[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.

[Characteristics of sodium metabolism in rats with experimental hypertension caused by chronic alimentary imbalance]. / Osobennosti obmena natriia u krys s éksperimental'noi gipertenziei, obuslovlennoi khronicheskim alimentarnym disbalansom.

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. A three-chamber model of 22Na metabolism was developed for the analysis of 22Na excretion from the body. This helped in establishing the heterogeneity of sodium metabolism in experimental animals. Besides that, it has been shown that not only sodium retention in the body, but also its redistribution between intra- and extravascular sections play an important role in the development of hypertension. Protein deficiency in the diet aggravates sodium metabolism disorders in experimental animals.

[The behavior of 125I microspheres of serum albumin in the body of rabbits administered the preparation selectively into the renal artery]. / Povedenie 125I-mikrosfer syvorotochnogo al'bumina v organizme krolikovv pri selektivnom vvedenii preparata v pochechnuiu arteriiu.

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 method of using microspheres as a radionuclide carrier was shown to hold promise for therapeutic purposes.

[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.

[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]. / Obmen natriia u krys vistar v usloviiakh khronicheskoi izotonicheskoi solevoi nagruzki posle predvaritel'nogo defitsita belka v diete po dannym radiometrii vsego tela s 22Na.

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]. / Osobennosti obmena natriia u krys linii Wistar v zavisimosti ot urovnia potrebleniia povarennoi soli po dannym radiometrii vsego tela s radionuklidom 22Na.

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)]. / Issledovanie mestnogo kapilliarnogo krovotoka s pomoshch'iu mechenykh mikrosfer al'bumina pri osteotomii verkhnei cheliusti (éksperimental'noe issledovanie).

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. The total reduction of the blood flow in the tissues of the osteotomized fragment as compared to that of the control group was 54.5% (in the 1st group), 39.3% (in the 2nd group) and 41% (in the 3rd group). The results of the study showed correlation between the blood flow rate reduction in the soft tissue structures and osseous tissue.

[Modeling of experimental hypertension by chronic salt loading combined with a low-protein diet in Wistar rats]. / Modelirovanie eksperimental'noi gipertonii s pomoshch'iu khronicheskoi solevoi nagruzki v sochetanii s nizkobelkovoi dietoi u krys Vistar.

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.

[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.

[Selective accumulation of 131I-labeled IKO-1 monoclonal antibodies in the tissues of mouse L 1210 lymphoid leukemia]. / Izbiratel'noe nakoplenie mechennykh 131I monoklonal'nykh antitel IKO-1 v tkani myshinogo limfoleikoza L 1210.

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. During in vivo experiments 131I anti-la MCA at a dose of 30 micrograms (specific activity of 32.10(10) Bq/mmol) was administered intravenously to BDF1 mice with transplantable lymphoid leukemia L1210. Radiometry of the organs 24 h after administration of antibodies showed their accumulation in a solid tumor localized on intestinum tenue mesenteriale. The ratio of concentrations of labelled antibodies (in % of the administered amount per 1 g) of tumor/blood was 2.4, that of tumor/liver--4.5. For normal nonimmune 125I-IgG this rate was 0.4 and 0.7, respectively. A high level of MCA in the blood is a factor decreasing MCA diagnostic potentialities. The use of F(a, b)-fragments may considerably decrease the role of this factor. The data obtained suggest a possibility of the use of MCA ICO-1 for in vivo radioimmunoassays of some hematological tumors.

[Experimental basis and clinical results of the use of short-term hyperglycemia in combined therapy of malignant tumors]. / Eksperimental'noe obosnovanie i klinicheskie rezul'taty primeneniia kratkovremennoi giperglikemii pri polifaktornoi terapii zlokachestvennykh opukholei.

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.

[57Co-bleomycetin distribution in the body of experimental animals with hyperglycemia]. / Raspredelenie 57Co-bleomitsina v organizme éksperimental'nykh zhivotnykh v usloviiakh giperglikemii.

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. The labeled antitumor antibiotic was also administered intraperitoneally (0.2-0.8 MBq per animal). The data on both the external radiometry in the area under the animal limb and the radiometry of separate organs and tissues showed that hyperglycemia markedly altered pharmacokinetics of the labeled antibiotic and retarded its elimination. With respect to the lungs it even increased the drug tropism and accumulation. This information may be useful in radionuclide diagnosis and therapy in particular of lung cancer. The time course of glucose concentration in blood was not an adequate criterion of hyperglycemia influence since the influence of hyperglycemia on retarding the drug elimination was also observed when the level of glucose in blood did not differ from the initial one.

[Effectiveness of the antitumor action of bleomycetin in short-term hyperglycemia]. / Effektivnost' protivoopukholevogo deistviia bleomitsetina v usloviiakh kratkovremennoi giperglikemii.

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.