X-ray Radiation Dose Research Articles

Effect of FBG Fiber Dosimeter Division in Sensing Capability for Low Radiation Doses

ر A fiber Bragg grating (FBG) as a dosimeter is developed in this simulation study (based on Optisystem 21 software) by dividing its region into five individual regions. The division includes the same properties for all regions, which is a standard SiO2 optical fiber material. In dosimeters, it is convenient to introduce dopants to increase the fiber sensitivity. The new design accepts dopants and can work without such a dopant. Measurements for sensing deflected signals from the FBG sensor confirmed increased sensitivity for low-rate radiation doses in comparison to one bulk region in a traditional fiber dosimeter. The sensitivity of this dosimeter is based on both the FWHM line shape function and the amplitude of the deflected signals. The FBG dosimeter sensor can respond to low-dose radiation in a noticeable manner according to the type of applied simulated effect. Dosimeter body division for multi-regions gives rise to sensitivity in comparison to the traditional bulk region. The measured FWHM from the line-shape function for overall observed signals fluctuates from 0.374 MHz under applied temperature, stress x, y, z, and strain to 0.358, 0.373, 0.3733, 0.368, and 0.3737 MHz, respectively. While this range follows different fitting functions: Sin, Exp.Decay, SinSqu., Exp.Decay3, and GaussAmpl. For last effects, according to measured effect. The same measurements were carried out for signal amplitude variation, with these effects giving a variety of relationships indicating their existing contribution. Results confirmed an efficient tool for use in sensing for low x-ray and gamma ray radiation dose applications versus traditional bulk FBG sensor type.

Quantitative spatial visualization of X-ray irradiation via redox reaction by dynamic nuclear polarization magnetic resonance imaging

The dose of X-ray irradiation is commonly measured by point assessment with an ionization chamber dosimeter. However, to achieve spatially accurate delivery of X-ray to avoid the exposure to normal tissues, an accurate imaging method for spatially and quantitatively detecting exposure is required. Herein, we present a novel method to visualize X-ray exposure using low-field dynamic nuclear polarization magnetic resonance imaging (DNP-MRI) with nitroxyl radical tempol as the chemical dosimeter. In this system, gel phantoms containing glutathione (GSH) and the paramagnetic tempol radical were used to monitor the deposited X-ray-irradiation via the redox reaction. The tempol radical level was evaluated by DNP-MRI whose signal intensity was linearly correlated with the radical concentration. The radical level in the presence of GSH decreased in proportion to the dose of X-irradiation deposited. In an imaging experiment simulating clinical radiotherapy, we used a clinical linear accelerator with a radiotherapy planning software to confirm the utility of the exposure imaging. The X-ray exposure and its distribution were clearly visualized on the gel phantom image acquired by DNP-MRI. The results were consistent with those specified in the radiotherapy plan where the intensity of the radiation beam was modulated. This exposure estimation will be useful for determining an accurate irradiation field and reducing off-target exposure in clinical settings.

Impacts of X-Ray irradiation on RBC, WBC and PLT by low doses (40kV and 80kV).

This study aimed to assess the impact of irradiation on red blood cells (RBCs), white blood cells (WBCs), and platelets (PLTs) using modest doses of X-ray radiation (40 kV and 80 kV). The blood samples were exposed to X-ray irradiation at 40 and 80 kV. A haematology analyzer system with automated capability was used to quantify cellular components, specifically WBCs, RBCs, and PLTs, both before and after exposure to radiation. The study found that irradiation reduced WBC and PLT numbers. When exposed to 40 kV and 80 kV voltages, the WBC and PLT improved statistically significantly (p = 0.001). Nonetheless, the statistical analysis revealed no statistically significant difference (p > 0.05) in red blood cell count between 40 and 80 kV doses. It can be concluded that the haematopoietic system exhibits a high degree of sensitivity to radiation exposure.

Pyrroloquinoline Quinone Alleviates Mitochondria Damage in Radiation-Induced Lung Injury in a MOTS-c-Dependent Manner.

Radiation-induced lung injury (RILI) is a prevalent complication of thoracic tumor radiotherapy and accidental radiation exposure. Pyrroloquinoline quinone (PQQ), a novel vitamin B, plays a crucial role in delaying aging, antioxidation, anti-inflammation, and antiapoptosis. This study aims to investigate the protective effect and mechanisms of PQQ against RILI. C57BL/6 mice were exposed to a 20 Gy dose of X-ray radiation on the entire thorax with or without daily oral administration of PQQ for 2 weeks. PQQ effectively mitigated radiation-induced lung tissue damage, inflammation, oxidative stress, and epithelial cell apoptosis. Additionally, PQQ significantly inhibited oxidative stress and mitochondrial damage in MLE-12 cells. Mechanistically, PQQ upregulated the mRNA and protein levels of MOTS-c in irradiated lung tissue and MLE-12 cells. Knockdown of MOTS-c by siRNA substantially attenuated the protective effects of PQQ on oxidative stress, inflammation, and apoptosis. In conclusion, PQQ alleviates RILI by preserving mitochondrial function through a MOTS-c-dependent mechanism, suggesting that PQQ may serve as a promising nutraceutical intervention against RILI.

Visualization of Biomolecular Radiation Damage at the Single-Particle Level Using Lanthanide-Sensitized DNA Origami.

Precise monitoring of biomolecular radiation damage is crucial for understanding X-ray-induced cell injury and improving the accuracy of clinical radiotherapy. We present the design and performance of lanthanide-DNA-origami nanodosimeters for directly visualizing radiation damage at the single-particle level. Lanthanide ions (Tb3+ or Eu3+) coordinated with DNA origami nanosensors enhance the sensitivity of X-ray irradiation. Atomic force microscopy (AFM) revealed morphological changes in Eu3+-sensitized DNA origami upon X-ray irradiation, indicating damage caused by ionization-generated electrons and free radicals. We further demonstrated the practical applicability of Eu3+-DNA-origami integrated chips in precisely monitoring radiation-mediated cancer radiotherapy. Quantitative results showed consistent trends with flow cytometry and histological examination under comparable X-ray irradiation doses, providing an affordable and user-friendly visualization tool for preclinical applications. These findings provide new insights into the impact of heavy metals on radiation-induced biomolecular damage and pave the way for future research in developing nanoscale radiation sensors for precise clinical radiography.

Investigation of X-rays Beams Uniformity in Radiotherapeutic Tumor Treatment Procedure Using LuAG:Ce Crystal Detectors.

In this study, Ce3+-doped Lu3Al5O12 garnet (LuAG) crystal detectors, with a density of ρ = 6 g/cm3 and an effective atomic number Zeff = 62, are proposed as promising materials for radiotherapy applications. This type of detector demonstrates excellent uniformity of structural and optical properties, high thermoluminescence (TL) light yield, optimal position of main TL glow peaks at temperatures around 245-295 °C, and high radiation stability. The set of TL detectors made from LuAG:Ce single crystal was used to evaluate the uniformity of dose and energy spectra of X-ray radiation from a clinical accelerator with 6 MV and 15 MV beams at the Department of Medical Physics, Oncology Center in Bydgoszcz, Poland, and γ-rays from a 60Co source at the National Institute of Oncology in Warsaw. The LuAG:Ce crystal detectors demonstrated highly promising results for registering X-ray radiation from accelerators with both 6 MV and 15 MV electron beams, as well as γ-rays from a 60Co source with energies of 1.17 and 1.33 MeV.

Tumor Microenvironment Reprogrammed Bimetallic Hybrid Nanostimulator for Triggering Radio-Cuproptosis-Immunotherapy.

Radio-immunotherapy driven by radiation-induced immunogenic cell death (ICD) is emerging as a potential opportunity to address conventional radiotherapy (RT) that is only applicable to localized tumor treatment. However, the effective activation of ICD during RT is severely limited by radiation dose, weak tumor immunogenicity, and radio-resistance caused by tumor microenvironment (TME). Herein, a novel bimetallic hybrid nanoscale coordination nanostimulator is first proposed by phosphate backbone doped with copper ions (Cu2+) and hafnium ions (Hf4+), and then modified with polyvinylpyrrolidone (PVP). The PVPylated Cu/Hf-doped phosphate nanostimulator (denoted as CHP) exhibits effective reprogramming of TME, including depletion of tumor endogenous glutathione (GSH), relief of tumor hypoxia and repolarization of M2 phenotypic macrophages, thus achieving tumor radiosensitization at low X-ray irradiation dose, gradually accumulation of tumor endogenous reactive oxygen species (ROS) and augmenting cuproptosis. In addition, cuproptosis can amplify RT-induced anti-tumor immunity through ICD activation, ultimately resulting in a robust anti-tumor immune response and long-term immunity, evidenced by distant tumor growth inhibition of 4T1-tumor-bearing models. More interestingly, it is discovered that CHP-mediated cuproptosis can be intensifiable during X-ray irradiation. Taken together, this work presents a novel radio-cuproptosis-immunotherapy cascade strategy, offering a new perspective for innovation in the treatment field of breast cancer.

Study of Radiosensitivity and Induction of Radiation Adaptive Response in Peripheral Blood Lymphocytes of Patients with Oncological Diseases Using the Micronuclear Test.

Radiosensitivity to low and medium doses of X-ray radiation and the ability to induce a radiation adaptive response (RAR) of lymphocytes during in vitro irradiation of peripheral blood of patients with cancer were studied. The criterion for cytogenetic damage was the frequency of micronuclei (MN) in cytochalasin-blocked binucleate lymphocytes in culture. It was found that the spontaneous level of cytogenetic damage in the lymphocytes of patients was 2.6 times higher than in healthy volunteers, and there was also significant interindividual variability in values compared to the control cohort. There were no differences in mean values for radiosensitivity to low and medium doses of X-ray between the study groups. There was no correlation between the spontaneous level of MN in lymphocytes and the radiosensitivity of individuals in both groups. RAR was induced with the same frequency and to the same extent in lymphocytes from both patients and healthy individuals.

X-Ray-Sensitizers: Organic Pharmaceutical Drug Intermediates Activated Directly by X-Rays to Efficiently Populate Triplet Excitons for Cancer Treatment

Radiotherapy is an important treatment for cancer, but it is associated with major side effects due to the high dose of radiation (generally more than 50 Gy). Because radiation’s low acute and late toxicity, many tumors are treated with fractionated radiation in small doses (< 2 Gy). Scintillator X-ray-induced photodynamic therapy is an efficient methodology for cancer management that employs small doses of X-ray irradiation (< 2 Gy) in a complex process. Here we screened pharmaceutical drug intermediates that are derivatives of thioxanthone (TX) and investigated TX-derived organic pharmaceutical molecules that efficiently undergo X-ray-sensitization to populate triplet excitons (singlet oxygen) for cancer therapy when exposed to low-dose X-ray irradiation. By modifying alkoxy side chain substitutions at the 2-position to tune the molecular packing and intermolecular interactions, the fluorescence and room-temperature phosphorescence of a series of TX derivatives were assessed under X-ray irradiation. The ability of these derivatives to generate singlet oxygen and their potential for treating tumors provide new opportunities for developing organic molecules with simple chemical structures, in which large numbers of triplets can be populated directly under ultralow-dose X-ray irradiation.

Efficacy and safety of a neurointerventional operation robotic assistance system in cerebral angiography

BackgroundAt present, neurointerventional surgery requires angiographers to perform operations in the digital subtraction angiography (DSA) room. Ionising radiation and chronic joint damage are still unavoidable for angiographers. Therefore, we researched...

СВЯЗЬ МЕЖДУ КЛЕТОЧНЫМ СТАРЕНИЕМ И ИЗМЕНЕНИЯМИ КОЛИЧЕСТВА И РАЗМЕРОВ ФОКУСОВ ФОСФОРИЛИРОВАННОГО ГИСТОНА Н2AX В ОБЛУЧЕННЫХ ФИБРОБЛАСТАХ ЧЕЛОВЕКА

Purpose: To analyze the relationship between cellular aging and changes in the number and size of phosphorylated histone H2AX (γH2AX) foci in human fibroblasts and their descendants (up to 15 passages) after exposure to low and high doses of X-ray radiation. Material and methods: The work was performed on a culture of human skin fibroblasts. Cells were irradiated in the exponential growth phase on an X-ray biological unit RUB RUST-M1 (Russia), equipped with two X-ray emitters, at a dose rate of 40 mGy/min (dose 100 mGy) or 850 mGy/min (doses 2000 and 5000 mGy) and temperature 4˚C. Immunocytochemical staining was used to assess the number and size of γH2AX foci and the proportion of proliferating cells using antibodies to γH2AX and Ki67 (a cell proliferation marker protein), respectively. To assess cellular senescence, the proportion of cells positive for senescence-associated β-galactosidase (CA-β-gal(+)) was analyzed. Statistical and mathematical analysis of the obtained data was carried out using the statistical software package Statistica 8.0 (StatSoft). Results: The studies showed that irradiation of cultured human fibroblasts at a low dose (100 mGy) does not lead to statistically significant changes in the number and size of γH2AX foci, as well as the proportion of non-proliferating and senescent cells in the progenies of irradiated cells up to the 15th passage after irradiation. The phenomenon of aging-associated persistence of an increased number and size of γH2AX foci in passages of cells irradiated at a dose of 5000 mGy was discovered. Mathematical analysis of the relationship between changes in the proportion of CA-β-gal(+) cells, the number and size of γH2AX foci in populations of irradiated cells indicates that radiation-induced cellular aging is more associated with the size, rather than the number, of γH2AX foci.

Development of a sterile insect technique as a control strategy for the Asian citrus psyllid: establishing the effect of sterilizing X-rays on fecundity, fertility, and survival.

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a major pest of citrus due to its role as the vector of the bacterium that causes huanglongbing. In commercial citrus, ACP control currently relies on the application of insecticides, which may not be sustainable long-term, nor practical in urban areas. The sterile insect technique (SIT) is an alternative strategy in which large numbers of pests are reared, sterilized using radiation, and then released into the field to compete with wild individuals for matings, suppressing population growth. As a fundamental step toward the development of SIT for ACP, this study sought to identify the optimum radiation dose required to sterilize ACP without affecting their survival and mating capacity. Virgin adult ACP of both sexes were subjected to doses of X-ray irradiation ranging from 40 to 480 Gy, then paired with a nonirradiated mate and allowed to produce offspring. Fecundity was estimated as the number of eggs laid, and fertility as the proportion of those eggs that hatched. Females were more radio-sensitive than males, exhibiting a major drop in fecundity at even the lowest dose and 100% sterility at 80 Gy. In contrast, a fivefold higher dose (400 Gy) did not achieve complete sterility in males, with around 5% offspring survival. However, F1 progeny of males exposed to 320 Gy or higher were subsequently found to be 100% sterile. This confirmation of inherited sterility suggests that balancing the sterilizing effects of radiation against its mortality-inducing effects may warrant further evaluation.

Effect of IRSL-BLSL-TSL reading modes combination on thermoluminescence (TL) response of BeO dosimeter.

The ultimate goal of this work is the study of the effect of luminescence stimulations and signals reading modes combinations on the thermoluminescence intensity and glow curve behaviour for the same X-ray irradiation dose. Three interesting stimulating and reading modes are considered, namely, infrared stimulated luminescence (IRSL), blue light-emitting diode stimulated luminescence (BLSL) and thermally stimulated luminescence (TSL). The studied stimulation and reading modes combination protocols are (Protocol 1) IRSL-TSL, (Protocol 2) IRSL-BLSL-TSL and (Protocol 3) BLSL-IRSL-TSL. Experiments are performed on beryllium oxide (BeO) dosimeter. Results demonstrate well that the combination of reading modes have direct impact on the TL signal in terms of intensity and glow curve shape. It was also found that when reading modes are correctly combined, particularly when IRSL is applied first, then BLSL and TL, it is possible to collect two or more exploitable signals of different stimulation types for the same irradiation that can be used for different purposes and final applications.

Renal Function and Survival are Reduced in a Polytrauma Acute Radiation Injury Rat Model with Extremity Trauma and Hemorrhage

The objective of this study was to evaluate whether the presence of radiation injury (RI) decreases survival in an established model of battlefield trauma and hemorrhage in rats. We hypothesized that the addition of radiation to our established traumatic hemorrhage model would increase mortality. Methods: On day zero (D0), male Sprague Dawley rats (n=6/group) received Buprenorphine SR prior to being anesthetized with isoflurane to perform catheterization of a carotid artery. Twenty-four hours later (day 1 or D1), rats were randomly assigned to 1 of 4 groups: 1- sham (no injury; no radiation); 2- RI only; 3- traumatic hemorrhage alone (ET+HEM); or 4- RI combined with traumatic hemorrhage (RI+ET+HEM). For RI and RI+ET+HEM groups, rats were anesthetized and placed inside a cabinet X-ray irradiator (MultiRad 350, Precision, CT) to receive a single sub-lethal X-ray dose of 5.5 Gy, delivered at 1 Gy/min, to induce acute radiation injury. For ET+HEM and RI+ET+HEM groups, under isoflurane, rat then received a unilateral extremity trauma injury. After 90 minutes, a conscious hemorrhage of 37% of the rat estimated blood volume was withdrawn. Rats were monitored for 14 days following injury or sham procedures and provided Buprenorphine SR as needed for pain. Rats remained un-resuscitated and renal function was assessed in vivo by glomerular filtration rate (GFR). GFR was measured with a probe non-invasively and securely strapped to the belly of the rat for about 2.5h. Samples for GFR were collected on D1, day 3 (D3), and day 15 (D15) (or terminal day) from the injury. Result: Sham rats had 100% survival at D15, while RI and ET+HEM rats both had 50% mortality. RI+ET+HEM rats, however, demonstrated 100% mortality by D15; differences in survival proportions were significant (P=0.005). Sham rats showed no significant decrease in GFR (1.0-1.2 ml/min/100g) from D1 to D15. Rats from RI group showed a slight decrease in GFR from D1 to D3 (1.2 to 0.9 ml/min/100g, respectively) at the D3 of measurement. By D15, GFR was 33% lower than D1 in RI group. ET+HEM group showed significant decline in GFR on D1 and D3. However, RI+ET+HEM group showed the most significant decline in GFR ( i.e., &gt;50% lower than sham group on D1 and D3), with little to no improvement over time. Conclusion: We developed a new rodent model of RI+ET+HEM by combining high dose of X-ray irradiation with traumatic hemorrhage, which allows acute (hours) as well as chronic (days) observation. While RI or ET+HEM alone produced significant mortality, the combination of traumatic hemorrhage with RI increased mortality to 100% before D15. Radiation injury combined with extremity trauma and hemorrhage results in significant impairment of renal function. Extremity trauma and hemorrhage impaired renal function more than radiation injury alone. Disclaimer: The views expressed in this abstract are those of the author(s) and do not reflect the offcial policy or position of the U.S. Army Medical Department, Department of the Army, DoD, or the U.S. Government. Supported by Biomedical Advanced Research and Development Authority (BARDA). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Growth and yield performance of X-ray irradiated cucumber

Cucumber (Cucumis sativus L.) is a very important fruit which makes its demand and consumption continually on the increase all over the world. X-ray is an ionizing radiation and a physical mutagen with great potentials in creating artificial variability in crops. The employment of x-ray irradiation has been underutilized in plant mutagenesis, hence this study sought to determine its effect on the germination and agro-morphological traits of cucumber. Cucumber seeds were obtained from an agro-allied store and exposed to x-ray radiation from a source 70 KVA at a distance of 90cm and doses 10, 20, 30 and 40mAs. The field experiment was carried out in duplicate using a Randomized Complete Block Design (RCBD). Irradiated and unirradiated (control) seeds were sown directly on a total of ten prepared plots measuring 2.44 by 1.50 m. The result generated in this study show a positive shift at the higher doses (30 and 40 mAs) with reduced number of days to fruit maturity and increased number of fruits per plant when compared to the control and other doses. A strong positive correlation was observed among some traits studied, indicating the possibility of such traits being under the influence of the same gene and the ability to be inherited together. Zonata, a chlorophyll mutant was observed at 30 mAs indicating how successful the dose was in inducing beneficial mutation on the Cucumber. Higher doses of x-ray irradiation as used in this study is therefore recommended for the genetic improvement of other vegetable and under developed crops.

Evaluation of low-dose computed tomography reconstruction using spatial-radon domain total generalized variation regularization

The x-ray radiation dose in computed tomography (CT) examination has been a major concern for patients. Lowing the tube current and exposure time in data acquisition is a straightforward and cost-effective strategy to reduce the x-ray radiation dose. However, this will inevitably increase the noise fluctuations in measured projection data, and the corresponding CT image quality will be severely degraded if noise suppression is not performed during image reconstruction. To reconstruct high-quality low-dose CT image, we present a spatial-radon domain total generalized variation (SRDTGV) regularization for statistical iterative reconstruction based on penalized weighted least-squares (PWLS) principle, which is called PWLS-SRDTGV for simplicity. The presented PWLS-SRDTGV model can simultaneously reconstruct high-quality CT image in space domain and its corresponding projection in radon domain. An efficient split Bregman algorithm was applied to minimize the cost function of the proposed reconstruction model. Qualitative and quantitative studies were performed to evaluate the effectiveness of the PWLS-SRDTGV image reconstruction algorithm using a digital 3D XCAT phantom and an anthropomorphic torso phantom. The experimental results demonstrate that PWLS-SRDTGV algorithm achieves notable gains in noise reduction, streak artifact suppression, and edge preservation compared with competing reconstruction approaches.

X-ray Induced Electric Currents in Anodized Ta2O5: Towards a Large-Area Thin-Film Sensor.

We investigated the characteristics of radiation-induced current in nano-porous pellet and thin-film anodized tantalum exposed to kVp X-ray beams. We aim at developing a large area (≫cm2) thin-film radiation sensor for medical, national security and space applications. Large area (few cm2) micro-thin Ta foils were anodized and coated with a counter electrode made of conductive polymer. In addition, several types of commercial electrolytic porous tantalum capacitors were assembled and prepared for irradiation with kVp X-rays. We measured dark current (leakage) as well as transient radiation-induced currents as a function of external voltage bias. Large transient currents (up to 50 nA) under X-ray irradiation (dose rate of about 3 cGy/s) were measured in Ta2O5 capacitors. Small nano-porous Ta and large-area flat Ta foil capacitors show similar current-voltage characteristic curve after accounting for different X-ray attenuation in capacitor geometry. The signal is larger for thicker capacitor oxide. A non-negligible signal for null external voltage bias is observed, which is explained by fast electron production in Ta foils. Anodized tantalum is a promising material for use in large-area, self-powered radiation sensors for X-ray detection and for energy harvesting.

Analysis of X-ray irradiation effects on the mortality values and hemolymph immune cell composition of Apis mellifera and its parasite, Varroa destructor

Varroa destructor is one of the most destructive enemies of the honey bee, Apis mellifera all around the world. Several control methods are known to control V. destructor, but the efficacy of several alternative control methods remains unexplored. Irradiation can be one of these unknown solutions but before practical application, the effectiveness, and the physiological effects of ionizing radiation on the host and the parasite are waiting to be tested. Therefore, the objective of our study was to investigate the effects of different doses (15, 50, 100, and 150 Gy) of high-energy X-ray irradiation through mortality rates and hemocyte composition changes in A. mellifera workers and record the mortality rates of the parasite. The mortality rate was recorded during short-term (12, 24, and 48 h) and long-term periods (3, 6, 12, 18, and 24d).The sensitivity of the host and the parasite in case of the higher doses of radiation tested (50, 100, and 150 Gy) been demonstrated by total mortality of the host and 90 % of its parasite has been observed on the 18th day after the irradiation. V. destructor showed higher sensitivity (1.52-times higher than the adult honey bee workers) at the lowest dose (15 Gy). A. mellifera hemocytes were influenced significantly by radiation dosage and the elapsed time after treatment. The higher radiation doses increased plasmatocyte numbers in parallel with the decrease in prohemocyte numbers. On the contrary, the numbers of granulocytes and oencoytes increased in the treated samples, but the putative effects of the different dosages on the recorded number of these hemocyte types could not be statistically proven. In summary, based on the outcome of our study X-ray irradiation can be deemed an effective tool for controlling phoretic V. destructor. However, further research is needed to understand the physiological response of the affected organisms.

Anti-tumor effect of high doses of carbon ions and x-rays during irradiation of Ehrlich ascites carcinoma cells ex vivo

The effect of carbon ions (12C) with the energy of 400 MeV/nucleon on the dynamics of induction and growth rate of solid tumors in mice under irradiation of Ehrlich’s ascites carcinoma cells (EAC) ex vivo at doses of 5–30 Gy relative to the action of equally effective doses of X-ray radiation was studied. The dynamics of tumor induction under the action of 12C and X-rays had a similar character and depended on the dose during 3 months of observation. The value of the latent period, both when irradiating cells with 12C and X-ray, increased with increasing dose, and the interval for tumor induction decreased. The rate of tumor growth after ex vivo irradiation of EAC cells was independent of either dose or type of radiation. The dose at which EAC tumors are not induced within 90 days was 30 Gy for carbon ions and 60 Gy for X-rays. The value of the relative biological effectiveness of carbon ions, calculated from an equally effective dose of 50% probability of tumors, was 2.59.

Сравнение радиопротекторных свойств рибоксина (инозина) и индралина при профилактическом введении в дозировках 100 мг/кг по критерию выживаемости облучённых мышей

Relevance: Due to the high chemical toxicity of all known effective radioprotectors, studies of the radioprotective properties of safer drugs are very relevant. A sufficient number of works are devoted to the radioprotective properties of ribonucleoside riboxin (inosine). However, studies comparing the direct radioprotective properties of riboxin and a recognized radioprotector, for example, indralin, using a survival test in irradiated animals have not yet been carried out. Purpose: Conduct a comparative assessment of the radioprotective properties of riboxin and indralin using a survival test in mice exposed to external X-ray radiation. Material and methods: The experiment was carried out on 200 male ICR (CD-1) mice of the SPF category in duplicate. In each experiment, the animals were divided into the following groups, separated by body weight, 10 animals each: vivar control, not exposed to drugs and radiation, radiation control, with preliminary intraperitoneal administration of sterile water and exposed to external X-ray radiation in doses of 6.0, 6.5 and 6.75 Gy, experimental groups exposed to irradiation in the indicated doses with preliminary intraperitoneal administration of riboxin at a dosage of 100 ml/kg body weight or indralin at a dosage of 100 ml/kg. Survival was assessed for 30 days after irradiation. The dose change factor was determined using probit analysis as the ratio of the radiation dose causing the death of half of the irradiated animals that received the drug to the radiation dose causing the death of half of the irradiated animals without administration of the drug. Results: The use of indralin before X-ray irradiation in doses of 6.0 Gy, 6.5 Gy and 6.75 Gy led to a statistically significant increase in the survival of animals compared to the group receiving Riboxin and control irradiation (р&lt;0,05, log-rank test). Using equations derived from Phinney probit analysis, LD50 doses were calculated for indralin and riboxin, from which dose change factors were calculated to be 1.8 and 1.07, respectively. Conclusion: Since riboxin has not demonstrated radioprotective properties, its preventive use with intraperitoneal administration under the conditions described in this paper, for leveling the effects of radiation can be considered ineffective.