Reduced High-Dose Radiation-Induced Residual Genotoxic Damage by Induction of Radioadaptive Response and Prophylactic Mild Dietary Restriction in Mice.

Radioadaptive response (RAR) describes a phenomenon in a variety of in vitro and in vivo systems that a low-dose of priming ionizing radiation (IR) reduces detrimental effects of a subsequent challenge IR at higher doses. Among in vivo investigations, studies using the mouse RAR model (Yonezawa Effect) showed that RAR could significantly extenuate high-dose IR-induced detrimental effects such as decrease of hematopoietic stem cells and progenitor cells, acute radiation hematopoietic syndrome, genotoxicity and genomic instability. Meanwhile, it has been demonstrated that diet intervention has a great impact on health, and dietary restriction shows beneficial effects on numerous diseases in animal models. In this work, by using the mouse RAR model and mild dietary restriction (MDR), we confirmed that combination of RAR and MDR could more efficiently reduce radiogenotoxic damage without significant change of the RAR phenotype. These findings suggested that MDR may share some common pathways with RAR to activate mechanisms consequently resulting in suppression of genotoxicity. As MDR could also increase resistance to chemotherapy and radiotherapy in normal cells, we propose that combination of MDR, RAR, and other cancer treatments (i.e., chemotherapy and radiotherapy) represent a potential strategy to increase the treatment efficacy and prevent IR risk in humans.

Citrulline, A Potential Biomarker of Radiation-Induced Small Intestine Damage.

Radiation damage assessment of the small intestine is important in nuclear accidents or routine radiotherapy of abdominal tumors. This article reviews the clinical symptoms and molecular mechanisms of radiation-induced small intestinal damage and summarizes recent research on biomarkers of such damage. Citrulline is the most promising biomarker for the evaluation of radiation-induced small intestinal damage caused by radiotherapy and nuclear accidents. This article also summarizes the factors influencing plasma citrulline measurement investigated in the latest research, as well as new findings on the concentration of citrulline in saliva and urine after different types of radiation.

Pesticide residues in tobacco leaves from the Kushtia district in Bangladesh.

In this study, tobacco leaf samples (n = 26) were collected from different areas in Kushtia to determine the presence of residues of cypermethrin, diazinon, heptachlor, methoxychlor dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethan (DDD) and dichlorodiphenyldichloroethylene (DDE). The analysis was conducted by a High Performance Liquid Chromatography (HPLC) system that was equipped with a photodiode array detector. Both cypermethrin and diazinon were detected in tobacco samples from six districts, namely, Mirzapur, Shahebnagar, Kodalipara, Pragpur, Farakpur and Taragunia. The highest concentration of cypermethrin was found in Kodalipara (2.00 ppm) while the highest concentration of diazinon was detected in a sample from Pragpur (0.15 ppm). The pesticide DDT was only detected in the sample from Pragpur at 4.00 ppm. This is the first study in Bangladesh that reports pesticide residue concentrations in tobacco leaf samples.