PubMed Health⌕ Search

Biomedical subjects

B Fertil

Publications and source records attributed to B Fertil.

44 records · Page 3Linked to original sources
PubMed1984

Detection in situ of gamma-ray-induced DNA strand breaks in single cells: enzymatic labelling of free 3'-OH ends.

We report a procedure allowing the detection and counting of free 3'-OH DNA strand extremities in single cells in situ. Terminal transferase (TdT) catalysed the incorporation of 3H-dGMP into fixed nuclei of human colonic adenocarcinoma cells (HT29), using free 3'-OH ends as initiator. Radioactivity was detected by autoradiography and determined quantitatively with a rapid image-processing system for grain counting. The initiator activity for TdT increases with the dose of gamma-rays in the dose range 2.5-20 Gy.

Adenocarcinoma↗
PubMed1984

Mean inactivation dose: a useful concept for intercomparison of human cell survival curves.

The mean inactivation dose (D) is calculated for published in vitro survival curves obtained from cell lines of both normal and neoplastic human tissues. Cells belonging to different histological categories (melanomas, carcinomas, etc.) are shown to be characterized by distinct values of D which are related to the clinical radiosensitivity of tumors from these categories. Compared to other ways of representing in vitro radiosensitivity, e.g., by the multitarget parameters D0 and n, the parameter D has several specific advantages: (i) D is representative for the whole cell population rather than for a fraction of it; (ii) it minimizes the fluctuations of the survival curves of a given cell line investigated by different authors; (iii) there is low variability of D within each histological category; (iv) significant differences in radiosensitivity between the categories emerge when using D. D appears to be a useful concept for specifying intrinsic radiosensitivity of human cell lines.

Ataxia Telangiectasia↗
PubMed1980

Radiosensitivity and repair of radiation damage in human HF19 fibroblasts.

Survival curves of HF 19 fibroblasts exhibit a continuous curvature, whether the cells are irradiated in exponential growth phase or in plateau phase and whether plating occurs immediately after irradiation or is delayed. The quadratic model is well suited for the fitting and the comparison of the curves obtained under different conditions. At the survival level of 10(-4), the split-dose method leads to the demonstration of the repair of sublethal damage by growing cells. By combining the split-dose method with delayed plating, we could demonstrate that plateau phase cells repair both sub-lethal as well as potentially lethal damage to a great extent. The parameters of the survival curve of fibroblasts irradiated in plateau phase and plated 24 hours later are similar to those of a large number of mammalian cell lines. When the results are fitted with the quadratic model, it is seen that delayed plating of plateau phase cells results in a proportional reduction of the parameters alpha and beta, suggesting that repair involves the damage corresponding to the two mechanisms described by the quadratic model and affects them to the same extent.

Autoradiography↗
PubMed1978

Effects of low dose rate irradiation on the division potential of cells in vitro. IV. Embryonic and adult human lung fibroblast-like cells.

Early and late passage human embryonic lung fibroblasts were compared with early passage adult lung fibroblasts with regards to their survival (number of population doublings), after low dose rate ionizing radiation. It was found that early passage embryonic cells are quite resistant to this type of radiation. Late passage embryonic and early passage adult fibroblasts are more sensitive to ionizing radiations. The results suggest that cell aging is accompanied by an increased sensitivity to low dose rate ionizing radiation and favor the idea that aging in vitro, expressed as a function of the fibroblast division potential, is correlated with aging in vivo.

Cell Division↗