Radioresistance is among the main impediments in cancer therapy. The purpose of radiotherapy is to irradiate cancer cells, thereby damaging their DNA and inducing cell death. Cancer cells usually induce various types of cell death. To better understand and hopefully overcome radioresistance, we analyzed the X-ray irradiation-induced cell death type using long-term live-cell imaging. We observed dead cells floating in the culture medium after irradiation displaying the signs of apoptosis (type I cell death), autophagic cell death (type II cell death), and necrosis or necroptosis (type III cell death) based on their morphological characteristics. Furthermore, we confirmed that irradiation induces another type of cell death, mitotic catastrophe (MC), at a high frequency. Type I–III cell death could be induced in few cells directly after irradiation, and type I–III cell death is thought to be induced sporadically via MC. However, MC was induced less frequently in radioresistant cells. Therefore, if MC could be efficiently induced in radioresistant cells, we might be able to overcome radioresistance in cancer cells. In this review, we describe long-term live-cell imaging as a powerful tool in radiation-induced cell death-related studies.

The intestinal tract is a representative radiosensitive tissue and a risk organ in radiotherapy that limits the prescribed dose to tumors in the abdominal and pelvic regions. High-dose radiation damage to intestinal tissue induces the loss of intestinal epithelial stem cells, and it is now becoming clear that this process consists of two steps: crypt cell death regulated by p53 and exacerbation caused by inflammatory immune responses. Transcriptional regulators that enhance p53 function without enhancing apoptosis are effective in controlling the first step. The common activity of these p53 modulators that promote such functions is that they are able to suppress apoptosis without impairing p21-mediated cell cycle arrest. Regulating the second step can be achieved by agonists of Toll-like receptor signaling pathways that enhance the priming signal of pyroptosis and inhibitors that suppress the activity of the inflammasome. In this review, we outline the molecular mechanisms of each process and discuss strategies for effectively controlling the acute radiation-induced gastrointestinal syndrome.

It is necessary to accurately assess the deposition of fallout radionuclides on plants to ascertain the degree of risk and deleterious effects on public health. Therefore, a study of ¹³⁷Cs and ⁶⁰Co transfer factors (TF) from soil to eight tropical vegetables has been conducted by using a pot treatment system in the Green House of the Center. The research aims to determine the transfer factor of ¹³⁷Cs and ⁶⁰Co from soil to tropical vegetables such as spinach, swamp cabbages, chilli, tomato, bitter melon, mustard green, eggplant and cassava. This experiment was carried out by using the complete random design to evaluate two treatments, consisting of the soil contaminated with ¹³⁷Cs and ⁶⁰Co and without both radionuclides (¹³⁷Cs and ⁶⁰Co). The number of experiments for each vegetable was 12 pots and the control plant also was 12 pots. After being harvested, the weight of dried tropical vegetables and soil was measured. Transfer factor was determined according to the accumulation of ¹³⁷Cs and ⁶⁰Co concentrations in these tropical vegetables and soil by counting them using a gamma spectrometer. The transfer factors of ¹³⁷Cs and ⁶⁰Co from dry soil to dry tropical vegetable was found between 0.0153–0.5688 and 0.0024–0.2688, respectively. The lowest and highest TF were found in tomato and bitter melon, respectively for ¹³⁷Cs and ⁶⁰Co radionuclides.

Air pollution is one of the biggest problems in many cities worldwide. Chiang Mai is a city that also faces this problem, especially during the dry season. Due to its topography, Chiang Mai has various elevation areas, resulting in the dispersion of pollution at different altitude locations that should be measured in order to evaluate health hazards at different locations. In this study, the concentrations of PM2.5 and PM10 were measured at different altitudes in Chiang Mai, Thailand. At the same time, the ambient dose equivalent rate was monitored. The measurement results showed that the average concentration of PM2.5 and PM10 around urban areas was 23±13 µg m^-3 and 47±18 µg m^-3, respectively, and was 14±9 µg m^-3 and 29±14 µg m^-3, respectively, around outside urban areas. Moreover, a minor effect of altitude was observed from the measurement locations outside urban areas. The PM2.5 and PM10 concentrations tend to increase with increasing altitude. However, there was no significant difference in ambient dose equivalent rates at different altitudes. The average ambient dose equivalent rate in this study was observed at about 95±12 nSv h^-1.

To prompt precise understanding of radiation effects for young scientists, the 9th Educational Symposium on Radiation and Health by Young Scientists (ESRAH 2022) was held online on December 3–4, 2022. The number of participants of the ESRAH 2022 was 54 who studied various radiation research contents, such as radiation measurement, physics, biology, and therapy. This symposium featured four educational lectures by researchers from Thailand, Indonesia, Hungary, and Japan and 23 short presentations by young researchers and students. Due to the COVID-19 disaster, the ESRAH 2022 was forced to be held online; however, this year we could continuously provide a chance for communicating the latest research outcomes each other without any fatal troubles during online meeting. In this meeting report, we provide the organizing procedure for online holding during the COVID-19, and summarize the contents of Educational Lectures and Short Presentations. These would provide an approach holding international symposiums under a possible pandemic in the future but also present recent development of radiation research by young scientists.