[Radioadaptive enhancement of the repair of UV-induced postreplication gaps in Escherichia coli cells deficient in DNA repair].

In UV-irradiated E. coli WP2 uvrA, deficient in excision repair of DNA with pyrimidine dimers, gamma-irradiation in low doses (radioadaptation) before UV-irradiation leads to the intensification of postreplication repair of DNA. This process in WP2 uvrA polA and uvrA lexA mutants is less than in WP2 uvrA cells, but in WP2 uvrA recA both postreplication repair and its radioadaptive intensification are absent.

[Myocardium of mdx mice contains factor(s) that damage DNA structure and retard DNA reparation after gamma-irradiation (experiences in modeling system)].

We studied the action of saline extracts of ventricle myocard (EM) of C57BL and mdx mice on DNA structure and repair of one-strand breaks of DNA in a modelling system. The system involves DNA repair in E. coli WP2 cells after gamma-irradiation.

[Radioadaptive enhancement of the repair of UV-induced postreplication gaps in Escherichia coli DNA].

Postreplication DNA repair (PRR) in UV-irradiated Escherichia coli WP2 uvrA (tryptophan-dependent strain) and K12 AB1886 uvrA6 pre-irradiated by gamma-rays in low doses (radioadaptation, the first stress effect) has been investigated. PRR was found to be more effective after incubation in the growth medium (for 45-60 min) than in non-radioadapted cells: the repair of postreplication gaps increased by 6-15%. If cells of WP2 uvrA strain were incubated after UV-irradiation in media lacking tryptophan or casamin acids (the second stress effect), PRR was seen to increase as early as within 15 min of incubation and it is more effective than at the first stress.

[ Effect of gamma radiation, cis-diamminedichloroplatinum and its derivates on the Escherichia coli cell survival and potentiality for adaptive response].

The sensitivity to the lethal effect of gamma-rays, cis- and trans-diamminedichloroplatinum (DDP), cis- and trans-iminoethers of DDP (IE) was compared in two groups of E. coli--K12 and B. In all experiments, cells of wild types appeared to be most resistant to these agents.