International journal of radiation biology最新文献

The incident of Chernobyl Nuclear Power Plant (CNPP) explosion has pioneered a plethora of studies unfolding various biological effects of radiation stress on several living systems. Determining radiation dose rates at which both acute and chronic biological effects occur in different biological systems will aid in the ex-situ generation of radiation-tolerant organisms. So far, the accumulation of data on different radiation doses from Chernobyl area demonstrating various biological impacts has not been documented altogether vastly. Therefore, this review aims to document the recorded doses in CNPP over the years at which different biological changes have been observed in plants, soil, aquatic organisms, birds, and animals. A total of 72 peer-reviewed papers obtained from PubMed, Google Scholar, Scopus, and Research4life were included in this review. A few factors have come under attention in this review. Firstly, plant and soil systems combinedly showed the most published studies after the catastrophe where plants showed a higher frequency of DNA methylation in their genome to resist radiation stress. Secondly, reduced species abundance, chromosomal aberrations, increased sterility, and mortality were mostly observed in the aftermath of Chernobyl catastrophe among plants, soil, aquatic organisms, birds, and small mammals. Furthermore, major scares of data after 2018 were prominently observed. Very few studies on radiation dose levels after 2018 are available. Hence, a major research area has emerged for radiation biologists to study present radiation levels and any genetic changes in the recent generation of the original victim species. This will help provide a standard dataset that can act as a reference resource for radiation biologists and future research on the impact of both acute and chronic radiation on the different biological systems.

Purpose: The North-western Himalayan region requires unique varietal traits for the cultivation and quality of grain produced. Wheat varieties released for this zone in the past remained very popular among the farmers. However, with the passage of time certain traits such as the appearance of pathogenic rust races and grain softness have become threat to the fecundity of these genotypes and needs immediate improvement in this region. Mutation breeding facilitates improving one or two traits of a popular cultivar and to generate variability for most of plant traits upon which selection can be imposed. The purpose of this study is to evaluate the mutagenic sensitivity, effectiveness and efficiency of physical and chemical mutagens in four bread wheat varieties with differential grain texture.

Materials and methods: Four bread wheat varieties; HS 490, HPW 89, HPW 360 and HPW 251 were irradiated using six doses of gamma rays (γ-rays) ranging from 175 to 300 Gy; Co⁶⁰ source (BARC, Mumbai, India) and six doses of ethyl methane sulfonate (EMS) ranging from 0.3 to 1.3%; EMS (Sigma-Aldrich, Bangalore, India) to assess their mutation sensitivity, effectiveness, efficiency and spectrum of induced macro-mutations in M₁ and M₂ generation.

Results: Based on mutagen sensitivity tests, both gamma rays and ethyl methane sulfonate had similar effects as the doses/concentrations increased in all four varieties. Ethyl methane sulfonate had a discernible effect on seed germination and growth parameters as compared to gamma irradiated treatments. Pollens viability studies confirmed the differential effects of both mutagens on germination and plant survivability. The LD₅₀ and LC₅₀ values varied between 290-315 Gy for gamma rays and 0.90-1.35% for EMS under controlled laboratory conditions, however, the range substantially differs for gamma rays (240-290 Gy) and for EMS (0.50-1.1%) under field conditions, irrespective of the variety treated. The frequency of chlorophyll mutations was low and showed a linear correlation with the doses/concentrations of the mutagen. A total of 117 putative mutants with desirable agro-morphological characteristics were also isolated. Mutagenic effectiveness and efficiency results showed that gamma irradiation doses of 250-300 Gy and ethyl methane sulfonate of 0.7-1.3% were most potent for an effective mutation breeding programme in wheat crop.

Conclusions: It was found that semi-hard textured varieties showed higher sensitivity to chemical mutagens as compared to soft-textured varieties. Gamma irradiation dose of 250-300 Gy and ethyl methane sulfonate concentration of 0.7-1.3% were found to be most effective and efficient across four bread wheat varieties and can be used in large scale mutagenesis programmes.

Purpose: DNA damage accounts for most biological effects of ionizing radiation. Antioxidants are known for their protective effect by preventing DNA damage. This pilot study aimed to evaluate the potential radioprotective effect of Natural SOD^®, a green barley juice rich in antioxidants, on DNA damage in the testes and lymphocytes of Wistar rats exposed to ionizing radiation.

Materials and methods: Male Wistar rats (n = 15) were selected and equally divided into three groups. Rats in one of the groups were pretreated orally with Natural SOD^® for 14 days, while rats in another group were sham-pretreated with saline solution. Rats in both these groups were afterwards subjected to a single dose of 6 Gy X-ray whole-body irradiation. The control group did not receive any treatment and was not irradiated. Shortly after X-ray exposure, all rats were sacrificed and testes and blood were collected. Gamma-H2AX and histopathological assessment in the testes, along with comet assay of lymphocytes were performed.

Results: Histopathological examination of the testes showed no significant architectural alterations. Immunofluorescent staining of γ-H2AX revealed more DNA double-strand break sites in testicular cells from sham animals compared to Natural SOD^® pretreated rats. Alkaline comet assay results showed increased DNA damage in lymphocytes of irradiated rats compared to the control group with little differences between the pretreated groups. Animals pretreated with Natural SOD showed slightly reduced DNA damage compared to sham-pretreated rats. These findings suggest a potential protective effect of Natural SOD^® against radiation-induced DNA damage.

Conclusions: Natural SOD^® exhibited a potential prophylactic radioprotective effect in rats, particularly in testes. Further investigations to determine medium and long-term effects of X-ray in animals administered Natural SOD^® are needed to better estimate the radioprotective effect.

Purpose: Assessment of absorbed doses on organs and tissues of miners during radon exposure in the Schneeberg mines in the sixteenth century and calculation of the probability of occurrence of radiation-induced lung cancer and lung fibrosis, considering the life expectancy characteristic and the absence of smoking.

Materials and methods: The expected radon concentration at the Schneeberg mines has been estimated using published data. Modeling of the accumulation of radon in the working tunnels of mine workings was carried out using the RESRAD-Build 4.0, based on the radium concentration in soil and geometric parameters of the mining tunnel from the engravings in Agricola's book. The dynamics of radionuclides in the human body were performed using the WinAct software in accordance with data from ICRP Publications 130 and 137. The values of absorbed doses on the tissues of the respiratory tract were obtained using the IDAC 2.1 program. Several models based on the epidemiology of uranium miners have been used to calculate radiation risks from radon exposure. The probability of male survival at birth and the age-specific frequency of spontaneous lung cancer not associated with radiation for miners of the sixteenth century (nonsmoking men aged 20-40 years) were estimated to properly calculate the radiation risks.

Results: The expected radon concentration in the Schneeberg mines was assessed in the range of 75-100 kBq m^-3. The average value of the equilibrium factor was estimated as 0.49 ± 0.03. The annual exposure of miners to radon decay products was assessed as 125-165 WLM year^-1. The annual values of absorbed doses to different sections of the respiratory tract were calculated, the maximum absorbed doses of α-radiation are formed on the bronchial and bronchiolar regions of the lungs (2.23 Gy year^-1). The deterministic effects as radiation fibrosis of the lungs with 10 years of experience in the mines of Schneeberg have a probability of occurrence from 60 to 100%. All the models used for radiation risk assessments showed that the lifetime risk of developing lung cancer for nonsmoking Schneeberg miners is many times lower than the risk of developing deterministic radiation effects. In contrast, for the smoking cohort of miners in the nineteenth century lung cancer become the dominant cause of death.

Conclusions: The deterministic radiation effects of Schneeberg miners in sixteenth century, exposed to extremely high levels of radon, such as radiation pneumosclerosis or pulmonary fibrosis, are more likely than the development of radiation-induced lung cancer.

Purpose: Evaluate the structural damage and the changes in the photosynthesis and transpiration rates of aquatic lirium leaves caused by ultrasound (US) irradiation in search of environmentally friendly methodologies for the control of this weed.

Materials and methods: Aquatic lirium plants were extracted from Xochimilco water canals in Mexico City. A part of the group of plants was selected for irradiation, and the rest formed the control group. The irradiation plants group was exposed to US irradiation of 17 kHz frequency and 30 W × 4 output power for 2 h, at noon and 25 °C room temperature. The structural analysis was done with a MOTICAM 1 digital camera, 800 × 600 pixels, incorporated into the MOTIC PSM-1000 optical microscope and edited with Motic Images Plus 2.0 ML software. The total stomata density and the damaged stomata density were determined by dividing the numbers of total and damaged stomata by the visual field area (67,917 mm²), respectively. The leaves' photosynthesis and transpiration rates were measured using an LI-6400XT Portable Photosynthesis System.

Results: Significant damage was observed in the stomata and epidermal cells, finding that the average ratio between the damaged and total stomata densities as a function of time (days) showed an exponential increase described by a Box-Lucas equation with a saturation value near unity and a maximum rate of change of the density of damaged stomata on zero-day (immediately after irradiation), decreasing as the days go by. The transpiration rate showed a sudden increase during the first hour after irradiation, reaching a maximum of 36% of its value before irradiation. It then quickly fell during the next 6 days and more slowly until the 21st day, decreasing 79.9% of its value before irradiation. The photosynthetic rate showed similar behavior with a 37.7% maximum increment and a 73.6% minimum decrease of its value before irradiation.

Conclusions: The results of structural stomata damage on the ultrasound-irradiated aquatic lirium leaves are consistent with an excessive ultrasound stimulation on stomata's mechanical operation by guard cells that produce the measured significant increase of the photosynthetic and transpiration rates during the first hour after irradiation. The initial high evaporation could alter the water potential gradient, with a possible generation of tensions in the xylem that could cause embolism in their conduits. The loss of xylem conductivity or hydraulic failure would be consistent with the observed significant fall in the photosynthesis and transpiration rates of the aquatic lirium leaves after its sudden rise in the first hour after irradiation.

Purpose: To provide an updated summary of recent advances in the application of gamma irradiation to elicit secondary metabolism and for induction of mutations in plant cell and organ cultures for the production of industrially important specialized metabolites (SMs).

Conclusions: Research on the application of gamma radiation with plants has contributed a lot to microbial decontamination of seeds, and the promotion of physiological processes such as seed germination, seedling vigor, plant growth, and development. Various studies have demonstrated the influence of gamma rays on the morphology, physiology, and biochemistry of plants. Recent research efforts have also shown that low-dose gamma (5-100 Gy) irradiation can be utilized as an expedient solution to alleviate the deleterious effect of abiotic stresses and to obtain better yields of plants. Inducing mutagenesis using gamma irradiation has also evolved as a better option for inducing genetic variability in crops, vegetables, medicinal and ornamentals for their genetic improvement. Plant SMs are gaining increasing importance as pharmaceutical, therapeutic, cosmetic, and agricultural products. Plant cell, tissue, and organ cultures represent an attractive alternative to conventional methods of procuring useful SMs. Among the varied approaches the elicitor-induced in vitro culture techniques are considered an efficient tool for studying and improving the production of SMs. This review focuses on the utilization of low-dose gamma irradiation in the production of high-value SMs such as phenolics, terpenoids, and alkaloids. Furthermore, we present varied successful examples of gamma-ray-induced mutations in the production of SMs.

Purpose: Swiss Cheese (Monstera adansonii) is an ornamental plant valued for its exotic leaves with openings and for the variety of colors. The technique of controlled exposure to gamma radiation was investigated to induce variegation (color change) in the leaves of this plant.

Materials and methods: Monstera adansonii cuttings were irradiated with different doses of radiation with ⁶⁰Co gamma rays (0, 1, 5, 10, 15, and 20 Gy) and evaluated for size, color, health, and growth.

Results: Cuttings irradiated with 1 and 5 Gy exhibited temporary variegation in leaf color, but did not maintain these characteristics over time. Cuttings with higher doses of radiation (10, 15, and 20 Gy) did not survive well and showed a reduction in growth, number of leaves, health, and sprouting rate.

Conclusions: This research concludes that gamma radiation can affect the development of cuttings and shows the potential to induce variegation at lower doses, but more studies and prolonged observation are needed to determine whether this technique can produce variegation in a consistent and lasting way in M. adansonii. Therefore, although promising initial results have been observed, it is premature to state that gamma radiation is an effective method for inducing variegation in this plant.

Purpose: To provide a synthesis of the published evidence pertaining to the intergenerational health effects of parental preconceptional exposure to ionizing radiation in humans.

Methods: The study populations are the descendants of those who were exposed to ionizing radiation prior to conception. A Boolean search identified publications for review in accordance with Office of Health Assessment and Translation guidelines. Initially, a risk of bias assessment was conducted for each published study and relevant data extracted. Information was organized into adverse health outcome groups and exposure situations. To make an assessment from the body of evidence within each group, an initial confidence rating was assigned, before factors including inconsistencies between studies, magnitude of effect, dose response and confounders were considered. From this, 'an effect', 'no effect' or whether the evidence remained 'inadequate' to determine either effect or no effect, was ascertained. This assessment was based primarily upon the author's conclusions within that evidence-base and, by binomial probability testing of the direction of effect reported.

Results: 2441 publications were identified for review which after screening was reduced to 127. For the majority of the adverse health groups, we find there to be inadequate evidence from which to determine whether the health effect was, or was not, associated with parental preconceptional radiation exposure. This was largely due to heterogeneity between individual study's findings and conclusions within each group and, the limited number of studies within each group. We did observe one health grouping (congenital abnormalities) in occupationally exposed populations, where an increase in effect relative to their controls or large magnitude of effects, were reported, although it is noted that the authors of these studies interpreted their findings as most likely not to be associated with parental radiation exposure.

Conclusions: We find there to be a lack of evidence to enable the formal assessment of radiation-related adverse effects in offspring of exposed humans. This is not the same as there being no clear evidence that effects may occur but does infer that if adverse health effects do arise in children of exposed parents, then these effects are small and difficult to reproducibly measure. Inconsistencies in designing studies are unavoidable, however we highlight the need for an element of standardization and, more sharing of primary datasets as part of open access initiatives, in order for future reviews to make reasonable conclusions. Overall, there is a need for future work to ensure comparable measures between studies where possible.

Purpose: Neuroblastoma, a prevalent childhood tumor, poses significant challenges in therapeutic interventions, especially for high-risk cases. This study aims to fill a crucial gap in our understanding of neuroblastoma treatment by investigating the potential molecular impacts of short- and long-term pulsed magnetic field exposure on the neuronal apoptosis mechanism in an in vitro model of neuroblastoma treated with oleic acid (OA).

Materials and methods: Cells were cultured and divided into six following experimental groups: (I) Nontreated group (NT); (II) OA-treated group (OA); (III) Group treated with OA after being exposed to the pulsed magnetic field for 15-min (15 min PEMF + OA); (IV) Group treated with OA after being exposed to the pulsed magnetic field for 12 h (12 h PEMF + OA); (V) Group exposed to the pulsed magnetic field for 15 min (15 min PEMF); and (VI) Group exposed to the pulsed magnetic field for 12 h (12 h PEMF). Cell viability, rates of apoptosis, and mRNA levels of key apoptotic genes (TP53, Bcl2, Bax, and Caspase-3) were assessed.

Results: Significant reductions in cell viability were observed, particularly in the group treated with OA following long-term pulsed magnetic field exposure. Flow cytometry revealed elevated apoptosis rates, notably in the early stages of apoptosis. qRT-PCR analysis demonstrated increased expression of cleaved Caspase-3, Bax/Bcl2 ratio, and TP53 in cells treated with OA following long-term pulsed magnetic field exposure, signifying enhanced apoptotic pathways.

Conclusions: The findings indicate that long-term pulsed magnetic field exposure and OA treatment exhibit potential synergistic effects leading to the induction of apoptosis in SH-SY5Y cells. We have concluded that stimulations of pulsed magnetic field have the potential to serve as an adjuvant therapy for oleic acid-based treatment of neuroblastoma.

Purpose: To evaluate the effects of 1800 MHz continuous wave (CW) and global system for mobile communications (GSM) modulated radiofrequency electromagnetic field (RFEMF) exposures on signal transduction (ST) protein and cytokine expression in differentiated human-derived monocytic THP-1 cells.

Materials and methods: THP-1 cells were differentiated into adherent macrophage-like cells using phorbol 12-myristate 13-acetate (PMA). Following differentiation, cells were exposed to 1800 MHz CW or GSM modulated RFEMF for 0.5, 4, or 24 h at a specific absorption rate (SAR) of 0 (sham) or 2.0 W/kg. Concurrent positive controls (lipopolysaccharide for cytokines; anisomycin for ST proteins) and negative controls were included in each experiment. The expression levels of cytokines (GM-CSF, IFN-γ, IL-1β, IL-6, IL-10, TNF-α) from culture media and phosphorylated and total ST proteins (CREB, JNK, NF-κB, p38, ERK1/2, Akt, p70S6k, STAT3, STAT5) from cell lysates were assessed using Milliplex magnetic bead array panels.

Results: No consistent effect of RFEMF exposure was observed in differentiated THP-1 cells. A statistically significant effect of overall exposure condition was observed for IL-6 with GSM modulation (P = 0.042), but no difference between RFEMF and sham for any exposure condition remained following adjustment for multiple comparisons (P ≥ 0.128). No statistically significant effect of exposure condition was detected for any other cytokine evaluated with either of the RFEMF modulations (P ≥ 0.078). There were no statistically significant changes in expression levels for any of the ST proteins under any studied exposure condition (P ≥ 0.320).

Conclusions: In this study, no evidence of changes were observed in differentiated human derived THP-1 cells following exposure of up to 24 h to 1800 MHz RFEMF at SARs of 0 and 2.0 W/kg on the expression of ST proteins or cytokines.