.

No correlation between the sensitivity to induction of liver tumours by ortho-aminoazotoluene and predisposition to spontaneous development of these tumours was found in mice. Under crossing the predisposition to spontaneous tumours was inherited dominantly, while sensitivity to their induction was inherited by the intermediate type. Spontaneous hepatomas were more frequent in males, whereas induced onesin females of the same genotype.