International journal of radiation biology最新文献

Purpose: This mini-review aims to synthesize current knowledge regarding radiation-induced effects on female fertility and reproductive capacity, and to identify knowledge gaps relevant to radiation protection.

Methods: We critically examined evidence from developmental biology, animal models, clinical studies, and epidemiological investigations. Key topics include germ cell and follicle biology, radiation dose thresholds, therapeutic exposures, and environmental and occupational contexts.

Results: Female germ cells are highly radiosensitive, with animal models indicating a mean lethal dose as low as 0.05-0.15 Gy in primordial oocytes. In humans, pelvic irradiation increases risks of acute ovarian failure, premature ovarian insufficiency, and infertility, depending on dose and age at exposure. Cranial irradiation further impairs fertility through damage to the hypothalamic-pituitary axis. In contrast, evidence from occupational and environmental exposures is scarce, with most studies addressing miscarriage or perinatal outcomes rather than infertility itself.

Conclusions: While advances in oncofertility research have clarified therapeutic risks, systematic data on environmental and occupational exposures are lacking. Strengthened prospective studies and integration of fertility-specific biomarkers are urgently needed to inform comprehensive radiation protection strategies.

Purpose: This study assesses the radiological impact of radionuclide dispersion for the first four days after a hypothetical nuclear accident scenario, utilizing the HotSpot Health Physics software developed by the Lawrence Livermore National Laboratory (LLNL).

Materials and methods: A Gaussian plume model was used to estimate the dispersion of I-131 and Cs-137 under various atmospheric conditions.

Results: The study's key findings include an analysis of the Total Effective Dose Equivalent (TEDE) along a simulated contamination plume, highlighting the impact of atmospheric stability on radiation levels. It also assesses the radiobiological risks, noting that young people and women are especially vulnerable, as the risk of thyroid or leukemia may vary by a factor of 10⁴ depending on location and atmospheric stability conditions. The analysis also indicated that the TEDE generated by the inventory release could range from 0.1 to 10 Sv of whole-body exposure within the first 10 km downwind under stable atmospheric conditions.

Conclusions: Even minor fluctuations in TEDE caused by local atmospheric stability can significantly affect the estimated risks of thyroid cancer and leukemia. This may alter the logistical resources required and the epidemiological methods used to identify and prioritize concerns. Implementing environmental monitoring and strategies such as distributing stable iodine and enforcing dietary restrictions during the initial phases of nuclear emergencies may be guided by risk assessments based on simulations.

Purpose: Radiation exposure can lead to acute radiation syndrome and systemic inflammation, highlighting the need for accessible tests to assess exposure and its biological effects. This study investigated changes in inflammatory markers derived from CBC in male Wistar rats exposed to total-body irradiation with 6 MV LINAC photons delivered at doses of 6 Gy and 8 Gy, at a dose rate of 200 cGy/min.

Methods: A total of 42 rats were randomized into eight groups: control, sham, and irradiated groups. These groups were evaluated at 0-, 24-, and 48-hours post-exposure. Blood samples were analyzed for standard CBC values and derived ratios, such as the NLR (Neutrophil-to-Lymphocyte Ratio), PLR (Platelet-to-Lymphocyte Ratio), MLR (Monocyte-to-Lymphocyte Ratio), HLR (Hemoglobin-to-Lymphocyte Ratio), PMR (Platelet-to- Monocyte Ratio), SII (Systemic Immune-Inflammation Index), and SIRI (Systemic Inflammatory Response Index).

Results: Two-way ANOVA revealed significant time-dependent increases in NLR, PLR, HLR, and SII (p < .001 for all), independent of the radiation dose. MLR and PMR showed significant effects related to both time and dose, with higher values observed at 24-48 hours post-exposure.

Conclusion: Our results indicate that the duration following irradiation influences most ratio-based indices, which appear to be sensitive in detecting early responses to radiation effects. This makes them rapid and cost-effective methods for monitoring radiation injury.

Background: In radiotherapy (RT), the dose given to the organs at risk (OAR) is as important as the dose received by the tumor. FF (Flattening Filtered) and FFF (Flattening Filter Free) treatment techniques used in RT offer different advantages in terms of their effects on target and critical organs. Treatment duration varies depending on the number of monitor units (MU) delivered per unit time. The aim of this study was to investigate biochemically and histopathologically the damage in healthy laryngeal tissue exposed to 600 MU/min FF and 2400 MU/min FF ionizing radiation under different fractionation protocols. Also to investigate the radioprotective effect of melatonin against the radiological damage.

Methods: The 78 rats included in the study were divided into 10 groups. Control and melatonin-only groups did not receive RT. The other 8 groups received FF and FFF ionizing radiation in different dose fractions. Half of the radiation group received melatonin 15 min before RT.

Results: No histological and biochemical differences were observed in the control and MLT only groups. Radiobiological damage was statistically significantly lower in the RT+MLT group compared to the RT only group.

Conclusions: It has been observed that melatonin has a protective effect against tissue damage caused by radiation exposure in healthy laryngeal tissue.

Introduction: Bacterial endospores are highly resistant to environmental stressors. Their resistance complicates sterilization efforts, leading to exploration of novel inactivation techniques. Radiation in the water window spectral range (284-543 eV), typically studied using synchrotron sources, offers high contrast for bio-imaging and potential for efficient spore inactivation due to its high absorption and shallow penetration.

Methods: A compact pulsed laser-plasma soft X-ray source was used to irradiate Bacillus subtilis spores in the water window spectral range. A combination of STEM-EDS and Geant4 Monte Carlo simulations provided data on spore geometry, elemental composition, and dose deposition. The spores were deposited on glass coverslips, dried, irradiated in vacuum, and resuspended for viability testing. Spore survival was assessed via colony-forming units, and the survival curve was fitted with a modified biphasic model.

Results: The decimation dose (D₁₀) was reached in less than one second at a 10 Hz repetition rate, indicating high inactivation efficiency. Effective photoabsorption coefficients were calculated from simulations and validated against tabulated values. Average dose rates in the spore core reached 2.4 kGy·s^-1, with peak values exceeding 10¹¹ Gy·s^-1. The survival curve exhibited biphasic kinetics with saturation behavior due to spore clustering.

Discussion: The study confirms that soft X-rays in the water window range are highly effective in rapidly inactivating bacterial spores. The efficiency is attributed to the spectral region's short attenuation lengths and high absorption cross-sections, aligning with data from conventional ionizing sources.

Purpose: Sprouting boosts bioactive compounds in Brassicaceae, including glucosinolates, amino acids, and anthocyanins. This study examined gamma radiation seed priming effects on growth, metabolism, and bioactive accumulation in Nasturtium officinale, Eruca sativa, and Raphanus raphanistrum sprouts.

Materials and methods: Seeds of the three species were primed with gamma radiation (0.1 kGy/h) and grown under controlled conditions. Biomass was measured; metabolic profiling quantified glucosinolates, amino acids, flavonoids, and anthocyanins. Enzymatic activities for glucosinolate and flavonoid biosynthesis were assessed. Antioxidant potential was assessed using FRAP and DPPH assays; antimicrobial activity was tested against Escherichia coli and Enterococcus faecalis. Microbial counts (APCs and Coliforms) were measured.

Results: Gamma radiation increased biomass by 48%, 36%, and 71% in N. officinale, E. sativa, and R. raphanistrum, respectively. Glucosinolates rose, especially glucoerucin (up to 227% in E. sativa) and glucoraphenin (up to 60%), linked to higher precursor amino acids (leucine, tryptophan, methionine), glutathione, and activities of glutathione S-transferase and sulfotransferase. Myrosinase activity increased, boosting sulforaphane. Flavonoids surged: quercetin (48 -191%), kaempferol (75 -172%), anthocyanins (42 -60%), with elevated PAL, CHS, 4CL, and C4H activities. Antioxidant and antimicrobial (40 -77%) potentials improved, though APCs and coliforms rose.

Conclusions: Gamma radiation priming enhances growth, secondary metabolite accumulation, antioxidant potential, and antimicrobial activity in Brassicaceae sprouts. It offers a promising method to improve the nutritional and functional qualities of edible sprouts, aiding food safety and health.

Purpose: Low-dose ionizing radiation (LDIR) was reconnoitered to improve the reproductive fitness of radio-sterilized moths, Spodoptera litura (Fabr.) to be used in exercising radiation mediated 'Inherited sterility (F1) technique (IS) for this Lepidopteran pest suppression.

Materials and methods: Various reproductive features were evaluated of the partially sterilized male moths (irradiated at 130 Gy), primed with potential hormetic doses (0.75-1 Gy as LDIR) in their ontogeny, in relation to response of unprimed sterilized moths. The expression of genes related to sperm dynamics and viability was ascertained in primed radio-sterilized moths. Mating competitiveness of 1 Gy (egg) primed radio-sterilized male moths was assessed in field simulated cages.

Results: Radio-sterilized male moths, having prior hormetic exposure in various ontogenic stages, viz., 0.75 Gy (egg), 1 Gy (egg/larva/pupa), showed longer lifespan, increased mating success, and enhanced sperm dynamics in comparison to unprimed radio-sterilized male moths. The expression of genes related to sperm dynamics was affected in sterilized moths but low dose priming improved their expression in sterilized moths. The expression of viability genes-foxo and Sirtuin2like was down regulated unlike the up-regulated expression of atm, sod, cat, and p53 in radio-sterilized male moths in comparison to control, whereas priming influenced the expression of these genes in the sterilized moths. A higher mating competitiveness value (CV) was observed in LDIR primed radio-sterilized moths as compared to unprimed sterilized males.

Conclusion: These findings indicate that radiation hormesis might be employed as promising mode to enhance the reproductive viability of the radio-sterilized male moths to be used in this nuclear tactic.

Purpose: High linear energy transfer (LET) radiation is more harmful than low LET radiation because it deposits energy in a concentrated manner, resulting in clustered DNA damage (CDD). Double strand breaks (DSBs) are among the most damaging types of DNA damage, and if not repaired, they may trigger cell death. DSBs can be repaired through three mechanisms: non-homologous end joining (NHEJ), homologous recombination (HR), and theta-mediated end joining (TMEJ). This study aimed to assess how these pathways contribute to repairing DSBs induced by low LET X-ray and proton radiation, and high LET alpha-particle radiation.

Materials and methods: We used mouse embryonic stem (mES) cells lacking key repair proteins to examine clonogenic survival and the formation and resolution of 53BP1 foci, a DNA damage marker, after exposure to X-ray, proton, and alpha-particle radiation.

Results and conclusions: The results showed increased sensitivity to X-ray and proton radiation in NHEJ, HR, and TMEJ repair-deficient cell lines compared to wild-type cells, with similar trends for both radiation types. Notably, Rad54-deficient cells showed slower resolution of 53BP1 foci after proton exposure, indicating increased reliance on HR for repairing proton-induced DSBs. Clonogenic survival assays revealed a relative biological effectiveness (RBE) of 4.6-5.8 for alpha-particles compared to protons and X-rays, confirming that alpha-particles are more effective at causing cell death. Our findings suggest that TMEJ is important for repairing DSBs caused by alpha-particles. This study highlights differences in repairing low LET versus high LET DNA damage, offering new insights for radiation biology and therapeutic strategies.

Aim: Glioblastoma (GBM) is an aggressive brain tumor characterized by resistance to temozolomide (TMZ) and radiotherapy. This study investigates the role of long non-coding RNA POT1-AS1 in modulating TMZ resistance (TMZR) and radiation-resistant (RR) in GBM by regulating ferroptosis via the IGF2BP2/glutathione peroxidase 4 (GPX4) pathway.

Methods: Human GBM cell lines, including TMZR and RR variants, were analyzed. POT1-AS1 expression was silenced using shRNA in U-87MG RR and U-87MG TMZR cells. The impact of POT1-AS1 knockdown on ferroptosis was evaluated by measuring iron concentration, reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH) levels. GPX4 protein expression was also analyzed. Ferroptosis inhibition experiments were conducted using Fer-1. The stability of GPX4 mRNA was assessed by RNA immunoprecipitation (RIP) assays.

Results: POT1-AS1 and GPX4 were significantly overexpressed in U-87MG RR and TMZR cells. Knockdown of POT1-AS1 increased ferroptosis markers, including elevated iron and ROS levels, reduced GSH content, and downregulated GPX4 expression. POT1-AS1 knockdown sensitized GBM cells to TMZ and radiation. Additionally, the ferroptosis inhibitor Fer-1 reversed the effects of POT1-AS1 knockdown. RIP assays confirmed the interaction between POT1-AS1, IGF2BP2, and GPX4 mRNA, highlighting the POT1-AS1/IGF2BP2/GPX4 axis as a key regulator of ferroptosis.

Conclusions: POT1-AS1 promotes TMZ and radiation resistance in GBM by regulating ferroptosis through the IGF2BP2/GPX4 axis. Targeting this pathway may offer a new therapeutic strategy for overcoming GBM treatment resistance.

Purpose: This study aims to evaluate metabolic alterations in blood and urine samples from breast cancer patients undergoing adjuvant radiotherapy (RT) to identify potential biomarkers for radiation exposure and contribute to the development of biodosimetry tools, such as for use in nuclear incidents.

Materials and methods: Postmenopausal breast cancer patients (n = 20) undergoing postoperative RT were included in this prospective observational study. Blood and urine samples were collected at a total of six time points before, during, and after RT. Metabolic analysis was performed using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry and multivariable analyses, including partial least squares-discriminant analysis (PLS-DA) and random forest methodology, were used to identify discriminating metabolites. All analyses were performed using R version 4.1.2.

Results: Univariate analysis of blood samples showed significant downregulation of five metabolites during RT (week 5 + 6) compared to pre-RT: Hypoxanthine, 3-hydroxyisobutyric acid, L-lactic acid, pyruvic acid and xanthine (all p < .05). No statistically significant changes were found in urine samples. Multivariate analysis using PLS-DA identified a bundle of metabolites associated with radiation exposure, including diverse amino acids, purines, and bile acids. Extreme gradient boosting demonstrated moderate model performance in discriminating irradiated subjects with an AUC of 0.669 in blood samples.

Conclusions: This study identified several metabolites altered by RT in blood, providing insight into the metabolic impact of radiation exposure. These findings could provide a basis for developing diagnostic tools to detect radiation exposure. Further studies with larger and more diverse cohorts are needed to validate these biomarkers.