Radiation-induced bystander effect (RIBE) was first reported by Nagasawa et al. [1] showed that exposure to very low doses of alpha particles initiated sister chromatid exchange in more cells than that could have been hit by an alpha particle as estimated. Thereafter, different biological endpoints, such as chromosomal aberration, sister chromatid exchange, mutation, apoptosis and changes in th...

Defects in DNA replication are associated with genetic instability and cancer development, as illustrated in Bloom syndrome. Features of this syndrome include a slowdown in replication speed, defective fork reactivation and high rates of sister chromatid exchange, with a general predisposition to cancer. Bloom syndrome is caused by mutations in the BLM gene encoding a RecQ helicase. Here we rep...

We describe a system that uses pulsed-field gels for the physical detection of recombinant DNA molecules, double-strand DNA breaks (DSB) and sister-chromatid exchange in the yeast Saccharomyces cerevisiae. The system makes use of a circular variant of chromosome III (Chr. III). Meiotic recombination between this ring chromosome and a linear homolog produces new molecules of sizes distinguishabl...

In the Chinese hamster cell line CHEF-125, sister chromatid exchanges occurred at a rate of a little higher than one per three chromosomes for each cell cycle. The exchanges were detectable by labeling with H(3)-thymidine and autoradiographic analyses of chromosomes at the second and subsequent metaphases after labeling had occurred. To test the hypothesis that sister chromatid exchanges are ca...

Human lymphocyte culture of two healthy donors was carried out.[3] Later, metaphases were examined for different types of aberrations. For sister chromatid exchange analysis, bromodeoxyuridine (10 μg/ml) was added at the beginning of the culture.[4] Cell cycle kinetics was studied by the BrdU‐Harlequin technique using the replication index (RI) calculated by the standard formula.[5] The Student...

The mechanisms of formation of sister chromatid exchanges (SCEs) and chromosome aberrations following inhibition of poly(ADP-ribose) polymerase by 3-aminobenzamide were studied in Chinese hamster ovary cell lines deficient in different repair pathways. The results confirm earlier findings that (a) the 'spontaneous' SCEs are formed due to the incorporated BrdU in the DNA, (b) 'spontaneous' and i...

Photodynamic therapy (PDT) was recently introduced in clinical practice for the management of cancer. As far as PDT relies on the combined action of a photosensitizer and a laser source, there is a need to evaluate the genotoxic and mutagenic potential of this treatment modality. This paper reports the effects of various photosensitizer and photo-irradiation doses on lethality to the MIA PaCa c...

We found that 9L-2 cells, a cell line derived from the in vivo 9L rat brain tumor model, are approximately 8-fold more resistant to the cytotoxic effect of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) than are sensitive 9L cells. Treatment with BCNU induces sister chromatid exchanges in both lines, but to produce similar levels of exchanges, 9L-2 cells must be treated with a 14-fold higher conce...