Ionizing radiations produce deleterious effects in the living organisms and the rapid technological advancement has increased human exposure to ionizing radiations enormously. There is a need to protect humans against such effects of ionizing radiation. Attempts to protect against the deleterious effects of ionizing radiations by pharmacological intervention were made as early as 1949 and effor...

The DNA repair mechanisms involved in hyperthermia-induced radiosensitization with proton and carbon ion radiation exposure were investigated in the present study. In a previous study, Chinese hamster ovary (CHO) cells were exposed to low linear energy transfer (LET) photon radiation. These cells can be sensitized by hyperthermia as a result of inhibition of homologous recombination (HR) repair...

Ionizing radiation is carcinogenic, but genotype is a key determinant of susceptibility. Mutational DNA damage is generally attributed to cause disease, but irradiation also affects multicellular interactions as a result of poorly understood bystander effects that may influence carcinogenic susceptibility. In this study, we show that the bone marrow of irradiated mice will retain the ability to...

Radiation lethality is largely attributed to radiation-induced DNA double-strand breaks (DSBs). A range of structural complexity is predicted for radiation-induced DSBs. However, this lesion has never been analyzed in isolation at the molecular level. To address this problem, we have created authentic site-specific radiation-induced DSBs in plasmid DNA by triplex-forming oligonucleotide-targete...

The radioprotective effect of indralin in rhesus monkeys was examined over 60 d following gamma irradiation. Male and female rhesus macaques (Macaca mulatta) 2-3-years-old and weighing 2.1-3.5 kg were used. Animals were exposed to total-body gamma irradiation from (60)Co at a dose of 6.8 Gy (lethal dose, 100% lethality over 30 days). Indralin (40-120 mg kg(-1)) was administered intramuscularly ...

Acute endothelial cell apoptosis and microvascular compromise couple gastrointestinal tract irradiation to reproductive death of intestinal crypt stem cell clonogens (SCCs) following high-dose radiation. Genetic or pharmacologic inhibition of endothelial apoptosis prevents intestinal damage, but as the radiation dose is escalated, SCCs become directly susceptible to an alternate cell death mech...

Protection of the hematopoietic system from radiation damage, and/or mitigation of hematopoietic injury are the two major strategies for developing medical countermeasure agents (MCM) to combat radiation-induced lethality. In the present study, we investigated the potential of 7, 8-diacetoxy-4-methylthiocoumarin (DAMTC) to ameliorate radiation-induced hematopoietic damage and the associated mor...

Pharmacologic inhibitors of poly(ADP-ribose) polymerase (PARP) putatively enhance radiation toxicity in cancer cells. Although there is considerable information on the molecular interactions of PARP and BRCA1- and BRCA2-deficient cancers, very little is known of the PARP inhibition effect upon cancers proficient in DNA double-strand break repair after ionizing radiation or after stalled replica...