1987 年 3 巻 3 号 p. 241-250
Specimens were prepared from autopsied and biopsied human liver and lymph nodes and from Thorotrast granulomas surgically removed from patients who had been injected with this colloidal thorium dioxide. The lattice images of Thorotrast particles in the liver, lymph nodes, and Thorotrast granuloma, and in the Thorotrast solution, were observed by high-resolution electron microscopy. The fringe spacing of 0.32nm corresponding to the (111) atomic plane of ThO2 was determined. The mean particle sizes in the tissues and solution were estimated to be 10.8 and 8.1nm, respectively. Two kinds of recrystallization pattern were observed at the boundaries of particles in granular aggregates. Calcium needles coexisted with Thorotrast particles only in Thorotrast granulomas. The atomic rearrangement was more remarkable in the tissues than in the Thorotrast solution. Based on these experimental data, a model is proposed to explain the mechanism for the growth of granular aggregates of Thorotrast in human tissues; macrophages may take up Thorotrast particles and those particles may then unite tightly through atomic rearrangement.
