International journal of radiation biology最新文献

Purpose: This study explores how the combination of spatially-fractionated radiation therapy (SFRT) and gold nanoparticles (AuNPs) differentially affects DNA damage in melanoma and fibroblasts.

Methods and materials: Melanoma and fibroblast monocultures and a preliminary co-culture were grown. For AuNP conditions, cells were incubated with 10 µg/mL AuNPs. A 120 kVp X-ray beam was used. The γH2AX marker was used to assess DNA damage, following immunocytochemistry. γH2AX kinetics were investigated in melanoma following 100 and 10 Gy SFRT. DNA damage was assessed in monocultures and co-cultures 1 hour post-SFRT and open beam irradiation.

Results: γH2AX intensity peaked 1 hour post-SFRT, with an exponential decline over 12 hours. A higher γH2AX intensity and more rapid signal decrease was seen after 100 Gy. In monocultures, a 3.4-fold greater γH2AX intensity was seen in melanoma following 10 Gy open beam radiation with AuNPs compared to radiation alone, and a 1.2-fold increase in fibroblasts. A dose-dependent and AuNP-mediated increase in γH2AX intensity was seen in both monocultures post-SFRT. AuNPs had a substantial DNA damage effect on co-cultured melanoma, with an average fold increase of ∼1.5 across SFRT doses. The co-cultured fibroblast γH2AX intensity remained comparatively low, with an average increase of 1.1-fold.

Conclusion: This study revealed a differential cell type response in monoculture versus co-culture following AuNPs and irradiation. Both monocultures exhibited up to 1.6-fold increase in DNA damage following combined therapy compared to radiation only. In co-culture, combined treatment increased DNA damage relatively more in melanoma. These findings show promise in selectively enhancing DNA damage in melanoma.

Purpose: This study investigated the radioprotective effect of melatonin (Mel) on small intestinal damage in healthy rats exposed to Flattening Filter (FF) and Flattening Filter Free (FFF) X-rays during radiotherapy, with a comparative evaluation of the biological effects of FF and FFF irradiation on intestinal tissue injury.

Materials and methods: Forty male Sprague-Dawley rats (12 weeks, 250±20 g) were randomly assigned to five groups. Group 1 (Control) received no treatment. Group 2 (FF) was exposed to 8 Gy radiotherapy at 4 Gy/min to the abdominopelvic region. Group 3 (FF+Mel) received melatonin 15 minutes before the same irradiation. Group 4 (FFF) was treated with 8 Gy at 14 Gy/min, and Group 5 (FFF+Mel) received melatonin before this exposure. Intestinal tissues were collected 48 h after the experimental procedures and evaluated histopathologically using hematoxylin-eosin (H&E) and periodic acid-Schiff (PAS) staining, immunofluorescently by 8-hydroxy-2'-deoxyguanosine (8-OHdG) antibody labeling, and biochemically by measuring serum 8-OHdG and malondialdehyde (MDA) levels.

Results: Significant histopathological differences were observed between the control (G1) and irradiated groups (FF (G2); FFF (G4)), including mucosal disruption, crypt loss/dilatation, goblet cell reduction, and hemorrhage. In addition, 8-OHdG expression was significantly higher in the FFF group (G4) compared to the FFF+Mel group (G5) (p<0.05). Biochemically, both 8-OHdG and MDA levels were elevated in irradiated groups (G2, G4) compared with controls (p<0.05). Notably, melatonin administration significantly reduced oxidative stress markers, with differences between FF (G2) and FF+Mel (G3), as well as FFF+Mel (G5) (p<0.05).

Conclusion: Melatonin significantly reduced radiotherapy-induced oxidative stress and apoptosis in healthy small intestinal tissue histopathologically and biochemically. These findings suggest that melatonin may act as an effective radioprotective agent by preserving small intestinal integrity during abdominopelvic radiotherapy.

Purpose: Under various scenarios accompanied by increased levels of ionizing radiation, an understanding of how the most important plant parameters change at different radiation doses is essential. In this study, we aimed to perform a comparative analysis of morphometric and physiological parameters and electrical signals in plants at different radiation doses in order to test the hypothesis of higher radiosensitivity of signaling processes compared to other plant parameters.

Materials and methods: Studies were conducted on 14-15-day-old wheat plants (Triticum aestivum L.). The irradiation doses (accelerated electrons, 3 MeV) for dry seeds were 25, 50, 75, 100, 200, 400 Gy. Photosynthetic activity, pigment composition, and transpiration rates were recorded using PAM fluorimetry, hyperspectral imaging, and infrared imaging, respectively. Signaling processes were assessed using parameters of electrical signals induced by an additional stimulus.

Results: Threshold doses for statistically significant changes in morphometric parameters such as length, area, and weight are 50-75 Gy. For physiological parameters, including photosynthesis (Ф_PSII, NPQ), and transpiration, thresholds are also 50-75 Gy. Electrical signal parameters statistically significant differences compared to the control group even at the lowest dose studied, 25 Gy.

Conclusions: The key result is the discovery that the highest sensitivity to radiation was demonstrated by signals, rather than traditionally measured morphometric and physiological indicators. This discovery is important for solving the problems of space biology, explaining the behavior of plants in areas contaminated with radionuclides, and for the targeted breeding of radioresistant plants.

Purpose: Irradiation of the testes can have adverse effects on their structure and function, potentially leading to infertility. Medications that can show antioxidant activity, such as losartan may mitigate the irradiation-related deleterious effects. The goal of this study was to evaluate the impact of irradiation on rat testes fatty acid (FA) and lipid profiles, as well as to assess the effectiveness of losartan in mitigating radiation-induced changes over 2-and 60-days.

Materials and methods: Forty-six male Wistar rats were allocated into six groups: control (CTR2 and CTR60), irradiated (IR2 and IR60), and irradiated and treated with losartan (IRLOS2 and IRLOS60), euthanized 2- or 60-days post-irradiation to assess acute and late testicular effects. The FA and lipidome plasticity were evaluated by using gas chromatography-mass spectrometry and C18-liquid chromatography-mass spectrometry, respectively.

Results: Groups irradiated after 60-days, without and with losartan, showed a significant decrease in testicular content in FA 16:0, FA 22:6 n-3 and FA 22:5 n-6. Changes in the testicular lipidome, particularly in lipid species belonging to triacylglycerols (TG) and phospholipid classes including phosphatidylcholine (PC), lysophosphatidylcholine (Lyso-PC), phosphatidylserine (PS), and cardiolipin (CL), were observed. TG species were downregulated in irradiated testicular samples, but losartan was able to prevent the downregulation of several TG species containing polyunsaturated fatty acids in testes irradiated after 60-days. After 60-days, several PC lipid species (vinyl-ether or ether-linked), endogenous antioxidants, were significantly increased in testicular tissues exposed to irradiation and losartan. However, the effect was less pronounced in the presence of losartan, suggesting the protective effect of the drug. Conversely, PS, lyso-PC, and CL levels were reduced in irradiated testes after 60-days but losartan could not mitigate those effects.

Conclusion: These lipidomic findings support previous morphological data indicating that losartan helps preserve testicular function, minimizing the effects of radiation.

Purpose: Cowpea (Vigna unguiculata L. Walp.) suffers from a narrow genetic base that limits breeding progress under climate and environmental stress. This study aimed to evaluate the combined effects of gamma irradiation and silver nanoparticles (AgNPs) on the agronomic traits and genetic diversity of cowpea to identify potential mutant lines with superior performance and variability for breeding purposes. Gamma radiation alone was excluded from downstream evaluation owing to its lethality at 150-200 Gy.

Materials and methods: Seeds of cowpea cultivar Dokki 331 were treated with gamma radiation (150 and 200 Gy) and AgNPs at 50, 75, and 100 ppm, applied individually and in combination. Treated and control seeds were grown through two generations (M₁ and M₂) under field conditions. Data were collected on emergence, vegetative growth, branching, flowering, pod traits, seed morphology, and yield components. Genetic diversity was assessed using 20 ISSR primers, and polymorphism indices (PIC, MI, and gene diversity) were calculated.

Results: High doses of gamma irradiation were lethal, while AgNPs enhanced vegetative vigor and reproductive traits in a dose dependent manner. Moderate doses (150 Gy × 50-75 ppm) stimulated pod formation and seed weight, whereas higher doses (200 Gy × 100 ppm) inhibited growth. M₂ plants showed improved agronomic performance, with up to 47 pods, longer pods (12.7 cm), 10-11 seeds per pod, and heavier 100 seed weight (20.7 g) compared to controls. Molecular analysis revealed 293 ISSR bands, with 37 polymorphic (≈12.6% polymorphism). High PIC values (0.22-0.50) confirmed substantial genomic variation.

Conclusions: The integration of gamma irradiation and AgNPs effectively induced beneficial variability in cowpea, enhancing key agronomic traits and generating detectable molecular polymorphism. The identified elite mutant lines and informative ISSR primers can serve as valuable resources for future breeding programs aimed at improving yield and stress resilience.

Purpose: Studies conducted in areas affected by the Chernobyl and Fukushima nuclear accidents have revealed that ionizing radiation can cause morphological abnormalities in coniferous trees. This study aimed to evaluate morphological abnormalities in the area affected by the Kyshtym disaster, one of the three most severe nuclear accidents in modern human history.

Materials and methods: This study was conducted in the zone of the East Ural Radioactive Trace (EURT), which was formed as a result of the Kyshtym disaster in 1957. Current annual radiation doses absorbed by Scots pine needles (Pinus sylvestris) in the EURT impact zone (2.69-16.51 mGy/year) were 11.4-fold higher than background levels, while those in the buffer zone (0.56-1.48 mGy/year) were, on average, 1.3-fold higher.

Results: Across a gradient of radioactive contamination young Scots pines exhibited varying frequencies of morphological abnormalities due to ionizing radiation exposure, fungal infections (Cronartium pini, Dothistroma septosporum, Lophodermella sulcigena, Melampsora pinitorqua), and damage by artiodactyl animals (Alces alces, Capreolus pygargus) or insect pests (Retinia resinella, Bupalus piniarius, Diprion pini). We distinguished two groups of effects: in the first group morphological abnormalities are formed mainly under the influence of biogenic factors (multi-toppedness, bushy crowns, abnormal shoot shape, bud lesions); chronic irradiation in these cases affects the state of young Scots pines indirectly, stimulating the development of dormant buds. In the second group, most of the observed morphoses can be considered the result of direct radiation action (number, size, and shape of needles, shortened late-forming shoots as a sign of the recovery process).

Conclusions: The analysis of the morphoses in young Scots pine trees in the zone of radioactive contamination demonstrated the need to consider the direct and indirect influence of different environmental factors, including radiation, as well as their interaction.

Purpose: Gene expression analysis provides a minimally invasive approach for biological dosimetry. To advance point-of-care applications, this study aimed to establish and validate an improved gene expression biodosimetry system by employing an expanded panel of radiation-responsive genes in human peripheral blood.

Methods: Human B lymphoblastoid cells (AHH-1) and peripheral blood from 10 healthy donors were irradiated with ⁶⁰Co γ-rays at doses of 0, 1, 2, 4, 6, and 8 Gy (dose rate: 1 Gy/min). The expression patterns of four candidate transcriptional biomarkers (ZMAT3, SESN1, AEN, and TRIAP1) and a panel of radiation-responsive genes were characterized at 6-48 h post-irradiation. The impact of different dose rates (0.2, 1, and 2 Gy/min) on these gene expressions was also investigated. For each gene, calibration curves were established by fitting a linear regression between the logarithm of absorbed dose and ΔCt values. Gene selection and model construction were performed using stepwise regression to obtain optimized multi-gene models. The accuracy of these dosimetry models for dose prediction was validated in independent ex vivo and in vivo cohorts.

Results: The four candidate genes exhibited robust, dose-dependent expression from 6 to 48 h post-irradiation, independent of dose-rate variations (0.2-2 Gy/min). Most genes in the expanded panel, including the candidates, showed strong linear relationships between log2 of dose and ΔCt values across all time points when the 0 Gy point was excluded from regression (R² > 0.90, S < 0.50). Based on these validated genes, optimized multi-gene models achieved high predictive accuracy (R² = 0.81-0.89) with fewer genes. Furthermore, these improved models demonstrated accurate dose estimation capabilities when validated with both ex vivo- and in vivo-irradiated peripheral blood samples.

Conclusions: Our study expanded the panel of reliable radiation biomarkers and developed optimized multi-gene models for accurate dose estimation, thereby advancing the standardization and practicality of gene expression biodosimetry.

Purpose: This study investigates the effect of X-ray irradiation of starter culture (S. thermophilus and L. delbrueckii subsp. bulgaricus) on yogurt fermentation and quality.

Materials and methods: The starter cultures Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus were exposed to X-ray radiation using Xstrahl 320 medical irradiator with an energy of 150-320 keV with a dose rate of 1.67 cGy/s. The starter cultures were exposed to 60-120 cGy radiation before fermentation and evaluation of their physicochemical properties during 14-day storage.

Results: The results showed that exposure of the starter culture to 60 cGy, 80 cGy, and 120 cGy delayed yogurt fermentation by 6.5, 6, and 6 hours, respectively, in comparison with the control yogurt (5.5 h). The starter culture irradiated at 60 cGy showed the lowest acidification rate and reduced post-acidification during refrigerated storage. This reduced acidification rate limited pH drift after fermentation, resulting in a more relaxed casein network and reduced syneresis. In contrast, higher irradiation doses (80 and 120 cGy) selected metabolically robust cells capable of sustained acid production during storage. The pH of all the yogurt samples decreased slightly during storage, but not enough to weaken or destabilize the electrostatic interaction between the casein networks. Total viable bacterial counts decreased in all yogurt samples, with the 80 cGy sample showing the lowest viability during storage.

Conclusion: Irradiation increased fermentation time and decreased viability of the starter culture while simultaneously improving post-acidification and syneresis during storage. However, changes to the physicochemical properties of the yogurt samples were not significant enough to cause any negative impact on yogurt quality.

Purpose: This article analyzes intracellular processes of adaptation to the nutrient medium and radiation exposure.

Methods: The analysis uses experimental data on the effects of nutrient medium on yeast cells and published research of cellular responses to radiation exposure.

Results: Adaptation of cells to both the nutrient medium and external radiation exposure revealed the consistent formation of pseudo-wild cell centers (PWCs) dependent on the environment and genotype. These quasi-equilibrium foci change as PWCs undergo modification, death, and proliferation. The cellular adaptation system demonstrates an interaction between the environment, genes, and proteins. Adaptation depends on external active energy, and is associated with variability in the secondary structure of genes and the tertiary structure of proteins.

Conclusions: Adaptation creates an energy-dependent sequence of quasi-equilibrium states of PWC foci by optimizing the conformational structures of genes and proteins. From a physical perspective, the active energy of a changing environment disrupts but immediately optimizes genetic structures according to the principle of free energy minimization; quasi-equilibrium foci of PWCs are continuously formed, ensuring diversity, stability, and reproduction under suitable conditions.

Purpose: Accurate biodosimetry is essential in accidental radiation exposure scenarios, particularly when physical dosimetry is unavailable. Chromosomal aberrations, especially dicentrics and micronuclei, serve as key biomarkers, with dicentrics considered the gold standard. Manual scoring is labor-intensive and time-consuming, limiting its utility during large-scale emergencies; therefore, this study aimed to compare manual and semi-automated scoring (DCScore and MNScore) for speed and accuracy in dose estimation.

Materials and methods: Dose-response curves (0-5 Gy; ⁶⁰Co γ-ray) for dicentrics and micronuclei were established using blood samples from three volunteers. Validation was performed using four dose-blinded samples for both cytogenetic endpoints. Manual and semi-automated scoring methods were compared for curve parameters, correlation, estimated dose accuracy, and processing time.

Results: Both scoring modes demonstrated strong correlations (DC: R² = 0.935; MN: R² = 0.993), though curve coefficients differed. Estimated doses from blinded samples were largely consistent with reference doses, with semi-automated dicentric analysis showing superior accuracy at most dose points. At 4 Gy, minimal deviations were observed (+2.0% for semi-automated DC and +6.4% for manual MN). Semi-automated DC analysis was more than twice as fast and MN analysis approximately five times faster than manual scoring.

Conclusions: Semi-automated scoring significantly improves biodosimetric throughput without compromising accuracy. Its faster analysis and minimal dose estimation errors make it highly suitable for rapid triage during radiological emergencies and mass exposure scenarios.