International journal of radiation biology最新文献

Objective: To establish and validate a dose-response curve for dicentric chromosomes (DC) induced by X-rays in human peripheral blood in vitro using semi-automated scoring.

Methods: Peripheral blood samples were collected from three healthy individuals and exposed to X-ray doses of 0, 0.25, 0.5, 0.75, 1, 2, 3, 4, and 5 Gy at a dose rate of 1.158 Gy/min. Dicentric chromosomes in metaphase were scored both full- and semi-automatically, and a dose-response curve was generated with CABAS software based on dicentric yields. Dose estimations were then performed for 12 biodosimetry standard samples and one sample from a patient with X-ray-induced skin injury.

Results: Dicentric yields increased with X-ray doses from 0 to 5 Gy (r = 0.943, P < 0.01). The dose-response association followed a linear-quadratic model: Y = 0.0002 (± 0.0001) + 0.0379 (± 0.0032) × D + 0.0253 (± 0.0014) × D² (R² = 0.998, P < 0.01), where Y represents dicentric yields and D is the dose. The estimated dose for 12 validation samples aligned closely with actual doses. The estimated whole-body average absorbed dose for the patient was 0.73 Gy, with observed DC over-dispersion suggesting partial body exposure. By using the Dolphin model, this dose was refined to 2.22 Gy and estimated irradiated body volume was 35.94%, consistent with clinical diagnosis.

Conclusions: The dose-response curve developed using semi-automated scoring offer a reliable and efficient approach for dose estimation and clinical diagnosis in nuclear radiation emergencies. It could also support retrospective biodosimetry of partial-body, non-uniform radiation exposure.

Purpose: The effect of gamma irradiation on the reproductive performance of Bactrocera correcta was studied to explore the potential application of the sterile insect technique.

Materials and methods: Radio-biological studies involved dose-response experiments in the range of 10-70 Gy. Reproductive behavior of seven days old pupae of B. correcta was ascertained by evaluating fecundity and fertility. The ability of the released flies to mate with the wild population was evaluated by mating competitiveness, flight activity, and performance of sterile males in the field net condition.

Results: Maximum B. correcta adult emergence was recorded in 10 Gy while reduced adult emergence was scored at 60 Gy. Among the crossings, IM X UF showed the lowest eggs hatchability (0.52%) in 30 Gy followed by 20 Gy (7.61%) and 10 Gy (26.22%). Egg hatching was not observed in UM X IF and IM X IF crosses. No significant difference was observed in flight activity of adults at different heights. Adult mortality increased with increasing radiation doses. A significant variation was depicted in the estimated mating competitiveness of different ratios of sterile males and the maximum was recorded in 1:1:9 ratio. The performance of sterile males on guava fruits in laboratory and field net conditions showed a significant reduction in pupae and adults at 30 and 40 Gy as compared to unirradiated adults.

Conclusions: Gamma irradiation of seven days old pupae of B. correcta at 30-40 Gy and releasing of sterile males at 1:1:9 ratio would suppress the guava fruit fly in the field successfully.

Purpose: Radiotherapy for cancer treatment or unintentional exposure to ionizing radiation causes severe damage to the unaffected tissues of the digestive system, including gastrointestinal (GI) tract. Radiation exposure leads to an inflammatory response, and uncontrolled inflammation exacerbates radiation-induced tissue injury. Bixin is a liposoluble apocarotenoid isolated from Bixa orrellana seeds, which effectively attenuates several inflammatory diseases. In this study, we investigated whether bixin mitigated radiation-induced intestinal damage through an examination of its role in inflammation and the protection of the epithelial barrier.

Materials and methods: To determine the therapeutic effects of bixin in treating radiation-induced intestinal damage, we carried out histological analyses, inflammatory response examinations, and barrier function assessments using a mouse model of radiation-induced enteropathy.

Results: We uncovered that bixin effectively mitigates radiation-induced enteropathy by suppressing the inflammatory response, reducing inflammatory cell accumulation, and limiting cytokine expression in the radiation-induced intestinal injury. In a mouse model of acute radiation-induced intestinal injury, treatment with bixin enhanced nuclear factor erythroid-2-related factor 2 (NRF2) activation and promoted tight junction expression in the epithelium, while also hindering bacterial translocation to the mesenteric lymph nodes.

Conclusion: Bixin represents a potential therapeutic candidate for the treatment of radiation-induced enteropathy.

Purpose: The aim of this study was to investigate the radiobiological effects underlying the inhibition of breast cancer (BCa) following radiotherapy in nude mice models, and to evaluate the impact of changes in immunohistochemical parameters induced by FF and FFF beams.

Materials and methods: The study included thirty-six adult nude mouse models, which were randomly assigned to five groups: control (G1), breast cancer (BCa) (G2), FF-400 MU/min (G3), FFF-1100 MU/min (G4), and FFF-1800 MU/min (G5). The control group received neither radiation nor treatment, while the BCa group had a cancer model without radiation. The BCa models were subjected to a single dose of 20 Gy of radiotherapy at varying dose rates. Twenty days after the implantation of the MCF-7 cancer cell line, the nude mice were irradiated and sacrificed 48 h later for ER, PR, HER-2, Ki-67, CD-133, Caspase-3, APAF-1, NOS-2 and NOS-3 IHC analysis.

Results: A statistically significant decrease in IHC staining values for ER, Ki-67 and NOS-2 was observed in the FF-400 MU/min, FFF-1100 MU/min and FFF-1800 MU/min groups due to radiotherapy compared to the BCa group. The FFF beams demonstrated superior efficacy in the treatment of BCa. The significant differences in Caspase-3 and APAF-1 levels were found between BCa and control groups, while CD-133, NOS-3, HER-2, and PR staining showed no differences between groups.

Conclusions: It was concluded that FFF beam was more effective than FF beam for BCa, especially on ER, Ki-67 and NOS-2 IHC parameters.

Purpose: The effects of ionizing radiation on living organisms are mainly known as the generation of reactive oxygen species (ROS), apoptosis, and DNA damage. Small GTPases (RhoA, Rac1, Cdc42) are known to have roles in the regulation of oxidative stress and apoptosis. The aim of this study was to investigate the role of the RhoA molecule in testicular tissue damage due to oxidative stress and apoptosis induced by ionizing radiation.

Material and method: In this study, testicular tissues and blood samples obtained from our previous study were examined. In that study, rats were exposed to ionizing radiation at three different doses (0.02 Gy, 0.1 Gy, 5 Gy). Then tissue and blood samples were taken at three different times (2 hours, 24 hours, and 7 days) after irradiation. Immunohistochemical staining was performed to evaluate RhoA and cleaved caspase-3 expressions, while RhoA activity was assessed by G-LISA assay in testicular tissues. Serum malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity were analyzed to evaluate oxidative stress.

Results: The expression and activation of RhoA demonstrated a time-dependent increase across all levels of radiation doses. Similarly, the expression of cleaved caspase-3 also exhibited a time-dependent increase, consistent with the effects of radiation-induced damage observed in all experimental groups. After exposure to radiation, serum levels of MDA increased, while the activity of SOD decreased.

Conclusion: Our findings suggest that RhoA may contribute to radiation-induced testicular tissue damage by increasing oxidative stress and apoptosis.

Purpose: Growing evidence from the Japanese atomic bomb survivors, and occupationally and medically exposed groups indicates that ionizing radiation could increase the risk of various diseases of the circulatory system (DCS), even at low levels of exposure. As radiation protection systems increasingly consider the possibility of individualized radiation protection, better understanding is needed of the factors that may impact radiation-related risk, whether intrinsic (such as age, sex or genetics), or extrinsic (such as smoking). Here, we comprehensively review potential effect modification of radiation exposure and the risk of DCS in medical, occupational and environmental settings.Conclusion: Several studies indicate potential effect modification, usually detrimental, with use of anthracycline in medical settings. There was some indication that younger age at exposure increased risk for various DCS outcomes, but this was less consistent across studies and settings. Interpretation of the data is complicated by considerations of statistical power, differences in specific disease outcomes, and narrow ranges of exposure and/or potential modifiers within studies. Future studies with well-defined exposure over a wide range of ages, along with biological samples, are required to better inform the nature of these interactions.

Background: MicroRNAs (miRNAs) are a group of small non-coding RNAs that substantially participate in regulating gene expression. Their participation in cancer development encompasses various critical pathways, spanning from cell transformation to the progression of tumor cells, metastasis, and even resistance to treatment. This study aimed to assess the impact of miR-206 on radiosensitivity in breast cancer (BC) cells, SIRT1 activity, and p53 acetylation.

Method: miR-206 mimic or inhibitor was transfected into BC cell lines and exposed to X-ray radiation. MTT and colony-forming assays were used to estimate cell viability, and apoptosis was inspected using flow cytometry. SIRT1 enzymatic activity was assessed by a fluorescence method. The protein levels of p53 and its acetylation status were evaluated using western blotting. miR-206 levels were assessed in the breast tumor, marginal, and normal control tissue.

Results: The expression of miR-206 was significantly reduced in BC cell lines and tumor tissue compared to normal tissue. miR-206 reduced cell viability and induced apoptosis, and could enhance the suppressive effects of irradiation on cell viability, colony formation, and its ability to induce apoptosis. miR-206 effectively suppressed SIRT1 activity in BC cells. Moreover, miR-206 significantly increased the levels of p53 and its acetylated form.

Conclusion: The upregulation of miR-206 enhanced the efficacy of radiotherapy by promoting apoptosis and reducing cell survival. It also resulted in elevated levels of p53 and its acetylation. Therefore, miR-206 may be considered a promising candidate for radiosensitizing BC cells.

Background: It is important to reduce the exposure to ionizing radiation, which is increasing due to medical diagnosis and treatments, and to determine the damage in the organism and the biological response to it. We aimed to investigate the radiological and biological effects of dose reduction in computed tomography pulmonary angiography (CTPA), which is increasingly used.

Methods: 123 patients who underwent CTPA with suspicion of pulmonary thromboembolism were divided into three groups and imaging was performed at three different kilovolt (kV) values (80, 100 and 120). Diagnostic quality, radiation exposure parameters (effective dose and dose length product [DLP]), oxidative stress parameters such as total oxidant status (TOS), malondialdehyde (MDA), oxidative stress index (OSI) and total antioxidant status (TAS) in pre- and post-scanning blood samples were evaluated. DNA was determined by comet assay.

Results: No significant difference was found in terms of diagnostic quality between the three groups (p > .005). Radiation exposure parameters increased statistically significantly in line with the kV values (p < .05). The smallest increase in DNA damage after scan was detected in the group with the 80 kV(p = .001). The increase in TOS, MDA and OSI values after imaging in all three groups was not statistically significant (p > .005). The decrease in TAS values was statistically significant only in groups II and III (p < .005).

Conclusion: CTPA can be performed at a low kV of 80 kV without loss of diagnostic quality. Unlike the increase in DNA damage as the kV value increased, the increase in oxidative stress parameters was not found to be significant. In addition, the decrease in TAS value was significant only for the 100 kV and 120 kV groups.

Purpose: Buckwheat is a major traditional crop of hilly regions, capable of growing in adverse climatic conditions. During the survey, it was reported that prolonged consumption of buckwheat leads to digestive problems and numbness. The present study was conducted to study the effect of γ-irradiations on buckwheat to make them suitable for daily consumption.

Materials and methods: Buckwheat seeds were irradiated by 100, 200, 300, 400, 500, 600, 700, and 800 Gy doses of γ-radiations, to access the phytoconstituent variability using standard methods.

Results: Significant (p < 0.05) increase in total phenol, total flavonoid, total antioxidant activity, rutin, β-carotene, iron, calcium up to 6.23, 16.48, 18.62, 19.06, 8.08, 47.66, 32.74% in common buckwheat and 9.58, 16.66, 39.16, 9.19, 9.00, 53.99, 36.75% in tartary buckwheat was found by increasing doses of γ-radiations up to 800 Gy. Significant decrease was found in phytate, tannin, and oxalate content up to 18.92, 17.95, 15.32% in common buckwheat and 24.73, 19.72, 24.07% in tartary buckwheat.

Conclusions: It can be concluded that 800 Gy dose of γ-radiation, maximally increased the nutritional value by significant (p < 0.05) increase in nutrients and their bioavailability. This makes buckwheat more amenable for daily consumption to fulfill RDA, by Himalayan population depending on traditional foods without any digestive problem. Furthermore, significant increase in rutin by γ-radiations will be useful to fulfill the demand of cosmetic and pharmaceutical industries. But minimization of reduction loss for some nutrients by γ-radiations is the thrust area for future research.

Purpose: The study focused on developing a rapid PCR-based detection method and employing gamma irradiation techniques to manage Ralstonia solanacearum, aiming to produce brown rot-free export-quality potatoes. This initiative seeks to enhance potato exports from Bangladesh.

Materials and methods: Samples of potato tubers and soil were collected from various commercially significant potato-growing areas, resulting in a total of 168 Ralstonia solanacearum isolates from potato tubers and soil across 12 regions. The detection of R. solanacearum in the enriched tuber extract and soil were conducted using the primer pairs (PS-1, PS-2) and (759, 760). For the gamma irradiation experiment, petri dishes containing R. solanacearum cultures were subjected to different doses of gamma rays at the Bangladesh Institute of Nuclear Agriculture using a ⁶⁰Co source. The irradiation doses applied to the samples were 0-6.0KGy.

Results: Morphological identification based on pink/light red colonies on TTC medium was confirmed R. solanacearum in 148 isolates. PCR using species-specific primers (PS-1/PS-2) and (759, 760) verified 26 isolates (14 tubers, 12 soil), producing 553 bp and 281 bp fragments in latently infected tubers and soil samples respectively. Gamma irradiation at 2.5 kGy damaged R. solanacearum's DNA and cells, preventing brown rot, while higher doses eliminated it entirely. This offers a promising strategy to enhance safety of stored potatoes, potentially mitigating economic losses from this quarantine pathogen.

Conclusion: The study developed a PCR detection method and gamma irradiation techniques to manage R. solanacearum, enhancing the export quality of potatoes.