Long-term Effects Of Radiation Research Articles

Evidence for Persistent Radiation-Related Injury to the Immune System in Patients With Local Breast Cancer

Severe and prolonged lymphopenia is well described in the literature as a consequence of local radiation and is associated with early death and impaired responses to immunotherapy. In animals, localized radiation results in histologic changes in lymph nodes that are distant from the radiation field. The sustained effects of radiation on distant lymph nodes in humans has not been previously described. This study was designed to assess changes in lymph nodes architecture outside the radiation field in women with breast cancer months after radiation treatment. Seven women were enrolled on a protocol to collect a distal abdominal lymph node during breast reconstruction with a deep inferior epigastric perforators (DIEP) flap. Five patients previously received chest wall irradiation on average 608 days prior to reconstruction while two patients did not receive radiation. The abdominal lymph node was compared to the initial (pre-radiation) mastectomy surgery lymph node by a blinded hematopathologist. The lymph node cellularity was graded by density score. The five patients who underwent radiation had striking reductions in their lymph node cellularity: average baseline score of 3 ± 1.2 with post lymph node density score of 1.2 ± 0.5, when compared to the two unirradiated patients: average baseline score of 4 with post lymph node density score of 3 ± 1.4. This small study suggests that localized radiation may have long-term impacts on distal lymph node basins in humans as has been seen in animals. Future studies evaluating prolonged systemic lymphopenia following radiation are needed to document the long-term systemic effects of local radiation, and the overall implications of this finding.

Radiation Exposure and Lifetime Attributable Risk of Cancer Incidence and Mortality from Low- and Standard-Dose CT Chest: Implications for COVID-19 Pneumonia Subjects.

Since the novel coronavirus disease 2019 (COVID-19) outbreak, there has been an unprecedented increase in the acquisition of chest computed tomography (CT) scans. Nearly 616 million people have been infected by COVID-19 worldwide to date, of whom many were subjected to CT scanning. CT exposes the patients to hazardous ionizing radiation, which can damage the genetic material in the cells, leading to stochastic health effects in the form of heritable genetic mutations and increased cancer risk. These probabilistic, long-term carcinogenic effects of radiation can be seen over a lifetime and may sometimes take several decades to manifest. This review briefly describes what is known about the health effects of radiation, the lowest dose for which there exists compelling evidence about increased radiation-induced cancer risk and the evidence regarding this risk at typical CT doses. The lifetime attributable risk (LAR) of cancer from low- and standard-dose chest CT scans performed in COVID-19 subjects is also discussed along with the projected number of future cancers that could be related to chest CT scans performed during the COVID-19 pandemic. The LAR of cancer Incidence from chest CT has also been compared with those from other radiation sources, daily life risks and lifetime baseline risk.

Effects of 2.45 GHz Non-Ionizing Radiation on Anxiety-Like Behavior, Gene Expression, and Corticosterone Level in Male Rats.

Introduction: The effects of short-term and long-term exposures to 2.45 GHz radiofrequency electromagnetic radiation (RF-EMR) on anxiety-like behavior, corticosterone level, and gene expression were investigated. The goal of this study was to explore the effect of electromagnetic fields of 2.45 GHz on clinical signs such as body weight and anxiety-like behavior, including the elevated plus maze test and open-field test, and also on messenger RNA (mRNA) expression of Bax (Bcl2-associated x) and Bcl-2 (B-cell lymphoma 2) genes on the cognitive memory functions in an animal model of rats. Methods: The animals were classified into eight groups, sham groups and exposed groups for short-term and long-term exposures to the same dose of RF-EMR for one hour daily. The Wi-Fi equipment in the sham control group was not turned on during the experiment. Both genes were further confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR). The semi-quantitative PCR method of electromagnetic fields in the 2.45 GHz range impacted the expression of Bax and Bcl-2 genes in the rat's memory. Results: The present study exhibited that short-term radiation could decrease the percentage of entry into the open arm and the percentage of time spent, while there were no substantial impacts on the long-term radiation effect. Our data support the hypothesis that short-term exposure worked as a systemic stressor, raising plasma corticosterone and changing glucocorticoid receptor expression in the hippocampus. Conclusion: Additional research on this specific frequency and amount of radiation is required to discover strategies for protecting the nervous system from the detrimental effects of RF-EMR radiation.

Aging of Polymeric Insulators under Various Conditions and Environments: Another Look

Polymeric insulators have lightweight, excellent hydrophobicity and convenient transportation and installation. They are widely used in the external insulation for distribution and transmission lines. However, due to the long-term effects of pollution, ultraviolet radiation, discharge, temperature, humidity, altitude and other natural and complex environmental and service factors, the silicone rubber and other materials of polymeric insulators gradually age and lose their hydrophobicity and electrical insulation characteristics. The operability is significantly reduced, which seriously affects the safety and reliability of the power system. Hence, there is a need for assessing and evaluating the long-term aging and degradation of polymeric insulators under various operating conditions and environments. In this review, the various aging and characterization techniques of the polymeric insulators and their aging performance under the action of multiple factors are discussed. To enhance the performance of polymeric insulators, nano-coating, surface treatment and other techniques are also indicated. In addition, future potential fields that should be explored from a high-voltage electrical insulation perspective are also presented.

Risk of Diabetes Mellitus after Radiotherapy for Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

<h3>Purpose/Objective(s)</h3> The long-term effect of radiation on pancreas has been mostly studied for pediatric patients with the lack of individual radiation dosimetric data. The purpose of this study was to investigate the effect of radiotherapy (RT) on the risk of newly developed diabetes mellitus (DM) in patients with gastric mucosa-associated lymphoid tissue lymphoma (GML) using individual radiation dosimetric analysis. <h3>Materials/Methods</h3> We retrospectively reviewed 225 patients without history of DM who received curative aim treatment for stage IE GML between August 2007 and June 2020. Involved site RT to the whole stomach was delivered in 83 patients (36.9%). The pancreas was delineated in each patient's computerized tomography scan for dosimetric analysis. <h3>Results</h3> At a median follow-up time of 49.0 months (range, 3.0-155.3 months), the 3-year cumulative incidence of DM was 3.9% in all patients, and 7.9% and 1.6% in patients who received and did not receive RT, respectively (p=0.009). The mean pancreatic dose (D_mean) was independently associated with DM (p=0.027). As a result of recursive partitioning analysis, patients were classified into low (D_mean <21 Gy), intermediate (D_mean ≥21 Gy and BMI <27.0kg/m²), and high-risk groups (D_mean ≥21 Gy and BMI ≥27.0kg/m²) with 5-year DM incidence of 1.5%, 6.3%, and 54.3%, respectively (p<0.001). <h3>Conclusion</h3> Our results indicate that incidental irradiation to the pancreas can increase the risk of DM, which was dependent on pancreas D_mean. In addition, not only reducing pancreas D_mean but also controlling BMI may need to be combined to effectively prevent DM after RT.

Preclinical Research Platform for Ocular FLASH Irradiation

<h3>Purpose/Objective(s)</h3> Normal tissue sparing effects from FLASH radiotherapy (RT) are potentially transformative for the treatment of ocular cancers. Reducing damage to the abundant at-risk structures within the eye can prospectively increase visual retention rates, relax treatment margins, and eliminate the need for motion tracking by surgically implanted fiducials. To date, no prior work has explored FLASH-RT effects in the context of the eye. In this work, we have conducted a pilot study of x-ray FLASH effects for ocular irradiation in a preclinical mouse model by measuring the functional and pathological changes in healthy eyes following FLASH or conventional (CONV) dose rate irradiation. <h3>Materials/Methods</h3> An immobilization device was designed to enable focal irradiation to a single mouse eye using a FLASH-capable rotating anode x-ray tube. A 5 mm diameter lead collimator was manufactured to encompass the 3 mm target of the entire eye. Dose and dose rate measurements were performed with calibrated radiographic EBT3 films. Cone-beam CTs were acquired of four C57BL6J mice in immobilization to confirm setup reproducibility, quantified by the mean Hausdorff distance between bone segmentations. Healthy 8-week-old C57BL6J mice were irradiated with 150 kVp x-rays to doses of 21 Gy or 34 Gy at FLASH (right eye) and CONV (left eye) dose rates, respectively. Both eyes were irradiated to limit the influence of varying baseline vision between animals in our analysis. Visual acuity was assessed in 3 mice per dose level using scotopic electroretinography (ERG) up to 2 months post irradiation. Histopathological changes were assessed through H&E staining of harvested eyes. <h3>Results</h3> Mouse setup in our immobilization device was highly reproducible, with a mean Hausdorff distance of 0.34 ± 0.10 mm. Measured dose rates within the field were 67.0 ± 1.9 Gy/s and 1.2 ± 0.1 Gy/s at FLASH and CONV settings, respectively. ERGs revealed that FLASH-irradiated eyes at 21 Gy retained visual function up to 2 months post irradiation, while 21 Gy CONV induced blindness at all sampled time points with more severe surrounding skin effects. At 34 Gy, all eyes were blinded within 1 week, with comparable skin toxicities in the irradiated areas regardless of dose rate. Pathological assessment showed a loss of the photoreceptor layer of the retina from CONV irradiation, which remained intact in FLASH-treated mice. <h3>Conclusion</h3> We have developed a novel platform to study x-ray FLASH effects from ocular irradiation in mice. Functional ERG assay revealed a preservation of visual function from 21 Gy at FLASH dose rates that was not present from 21 Gy CONV. Differential damages between FLASH and CONV irradiations were confirmed through histopathology. This first demonstration of FLASH normal tissue sparing effects in a mouse eye model presents a unique and promising translation opportunity for clinical FLASH treatment. Further studies are ongoing to explore the long-term effects of FLASH radiation on vision and its efficacy on intraocular tumors.

A simple analytical model for a fast 3D assessment of peripheral photon dose during coplanar isocentric photon radiotherapy.

Considering that cancer survival rates have been growing and that nearly two-thirds of those survivors were exposed to clinical radiation during its treatment, the study of long-term radiation effects, especially secondary cancer induction, has become increasingly important. To correctly assess this risk, knowing the dose to out-of-field organs is essential. As it has been reported, commercial treatment planning systems do not accurately calculate the dose far away from the border of the field; analytical dose estimation models may help this purpose. In this work, the development and validation of a new three-dimensional (3D) analytical model to assess the photon peripheral dose during radiotherapy is presented. It needs only two treatment-specific input parameter values, plus information about the linac-specific leakage, when available. It is easy to use and generates 3D whole-body dose distributions and, particularly, the dose to out-of-field organs (as dose–volume histograms) outside the 5% isodose for any isocentric treatment using coplanar beams [including intensity modulated radiotherapy and volumetric modulated arc therapy (VMAT)]. The model was configured with the corresponding Monte Carlo simulation of the peripheral absorbed dose for a 6 MV abdomen treatment on the International Comission on Radiological Protection (ICRP) 110 computational phantom. It was then validated with experimental measurements using thermoluminescent dosimeters in the male ATOM anthropomorphic phantom irradiated with a VMAT treatment for prostate cancer. Additionally, its performance was challenged by applying it to a lung radiotherapy treatment very different from the one used for training. The model agreed well with measurements and simulated dose values. A graphical user interface was developed as a first step to making this work more approachable to a daily clinical application.

Impact of post-Chernobyl radiation on flow cytometry parameters of human sperm.

The aim of this study was to analyse the long-term radiation effects on human sperm. In total, 104 samples of male donors from 2 regions of Ukraine were tested. Group 1 consisted of 32 donors from the Ivano-Frankivsk region, group 2 included 72 volunteers from the Zhytomyr region. The average age of donors in both groups was 35 ± 6 years (range 24-49). To assess the level of apoptosis, membrane mitochondrial potential, concentration of reactive oxygen species, and ploidy of sperm, flow cytometry was performed. The individual equivalent dose of group 1 was < 0.4 mSv and of group 2 ≥ 0.4 mSv. Live spermatozoa with signs of apoptosis were significantly higher (p < 0.05) in group 2 in comparison to group 1 (15.6% and 11.2%, respectively). Spermatozoa without violating integrity were 73.2% in group 1 and approximately 16% higher than the indices of group 2. The percentage of dead necrotic spermatozoa was twice as high in men with a predicted equivalent dose of ≥ 0.4 mSv than in comparison group. A higher percentage of spermatozoa with low mitochondrial membrane potential, di- and tetraploid was found in group 2. An equivalent individual dose of ≥ 0.4 mSv can cause a decrease in mitochondrial potential, an increase in the production of spermatozoa with pathological ploidy, as well as to provoke increasing apoptosis in cells.

Risk of Diabetes Mellitus after Radiotherapy for Gastric Mucosa-Associated Lymphoid Tissue Lymphoma.

Simple SummaryIn patients with gastric mucosa-associated lymphoid tissue lymphoma (GML), irradiation of the pancreas is inevitable owing to its anatomical proximity to the stomach. This is the first study to demonstrate the association between RT exposure and the risk of development of diabetes mellitus (DM) in patients with GML by measuring individual-based dose parameters of the pancreas. The findings of this study demonstrate the association between incidental pancreatic irradiation and DM. Obesity and sex were key risk factors for DM. Considering the risk of DM, the pancreas should no longer be neglected during RT planning, particularly in male patients and patients with obesity.The long-term effect of radiation on the pancreas in pediatric patients has been studied without individual radiation dosimetric data. This study investigated the effect of radiotherapy on the risk of developing diabetes mellitus (DM) in patients with gastric mucosa-associated lymphoid tissue lymphoma (GML), using individual radiation dosimetric analysis. Retrospective analysis reviewed the data of 225 patients without a history of DM receiving curative treatment for stage IE GML. Involved-site radiotherapy was delivered to the whole stomach in 83 patients. The pancreas was delineated in each patient’s computed tomography scan for dosimetric analysis. At a median follow-up of 49.0 months, the 5-year cumulative incidence of DM was 4.5%, 9.6%, and 1.6% in all patients, patients who received radiotherapy, and patients who did not receive radiotherapy, respectively (p = 0.009). Mean pancreatic dose (Dmean; p = 0.009), sex (p = 0.043), and body mass index (BMI; p = 0.008) were independently associated with DM. Using recursive partitioning analysis, patients were classified into low, intermediate, and high-risk groups, with 5-year DM incidence rates of 0.0%, 3.1%, and 15.6%, respectively (p < 0.001). Incidental irradiation of the pancreas can increase the risk of DM, which may be stratified according to patient sex and BMI.

Long-Term Effects of Radiation on Lymphocytes and Risk of Opportunistic Infections.

ObjectivesLymphocytes are very sensitive to ionizing radiation. The long-term effects and the risk of permanent immune compromise are not well defined in spite of more than a century of therapeutic radiation. The contemporary analysis is made more difficult in that most patients also receive immunosuppressive chemotherapy.MethodsCohort-all patients that underwent a prostate biopsy from 2002 to 2007. Those (n=1118) with at least two blood counts, with one at a minimum of 10 years after biopsy, were included. We identified three groups: those that received no treatment (due to benign biopsy findings or active surveillance), those undergoing prostate cancer surgery, and those undergoing radiation therapy. Blood counts were collected and analyzed for differences with a median follow-up of 178 months. Also evaluated was the risk of opportunistic infections.ResultsThe median granulocyte count gradually increased with time, with no difference between the groups. Overall, the median lymphocyte count decreased from baseline over time (with a slight rise at 20 years). For the no treatment and surgery groups, the lymphocyte counts declined, but due to the initial decline after radiation therapy, that group saw a slow improvement. By 20 years, there was no difference between the groups. Most patients’ counts remained in the normal range throughout. The risk of defined opportunistic infections was low (12%) with no difference between the groups.ConclusionPelvic radiation has minimal lasting effects on lymphocyte and granulocyte counts. In addition, patients receiving radiation do not appear to be significantly immunocompromised.

International multi-centre study of potential benefits of ultraviolet radiation protection using contact lenses

PurposeTo examine the effects of long-term ultraviolet radiation (UVR) blocking wearing contact lenses on ocular surface health, eye focus and macular pigment. Method210 pre-presbyopic patients were recruited from Birmingham UK, Brisbane Australia, Hong Kong China, Houston USA and Waterloo Canada (n = 42 at each site). All patients had worn contact lenses for ≥ 5 years, half (test group) of a material incorporating a UVR-blocking filter. Ocular health was assessed using slit-lamp biomicroscopy and UV autofluorescence. Accommodation was measured subjectively with a push-up test and overcoming lens-induced defocus. Objective stimulus response and dynamic measures of the accommodative response were quantified with an open-field aberrometer. Macular pigment optical density (MPOD) was assessed using heterochromatic flicker photometry (MPS II). ResultsThe two groups of participants were matched for age, sex, race, body-mass-index, diet, lifestyle, UVR exposure, refractive error and visual acuity. Limbal (p = 0.035), but not bulbar conjunctival redness (p = 0.903) was lower in eyes that had worn UVR-blocking contact lenses compared to controls. The subjective (8.0 ± 3.7D vs 7.3 ± 3.3D; p = 0.125) and objective (F = 1.255, p = 0.285) accommodative response was higher in the test group, but the differences did not reach significance. However, the accommodative latency was shorter in eyes that had worn UVR-blocking contact lenses (p = 0.003). There was no significant different in MPOD with UVR filtration (p = 0.869). ConclusionsBlocking the transmission of UVR is beneficial in maintaining the eye’s ability to focus, suggesting that presbyopia maybe delayed in long-term UVR-blocking contact lenses wearers. These lenses also provide protection to the critical limbal region.

Evaluation of influencing factors on the radiation dose of hospitalized neonates: Maturity status and type of disease

Context: Premature neonates have multiple medical and surgical problems; therefore, hospitalization and imaging are required. Recently there has been too much concern about the long-term effects of radiation in neonates. In this survey, we assessed the frequency of imaging and radiation dose in neonates hospitalized in neonatal intensive care unit (NICU) in our University-affiliated hospital. Materials and methods: This was a retrospective cross-sectional study conducted during a year (2019–2020) on 291 neonates. The information has been gathered from Health Information System and picture archiving and communication system, and analyzed with SPSS version 22. Results: 291 neonates were included in the study, from which 175 (60%) neonates were preterm and 116 (40%) neonates were term neonates. The mean gestational age (GA) was 35.5 weeks and the mean hospital admission duration was 15.8 days. The mean number of portable and non-portable imaging procedures was 5.13 and 0.62 for preterm and term neonates, respectively. There is a statistically significant relationship between gastrointestinal disease and the number of abdominal X-rays. There is also a statistically significant relationship between acute respiratory distress syndrome (ARDS) and chest X-rays; there is no statistically significant relationship between pneumonia and the number of chest X-rays in the hospital course. The mean accumulation effective doses in preterm and term neonates in-hospital course were 0.549 and 0.498 mSv, respectively. Discussion: The neonates in NICU are more susceptible to radiation hazards due to numerous imaging than other neonates. Portable imaging is eight times more dosing than non-portable imaging, so due to the scattered radiation from portable devices, the actual radiation dose may be higher than what we estimated. No brain CT scan was done for the neonates with convulsion because of using safer and more valuable modalities; so we could recommend radiologists and pediatrics to use substitute modalities like sonography and MRI instead of CT scan and X-rays.

Radiotherapy alters expression of molecular targets in prostate cancer in a fractionation- and time-dependent manner

The efficacy of molecular targeted therapy depends on expression and enzymatic activity of the target molecules. As radiotherapy modulates gene expression and protein phosphorylation dependent on dose and fractionation, we analyzed the long-term effects of irradiation on the post-radiation efficacy of molecular targeted drugs. We irradiated prostate cancer cells either with a single dose (SD) of 10 Gy x-ray or a multifractionated (MF) regimen with 10 fractions of 1 Gy. Whole genome arrays and reverse phase protein microarrays were used to determine gene expression and protein phosphorylation. Additionally, we evaluated radiation-induced pathway activation with the Ingenuity Pathway Analysis software. To measure cell survival and sensitivity to clinically used molecular targeted drugs, we performed colony formation assays. We found increased activation of several pathways regulating important cell functions such as cell migration and cell survival at 24 h after MF irradiation or at 2 months after SD irradiation. Further, cells which survived a SD of 10 Gy showed a long-term upregulation and increased activity of multiple molecular targets including AKT, IGF-1R, VEGFR2, or MET, while HDAC expression was decreased. In line with this, 10 Gy SD cells were more sensitive to target inhibition with Capivasertib or Ipatasertib (AKTi), BMS-754807 (IGF-1Ri), or Foretinib (VEGFR2/METi), but less sensitive to Panobinostat or Vorinostat (HDACi). In summary, understanding the molecular short- and long-term changes after irradiation can aid in optimizing the efficacy of multimodal radiation oncology in combination with post-irradiation molecularly-targeted drug treatment and improving the outcome of prostate cancer patients.

Analysis of the long-term effects of solar radiation on the indoor thermal comfort in office buildings

Windows play a critical role in building energy consumption and thermal comfort. Although many different models have been adopted for developing standards for indoor thermal comfort evaluation, the impact of solar radiation on occupant thermal sensation is still overlooked. In this study, the SMRT-Air temperature deviation method, in which the impact of solar radiation can be assessed based on the deviation of the solar-adjusted mean radiant temperature from air temperature, was developed to help the designer conveniently evaluate the impact of solar radiation on indoor thermal comfort in initial design stage. This method was applied to evaluate the effect of solar radiation on occupants in office buildings under different orientation and climate zones in China. The results show that the effect of solar radiation on thermal comfort is more severe in cold climate zones. Controlling the amount of solar radiation transmitted by windows facing east and west is more critical than for windows oriented in other directions. An appropriate decrease SHGC of windows from the current standard requirements can reduce over 86% discomfort times when SHGC decrease to 0.3 in all climate zones. The outcomes of this study can help designers implement appropriate measures for improving indoor thermal comfort.

Cranial irradiation impairs intrinsic excitability and synaptic plasticity of hippocampal CA1 pyramidal neurons with implications for cognitive function.

Radiation therapy is a standard treatment for head and neck tumors. However, patients often exhibit cognitive impairments following radiation therapy. Previous studies have revealed that hippocampal dysfunction, specifically abnormal hippocampal neurogenesis or neuroinflammation, plays a key role in radiation-induced cognitive impairment. However, the long-term effects of radiation with respect to the electrophysiological adaptation of hippocampal neurons remain poorly characterized. We found that mice exhibited cognitive impairment 3 months after undergoing 10 minutes of cranial irradiation at a dose rate of 3 Gy/min. Furthermore, we observed a remarkable reduction in spike firing and excitatory synaptic input, as well as greatly enhanced inhibitory inputs, in hippocampal CA1 pyramidal neurons. Corresponding to the electrophysiological adaptation, we found reduced expression of synaptic plasticity marker VGLUT1 and increased expression of VGAT. Furthermore, in irradiated mice, long-term potentiation in the hippocampus was weakened and GluR1 expression was inhibited. These findings suggest that radiation can impair intrinsic excitability and synaptic plasticity in hippocampal CA1 pyramidal neurons.

Can operator-controlled imaging reduce fluoroscopy time during flexible ureterorenoscopy?

IntroductionFluoroscopy is routinely used during ureterorenoscopy. According to the ‘As Low As Reasonably Achievable’ (ALARA) principle, radiation exposure should be kept as low as reasonably achievable to decrease the risk of negative long-term effects of radiation for patients and medical staff. This study aims to assess if operator-controlled imaging during flexible ureterorenoscopy for nephrolithiasis could reduce fluoroscopy time when compared to radiographer-controlled imaging.Material and methodsThis study was a bicentric, retrospective comparison between patients treated for nephrolithiasis with flexible ureterorenoscopy with either operator-controlled imaging or radiographer-controlled imaging. A total of 100 patients were included, 50 were treated with operator-controlled imaging and 50 with radiographer-controlled imaging. Patients undergoing flexible ureterorenoscopy with a total stone burden <20 mm and data on radiation exposure were included. Patient characteristics, stone characteristics, surgical details and fluoroscopy time were recorded for each patient and both groups were compared. Patient data were expressed as median. A 2-sided p-value <0.005 was considered statistically significant.ResultsThis study found no significant differences between both groups regarding the patient and stone characteristics. However, it found a significant shorter fluoroscopy time in the operator-controlled imaging group of 33.5 seconds (IQR 16.0–70.0) compared to 57.0 seconds (IQR 36.8–95.3) in the radiographer-controlled imaging group (p = 0.001).ConclusionsThis study shows that operator-controlled imaging in flexible ureterorenoscopy could reduce fluoroscopy time when compared to radiographer-controlled imaging. Operator-controlled imaging might therefore allow urologists to perform ureterorenoscopy with greater independence while additionally reducing fluoroscopy time and its consequent negative effects for medical staff and patients.

REMOTE EFFECTS OF POST-CHORNOBYL IRRADIATION ON THE BIOCHEMICAL CHARACTERISTICS OF MALE SPERMATOZOA

The present research aim was analysis of long-term radiation effects on biochemical characteristics of sperm collected from donors originating from radioactive-polluted territories of Ukraine, namely Zhytomyr oblast, Ivano-Frankivsk oblast, Kyiv oblast and Poltava oblast. Apart from this, the role of radiation component in sperm damaging was assessed. It was found that in the most radiation polluted region - Zhytomyr the sperm samples were characterized by a large proportion of degenerative spermatozoa along with immobile sperms. Early signs of apoptosis development in spermatozoa were shown to progress gradually from Poltava to Zhytomyr. Thus, the apoptotic index for sperm samples was highest in Zhytomyr and lowest in Poltava. Also, raise in accumulated radiation dose was associated with elevation of ROS production in sperm samples. It was shown that the ROS production for Zhytomyr donors was threefold more than for Poltava’s donors and almost twofold more than for donors from Ivano-Frankivsk. Also we found differences in the mitochondrial potential (∆ψ) of spermatozoa too. The total ∆ψ tended to drop down depending on the mean value of radiation accumulated dose, for Kyiv and Zhytomyr the mean values being significantly less than for Poltava. Thus, our investigations have shown that subjects living on radiation polluted territories may generate a great deal of damaged spermatozoa with the hidden molecular and cellular lesions. The latter would predispose inhabitants of radiation polluted regions to male-infertility.

Long-Term Sex- and Genotype-Specific Effects of 56Fe Irradiation on Wild-Type and APPswe/PS1dE9 Transgenic Mice.

Space radiation presents a substantial threat to travel beyond Earth. Relatively low doses of high-energy particle radiation cause physiological and behavioral impairments in rodents and may pose risks to human spaceflight. There is evidence that 56Fe irradiation, a significant component of space radiation, may be more harmful to males than to females and worsen Alzheimer’s disease pathology in genetically vulnerable models. Yet, research on the long-term, sex- and genotype-specific effects of 56Fe irradiation is lacking. Here, we irradiated 4-month-old male and female, wild-type and Alzheimer’s-like APP/PS1 mice with 0, 0.10, or 0.50 Gy of 56Fe ions (1GeV/u). Mice underwent microPET scans before and 7.5 months after irradiation, a battery of behavioral tests at 11 months of age and were sacrificed for pathological and biochemical analyses at 12 months of age. 56Fe irradiation worsened amyloid-beta (Aβ) pathology, gliosis, neuroinflammation and spatial memory, but improved motor coordination, in male transgenic mice and worsened fear memory in wild-type males. Although sham-irradiated female APP/PS1 mice had more cerebral Aβ and gliosis than sham-irradiated male transgenics, female mice of both genotypes were relatively spared from radiation effects 8 months later. These results provide evidence for sex-specific, long-term CNS effects of space radiation.

Heating Effects in the Structure of Non-metamict Allanite-(La) from Palawan, Philippines

Allanite is one of the most common sources of rare-earth elements (REEs) and contains significant amounts of thorium (Th) and uranium (U). The presence of radioactive Th and U nuclides in the mineral exposes it to long-term radiation. Like other natural minerals containing Th and U, allanite can be used as a natural analog to understand the long-term radiation effects in high-level nuclear waste (HLW) matrices. Allanite group mineral is generally found in the amorphous phase due to structural damage induced by self-irradiation. In this work, crystalline allanite-(La) samples collected in San Vicente, Palawan, Philippines – having a low absorbed -dose of ~ 1014 α-decays/ mg – were heated at 450, 650, and 850 °C to study the response of non-metamict allanite to heating at elevated temperatures, particularly at the early stages of exposure to alpha-particle radiation. An increase in structural order was observed upon heating to 450 and 650 °C, which is exhibited by a decrease in the unit cell volume by 1.6% and a decrease of the full width at half maximum (FWHM) of selected Bragg planes. It was evident that certain Bragg planes respond differently to the annealing temperatures with preferential reorientation. After annealing at 850 °C, however, the loss of OH bonds was observed in the infrared (IR) spectra, and the broadening of Bragg peaks was seen in the x-ray diffraction (XRD) patterns, suggesting an onset of structural degradation. Surface cracks are also seen in the scanning electron microscope (SEM) images. The study shows that the non-metamict allanite-(La) mineral structure responds to heating similarly to that of metamict ones reported in the literature. This study will provide data on the properties of allanite as part of the ongoing studies on radiation damage in silicate matrices.

State of Immunological Reactivity of Rat’s Body after Exposure to Different Doses of γ-Radiation in a Long Period and their Offense of the 1st Generation

Abstract&#x0D; BACKGROUND: Recently, the problem of changes in immunological reactivity has become important with the growth of immunodeficiency states of a different nature. [4]. High radiosensitivity of the immune system, its stability in time and the irreversibility of some post-radiation changes can contribute to the development of long-term effects of radiation [2,3,6]. One of the tasks of modern medicine and biology is to study the effect of chronic or fractionated ionizing effects on the body's immune system both in the early and late periods of irradiation and their 1st generation descendants [1,2,3,11,12]. Therefore, it is necessary to study the long-term effects of sublethal and fractionated effects of g-radiation on the immunological reactivity of the organism, nonspecific phagocytic resistance and their 1st generation descendants.&#x0D; AIM: The aim of this study was to study the long-term effects of sublethal and fractionated effects of g-radiation on the immunological reactivity of the organism, nonspecific phagocytic resistance and their 1st generation descendants..&#x0D; METHODS: 7 series of experiments were performed on 105 white outbred sexually mature rats. 1-series intact (n=15), 2nd series - (n = 15) irradiated with a sublethal dose of 6 Gr. (1 month), 3rd series - irradiated with a sublethal dose (3 months, n = 20), 4 - descendants 1 - generations after sublethal dose, 5 series - irradiated with a fractionated dose (1 month), 6 series - irradiated with a fractionated dose (3 months), 7 - descendants of the 1st generation after fractionated -irradiation. Each series used 15 animals. Irradiation of animals 2 - 3 - 4 series was carried out on the Russian radiotherapy device "Agat-RM" -rays 60Co, the dose of sublethal irradiation is 6 Gr. Irradiation of animals of 5-6-7 series was carried out on the Russian radiotherapy device "Agat-RM" with 60Co-rays with topometric and dosimetric preparation of experimental animals, which facilitates the administration of a fractionated dose of 2 Gr. to animals three times within 3 weeks.&#x0D; RESULTS: In the long-term period after fractionated g-irradiation in the T-system of immunity, the following changes occur: against the background of an increase in the total number of lymphocytes, there is a decrease in the pool of CD3 +, CD4 + lymphocytes, immunoregulatory index, normalization of the lymphokine-producing ability of lymphocytes and a decrease in the pool of CD8 + lymphocytes. In the long-term period after fractionated g-irradiation in the humoral link of immunity, an increase in the absolute amount of CD19 + by 3.5 times was noted, which significantly exceeded the indicators of both control and intact animals. The percentage of this pool of cells exceeded the data of intact ones by 1.7 times. In the studied time period, the antibody-producing ability in the spleen increased from 22 ± 1.3 to 45 ± 2.6, without reaching, however, the level of intact animals. At the same time, there was a significant decrease in the suppression index to 13% (P&lt;0.001) and the CIC concentration by 14 times (P&lt;0.001) in the blood serum. The indicators of F/n and NST-test were high by 1.43 and 2.46 times, respectively. So, in the long-term period after exposure to a fractionated dose of g-radiation, the nonspecific phagocytic resistance of the organism is increased.&#x0D; CONCLUSIONS: The tension in the humoral link of immunity is manifested by a decrease in the quantitative and qualitative indicators and an increase in the functional and metabolic activity of neutrophils.&#x0D;