[A modification in the radiation reaction of normal and tumor tissues in mice induced by N-methylformamide].

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.

[Characteristics of sodium metabolism in rats with experimental hypertension caused by chronic alimentary imbalance].

Beginning from 1.5 month of life Wistar rats were kept under conditions of chronic 1 and 2% salt loading combined with a low-protein diet (6-8% of protein VS, as compared with 23-24% in the normal diet). At the age of 14-16 months when a stable hypertension developed due to the above alimentary imbalance, their sodium metabolism was studied using whole-body radiometry with 22Na.

[The behavior of 125I microspheres of serum albumin in the body of rabbits administered the preparation selectively into the renal artery].

Intraarterial selective injection of serum albumin microspheres into the kidney resulted in embolization of the vessels with microspheres of different sizes. In vivo radiometry made it possible to improve the localization of microspheres and their distribution in the animals' bodies at varying time of observation. Pathomorphological investigations showed optimum sizes of microspheres causing prolonged retention of microparticles at the site of injection without considerable morphological changes of body tissues.

[The radiation sensitizing activity of metronidazole and iso-metronidazole (1-(2-hydroxyethyl)-2-methyl-4-nitroimidazole)].

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.

[Sodium metabolism in Wistar rats exposed to chronic isotonic salt load after preliminary protein deficiency in the diet according to radiometry of the whole body with 22-Na].

The long-term preliminary protein deficiency in the diet gives rise to irreversible changes in sodium metabolism in experimental animals exposed subsequently to chronic salt load combined with full-value feeding. Apparently such changes do not go, however, beyond the compensatory potentialities of the body exposed to isotonic salt load, since the systolic arterial pressure does not undergo any material changes throughout the whole experiment.

[Characteristics of sodium metabolism in Wistar rats in relation to the uptake of sodium chloride studied by whole body Na-22 radiometry].

The rate of sodium elimination was shown to be inadequate to sodium uptake in rats exposed to prolonged salt loading, the higher the load, the greater the inadequacy. Sodium distribution between vascular and extravascular spaces of the body was also disproportionate in conditions of both excessive and low sodium uptake.

[Study of local capillary circulation using labeled albumin microspheres during osteotomy of the maxilla (experimental study)].

The authors presented the results of experiments on 14 random bred dogs in whom fragmentary osteotomy of the maxilla at the level of 7 perpendicular 7 teeth was performed with subsequent investigation of the volumetric blood flow rate in soft and osseous tissues of the osteotomized fragment using labeled albumin microspheres. The animals were divided into 4 groups (the study group and control groups). The volumetric blood flow rate was investigated over time with the monitoring of the CV system 1 (the 2nd group), 6 (the 3rd group) and 24 h (the 4th group) after operation.

[Inhibition of transplantable tumors in mice by monomethylformamide].

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.

[Modeling of experimental hypertension by chronic salt loading combined with a low-protein diet in Wistar rats].

Combination of chronic salt loading with protein-poor diet produces experimental hypertension with natrium consumption near to physiological. The present model is characterized, compared to the existing one, by stage development, moderate arterial blood pressure elevation and absence of "salt toxicosis" and may be thus considered more adequate for experimental investigation of primary arterial hypertension pathophysiology.

[Selective accumulation of 131I-labeled IKO-1 monoclonal antibodies in the tissues of mouse L 1210 lymphoid leukemia].

Monoclonal antibodies (MCA) ICO-1 of IgG3 isotype against 1a-like human antigens were labelled with 131I using chloramine T; a radionuclide-bound fraction was isolated by radiochromatography. Basing on the results of assessment of complement-dependent cytotoxicity against lymphocytes from the lymph nodes of BDF1 mice a conclusion was made that MCA immunological reactivity changed slightly after radionuclide tracer administration. In vitro experiments with a panel of normal and malignant cells showed 131I-MCA binding with cells of mouse lymphoid leukemia L1210 and hemocytoblastosis La as well as with spleen and lymph node normal lymphocytes.

[Experimental basis and clinical results of the use of short-term hyperglycemia in combined therapy of malignant tumors].

Proceeding from an analysis of the literature and their own data on radio- and thermodifying properties of hyperglycemia the authors have proposed a scheme of polyfactor therapy of malignant tumors including the following succession of exposures under clinical conditions: irradiation (the 1st fraction)--a chemotherapeutic drug--hyperglycemia--hyperthermia--irradiation (the 2nd fraction). The interval between exposures should be the least, best of all exposures should follow one another in a quick succession. Using the experimental data for determination of methods of therapy of transition and metastatic tumors of the upper respiratory tracts, satisfactory clinical results were obtained with regard to survival and the absence of local radiation reactions.

[Effectiveness of the antitumor action of bleomycetin in short-term hyperglycemia].

Experimental studies on rats with sarcoma 45 showed that antitumor efficacy of bleomycetin could be markedly increased by inducing short-term hyperglycemia. It was noted that the theoretical value of the additive effect of these factors was lower than the experimental one. This is in favour of the synergistic mechanism of bleomycetin action under conditions of hyperglycemia.

[57Co-bleomycetin distribution in the body of experimental animals with hyperglycemia].

Distribution of 57Co-bleomycetin in organs and tissues of rats with experimental short-term hyperglycemia was studied. Hyperglycemia was induced by intraperitoneal administration of 40 per cent glucose solution in doses of 1 to 10.4 g/kg.

[Metastasis of Lewis carcinoma during local UHF hyperthermia].

The paper is concerned with the results of a study of the relation of a metastatic spreading of mouse Lewis carcinoma to temperature distribution in the area of a tumor and healthy tissue damage. It was shown that a significant metastatic spreading inhibition was observed in selective MWF-hyperthermia (43-46 degrees C, 30 min). In the absence of a selective hyperthermal exposure when both tumors and healthy tissues were damaged (at the same thermal dose), there was a tendency to metastatic spreading enhancement.

Sodium metabolism in Wistar rats during a chronic high-salt or a low-protein diet: 22Na determination by radiometry.

Whole body radiometry was employed to monitor 22Na radionuclide metabolism in Wistar rats of either sex, aged six months and 1.3 years, kept under normal conditions or on a low-protein diet or during chronic salt load over a period of one year. In all the groups studied, the differences in sodium metabolism according to sex and age were determined.

[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].

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.

[Immunohistochemical and electron microscopic identification of serotonin, melatonin and beta-endorphin in the granules of natural killers].

The ability of serotonin, melatonin and beta-endorphin synthesis by secreting granules of natural killer cells (NK cells) was established by immunohistochemical method. It was shown that cytotoxic effect of NK cells can be to a certain extent related to the presence of secreting granules. A possible direct contribution of NK cell-synthesized hormones to the natural killer antitumour effect is discussed.

[Enhancement by metronidazole of the antitumor effect of cyclophosphane].

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.