[The status of lymphocytes from immunocompetent organs in the development of experimental tumors from 1H-NMR data].

Thymus and lymph node lymphocytes in L-1210 ascite lymphoma, Lewis tumor, 22a hepatoma have been studied by NMR. Lymphocyte 1H-NMR spectra can to a certain extent reflect the state of immune system of an organism, in particular, they can sense both transformation of lymphocytes, and development of several tumors which are not accompanied by transformation of lymphocytes. In the latter case, changes in lymphocyte spectra takes place at terminal stages of carcinogenesis and are less pronounced than at transformation of lymphocytes.

[Inoculability and threshold effects in transplantation of experimental tumors].

Inoculability of various experimental tumors (spontaneous, chemically-induced, solid, ascitic and leukemic) versus the amount of inoculated tumor cells (10(0)-10(7)) was studied. With small amounts of cells (10(2)-10(3)), inoculability of some tumors appeared to be nil, while in certain long-passaged neoplasms, particularly, leukemia, as few as 5-10 cells were enough. The data obtained pointed to a threshold in experimental tumor transplantation.

[1H-NMR spectroscopy of the cell membranes of thymus lymphocytes in AKR mice].

360 MHz 1H NMR was used to monitor the changes of AKR mice thymus lymphocytes in cases of spontaneous and transplantable leukemia and vincristine administration. A comparison of relative signal intensities of methyl and methylene fatty acid chains protons and phosphatidylcholine headgroups protons enables to monitor leukemia development and vincristine effect. Spin-lattice relaxation curves of the same protons of leukemic thymi lymphocytes are well fitted by biexponential functions, bringing evidence for two regions with different lipid mobility.

[Levels of labile phosphorus-containing metabolites].

The work deals with the investigation of possible use of 31P-NMR for revealing metabolism changes in the mouse liver during the development of leukemia. This method was shown to permit observation of the extreme pattern of relative concentrations of sugar phosphate and bioorganic phosphate in the latent period. This observed increase in the metabolic activity of hepatocytes correlates with biophysical shifts found by other methods.

[Metronidazole: basic experimental results and clinical prospects].

The paper is concerned with the effect of metronidazole, one of the radiosensitizers of hypoxic cells. Analysis of the literature data has shown that at present metronidazole can be used to enhance the sensitivity of hypoxic cells to irradiation, chemotherapeutic drugs and as a cytotoxic agent. These effects are determined by the radiation-chemical mechanism, the toxic effect of recovery products, a decrease in the content of nonprotein sulfhydryl compounds, the suppression of cell regeneration resulting from lethal injuries.

[Hemolytic resistance of erythrocytes in the development of experimental tumors].

Peculiarities of variations in the mechanical resistance of erythrocytes from mice with tumours were studied depending on the growth stage of tumours (lymphoma NK/Ly and sarcoma S-37). The accumulation of erythrocytes with the increased mechanical resistance at the stage of rapid tumour development (on the 4 to 6th days) was revealed by the kinetic method of ultrasonic haemolysis. Quantitative parameters of ultrasonic haemolytic resistance of erythrocytes from normal and tumour-bearing mice were used as criteria for the red blood cell changes depending on the cell age in blood.

[Trypsin inhibitor from Gleditsia triacanthos L. seeds].

The trypsin inhibitor from Gleditsia triacanthos (L.) seeds was purified by affinity chromatography on a column with trypsin-Sepharose 4B. The isolated inhibitor is a single-chain protein with molecular weight of about 20 000.

[Conformational changes during proteinase inhibitor proteins interaction with chymotrypsin].

Using CD-spectroscopy and fluorescent probe technique, the formation of complexes of chymotrypsin with two highly efficient protein inhibitors of plant origin, e. g. inhibitors from pea seeds and potato tubers, was studied.

[Modification of tyrosine residues in the protein inhibitor of potato proteinases].

Treatment of a native protein inhibitor of proteinases by tetranitromethane results inmodification of 3 (out of 8) tyrosine residues in each of the two subunits within the inhibitor molecule. Nitration of surface tyrosines does not change the corformation of the protein and has no effect on its ability to inhibit chymotrypsin. At the same time the tetranitromethane-treated inhibitor possesses a decreased activity with respect to trypsin.

[Circular dichroism spectra of protein proteinase inhibitors].

The circular dichroism spectra of two protein proteinase inhibitors were studied. The CD spectrum of the kidney bean inhibitor is similar to those of other low molecular weight inhibitors from legume seeds. The potato inhibitor in its native state is characterized by a low content of alpha-helices, which is increased in the presence of sodium dodecyl sulfate.

Kinetics of changes in lymphoid organ weight and the cellular composition under leukosis of the latter, inoculated with different amounts of cells.

The authors studied the kinetic pattern of weight change in lymph glands, spleen, thymus, and their cellular composition during the development of mouse reticulosarcomatosis and Shvets' leukosis when the transplant contained different numbers of tumor cells. They found that during the development of reticulosarcomatosis, the weight of lymph glands and their content of lymphocytes and plasmocytes undergo enormous changes; the weight of the spleen and its content of lymphocytes increase gradually while the kinetic curve of plasma cell changes presents two maxima. During the development of Shvets' leukosis, the weight of spleen and lymph glands and their lymphocyte content change enormously while the number of plasmocytes rises exponentially.

[Interaction of protein inhibitor from potato (protein with pI 7.3) with proteinases].

The interaction between protein inhibitor of serine proteinases from potato (protein with pI 7.3) and enzymes was investigated. The main complex present in mixtures of the inhibitor with trypsin, chymotrypsin or subtilisin contained one dimeric inhibitor molecule and one molecule of either enzyme.

[Kinetic patterns of the development of transplantable AKR leukemia].

Under study was the kinetics of the development in primary passages of AKR leukemia transplanted by different number of cells. The indices of the leukemic process (the spleen, lymph nodes, the liver, thymus, blood leucocytes) vary with time in extreme curves. The leukemia transplantability is reduced from 100% to 24% with lessening of the transplant from 10(4) to 10(1) cells.

[Physico-chemical properties of a protein-inhibitor of serine proteinases from the potato].

Serine proteases inhibitor with pl-7.3, isolated from potatoe tubers by isoelectric focusing procedure as described previously (V.V.