Early and Late Effects of Low-Dose X-ray Exposure in Human Fibroblasts: DNA Repair Foci, Proliferation, Autophagy, and Senescence.

The effects of low-dose radiation exposure remain a controversial topic in radiation biology. This study compares early (0.5, 4, 24, 48, and 72 h) and late (5, 10, and 15 cell passages) post-irradiation changes in γH2AX, 53BP1, pATM, and p-p53 (Ser-15) foci, proliferation, autophagy, and senescence in primary fibroblasts exposed to 100 and 2000 mGy X-ray radiation.

Residual Foci of DNA Damage Response Proteins in Relation to Cellular Senescence and Autophagy in X-Ray Irradiated Fibroblasts.

DNA repair (DNA damage) foci observed 24 h and later after irradiation are called "residual" in the literature. They are believed to be the repair sites for complex, potentially lethal DNA double strand breaks. However, the features of their post-radiation dose-dependent quantitative changes and their role in the processes of cell death and senescence are still insufficiently studied.

Effects of combined exposure to modeled radiation and gravitation factors of the interplanetary flight: Monkeys' cognitive functions and the content of monoamines and their metabolites; cytogenetic changes in peripheral blood lymphocytes.

In a study on primates (Macaca mulatta), neurobiological and radiobiological effects have been studied of the synchronous combined action of 7-day antiorthostatic hypokinesia and exposure of the monkeys' head first to γ-rays during 24 h and then to accelerated C ions. The neurobiological effects were evaluated by the cognitive functions which model the basic elements of operator activity and the concentration of monoamines and their metabolites in peripheral blood. The radiobiological effects were evaluated by the chromosomal aberration and DNA double-strand break (DSB) yield in peripheral blood lymphocytes.

Immunocytochemical Localization of XRCC1 and γH2AX Foci Induced by Tightly Focused Femtosecond Laser Radiation in Cultured Human Cells.

To assess the prospects for using intense femtosecond laser radiation in biomedicine, it is necessary to understand the mechanisms of its action on biological macromolecules, especially on the informational macromolecule-DNA. The aim of this work was to study the immunocytochemical localization of DNA repair protein foci (XRCC1 and γH2AX) induced by tightly focused femtosecond laser radiation in human cancer A549 cells. The results showed that no XRCC1 or γH2AX foci tracks were observed 30 min after cell irradiation with femtosecond pulses of 10 W∙cm peak power density.

Signaling and physiological activity of the NO-donating agent TNICthio in human blood lymphocytes, Jurkat and MCF7 cell lines.

Signaling and physiological activities of the crystalline tetranitrosyl iron complex with thiosulfate-a NO-donor (TNICthio) were first studied on human cells in conditions of mono and combined application of HS and antioxidants. Comparative studies were performed on three cell lines: normal and leukemic T lymphocytes (Jurkat cells) and breast cancer MCF-7 cells (human breast adenocarcinoma). Also established was a high biological activity of TNICthio, as well as correlation between the levels of reactive oxygen species generation, the formation of double-strand breaks (DSB) in DNA and cell proliferation.