[Characteristics of osteosarcomas and morphological changes in the rat thymus during the combined action of gamma-radiation and 239Pu]. / Kharakteristika osteosarkom i morfologicheskikh izmenenii timusa krys pri sovmestnom vozdeistvii gamma-oblucheniia i 239Pu.

Under the combined effect of external gamma-irradiation and 239Pu, osteosarcomas occur more frequently and at earlier times, and have more pronounced multicentric pattern of growth and metastatic spreading than occurs with the two agents delivered separately. The difference is in the increased development of tumors and the decreased osteogenesis. Tumor carriers develop atrophy of thymus lymphoid tissue more frequently than normal ones.

[Lactate dehydrogenase and alkaline phosphatase activity of the serum and radiation-induced osteosarcoma in rats]. / Aktivnost' laktatdegidrogenazy i shchelochnoi fosfatazy v syvorotke krovi i osteosarkomakh, voznikshikh u krys pri radiatsionnom vozdeistvii.

Alkaline phosphatase (AP) and lactate dehydrogenase (LDG) activities are stained in rat blood serum and osteogenic sarcomas of different histostructure, which developed following a combined exposure of 239Pu (92.5 kBq/kg of body mass) and gamma-irradiation (103.2 mC/kg), as well as following separate exposures to these factors at the same doses. Alkaline phosphatase activities in blood serum and neoplastic bone tissues were found to correlate with the histostructure of osteogenic sarcomas, the distribution and the localization of metastases. Shifts in an isoenzymic spectrum of lactate dehydrogenase in neoplastic bone tissues and blood serum are observed, with a tendency to an increase in the LDG3 and LDG4 and to a decrease in the LDG5 fractions.

[Characteristics of a monolayer culture of bone marrow cells in rats with plutonium 239-induced osteosarcomas]. / Kharakteristika monosloinoi kul'tury kletok kostnogo mozga krys s osteosarkomami, indutsirovannymi plutoniem-239.

The report is concerned with a monolayer culture of bone marrow cells of rats in which optimal blastogenic dose (92.5 kBq/kg) induced osteosarcoma. The cell culture showed an enhanced rate of fibroblast-like cell proliferation (increased number of mitoses and symplasts and larger colonies of cells), apparent signs of radiation injury (pathologic mitoses, chromosome aberrations and gaps) as well as an increase in ploidy. Diffusion chamber measurements demonstrated osteogenic precursor-cells in osteosarcoma-bearing rats to be highly capable of bone formation. This relatively high ability seems to occur outside bone marrow as well.

[Experimental x-ray diagnosis of osteosarcoma]. / Rentgenodiagnostika osteosarkom v éksperimente

While using different methods of skeletal investigation, definite alterations were revealed in frequency of osteosarcomas under plutonium exposure (2.5 muC/Kg). The ratio of the corresponding values is 1:1,2:1,27:1,47. The highest incidence of osteosarcomas was noted in the complex roentgeno-morphological study (according to an extensive scheme of procurement of the osteomaterial) -- 39.8% In separate application of different methods of skeletal investigation the roentgenological method seems to be prefered: it determines more precisely the number of tumor nodes and the number of tumor-bearing rats, accordingly.