Follow-up studies on genome damage in children after Chernobyl nuclear power plant accident

Effect of adenosine treatment on ionizing radiation toxicity in zebrafish early life stages

The danger of ionizing radiation exposure to human health is a concern. Since its wide use in medicine and industry, the development of radioprotectors has been very significant. Adenosine exerts anti-inflammatory actions and promotes tissue protection and repair, by activating the P1 receptors (A1, A2A, A2B, and A3). Zebrafish (Danio rerio) is an appropriate tool in the fields of toxicology and pharmacology, including the evaluation of radiobiological outcomes and in the search for radioprotector agents. This study aims to evaluate the effect of adenosine in the toxicity induced by radiation in zebrafish. Embryos were treated with 1, 10, or 100 µM adenosine, 30 min before the exposure to 15 Gy of gamma radiation. Adenosine potentiated the effects of radiation in heart rate, body length, and pericardial edema. We evaluated oxidative stress, tissue remodeling and inflammatory. It was seen that 100 µM adenosine reversed the inflammation induced by radiation, and that A2A2 and A2B receptors are involved in these anti-inflammatory effects. Our results indicate that P1R activation could be a promising pharmacological strategy for radioprotection.

Pre-admission ambient air pollution and blood soot particles predict hospitalisation outcomes in COVID-19 patients

BACKGROUND

Air pollution exposure is one of the major risk factors for aggravation of respiratory diseases. We investigated whether exposure to air pollution and accumulated black carbon (BC) particles in blood were associated with coronavirus disease 2019 (COVID-19) disease severity, including the risk for intensive care unit (ICU) admission and duration of hospitalisation.

METHODS

From May 2020 until March 2021, 328 hospitalised COVID-19 patients (29% at intensive care) were recruited from two hospitals in Belgium. Daily exposure levels (from 2016 to 2019) for particulate matter with aerodynamic diameter <2.5 µm and <10 µm (PM2.5 and PM10, respectively), nitrogen dioxide (NO2) and BC were modelled using a high-resolution spatiotemporal model. Blood BC particles (internal exposure to nano-sized particles) were quantified using pulsed laser illumination. Primary clinical parameters and outcomes included duration of hospitalisation and risk of ICU admission.

RESULTS

Independent of potential confounders, an interquartile range (IQR) increase in exposure in the week before admission was associated with increased duration of hospitalisation (PM2.5 +4.13 (95% CI 0.74-7.53) days, PM10 +4.04 (95% CI 1.24-6.83) days and NO2 +4.54 (95% CI 1.53-7.54) days); similar effects were observed for long-term NO2 and BC exposure on hospitalisation duration. These effect sizes for an IQR increase in air pollution on hospitalisation duration were equivalent to the effect of a 10-year increase in age on hospitalisation duration. Furthermore, for an IQR higher blood BC load, the OR for ICU admission was 1.33 (95% CI 1.07-1.65).

CONCLUSIONS

In hospitalised COVID-19 patients, higher pre-admission ambient air pollution and blood BC levels predicted adverse outcomes. Our findings imply that air pollution exposure influences COVID-19 severity and therefore the burden on medical care systems during the COVID-19 pandemic.

Circ-CPSF1 Worsens Radiation-Induced Oxidative Stress Injury in Caenorhabditis elegans

Radioactive substances have been used in various aspects in daily life. However, high-energy radiation could cause environmental problems, which would damage the human body. Circular RNA (CircRNA) has great potential in the minimization of ionizing radiation damage. To find a potential diagnostic and therapeutic target for reducing the damage of ionizing radiation, we selected circRNA cleavage and polyadenylation specificity factor subunit 1 (circ-CPSF1) based on its up-regulated expression after X-ray radiation and explored its effect on response to ionizing radiation using Caenorhabditis elegans (C. elegans). Circ-CPSF1 was screened out and its up-regulated expression was verified. The measurement of lifespan and germ cell apoptosis showed that circ-CPSF1 RNAi treatment extended lifespan and reduced apoptotic germ cells. ROS levels were significantly reduced after the interference of circ-CPSF1 in C. elegans with radiation. Mitochondrial membrane potential assay showed that the suppression of circ-CPSF1 could alleviate mitochondrial damage after radiation. Relative genes expression showed the involvement of circ-CPSF1 in radiation mediated DNA damage response pathways and apoptosis pathways. In conclusion, circ-CPSF1 exerts deleterious effects on lifespan, eggs production and germ cell apoptosis of C. elegans through oxidative stress, the DNA damage response (DDR) pathway, and the core apoptotic pathway after ionizing radiation, indicating the potential of circ-CPSF1 to be an important therapeutic target of radiation damage.

INFLUENCE OF RADIOACTIVE BACKGROUND ON SEXUAL FUNCTION IN MEN FROM DIFFERENT REGIONS OF UKRAINE

OBJECTIVE

The article attempts to analyze the nature of sexual dysfunctions in patients living in areas exposed toionizing radiation as a result of the Chornobyl accident.

MATERIALS AND METHODS

A study of sexual function was carried out in 186 people (group I) living in the territoriesof Kyiv (Polisske, Chornobyl, Ivankiv, Borodianka, Vyshhorod, Makariv districts) and Zhytomyr (Malyn and Korostendistricts) regions. The control group consisted of persons who were born and lived on the territory of Ivano-Frankivsk and Chernivtsi regions (group II, n = 123). Diagnostics was carried out on an outpatient basis in accor-dance with the standards of the WHO and the Ministry of Health of Ukraine.

RESULTS

Analyzing the obtained research results, a significantly larger number of patients with sexual dysfunctionwas identified in group I (82.3 %) than in group II (44.7 %) (р < 0.01). Psychopathological disorders disturbed,respectively, 60.2 % and 41.4 % (p < 0.01). Complaints of decreased libido were presented by 25.8 % of the surveyedmen exposed to ionizing radiation, and 6.5 % of them were concerned about a sharp depression of libido. In groupII patients, this indicator was 14.6 % and 3.3 %, respectively. The integral index of «libido» of the ICEF question-naire revealed a statistically significant difference between the groups (9.23 ± 0.89 and 12.22 ± 1.26, respectively;р < 0.05). In patients exposed to ionizing radiation as a result of the Chornobyl accident, the concentration oftestosterone decreases, and the content of FSH, LH, as well as globulin, which makes sex hormones, increases.Erectile dysfunction in patients of group I was detected in 58.1 % of men, and in patients of group II - 35.0 % (р < 0.01).The difference in the integral indicators of the ICEF questionnaire between the groups was 1.3 times behind the«libido» domain. For other domains - by 1.5-1.6 times. In men living in the territories of Kyiv and Zhytomyr regions,erectile dysfunction occurs earlier and is characterized by a more severe course than in people born and lived in theterritory of Ivano-Frankivsk and Chernivtsi regions. Both in terms of low rates of normal erection (in patients ofgroups I and II, respectively 3.8 % and 13.3 %), and for high percentages of existing moderate/severe ED (respec-tively 71.0 % and 45.5 %), persons from group I are characterized by significantly worse data than persons fromgroup II (р < 0.01). Orgasm pathology was found in 40.3 % of patients in group I and in 25.2 % of patients in groupII (р < 0.01). The quality of life index according to the QoL index in the context of existing sexual disorders in groupI of patients was 4.7 ± 0.4, in patients of group II - 3.9 ± 0.2 (р < 0.05).

CONCLUSIONS

The data obtained indicate a tendency for a more significant violation of sexual functions in men whowere born and lived in territories exposed to radioactive contamination as a result of the Chornobyl accident.

"Living in Contaminated Areas"-Consideration of Different Perspectives

Following large-scale nuclear power plant accidents such as those that occurred at Chernobyl (Ukraine) in 1986 and Fukushima Daiichi (Japan) in 2011, large populations are living in areas containing residual amounts of radioactivity. As a key session of the ConRad conference, experts were invited from different disciplines to provide state-of-the-art information on the topic of "living in contaminated areas." These experts provided their different perspectives on a range of topics including radiation protection principles and dose criteria, environmental measurements and dose estimation, maintaining decent living and working conditions, evidence of health risks, and social impact and risk communication. A short summary of these different perspectives is provided in this paper.

Reproductive Effects of Exposure to Low-Dose Ionizing Radiation: A Long-Term Follow-Up of Immigrant Women Exposed to the Chernobyl Accident

The Chernobyl accident in 1986 spread ionizing radiation over extensive areas of Belarus and Ukraine, leading to adverse health effects in exposed children. More than 30 years later, exposed children have grown and became parents themselves. This retrospective study from Israel was aimed to evaluate whether Chernobyl-exposed women are at higher risk for adverse reproductive outcomes. Exposed immigrants were identified as high or low exposure based on Caesium-137 soil contamination levels registered in the town they lived in. The exposed group was age matched with three comparison groups: non-exposed immigrant women from the Former Soviet Union (FSU) excluding Belarus and the Ukraine, immigrants from other countries (Non FSU) and Israeli-born women at a ratio of 1:10. Chernobyl-exposed women were more likely to be nulliparous and have fewer children (2.1 + 0.8 vs. 3.1 + 1.8, p < 0.001), were more likely to undergo fertility treatments (8.8% vs. 5.8%, adjusted OR = 1.8, 95%CI 1.04-3.2, p = 0.036), and were also more likely to have anemia after delivery (49.4% vs. 36.6%, OR = 1.7, 95%CI 1.2-2.3, p = 0.001), compared to women in the combined comparison groups. The overall fertility of Chernobyl-exposed women seems to be reduced as reflected by the lower number of children and their greater need for fertility treatments.

Retrospective biodosimetry techniques: Focus on cytogenetics assays for individuals exposed to ionizing radiation

In the absence of physical data, biodosimetry tools are required for fast dose and risk assessment in the event of radiological or nuclear mass accidents or attacks to triage exposed humans and take immediate medical countermeasures. Biodosimetry tools have mostly been developed for retrospective dose assessment and the follow-up of victims of irradiation. Among them, cytogenetics analyses, to reveal chromosome damage, are the most developed and allow the determination of doses from blood samples as low as 100 mGy. Various cytogenetic tests have already allowed retrospective dose assessment of Chernobyl liquidators and military personnel exposed to nuclear tests after decades. In this review, we discuss the properties of various biodosimetry techniques, such as their sensitivity and limitations as a function of the time from exposure, using multiple examples of nuclear catastrophes or working exposure. Among them, chromosome FISH hybridization, which reveals chromosome translocations, is the most reliable due to the persistence of translocations for decades, whereas dicentric chromosome and micronuclei assays allow rapid and accurate dose assessment a short time after exposure. Both need to be adjusted through mathematical algorithms for retrospective analyses, accounting for the time since exposure and the victims' age. The goal for the future will be to better model chromosome damage, reduce the time to result, and develop new complementary biodosimetry approaches, such as mutation signatures.

The tubercular badger and the uncertain curve:- The need for a multiple stressor approach in environmental radiation protection

This article presents the results of a workshop held in Stirling, Scotland in June 2018, called to examine critically the effects of low-dose ionising radiation on the ecosphere. The meeting brought together participants from the fields of low- and high-dose radiobiology and those working in radioecology to discuss the effects that low doses of radiation have on non-human biota. In particular, the shape of the low-dose response relationship and the extent to which the effects of low-dose and chronic exposure may be predicted from high dose rate exposures were discussed. It was concluded that high dose effects were not predictive of low dose effects. It followed that the tools presently available were deemed insufficient to reliably predict risk of low dose exposures in ecosystems. The workshop participants agreed on three major recommendations for a path forward. First, as treating radiation as a single or unique stressor was considered insufficient, the development of a multidisciplinary approach is suggested to address key concerns about multiple stressors in the ecosphere. Second, agreed definitions are needed to deal with the multiplicity of factors determining outcome to low dose exposures as a term can have different meanings in different disciplines. Third, appropriate tools need to be developed to deal with the different time, space and organisation level scales. These recommendations permit a more accurate picture of prospective risks.

Ring chromosomes: from formation to clinical potential

Ring chromosomes (RCs) are circular DNA molecules, which occur rarely in eukaryotic nuclear genomes. Lilian Vaughan Morgan first described them in the fruit fly. Human embryos very seldom have RCs, about 1:50,000. Carriers of RCs may have varying degrees of symptoms, from healthy phenotype to serious pathologies in physical and intellectual development. Many authors describe common symptoms of RC presence: short stature and some developmental delay that could be described as a "ring chromosome syndrome." As a rule, RCs arise de novo through the end-joining of two DNA double-strand breaks, telomere-subtelomere junction, or inv dup del rearrangement in both meiosis and mitosis. There are family cases of RC inheritance. The presence of RCs causes numerous secondary chromosome rearrangements in vivo and in vitro. RCs can change their size, become lost, or increase their copy number and cause additional deletions, duplication, and translocations, affecting both RCs and other chromosomes. In this review, we examine RC inheritance, instability, mechanisms of formation, and potential clinical applications of artificially created RCs for large-scale chromosome rearrangement treatment.