120 M. N. MEISSEL, E. M. BEUMBEEG, T. M. KONDRATJEVA AND I. J. BARSKY 



We now pass to a discussion of the studies on the n.v. fluoi^escence 

 of the cells of radiosensitive and radiostable animal organs. In our 

 experiments, white rats were irradiated with X-rays (by the apparatus 

 RUM-3, 190 kV. 10 niA with 0-5 mm copper and 1 mm aluminium 

 filters) in doses of 900 to 1,000 r, the dose-rate l)eing 74 r/min. Cells of 

 the various organs were investigated immediately, and 4 hr after, 

 irradiation. 



Already, soon after irradiation, a marked increase was observed in 

 the intensity of idtraviolet fluorescence of the lymphocytes in the 

 lymph nodes (Fig. 7) and in the blood and the fluorescence of the 

 leucocytes. After irradiation there is a considerable increase in the u.v. 

 fluorescence of cells of the myeloid series in the bone-marrow. Barsky 

 obtamed the fluorescence spectra of normal myeloc^^tes and of the 

 same cells from the bone-marrow of irradiated animals (Fig. 8). Exam- 

 ination of the spectra revealed considerable changes in those of the 



300 



340 



380 



420 



Fig. 8. — Ultraviolet fluorescence spectra of individual myelocytes: 1, from the bone- 

 marrow of normal and 2, irradiated animals (rats) 4 hr after irradiation witli a dose of 



900 r. 



irradiated animals. The emission bands broaden and are somewhat 

 shifted in the direction of the longer wave-lengths. This bears evidence 

 of qualitative changes in the substances responsible for the fluor- 

 escence. No changes in the character and intensity of the fluorescence 

 could be detected in the liver cells either immediately after, a few hours 

 after or 24 hr after irradiation. Even on the 9th or lOtli day after 

 irradiation ^^"ith a dose of 500 r the liver cells fluoresced in the same way 

 as the controls. 



The necrobiotic changes of the cells in the bone-marrow and lymph 

 nodes of irradiated animals, wiiich we had described pi'eviously as 

 micronecrotic and which are clearly observed on fluorochroming with 

 acridine orange (on fluorescence microscojiy in the visible region), were 



