Hypersensitivity to low single doses and split-dose recovery: two manifestations of induced resistance that might be related.

Purpose: To study retrospectively the relationship between intrinsic radiosensitivity (SF2), and both the low-dose inducible response (alpha(s)/alpha(r)) and the amount of split-dose recovery (betaRR).

Materials And Methods: A total of 53 sets of experimental data obtained with 44 human cell lines were collected from the literature and the above relationships were studied.

Results: Analysis showed a statistically significant correlation between alpha(s)/alpha(r) and SF2 (p = 0.

Underestimation of the small residual damage when measuring DNA double-strand breaks (DSB): is the repair of radiation-induced DSB complete?

Purpose: To overcome the underestimation of the small residual damage when measuring DNA double-strand breaks (DSB) as fraction of activity released (FAR) by pulsed-field gel electrophoresis.

Materials And Methods: The techniques used to assess DNA damage (e.g.

Combined immunodeficiency associated with increased apoptosis of lymphocytes and radiosensitivity fibroblasts.

Severe immunodeficiency characterized by lymphopenia was found in two siblings, one of whom was examined in detail. The calcium flux, pattern of tyrosine phosphorylation of proteins, and interleukin 2 (IL-2) production and proliferation in response to mitogens suggested that the peripheral blood T cells activated normally. The peripheral blood T cells were shown to have an activated phenotype with increased expression of CD45RO+ and CD95/Fas.

Tumour size in cancer of the cervix.

In a randomized trial comprising 204 patients with operable cervical carcinomas stages I and II, two low-dose rates in gynaecological brachytherapy were compared. Treatment consisted of Cs-137 uterovaginal application followed by surgery (either immediate or delayed). The results for the two dose rates have been published previously.