[Ultrastructural characteristics of chondroblastomas]. / Ul'trastrukturnaia kharakteristika khondroblastom.

The ultrastructure of chondroblastomas and two new ultrastructural peculiarities typical of the given form of tumours are described. Being typical but not constant these peculiarities may be an additional argument indicating that such cells may be regarded as chondroblastoma cells. The ultrastructure of these cells is similar to that of normal epiphyseal chondrocytes and differs from the ultrastructure of chondrosarcoma cells.

[Action of thymosin on the ultrastructure of the bone marrow in the rat]. / Deistvie timozina na ul'trastrukturu kostnogo mozga krys.

A preparation isolated from thymus extract and possessing thymosin-like activity was studied for its influence on the ultrastructure of the rat bone marrow cells. A dose of the preparation adequate to therapeutic one (7 mg/kg) causes a transitory "irritation" (dystrophy and stimulation) in cellular elements of bone marrow. A supertherapeutic dose (70 mg/kg) has a definitely toxic effect on its cells and is characterized by an expressed tropism to the endothelium of sinusoids and capillaries.

[Ultrastructure of the bone marrow cells after 85Sr incorporation]. / Sostoianie ul'trastruktur kletok kostnogo mozga pri inkorporatsii 85Sr.

Ultrastructural manifestations of the reaction of the rat bone marrow cells to incorporation of the osteotropic isotope 85Sr in doses of 15 and 150 muCi/100 g of body weight were studied in the electron microscope. It was found that ultrastructures were affected mostly in unidentifiable, blast cells and cells from the reproduction-maturation pool of the myeloid and erythroid series as well as lymphocytes. The lesions consisted in focal cchanges of chromatin and interchromatin structures of the nucleus, nuclear envelope membranes, nucleoli, mitochondrial membranes, endoplasmic reticulum, and plasma membrane. The dynamics of these changes in relation to the time of exposure and irradiation dose were followed.