MORPHOLOGICAL AND CYTOLOGICAL STUDY OF HUMAN AMNION CELLS IN THE COURSE OF RECOVERY FROM RADIATION INJURY

Journal Article · Sun Jan 01 04:00:00 EST 1961 · Texas Rept. Biol. Med.

OSTI ID:4668412

Mizutani, M; Nakanishi, Yuh H; Pomerat, C M

Human amnion cells (Fernandes strain) cultured in vitro were irradiated with 1000-r doses of Co/sup 60/ gamma rays and examined by staining techniques for the next 5 days. The number of cells in the control cultures increased until a plateau was reached at 4 days, then began to decrease, perhaps due to an overgrowth of cells in the chambers. In contrast, irradiated cultures showed a progressive decrease in cell numbers during the 5-day period. During the first 3 days following irradiation, most cells became rounded, and finally disrupted. Mitotic index in nonirradiated cultures reached a max of 5.8% on the first day, then showed a gradual decrease. In the irradiated cultures, the mitotic activity of the cells was remarkably inhibited on the first day (0.8%), but it showed a sudden increase on the second day (9.1%), and reached max on the third day (15.7%). Then the mitotic index fell rapidly (2.3%), along with a decrease of cell population. The later higher values may result from the accumulation of the cells at metaphasic stage. Numbers of cells at prophase, anaphase, and telophase in irradiated cultures was much lower than that in nonirradiated controls through 5 days of observation. In most metaphasic figures the chromosomes showed abnormalities, such as fragmentation, stickiness, and clumping. These severe chromosomal aberrations might inhibit migration of chromosomes to the poles at anaphase, so that metaphasic cells underwent degeneration in this condition without advancing further. Control cultures showed a constant value of giant cells at 5 days (0.5--0.7%), while the incidence of giant cells on the second day was already higher in the irradiated cultures than in the controls. Then it increased markedly, due in part to a decrease in the total cell population, and reached a max (32%) on the third day after irradiation. The number of multinuclente cells, consisting of both giant and nongiant elements, significantly increased in irradiated cultures, as compared with control cultures. The rate of increase was linear from the second day (3.6%) to the fifth day (35.3%). On the fifth day following irradiation, approximates 70% of cells are giant elements. The modal value of chromosomes in the irradiated subline was maintained constantly at 73, in contrast to 75 in the parent line. This gradual shift in the modal value of chromosomes toward lower numbers with successive passages of cultures is suggestive of selective adaptation. (BBB)

• Research Organization: Univ. of Texas, Galveston
• NSA Number: NSA-17-035574
• OSTI ID: 4668412
• Journal Information: Texas Rept. Biol. Med., Journal Name: Texas Rept. Biol. Med. Vol. Vol: 19
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AMNION
BIOLOGY AND MEDICINE
CHROMOSOMES
COBALT 60
CYTOLOGY
EMBRYOS
GAMMA RADIATION
MALFORMATIONS
MAN
MITOSIS
POPULATIONS
PREGNANCY
RADIATION INJURIES
RECOVERY
TISSUE CULTURES
TISSUES