International journal of radiation biology最新文献

Purpose: High-linear energy transfer (LET) radiation is generally thought to be more biologically effective in various tissues than low-LET radiation, but whether this also applies to the circulatory system remains unclear. We therefore reviewed biological studies about the effects of high-LET radiation on the circulatory system.

Conclusions: We identified 76 relevant papers (24 in vitro, 2 ex vivo, 51 in vivo, one overlapping). In vitro studies used human, bovine, porcine or chick vascular endothelial cells or cardiomyocytes, while ex vivo studies used porcine hearts. In vivo studies used mice, rats, rabbits, dogs or pigs. The types of high-LET radiation used were neutrons, α particles, heavy ions and negative pions. Most studies used a single dose, although some investigated fractionation effects. Twenty-one studies estimated the relative biological effectiveness (RBE) that ranged from 0.1 to 130, depending on radiation quality and endpoint. A meta-analysis of 6 in vitro and 8 in vivo studies (selected based on the feasibility of estimating the RBE and its uncertainty) suggested an RBE of 6.69 (95% confidence intervals (CI): 2.51, 10.88) for in vitro studies and 1.14 (95% CI: 0.91, 1.37) for in vivo studies. The meta-analysis of these 14 studies yielded an RBE of 2.88 (95% CI: 1.52, 4.25). This suggests that high-LET radiation is only slightly more effective than low-LET radiation, although substantial inter-study heterogeneity complicates interpretation. Therapeutic effects have also been reported in disease models. Further research is needed to better understand the effects on the cardiovascular system and to improve radiation protection.

Purpose: Ionizing radiation (IR) has been shown to induce epithelial-mesenchymal transition (EMT) of alveolar epithelial cells (AECs), which is a critical cause of radiation-induced pulmonary fibrosis (RIPF). In this study, we investigated the role and molecular mechanisms of musashi2 (MSI2), an RNA-binding protein, in IR-induced EMT of AECs for aiming at potential therapeutic strategies to prevent RIPF.

Materials and methods: Changes in the expression levels of MSI2 and EMT markers (E-cadherin, N-cadherin, and Vimentin) induced by IR in AECs were detected by western blot (WB). Then, the effect of MSI2 on IR-induced EMT of AECs was investigated by observing morphological changes and detecting expression of MSI2 and EMT markers by WB and immunofluorescence (IF). RNA-Seq analysis, WB and RT-qPCR were used to identify the targets of MSI2.

Results: We observed that IR could cause a significant increase of MSI2 protein expression, a down-regulation of E-cadherin and an up-regulation of Vimentin and N-cadherin in AECs (MLE-12 and RLE-6TN cells). We also revealed that MSI2 was involved in regulating the alteration of morphology and EMT-related markers in AECs after irradiation, suggesting the occurrence of EMT regulated by MSI2. Moreover, we found the mechanism of MSI2 participating in EMT by regulating the expression of transcription factor ZEB1, acting as a downstream target of MSI2 in IR-induced EMT of AECs.

Conclusions: Our study unveils the critical role of MSI2 in IR-induced EMT of AECs and preliminarily elucidates its molecular mechanisms, providing new insights into the process of IR-induced pulmonary fibrosis.

Purpose: Microgreens have gained wide acceptance among consumers due to their low calorie content and rich composition of micronutrients and antioxidants, making them one of the best microgreen options. Therefore, this research is intended to investigate the effect of γ-rays on its growth and functional components and to confirm the possibility of using barley microgreens as a complementary and efficient food source.

Material and methods: Barley grains were exposed to various doses (10, 20, 30, and 40 Gy) of gamma rays, as well as the un-irradiated sample is considered as the control. The stimulating effects on growth and biochemical components of barley microgreens were evaluated.

Results: The results revealed that plant height increased significantly in response to gamma radiation exposure, and the maximum increase (23.87 cm) was obtained at a dose of 30 Gy. Otherwise, Ch a, Ch b, and carotenoid significantly increased (1.33, 0.941, and 0.181 mg/g FW), respectively at 30 Gy compared to the control (0.937, 0.448, and 0.132 mg/g FW), respectively. Also, the soluble sugars, proteins, and total free amino acids content were enhanced by increasing the dose level, and the maximum increase was noticed at 40 Gy of gamma rays. A remarkable increase was observed in the phenolic and flavonoid contents at 40 Gy (5.65 and 2.65 mg/g FW), respectively compared to control (4.57 and 2.16 mg/g FW). In the amino acids profile, glutamic acid was predominant, and the amino acids group was improved markedly by gamma rays compared with the control, and the dose of 40 Gy gave the greatest contents (141.60 µg/g DW), followed by 30 Gy (139.58 µg/g DW) in the control (121.34 µg/g DW). Current findings indicated that γ-rays have negative effects on γ-tocopherol, cholesterol, and stigmasterol, and the maximum decrease was observed with 40 Gy (21.774, 199.335, and 722.778 mg/kg DW), respectively. In contrast, it had positive effects on the values of ergosterol, α-tocopherol, and β-sitosterol (3580.674, 5255.511, and 5281.320 mg/kg DW), respectively.

Conclusions: The results showed that treatment of barley grain with low doses of gamma rays stimulated; growth, biochemical compound, and antioxidants production, increasing the nutritional value of barley microgreens, improving microgreens defense and supporting the use of these grains as a complementary and efficient food.

Background: Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) are the most common non-melanoma skin cancers, frequently affecting the facial region. High-Dose Rate (HDR) interstitial brachytherapy (iBT) offers a promising alternative to surgery, particularly in cosmetically sensitive areas like the nasal region. This study evaluates the clinical efficacy and esthetic outcomes of HDR iBT in the treatment of nasal BCC and cSCC.

Methods: This retrospective analysis included 10 patients with histologically confirmed primary nasal BCC or cSCC treated with HDR iBT between May 2021 and February 2023. Patients received HDR iBT as either a definitive treatment or post-surgery, depending on clinical indications. The treatment involved image-guided placement of interstitial catheters, with individualized dosimetric planning following GEC-ESTRO and ASTRO guidelines. Prescribed doses ranged from 40 to 45 Gy, delivered in 9-10 fractions.

Results: The cohort consisted of 80% male patients, with a median age of 69 years (IQR:49-83), and an equal distribution of BCC and cSCC. After a median follow-up of 23.5 months (IQR:19.5-31), all patients were alive, with a 90% complete response rate. Two patients experienced locoregional recurrences, successfully managed with salvage therapy. Acute toxicities included dermatitis (100%, with 60% grade 3) and pain (50%). Late toxicities were minimal, limited to grade 1 fibrosis (30%) and edema (20%). Esthetic outcomes, assessed via the Global Esthetic Improvement Scale, were excellent in most cases.

Conclusion: HDR iBT demonstrates high efficacy with favorable cosmetic outcomes, offering a viable, minimally invasive alternative to surgery for nasal BCC and cSCC.

Purpose: Cowpea (Vigna unguiculata (L.) Walp.) is a major legume crops for human consumption and livestock feed in tropical regions. Although its importance, the crop's production is subjected to numerous constraints, raising the need to develop outstanding genotypes. In this line, this study assesses the effects of gamma irradiation doses on cowpea genotypes to determine the LD50 and its effects on agro-morphological parameters.

Materials and methods: Healthy dry seeds of three cowpea genotypes, Bambey 21, Me51-M4-39M9, and Ndout violet pods (VP), were exposed to four doses of gamma-rays 0, 200, 300, and 400 Gy. Qualitative and quantitative parameters were evaluated since germination, and a two-way analysis of variance (ANOVA) was performed on the means of quantitative traits using R software.

Results: The results revealed that the LD50 on seed germination and plant survival ranged from 579 and 446.25 Gy, in Me51-M4-39M9, respectively. These values varied significantly among genotypes and revealed that low doses of gamma irradiation stimulated germination speed and had a positive effect on the early flowering of Ndout VP. Higher doses of gamma irradiation induced more severe mutations, causing visible effects such as changes in leaf color (albino, xantha, viridis, and variegation) and phyllotaxis. The frequency of chlorophyll mutants induced by gamma irradiation was found to be dose-genotype/dependent, with Bambey 21 being the most sensitive variety. Lower doses induced desirable mutations such as stem pigmentation and seed hilum coloration on Bambey 21 and Me51-M4-39M9. It has also had a positive impact on seedling height and leaf number in Bambey 21 and Ndout VP. However, high irradiation doses lead to a significant reduction in certain quantitative traits, such as plant height (PH), leaf length (LL), leaf width (LW), pod width (PWD), pod weight (PW), seed width (SWD), and seed weight. Analysis of the phenotypic performance of quantitative traits allowed us to cluster the four doses by genotype into three groups.

Conclusions: The optimum dose of gamma-irradiation in cowpea mutation breeding is genotype-dependent. The effects of gamma-irradiation on these traits and their relationships are highly dependent on the specific crop and genotype. Further research is needed to understand these effects underlying mechanisms and develop crop improvement strategies using gamma irradiation.

Purpose: Intravitreal bevacizumab has been utilized to mitigate radiation retinopathy, yet the potential role of intravitreal melatonin for its prevention remains unexplored. This study aims to evaluate and compare the efficacy of intravitreal melatonin and bevacizumab in preventing radiation retinopathy in an experimental animal model.

Materials and methods: Twelve healthy male New Zealand white rabbits (n = 24 eyes) received a single 3000 cGy irradiation dose in both eyes. Intravitreal melatonin (100 mcg/kg = 300 mcg/0.05 mL) was administered to the left eyes of six rabbits, and bevacizumab (1.25 mg/0.05 mL) to the left eyes of the remaining six, with sham injections given to the right eyes as controls. Six weeks after irradiation, bilateral enucleation was performed for biochemical and histopathological evaluation.

Results: Oxidative stress markers did not differ significantly between the groups (p = .827). Both melatonin and bevacizumab treatments markedly reduced axonal damage compared to the sham control group (p < .001). Melatonin also demonstrated a trend toward superior neuroprotective effects relative to bevacizumab, though this difference was not statistically significant (p = .07).

Conclusions: Intravitreal melatonin demonstrated efficacy comparable to bevacizumab in reducing radiation-induced retinopathy, with an encouraging trend toward enhanced neuroprotection. These findings position melatonin as a potential novel therapeutic for radiation retinopathy prophylaxis. Further research with larger, long-term studies is warranted to validate these results and investigate melatonin's broader applications in retinal protection.

Purpose: 1) To discontinue gradually the current non-probabilistic equivalent dose (E) methodology in the radiation protection (RP) with our proposed E0(HN) one; HN is H set of all tissue or organs (ToOs) irradiated. E0 is directly associated with probability of non-harmful effects of low levels of ionizing radiation; 2) To apply the radiation oncology normal tissue non-complication probability (NTCP0) methodology for evaluations in other radiation activity (RAs); and 3) To apply the SMp(x) function in the graphical models of UNSCEAR in order to a) To establish the lower limit of the 100%-risk deterministic region, i.e. 0%-safety deterministic one; b) To correct the representation of the "Hormetic" model; and c) To express with mathematical formulas these models. The two first aspects will represent corrections for these graphical models.

Methods: Radiobiological-probabilistic studies aimed to represent the stochastic health safety to the ToOs using NTCP0 and E0 as inherent probabilistic concepts.

Conclusion: The E0 methodology will represent to eliminate gradually the current E one, Sv, rem and expressing equivalent dose (H) in Gy. This study will push: 1) Improvements over the UNSCEAR graphical models; and 2) To extend to all RAs the NTCP0 methodology.

Purpose: The present study was carried out to evaluate the radioprotective activities of N-acetyl-L-tryptophan (L-NAT) using rodent and non-human primate (NHP) models.

Materials and methods: The antagonistic effect of L-NAT on the Transient receptor potential vanilloid-1 (TRPV1) receptor and substance P inhibition was determined using molecular docking and Elisa assays. The in vivo radioprotective activity of L-NAT was evaluated using whole-body survival assays in mice and NHPs. Radioprotective activity of L-NAT was also determined at the systemic level using quantitative histological analysis of bone marrow, jejunum, and seminiferous tubules of irradiated mice.

Results: Molecular docking studies revealed a strong binding of L-NAT with TRPV1 receptor at similar binding pockets to which capsaicin, an agonist of the TRPV1 receptor, binds. Further, capsaicin and gamma radiation were found to induce substance P levels in the intestines and serum of the mice, while L-NAT pretreatment was found to inhibit it. Significant whole-body survival (>80%) was observed in irradiated (9.0 Gy) mice that pretreated with L-NAT (150 mg/kg, b.wt. im) compared to 0% survival in irradiated mice that not pretreated with L-NAT. The quantitative histology of the hematopoietic, gastrointestinal, and male reproductive systems demonstrated significant protection against radiation-induced cellular degeneration. Interestingly, 100% survival was observed with irradiated NHPs (6.5 Gy) that pretreated with L-NAT (37.5 mg/kg, b.wt.im). Significant improvement in the hematology profile was observed after days 10-20 post-treatment periods in irradiated (6.5 Gy) NHPs that were pretreated with L-NAT.

Conclusion: L-NAT demonstrated excellent radioprotective activity in the mice and NHP models, probably by antagonizing TRPV1 receptor and subsequently inhibiting substance P expression.

Purpose: The aim of this study was to evaluate the effect of radiation pre-exposure on the survival, physiological, and fermentation activity of Saccharomyces cerevisiae.

Materials and methods: The low-dose (20-80 cGy) irradiation was conducted using the medical therapy installation Xstrahl 320, which has a maximum energy of 320 keV and a dose rate of 1 Gy/min. High-dose (1 and 5 kGy) exposure was achieved by an electron beam using the linear accelerator UELR-10-10S with a maximum energy of 10 MeV and a dose rate of 1 kGy/s.

Results: The results showed that hyper-radiosensitivity of the yeast exposed to low-dose radiation occurred at 20 cGy and induced radio-resistance occurred at doses from 40 to 60 cGy, increasing survival. The pre-exposure of S. cerevisiae to 60 cGy radiation conferred adaptation on the yeast to withstand repeated exposure to a higher dose (1 kGy). The irradiation of S. cerevisiae with low doses ranging from 20 to 80 cGy decreased its physiological and metabolic activity compared to the non-irradiated yeast samples. The viability of the yeast was totally lost after exposure to 5 kGy, resulting in the death of all the yeast.

Conclusions: The pre-exposure of S. cerevisiae to radiation resulted in a decline in growth, vitality, metabolic activity, and fermentation activity. However, pre-exposure of the yeast to low-dose radiation (40 and 60 cGy) induced an adaptive response, reducing the damaging effect usually experienced from high-dose (kGy) exposure.

Purpose: This simulation study compares the long-term health for military troops exposed by a drone dispersing low-dose radioactive material either in a ground-level explosion or aerial release. It examines the consequences of dispersing radioactive material using a drone through both ground-level explosions and aerial releases.

Materials and methods: The simulations were conducted over four days, without adjusting for radioactive decay, and considered six atmospheric stability classes.

Results: The findings indicate that ground-level explosions lead to higher total effective dose equivalent (TEDE) values across all atmospheric stability classes, especially in stable atmospheric conditions (Classes E and F). The excess relative risk of leukemia induced by radiation is also more significant in the ground-level explosion scenario, particularly for younger individuals (20 years old).

Conclusion: The study's findings indicate that ground-level dispersion of substances poses a greater risk to public health compared to drone-based dispersal methods. This risk is notably exacerbated under stable atmospheric conditions and is particularly pronounced among younger demographics. Such outcomes hold significant implications for policy formulation and strategic decision-making within the context of public health initiatives and military radiological operations.