[The assessment of biocenosis contamination in the region of radioactive waste storage (RWS) placing and influence of this storage on rodents].

The results of radiative and of chemical monitoring show definite contamination of this zone by 90Sr and toxic metals. The essential local contaminations of geosystems (up to 2.3 x 10(4) Bk/kg of soil) require in environmental condition assessment at biocenosis level. Biotesting found the increase of metallothioneines levels in kidney (up to 15.63 microg/g of tissue) and liver (up to 19.22 microg/g of tissue) of rodents inhabited in the region of RWS placing as compared with the control group (3.51 and 4.44 microg/g of tissue accordingly). Besides, the decrease of total quantity of leucocytes (by 14.5% as compared with the control group) and absolute quantity all forms of them in animal blood were noted. It was assumed the increase of protein--MT is the result of complex influence by ionizing radiation and toxic metals.

[Metallothionein content in tissue and neoplasms of mice under cadmium chloride administration and gamma irradiation. Increased radioresistance in mice with elevated level of metallothionein]. / Soderzhanie metallotioneinov v tkaniakh i opukholiakh myshei pri kombinirovannom deistvii kadmiia i gamma-izluchenia. Uvelichenie radiorezistentnosti myshei s povyshennym urovnem metallotioneinov.

It was confirmed that the survival of gamma-exposed mice became higher after preliminarily subcutaneous injections of cadmium chloride. It is supposed that radioresistance of mice is connected with the induction of metallothionein proteins by cadmium chloride.

[Increase in the level of metallothioneins in mouse liver after administration of cadmium chloride does not protect from combined radiation-thermal injury]. / Povyshenie soderzhaniia metalothioneinov v pecheni myshei posle vvedeniia khloristogo kadmiia ne zashchishchaet ot kombinirovannykh radiatsionno-termicheskikh porazhenii.

Effects of MT preinduction by cadmium chloride on the resistance to combined injury such as whole body gamma-irradiation at the dose of 7 Gy + thermal burn were investigated in (CBA x C57BL6)F1 mice. Normal level of MT markedly increased in mice liver but not in bone marrow cells if Cd was given subcutaneously (1 mg/kg) prior to combined injury. However, preinduction of MT did not reduce the lethal effects and bone marrow devastation caused by combined radiation injury. No differences in the leukopenia degree and in CFU-s number were observed between control and MT-induced mice. In summary, Cd-induced MT elevation in mice liver does not protect against the toxic and lethal effects caused by combined radiation injury.

[The survival of mice and the metallothionein content of their livers and kidneys as criteria for assessing exposure to pulsed neutron radiation]. / Vyzhivaemost' myshei i soderzhanie metallotioneinov v ikh pecheni i pochkakh kak kriterii otsenki vozdeistviia impul'snogo neitronnogo izlucheniia.

The effect of pulsed neutron radiation was studied in comparison with continuous neutron radiation and continuous gamma-radiation. Animal survival and induction of metallothionein (MT) synthesis in liver and kidney of mice exposed to equivalent doses were chosen as criteria for evaluation of radiation effects. It was found that the level of MT in liver and kidney of mice exposed to neutron radiation decreased 24 hours after irradiation and then continued decreasing in kidney for 48 hours after irradiation. This is evidence of more intensive free-radical processes initiated by pulsed neutron radiation. At the same time, RBE values of pulsed neutrons did not differ significantly from that of continuous neutron radiation.

Involvement of metallothioneins in regulation of macrophage activity after combined radiation and thermal injury.

The levels of reduced metallothioneins (MT) in peritoneal macrophages and liver of mice subjected to combined radiation and chemical injury displayed opposite changes: the macrophage level of MT decreased and the liver MT increased. Simultaneously, there was an increase in luminol- and lucigenin-dependent chemiluminescence of phagocytizing macrophages. Stimulation with CdCl2, a MT inducer, for three days before the injury increased the levels of MT in macrophages but decreased its liver levels. This effect was accompanied by a decrease in the intensity of the luminol-dependent but not lucigenin-dependent chemiluminescence. Administration of CdCl2 after the injury facilitated the induction of reduced MT in liver cells; however, its levels in macrophages remained low, and the intensity of their chemiluminescence did not decrease. The data suggest that MT is involved in oxidative metabolism and regulation of macrophage activity after combined radiation and thermal injury.

[The effect of an injection of N-methylformamide into mice on the cell cycle and cell morphology of ascitic hepatoma 22A]. / Vliianie in''ektsii mysham N-metilformamida na kletochnyi tsikl i morfologiiu kletok astsitnoi gepatomy 22A.

A cell differentiating agent N-methylformamide (MF) was studied for its antitumor activity against a murine ascitic hepatoma 22A. After a 48 hour NMF administration (i/p) the tumor cell number was monitored; the distribution of these cells in the cell cycle was registered by flow cytometry, ultrastructural changes were studied by electron microscope. The polar solvent MF inhibited tumor growth, reduced mitotic activity, and nuclear/cytoplasmic ratio, led to structural complication of endoplasmic reticulum and mitochondria. The analysis of these events is suggestive that in consequence of MF effect on tumor cells, proportion of G0/G1 and M cells was decreased, while the proportion of S and G2 cells was increased.

[The property of radiation in low doses and of low-intensity ionizing radiation to cause metallothionein induction]. / Svoistvo radiatsii v malykh dozakh i nizkointensivnogo ioniziruiushchego izlucheniia vyzyvat' induktsiiu metallotioneinov.

The effect of the increase in metallothionein content in hepatocytes of white mice located in conditions of chronic low dose rate and low-dose irradiation. In this work an opportunity of participation of metallothioneins, as the natural radioprotector and factor of nonspecific resistance, in adaptation of organisms to adverse environmental conditions was discussed.

[A modification in the radiation reaction of normal and tumor tissues in mice induced by N-methylformamide]. / Modifikatsiia radiatsionnoi reaktsii normal'nykh i opukholevykh tkanei myshei N-metilformamidom.

The effect of potential differentiation-inducing agent N-methylformamide on radiation response of murine normal and tumor cells (Lewis lung carcinoma, hematopoietic tissue and jejunum epithelial stem cells) was studied. The agent reduced or not altered radiation damage of tumor and epithelial cells in mice receiving NMF before irradiation. Sensitization to radiation was observed in endogenous spleen colony forming hemopoietic stem cells. When the agent was injected 15 min before irradiation the sensitizing effect was less pronounced. The highest effect was observed when agent was injected 24 h after irradiation of animals.

[The radiation sensitizing activity of metronidazole and iso-metronidazole (1-(2-hydroxyethyl)-2-methyl-4-nitroimidazole)]. / Die radiosensibilisierende Aktivität von Metronidazol und iso-Metronidazol (1-(2-Hydroxyäthyl)-2-Methyl-4-Nitroimidazol).

The effect of irradiation, metronidazole and iso-metronidazole on survival and number of tumor cells was analysed in vitro in mice that were inoculated with La-hemocytoblastosis--or Ehrlich-ascites-tumor cells after processing. It was shown that metronidazole and iso-metronidazole nearly have the same radiosensitizing activity on these conditions. The effect was dependent on concentration of compounds and cell type. With intraperitoneal application the iso-metronidazole was eliminated from Lewis-lung-carcinoma more slowly than from blood.

[Inhibition of transplantable tumors in mice by monomethylformamide]. / Zaderzhka rosta perevivnykh opukholei myshei monometil-formamidom.

The paper discusses the effect of a cell differentiation-inducing agent--monomethylformamide--on the growth of ascites hepatoma 22A, Ehrlich ascites tumor, thymoma EL-4, leukemia L1210, Lewis lung carcinoma and hemocytoblastosis La. A single injection of the drug into tumor-bearing mice inhibited the growth of the said neoplasms as shown by cell levels in ascites tumors, node size of Lewis lung carcinoma and survival in animals with hemocytoblastosis La. The analysis of the kinetics of inhibition of growth to be transient. For both tumors, the effect of 0.25 g/kg body weight and more showed exponential growth.

[Radiosensitizing and toxic action of metronidazole and isometronidazole (1-(2-hydroxyethyl)-2-methyl-4-nitroimidazole) on the cells of Ehrlich ascites cancer and hemoblastosis La in vitro]. / Radiosensibiliziruiushchee i toksicheskoe deistvie metronidazola i izometronidazola [1-(2-gidroksiétil)-2-metil-4-nitroimidazol] na kletki astsitnogo raka Erlikha i gemoblastoza La in vitro.

A study was made of Ehrlich ascites tumor growth and life span of mice bearing hemoblastosis La after inoculation of tumor cells subjected, in anaerobic conditions, to the effect of gamma-radiation and/or metronidazole and isometronidazole. It was shown that the cytotoxic effect of isometronidazole was less manifest than that of metronidazole the radiosensitizing effect, with a reference to anoxic tumor cells in vitro, being nearly the same.

[Enhancement by metronidazole of the antitumor effect of cyclophosphane]. / Usilenie metronidazolom protivoopukholevogo deistviia tsiklofosfana.

In experiments on mouse tumors (sarcoma-180, Ehrlich ascites tumor and hemoblastosis La) the ability of metronidazole to enhance the antitumor chemotherapeutic action of cyclophosphane was investigated. It was shown that metronidazole (1000 mg/kg) injected 60 min before cyclophosphane administration can elicit an almost two-fold increase in its radioprotective efficiency. The chemosensitizing effect of metronidazole depends on the drug concentration and the tumor type.

[Accumulation of 125J-triiodothyronine in the transplanted tumors of mice and rats]. / Nakoplenie 125J-triiodtironina v perevivnykh opukholiakh myshei i krys.

Investigations carried out in various transplantable tumours (Lewis carcinoma, carcinoma-37, melanoma B-16 in mice and sarcoma-45 in rats) did not show 125J-triiodothyronine accumulation by the tumour.

[Distribution kinetics and metabolism of triiodothyronine and thyroxine in the organs and tissues of mice with transplanted Lewis carcinoma]. / Osobennosti raspredeleniia i kinetiki obmena triiodtironina i tiroksina v organakh i tkaniakh myshei s perevivnoi kartsinomoi L'iuis.

A comparative analysis of triiodothyronine (T3) and thyroxine (T4) distribution in organs and tissues of tumour-bearing and intact mice conducted wih 125J labelled T3 and T4 has shown considerable differences in the accumulation character of these hormones in mice with Lewis carcinoma and in intact animals in the liver, kidneys, lungs, adrenal glands, lymphatic nodes. Low T3 and T4 concentration in the blood of tumour-bearing mice was observed during the whole period of study.

[Effect of a DNA-rubomycin complex on the molecular mass, radiosensitivity and reparation of gamma-induced single-stranded breaks in the DNA of sarcoma 180 cells]. / Vliianie kompleksa DNK-rubomitsin na molekuliarnuiu massu, radiochuvstvitel'nost'i reparatsiiu gamma-indutsirovannykh odnonitevykh razryvov v DNK kletok sarkomy 180.

The use of the DNA-rubomycin complex resulted in appearance of one-thread breaks (OB) in DNA and markedly increased the number of the DNA OB determined immediately after irradiation. The DNA-rubomycin complex decreased the volume of the repaired OB and induced postreparation degradation of the one-bond DNA (oDNA) in the sarcoma 180 cells. The effect of the decrease in the molecular mass of the oDNA 6 hours after the irradiation to the level of the initial damage is probably in favour of the fact that degradation takes place in the areas of the repaired breaks. The data indicated that the viscosimetric method for the analysis of the OB in DNA may be promising in estimation of the efficacy of radiation and chemotherapy of solid tumors.

[Effect of the antifolic preparation, tomizin, that possesses antitumor activity, on thyroid gland function]. / O vliianii antifolievogo preparata tomizina, obladaiushchego protivoopukholevoi aktivnost'iu, na funktsiiu shchitovidnoi zhelezy.

Experimental investigations and clinical observations on the use of alkylating antineoplastic agents demonstrated these to influence the thyroid function. It is worthwhile to assess the effect of the antimetabolite tomizine, displaying antineoplastic properties, on the function of this organ. Tests conducted on rats with sarcoma M-1 disclosed the maximally tolerated doses of tomizine to produce a marked inhibition of the thyroid function. The latter is attended by a reduced accumulation of introduced 131I in the iron. Structural changes in the thyroid occurring under the effect of tomizine are characterized by the lowering of the thyroid epithelium height, increased dimensions of the follicles and a diminished volume of the insular tissue. This also points to depression of the thyroid function. Disturbances in this organ taking place under the effect of a single introduction of tomizine may be reversible. Multiple administration of the drug produces persistent functional disorders in the organ.