[Unstable chromosome aberrations in lymphocytes of liquidators of the Chernobyl accident consequences]. / Nestabil'nye khromosomnye aberratsii v limfotsitakh uchastnikov likvidatsii posledstvii avarii na Chernobyl'skoi AES.

AIM: Analysis of peripheral blood lymphocytes for detecting unstable chromosome aberrations in liquidators of the Chernobyl disaster consequences and in residents of territories contaminated after the accident. MATERIALS AND METHODS: Peripheral blood lymphocytes were tested for unstable chromosome aberrations in 216 subjects who worked for different periods after the Chernobyl accident in 1986-1987 in the 30-km zone and at adjacent territories. The results were correlated to the duration of stay in the zone, terms of examination after the work, exposure dose fixed in the files, deviations in the health status and blood values, and with similar data on 21 residents of the stringent control regions of the Gomel district and 265 patients with different hematological diseases and donor blood samples exposed in vitro. RESULTS: Chromosome aberrations detected in the examined group are represented by dicentrics, paired and nonpaired fragments, acentric rings, and gaps. CONCLUSION: Although not everything is yet clear, we consider that detection of unstable chromosome aberrations of the dicentric type in lymphocytes of subjects who participated in liquidation of the accident consequences in remote periods after exposure persuasively proves that a radiation exposure, no matter what its dose was, took place, and hence, there are good grounds for including the subjects with aberrations in the high risk group. On the other hand, the absence of such aberrations does not rule out the detrimental effect of radiation on the organism.

[Strength of nucleic acid-protein interactions and synthesis of nucleic acids and proteins in the cell]. / Prochnost' nukleinovo-belkovykh vzaimodeistvii i sintez nukleinovykh kislot i belka v kletke.

Nucleoprotein-celite chromatography of cultivated cells nuclei, where incorporation of 3H-thymidine, 3H-UTP and 14C-aminohydrolysate into the cells was studied, enabled to detect that lowering of DNA-protein interactions in intact cells occurred simultaneously with a decrease in the rate of spontaneous macromolecular synthesis. The natural growth-regulating drugs, which inhibited distinctly DNA synthesis, inhibited RNA synthesis only slightly and stimulated protein synthesis within the first hours of the cells cultivation, prevented a decrease in tightness of DNA-protein bonds at the beginning of cultivation and then contributed to the reaction thus correlating with inhibition of RNA and protein synthesis. Definite interrelationship was found between alterations in the chromatin structural state and the cells functional activity. The cells lost their functional activity after pronounced decrease in tightness of DNA-protein bonds.

[Induction of the antileukemic activity in nonimmune allogeneic splenocytes using spleen hemoregulators]. / Induktsiia protivoleikoznoi aktivnosti u neimmunnykh allogennykh splenotsitov s pomoshch'iu gemoregulinov iz selezenki.

The leukemic mice treated with cyclophosphamide were injected twice a week with the allogenic splenocytes treated for 4 h with the substance isolated from the calf spleen. The leukemia growth inhibition was observed. Syngenic splenocytes were inactive. Allogenic but not syngenic splenocytes manifested a certain antileukemic activity observed in the Winn neutralization and 51Cr release tests, however this activity did not correlate quantitatively with more pronounced antileukemic action of cells in vivo.

[Effect of a substance isolated from the regenerating spleen on the chromatin structural organization and the leukosogenic activity of transplanted cells]. / Vliianie veshchestva, vydelennogo iz regeneriruiushchei selezenki, na strukturnuiu organizatsiiu khromatina i leikozogennuiu aktivnost' transplantirovannykh kletok.

When leukemic cells in vitro are treated with the substance isolated from the regenerating calf spleen, incorporation of 3H-thymidine into DNA is rapidly inhibited. The completeness of DNA synthesis restoration after washing off cells from the substance depends on the duration of the previous contact with the substance. It is the change in the structural organization of chromatin but not the very fact of inhibition of the ability of the cells to the DNA synthesis that is important for a decrease of transplantability of mice cells treated by the substance. The quicker the stability of the DNA/protein interaction in chromatin weakens due to the effect of the substance, the earlier the leukosogenic potential of the treated cells decreases.