Radiation-induced cell cycle arrests in Ehrlich ascites carcinoma cells in vivo.

Radiation-induced progression delay in G(1)/S, S and G(2)/M phases of p53 wild-type Ehrlich ascites carcinoma (EAC) cells growing in vivo was investigated by DNA flow cytometry. Different behavior patterns of EAC cells at the time after irradiation with low (2, 4, 6, 8 Gy) and high (10, 15, 20 Gy) doses were evaluated. While EAC cells showed a small progression delay in S phase and a dose-dependent block in G(2)/M phase after the irradiation with low doses, a clear additional block in G(1)/S phase was observed after irradiation with high doses. An assessment of the damage response and repair networks at the time after irradiation might have important implication for the development of cancer management and treatment.

[Main milestones of development and application of ductal cytometry at the Russian Federal Research Center for Radiology and Surgical Technology, St. Petersburg].

Ductal cytometry provides data on cellular DNA and RNA levels and overall profile of specific proteins identifiable by monoclonal antibodies. Results of its long-term use in clinical and oncological research are presented. Application of dosage ranging 0.28-1.1 mGy/sec was followed by stable 1.8-2-fold increase in the myelokariocyte profile cbering DNA synthesis. Bone marrow proliferation did not increase until relatively low dosage was used. A study of combined effects of prolonged gamma irradiation and lead and cadmium ions on rat's hemopoiesis pointed to radiation as the sole causative factor when cadmium chloride was used. Hemopoietic characteristics came back to normal when a combination of lead acetate and ionizing radiation was used, as a result of the oppositely directed action of the two factors. Standard monoclonal antibodies should not be employed for evaluating immunological vigor of patients with malignant gliomas due to the presence of a specific pathological link in their immune system.

[The combained effects of the long-term gamma-irradiation and heavy metall ions on the haematopoietic system of rats].

The combiened effects of different dose rates (0.625 microGy/s - 1.1 mGy/s) of gamma-irradiation and of cuprum and of cadmium ions on the haematopoietic system of rats were studied. It was found that only low dose rates (0.625-10 microGy/s, summary doses 0.5-2.0 Gy) of gamma-irradiation yields in the increasing proliferative activity of bone marrow. The number of myelocariocytos in S-phase was increased at 1.5-1.8 times. In case of the treatment with both cadmium chloride and radiation the changes in proliferative activity of bone marrow are completely due to the radiation factor. Combination of cuprum acetate and ionizing radiation induce opposite effects providing formal normalization of the haematopoietic characteristic of bone marrow up to 3, 6 and 12 months after the end of the radiation and the chemical exposure of the animal.

[Effect of chronic irradiation on the cell cycle of rat myelokaryocytes]. / Vliianie khronicheskogo oblucheniia na kletochnyi tsikl mielokariotsitov krys.

Rats were exposed to gamma-radiation within dose range from 0.12 to 4.0 Gy at dose rates from 0.625 microGy/s to 1.1 mGy/s. The changes in myelokaryocyte distribution within the cell cycle phases during the period of 1 to 18 months after irradiation were studied by the method of flow cytometry. A dose-dependent increase of cell percentage in S-phase after irradiation at low dose rates (from 0.625 to 10.0 microGy/s) was found. The effect was kept till the end of irradiated rats life.

[Pulse flow cytofluorimeter for the UV region of the spectrum]. / Impul'snyi protochnyi tsitofluorimetr dlia UF oblasti spektra.

A high-speed flow system for the automatic analysis of cells has been described. This device can register the fluorescence staining and ultra-violet fluorescence intensity of cells. The rate of measurement is more than 1000 cells per second. The resulting signals are processed and displayed as frequency distribution histograms, using a multichannel pulse height analyser.

[Apparatus for automatic recording of the intensity of ultraviolet fluorescence from individual cells]. / Ustanovka dlia avtomaticheskoi registratsii intensivnosti ul'trafioletovoi fluorestsentsii otdel'nykh kletok

The device enables to examine about 40 000--60 000 cells per min. The results are presented by the distribution curves of the ultraviolet fluorescence intensity.

[Study of mouse liver cell phosphorescence at deep cooling]. / Issledovanie fosforestsentsii kletok pecheni myshi pri glubokom okhlazhdenii

The spectrum and decay curves of phosphorescence of mouse liver cells at --180 degrees C was studied using the phosphorescence microscope. The phosphorescence studied was shown to involve two components with different life spans. Part of either component in the total spectrum is estimated. A conclusion is made that at least two different centers (or groups of centers) exist in cells with the same spectral region of phosphorescence with highly diverging life times of triplet states.

[Method of flow impulse cytofluorometry in the UV spectrum for the study of tumor cells in the whole blood]. / Metod protochnoi, impul'snoi tsitofliuorometrii vi UF dlia registratsii opukholevykh kletok v tsel'noi krovi.

Under consideration is the principal opportunity of using impulse cytofluorometers working in the UV spectrum for recording tumor cells in blood. The results of model experiments evidence the advantages of this method, however at present its sensitivity is not adequate enough.

[The mechanism of the formation of a circadian rhythm of bone marrow proliferation in rats]. / O mekhanizme formirovaniia sutochnogo ritma proliferatsii kostnogo mozga u krys.

Flow cytofluorimetry and statmokinetic method were used to study the circadian rhythm of bone marrow proliferation in Pliss' lymphosarcoma-bearing and intact rats. These data were compared to those obtained in the study of the mitotic activity of the bone marrow in cancer patients. It was found that, already at early stage, tumor affected the circadian rhythm of bone marrow proliferation, reducing the amplitude of oscillations. A model simulating formation of the circadian rhythm of the bone marrow was suggested basing on the possibility to arrest cells at the end of G1 phase. The rate of transition of G1 cells to S phase was determined not only by endogenous "set-points" of the rhythm which formed the basic wave of proliferation but also by conditions of animal upkeep.

[Possibility of using cytofluorometers to determine the ratio between normal and neoplastic cells]. / Vozmozhnost' ispol'zovaniia tsitofliurimetrov dlia opredeleniia sootnosheniia normal'nyjh i opukhelevykh kletok.

Principal possibility to use the pulsatile flowtype cytofluorometers for recording nontypical cells in biopsy material and the whole blood is considered.

[Flow-type pulsatile cytofluorometer with increased sensitivity]. / Protochnyi impul'snyi tsitofliuroimetr povyshennoi chuvstvitel'nosti.

A new cytofluorometer is described, with sensitivity twice as high as that of the existing units.

[The effect of soil extracts with different heavy metal levels on the viability of isolated blood system cells]. / Vliianie ékstraktov pochv s razlichnym soderzhaniem tiazhelykh metallov na zhiznesposobnost' izolirovannykh kletok sistemy krovi.

Short-term incubation of rat thymocytes, bone marrow cells, and macrophages with aqueous extracts of soil demonstrated positive correlations between damage to the cells and increased levels of copper, chromium, and manganese in the soil, while increased levels of zinc and lanthanum were associated with less pronounced changes in the cells.