Response of Swine Skin to Acute Single Exposures of X Rays: Quantification of the Epidermal Cell Changes

The preventive effect of vitamin D3 on radiation-induced hair toxicity in a rat model

“…This radiation-induced delay in cell cycle progression is due to a temporary arrest of cells in the G 1 /S or G 2 phases of the cell cycle (Maity et al, 1994) and its duration is related to the radiation dose and the cell population doubling time. It was shown that a single dose photon exposure of 1 Gy induces a cell cycle delay approximately 6-10% of the basal cell layer doubling time in the epidermis of mouse (Hegazy and Fowler, 1973), pig (Archambeau et al, 1979;Morris and Hopewell, 1988) and human (Nyman and Turreson, 1994). Cell cycle delay causes an accumulation of cells at the G 1 /S and G 2 /M boundaries.…”

Quantification of Rat Retinal Growth and Vascular Population Changes after Single and Split Doses of Proton Irradiation: Translational Study Using Stereology Methods

“…Examination of dose-survival curves for proliferating tissues such as the epidermis documented that the Gy of X rays for epidermal basement membrane cells quantified over 1 month (22,23). Visual appraisal of charts displaying the changes in cell numbers in the bone marrow, peripheral blood, and intestinal epithelium indicated that the response was the same as in the epidermis (24).…”

Determination of colony numbers in pig epidermis as an estimate for radiosensitivity. A rapid assay based on in vitro BrdU-labelling.

“…cells that had undergone at least four cell divisions, were counted. Although the limit of ¢16 cells per colony was arbitrary, it did exclude very small colonies where the number of divisions was more limited as these smaller colonies were unlikely to contribute signi®cantly to re-epithelialization [8].…”

“…In the past, several groups have attempted to determine radiation damage (more directly) using the number of colonies arising from surviving clonogenic cells as a parameter for epidermal radiosensitivity [4±7]. Various types of assays were used, such as (i) a macroscopic in vivo colony assay for rodent skin [5±7], (ii) autoradiographs of whole epidermal sheets for the detection of proliferating cells in mouse skin [4], (iii) crosssections of pig skin viewed by light microscopy [8], or (iv) blocking cells in mitosis followed by staining with Schiff's reagents using whole epidermal sheets from biopsies of pig skin [9]. A drawback of the macroscopic colony assay is the fact that smaller colonies are easily missed, while the use of autoradiographs and cross-sections is laborious and time consuming.…”