Radiation effects on atherosclerosis in atomic bomb survivors: a cross-sectional study using structural equation modeling.

Past reports indicated that total-body irradiation at low to moderate doses could be responsible for cardiovascular disease risks, but the mechanism remains unclear. The purpose of this study was to investigate the association between radiation exposure and atherosclerosis, an underlying pathology of cardiovascular diseases, in the Japanese atomic bomb survivors. We performed a cross-sectional study measuring 14 clinical-physiological atherosclerosis indicators during clinical exams from 2010 to 2014 in 3274 participants of the Adult Health Study cohort. Multivariable analyses were performed by using a structural equation model with latent factors representing underlying atherosclerotic pathologies: (1) arterial stiffness, (2) calcification, and (3) plaque　as measured with indicators chosen a priori on the basis of clinical-physiological knowledge. Radiation was linearly associated with calcification (standardized coefficient per Gy 0.15, 95 % confidence interval: CI [0.070, 0.23]) and plaque (0.11, 95 % CI [0.029, 0.20]), small associations that were comparable to about 2 years of aging per Gy of radiation exposure, but not with arterial stiffness (0.036, 95 % CI [- 0.025, 0.095]). The model fitted better and had narrower confidence intervals than separate ordinary regression models explaining individual indicators independently. The associations were less evident when the dose range was restricted to a maximum of 2 or 1 Gy. By combining individual clinical-physiological indicators that are correlated because of common, underlying atherosclerotic pathologies, we found a small, but significant association of radiation with atherosclerosis.

What lies beneath? Molecular evolution during the radiation of caecilian amphibians.

BACKGROUND: Evolution leaves an imprint in species through genetic change. At the molecular level, evolutionary changes can be explored by studying ratios of nucleotide substitutions. The interplay among molecular evolution, derived phenotypes, and ecological ranges can provide insights into adaptive radiations. Caecilians (order Gymnophiona), probably the least known of the major lineages of vertebrates, are limbless tropical amphibians, with adults of most species burrowing in soils (fossoriality). This enigmatic order of amphibians are very distinct phenotypically from other extant amphibians and likely from the ancestor of Lissamphibia, but little to nothing is known about the molecular changes underpinning their radiation. We hypothesised that colonization of various depths of tropical soils and of freshwater habitats presented new ecological opportunities to caecilians. RESULTS: A total of 8540 candidate groups of orthologous genes from transcriptomic data of five species of caecilian amphibians and the genome of the frog Xenopus tropicalis were analysed in order to investigate the genetic machinery behind caecilian diversification. We found a total of 168 protein-coding genes with signatures of positive selection at different evolutionary times during the radiation of caecilians. The majority of these genes were related to functional elements of the cell membrane and extracellular matrix with expression in several different tissues. The first colonization of the tropical soils was connected to the largest number of protein-coding genes under positive selection in our analysis. From the results of our study, we highlighted molecular changes in genes involved in perception, reduction-oxidation processes, and aging that likely were involved in the adaptation to different soil strata. CONCLUSIONS: The genes inferred to have been under positive selection provide valuable insights into caecilian evolution, potentially underpin adaptations of caecilians to their extreme environments, and contribute to a better understanding of fossorial adaptations and molecular evolution in vertebrates.

Unindicated multiphase CT scans in non-traumatic abdominal emergencies for women of reproductive age: a significant source of unnecessary exposure.

PURPOSE: To determine the frequency of unindicated CT phases and the resultant excess of absorbed radiation doses to the uterus and ovaries in women of reproductive age who have undergone CT for non-traumatic abdomino-pelvic emergencies. MATERIALS AND METHODS: We reviewed all abdomino-pelvic CT examinations in women of reproductive age (40 years or less), between 1 June 2012 and 31 January 2015. We evaluated the appropriateness of each CT phase on the basis of clinical indications, according to ACR appropriateness criteria and evidence-based data from the literature. The doses to uterus and ovaries for each phase were calculated with the CTEXPO software, taking into consideration the size-specific dose estimate (SSDE) after measuring the size of every single patient. RESULTS: The final cohort was composed of 76 female patients with an average age of 30 (from 19 to 40 years). In total, 197 CT phases were performed with an average of 2.6 phases per patient. Out of these, 93 (47%) were unindicated with an average of 1.2 inappropriate phases per patient. Unindicated scans were most frequent for appendicitis and unlocalized abdominal pain. The excesses of mean radiation doses to the uterus and ovaries due to unindicated phases were, respectively, of 38 and 33 mSv per patient. CONCLUSION: In our experience, unindicated additional CT phases were numerous with a significant excess radiation dose without an associated clinical benefit. This excess of radiation could have been avoided by widespread adoption of the ACR appropriateness criteria and evidence-based data from the literature.

Consequences of the radiation accident at the Mayak production association in 1957 (the 'Kyshtym Accident').

This paper presents an overview of the nuclear accident that occurred at the Mayak Production Association (PA) in the Russian Federation on 29 September 1957, often referred to as 'Kyshtym Accident', when 20 MCi (740 PBq) of radionuclides were released by a chemical explosion in a radioactive waste storage tank. 2 MCi (74 PBq) spread beyond the Mayak PA site to form the East Urals Radioactive Trace (EURT). The paper describes the accident and gives brief characteristics of the efficacy of the implemented protective measures that made it possible to considerably reduce doses to the exposed population. The paper also provides retrospective dosimetry estimates for the members of the EURT Cohort (EURTC) which comprises approximately 21 400 people. During the first two years after the accident a decrease in the group average leukocyte (mainly due to neutrophils and lymphocytes) and thrombocyte count was observed in the population. At later dates an increased excess relative risk of solid cancer incidence and mortality was found in the EURTC.

Level of perception of technical terms regarding the effect of radiation on the human body by residents of Japan.

BACKGROUND: This study aimed to examine the level of perception of the technical terms related to the effect of radiation on the human body among residents of the six prefectures of Miyagi, Fukushima, Tokyo, Aichi, Hiroshima, and Nagasaki in Japan. Miyagi and Fukushima were selected as devastated area by Great East Japan Earthquake. Tokyo and Aichi were selected as control. Hiroshima and Nagasaki were selected as the A-bombed area. METHODS: A total of 1030 respondents, 172, 173, 171, 173, 171, and 170, respectively, were surveyed. Differences in the recognition level of technical terms related to the effect of radiation on the human body among residents of the six prefectures were assessed. RESULTS: The highest recognition levels were reported by the respondents from Fukushima (17 items). Those from Miyagi scored the second highest recognition levels (10 out of the 17 terms); the second highest recognition levels for the remaining seven terms were marked by the respondents of Tokyo. Respondents in the Tohoku region had a better recognition for the technical terminology relevant to the effect of radiation on the human body. CONCLUSIONS: Our findings indicate a need for continued, comprehensive risk communication pertaining to health hazards of radiation exposure in Tohoku region. Concerted efforts by central/local governments and other stakeholders are required to allay the anxiety/stress related to radiation exposure among the residents.

Colony-stimulating factor 1 receptor blockade prevents fractionated whole-brain irradiation-induced memory deficits.

BACKGROUND: Primary central nervous system (CNS) neoplasms and brain metastases are routinely treated with whole-brain radiation. Long-term survival occurs in many patients, but their quality of life is severely affected by the development of cognitive deficits, and there is no treatment to prevent these adverse effects. Neuroinflammation, associated with activation of brain-resident microglia and infiltrating monocytes, plays a pivotal role in loss of neurological function and has been shown to be associated with acute and long-term effects of brain irradiation. Colony-stimulating factor 1 receptor (CSF-1R) signaling is essential for the survival and differentiation of microglia and monocytes. Here, we tested the effects of CSF-1R blockade by PLX5622 on cognitive function in mice treated with three fractions of 3.3 Gy whole-brain irradiation. METHODS: Young adult C57BL/6J mice were given three fractions of 3.3 Gy whole-brain irradiation while they were on diet supplemented with PLX5622, and the effects on periphery monocyte accumulation, microglia numbers, and neuronal functions were assessed. RESULTS: The mice developed hippocampal-dependent cognitive deficits at 1 and 3 months after they received fractionated whole-brain irradiation. The impaired cognitive function correlated with increased number of periphery monocyte accumulation in the CNS and decreased dendritic spine density in hippocampal granule neurons. PLX5622 treatment caused temporary reduction of microglia numbers, inhibited monocyte accumulation in the brain, and prevented radiation-induced cognitive deficits. CONCLUSIONS: Blockade of CSF-1R by PLX5622 prevents fractionated whole-brain irradiation-induced memory deficits. Therapeutic targeting of CSF-1R may provide a new avenue for protection from radiation-induced memory deficits.

[Influence of Detector Radiation Damage on CR Mammography Quality Control].

Recently, radiation damage to the detector apparatus employed in computed radiography (CR) mammography has become problematic. The CR system and the imaging plate (IP) applied to quality control (QC) program were also used in clinical mammography in our hospital, and the IP to which radiation damage has occurred was used for approximately 5 years (approximately 13,000 exposures). We considered using previously acquired QC image data, which is stored in a server, to investigate the influence of radiation damage to an IP. The mammography unit employed in this study was a phase contrast mammography (PCM) Mermaid (KONICA MINOLTA) system. The QC image was made newly, and it was output in the film, and thereafter the optical density of the step-phantom image was measured. An input (digital value)-output (optical density) conversion curve was plotted using the obtained data. The digital values were then converted to optical density values using a reference optical density vs. digital value curve. When a high radiation dose was applied directly, radiation damage occurred at a position on the IP where no object was present. Daily QC for mammography is conducted using an American College of Radiology (ACR) accreditation phantom and acrylic disc, and an environmental background density measurement is performed as one of the management indexes. In this study, the radiation damage sustained by the acrylic disc was shown to differ from that of the background. Thus, it was revealed that QC results are influenced by radiation damage.

Structural study of the X-ray-induced enzymatic reaction of octahaem cytochrome C nitrite reductase.

Octahaem cytochrome c nitrite reductase from the bacterium Thioalkalivibrio nitratireducens catalyzes the reduction of nitrite to ammonium and of sulfite to sulfide. The reducing properties of X-ray radiation and the high quality of the enzyme crystals allow study of the catalytic reaction of cytochrome c nitrite reductase directly in a crystal of the enzyme, with the reaction being induced by X-rays. Series of diffraction data sets with increasing absorbed dose were collected from crystals of the free form of the enzyme and its complexes with nitrite and sulfite. The corresponding structures revealed gradual changes associated with the reduction of the catalytic haems by X-rays. In the case of the nitrite complex the conversion of the nitrite ions bound in the active sites to NO species was observed, which is the beginning of the catalytic reaction. For the free form, an increase in the distance between the oxygen ligand bound to the catalytic haem and the iron ion of the haem took place. In the case of the sulfite complex no enzymatic reaction was detected, but there were changes in the arrangement of the active-site water molecules that were presumably associated with a change in the protonation state of the sulfite ions.

Astroglial U87 Cells Protect Neuronal SH-SY5Y Cells from Indirect Effect of Radiation by Reducing DNA Damage and Inhibiting Fas Mediated Apoptotic Pathway in Coculture System.

Recent studies provide the evidence that indirect effects of radiation could lead to neuronal cells death but underlying mechanism is not completely understood. On the other hand astroglial cells are known to protect neuronal cells against stress conditions in vivo and invitro. Yet, the fate of neuronal cells and the neuroprotective effect of coculture system (with glial cells) in response to indirect radiation exposure remain rarely discussed. Here, we purpose that the indirect effect of radiation may induce DNA damage by cell cycle arrest and receptor mediated apoptotic cascade which lead to apoptotic death of neuronal SH-SY5Y cells. We also hypothesized that coculture (with glial U87) may relieved the neuronal SH-SY5Y cells from toxicity of indirect effects radiation by reducing DNA damage and expression of apoptotic proteins in vitro. In the present study irradiated cell conditioned medium (ICCM) was used as source of indirect effect of radiation. Neuronal SH-SY5Y cells were exposed to ICCM with and without coculture with (glial U87) in transwell coculture system respectively. Various endpoints such as, cell survival number assay, Annexin V/PI assay, cell cycle analysis by flow cytometer, mRNA level of Fas receptor by q RT-PCR, expression of key apoptotic proteins by western blot and estimation of neurotrophic factors by ELISA method were analyzed into neuronal SH-SY5Y cells with and without co culture after ICCM exposure respectively. We found that ICCM induced DNA damage in neuronal SH-SY5Y cells by significant increase in cell cycle arrest at S-phase (***P < 0.001) which was further supported by over expression of P53 protein (**P < 0.01). While coculture (with glial U87), significantly reduced the ICCM induced cell cycle arrest and expression of P53 ((###) P < 0.001) neuronal SH-SY5Y cells. Further investigation of the underlying apoptotic mechanism revealed that in coculture system; ICCM induced elevated level of FAS mRNA level was significantly reduced ((###) P < 0.001) in neuronal SH-SY5Y cells which was followed by significant reduction in expression of key apoptotic protein i.e., FADD ((###) P < 0.001), caspase-8 ((###) P < 0.001), and cleaved caspase-3 ((###) P < 0.001) as compare to neuronal SH-SY5Y cells which received ICCM without coculture. Intriguingly, concentration of neurotrophic factors such as, GDNF and BDNF were significantly increased ((###) P < 0.001) in neuronal SH-SY5Y after coculture (with glial U87) cells. Hence, these findings infer that the receptor mediated pathway could be the one way through which indirect effects of radiation cause neurotoxicity. However, in co-cultures system (with glial U87) neuronal SH-SY5Y depicts remarkable resistance against ICCM induced neurotoxicity.

Comparative outcomes for three-dimensional conformal versus intensity-modulated radiation therapy for esophageal cancer.

Emerging data suggests a benefit for using intensity modulated radiation therapy (IMRT) for the management of esophageal cancer. We retrospectively reviewed patients treated at our institution who received definitive or preoperative chemoradiation with either IMRT or 3D conformal radiation therapy (3DCRT) between October 2000 and January 2012. Kaplan Meier analysis and the Cox proportional hazard model were used to evaluate survival outcomes. We evaluated a total of 232 patients (138 IMRT, 94 3DCRT) who received a median dose of 50.4 Gy (range, 44-64.8) to gross disease. Median follow up for all patients, IMRT patients alone, and 3DCRT patients alone was 18.5 (range, 2.5-124.2), 16.5 (range, 3-59), and 25.9 months (range, 2.5-124.2), respectively. We observed no significant difference based on radiation technique (3DCRT vs. IMRT) with respect to median overall survival (OS) (median 29 vs. 32 months; P = 0.74) or median relapse free survival (median 20 vs. 25 months; P = 0.66). On multivariable analysis (MVA), surgical resection resulted in improved OS (HR 0.444; P < 0.0001). Superior OS was also associated on MVA with stage I/II disease (HR 0.523; P = 0.010) and tumor length ≤5 cm (HR 0.567; P = 0.006). IMRT was also associated on univariate analysis with a significant decrease in acute weight loss (mean 6% + 4.3% vs 9% + 7.4%, P = 0.012) and on MVA with a decrease in objective grade ≥3 toxicity, defined as any hospitalization, feeding tube, or >20% weight loss (OR 0.51; P = 0.050). Our data suggest that while IMRT-based chemoradiation for esophageal cancer does not impact survival there was significantly less toxicity. In the IMRT group there was significant decrease in weight loss and grade ≥3 toxicity compared to 3DCRT.

X-ray magnetic resonance fusion modality may reduce radiation exposure and contrast dose in diagnostic cardiac catheterization of congenital heart disease.

BACKGROUND: Radiation exposure in the pediatric population may increase the risk of future malignancy. Children with congenital heart disease who often undergo repeated catheterizations are at risk. One possible strategy to reduce radiation is to use X-ray Magnetic Resonance Fusion (XMRF) to facilitate cardiac catheterization. METHODS: Catheterization data of patients who underwent diagnostic XMRF procedures between January 1, 2009 and February 1, 2012 were reviewed. Cases were matched 1:1 to contemporary controls who did not undergo XMRF based on weight and diagnosis and were compared in radiation exposure, contrast dose, and procedural and anesthesia times. RESULTS: Forty-four matched pairs were included. Baseline demographics were similar in both groups. Patients in the XMRF group had lower indices of radiation exposure measured by fluoroscopy time (14 vs. 16.4 vs. P = 0.047), dose-area product from fluoroscopy (513.2 vs. 589.1 µGy·m(2) , P = 0.042), total dose-area product (625.8 vs. 995.2 µGy·m(2) , P = 0.027), and total air kerma dose (94.5 vs. 153.8 mGy, P = 0.017). There was also a significant reduction in contrast dose (2 vs. 3.3 cc/kg, P <0.001). Procedural time tended to be shorter in the XMRF group but anesthesia time was significantly longer. CONCLUSION: Select diagnostic cardiac catheterization cases that utilized XMRF used less radiation and contrast than similar cases where XMRF was not used. Future work is needed to determine whether similar benefits can be extended to other types of diagnostic and complex interventional procedures.

Radioactive impact of the Fukushima nuclear accident on Shenyang in the northeast of China.

Environmental monitoring was carried out in Shenyang in the northeast of China after the Fukushima Daiichi nuclear accident which was caused by the earthquake and tsunami on 11 March 2011. The fission product radionuclide (131)I was detected as present in the atmosphere on the 20th day after the nuclear accident, while the radionuclides (134)Cs and (137)Cs were found in the atmosphere on the 27th day after the accident. The radionuclides (131)I, (134)Cs and (137)Cs continued to be present in the atmosphere for 25, 4 and 6 days, respectively, with maximum concentrations of 4.60 ± 0.2, 0.29 ± 0.06 and 0.42 ± 0.08 mBq m(-3). The contents of fission radionuclides in vegetables, drinking water and milk from Shenyang were below the detection limits. The atmosphere was slightly contaminated in Shenyang due to the Fukushima nuclear accident, but no contamination was detected in vegetables, milk and drinking water.

Negative Aspects of Self-Imposed Evacuation among Mothers of Small Children Following Japan's Fukushima Daiichi Nuclear Power Station Accident.

This study clarified the negative aspects of the self-imposed evacuation of mothers of small children seeking to avoid radiation exposure from the Fukushima Daiichi Nuclear Power Station accident on 11 March 2011. We conducted semi-structured interviews with 27 mothers, employing open-ended inquiries based on an interview guide. Our analysis of their responses using the Ka-Wakita-Jiro (KJ) method categorized the results into eight distinct groups comprising 142 labels. These categories included continued anxiety about the health effects of radiation, differences in risk perception, changes in spousal relationships, the inability to make friends and find support, living as a single parent, financial concerns, the unfamiliar feel of the area to which they evacuated, and uncertainty about the future. Despite their hardships, the mothers continued their self-imposed evacuation to avoid radioactivity. Our findings underscore that their anxieties about radiation exposure persisted even after self-imposed evacuation, leading to deteriorated relationships with key individuals who would have been involved in raising their children. These results offer valuable insights into the challenges experienced by the indirect victims of the nuclear accident, such as the mothers of small children.

Harnessing genomics to identify environmental determinants of heritable disease.

Next-generation sequencing technologies can now be used to directly measure heritable de novo DNA sequence mutations in humans. However, these techniques have not been used to examine environmental factors that induce such mutations and their associated diseases. To address this issue, a working group on environmentally induced germline mutation analysis (ENIGMA) met in October 2011 to propose the necessary foundational studies, which include sequencing of parent-offspring trios from highly exposed human populations, and controlled dose-response experiments in animals. These studies will establish background levels of variability in germline mutation rates and identify environmental agents that influence these rates and heritable disease. Guidance for the types of exposures to examine come from rodent studies that have identified agents such as cancer chemotherapeutic drugs, ionizing radiation, cigarette smoke, and air pollution as germ-cell mutagens. Research is urgently needed to establish the health consequences of parental exposures on subsequent generations.

Combining near- and far-field exposure for an organ-specific and whole-body RF-EMF proxy for epidemiological research: a reference case.

A framework for the combination of near-field (NF) and far-field (FF) radio frequency electromagnetic exposure sources to the average organ and whole-body specific absorption rates (SARs) is presented. As a reference case, values based on numerically derived SARs for whole-body and individual organs and tissues are combined with realistic exposure data, which have been collected using personal exposure meters during the Swiss Qualifex study. The framework presented can be applied to any study region where exposure data is collected by appropriate measurement equipment. Based on results derived from the data for the region of Basel, Switzerland, the relative importance of NF and FF sources to the personal exposure is examined for three different study groups. The results show that a 24-h whole-body averaged exposure of a typical mobile phone user is dominated by the use of his or her own mobile phone when a Global System for Mobile Communications (GSM) 900 or GSM 1800 phone is used. If only Universal Mobile Telecommunications System (UMTS) phones are used, the user would experience a lower exposure level on average caused by the lower average output power of UMTS phones. Data presented clearly indicate the necessity of collecting band-selective exposure data in epidemiological studies related to electromagnetic fields.

[The use of immunological characteristics of the peripheral blood for the purpose of forensic medical expertise of the subjects exposed to ionizing radiation].

The objective of the present study was the comprehensive evaluation of quantitative and functional metabolic characteristics of human leukocytes following in vitro irradiation of peripheral blood samples at a dose of 0.25, 0.50, 1.0, and 4.0 Gy for the development of a rationale for their application as biological markers of radiation exposure in forensic medical expertise of the subjects affected by supernormal ionizing radiation. The total number of leukocytes, lymphocytes, and their subpopulations as well as the functional and metabolic status of neutrophils were determined. The results of the study indicate the possibility of using a set of functional metabolic characteristics of human leukocytes as the additional forensic medical criteria for diagnostics of radiation impact on living subjects.

[Research on radiation hygiene problems].

The author presents brief historical reference on research in radiation hygiene problems, initiated by scientists in Central Institute for Occupational hygiene and Preventive hygiene (now--Federal State Budgetary Institution "Research Institute of Occupational Health" with Russian Academy of Medical Sciences).

Development of nomogram and discussion of radiotherapy effect for osteosarcoma survival.

This study aimed to develop a predictive system for prognostic evaluation of osteosarcoma patients. We obtained osteosarcoma sample data from 1998 to 2016 using SEER*Stat software version 8.3.8, and established a multivariable Cox regression model using R-4.0.3 software. Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The diagnosis of the model was completed through influential cases, proportionality, and multicollinearity. The predictive ability of the model was tested using area under the curve (AUC), calibration curves, and Brier scores. Finally, the bootstrap method was used to internally verify the model. In total, data from 3566 patients with osteosarcoma were included in this study. The multivariate Cox regression model was used to determine the independent prognostic variables. A nomogram and Kaplan-Meier survival curve were established. The AUC and Brier scores indicated that the model had a good predictive calibration. In addition, we found that the radiotherapy appears to be a risk factor of patients with osteosarcoma and made a discussion. We developed a prognostic evaluation system for patients with osteosarcoma for 1-, 3-, and 5-year overall survival with good predictive ability using sample data extracted from the SEER database. This has important clinical significance for the early identification and treatment of high-risk groups of osteosarcoma patients.

Monitoring synchrotron X-ray-induced radiolysis effects on metal (Fe, W) ions in high-temperature aqueous fluids.

Radiolysis-induced effects on aqueous tungsten ions are observed to form a precipitate within seconds upon exposure to a synchrotron X-ray micro-beam in a WO(3) + H(2)O system at 873 K and 200 MPa. In situ Fe K-edge energy-dispersive X-ray absorption spectroscopy (ED-XAS) measurements were made on Fe(II)Cl(2) aqueous solutions to 773 K in order to study the kinetics of high-temperature reactions of Fe(2+) and Fe(3+) ions with transient radiolysis species. The radiolytic reactions in a fluid sample within a hydrothermal diamond anvil cell result in oxidation of the Fe(2+) ion at 573 K and reduction of Fe(3+) at temperatures between 673 and 773 K and of the Fe(2+) ion at 773 K. The edge-energy drift evident in the ED-XAS data directly reflects the kinetics of reactions resulting in oxidation and/or reduction of the Fe(2+) and Fe(3+) ions in the aqueous solutions at high temperatures. The oxidation and reduction trends are found to be highly consistent, making reliable determinations of reaction kinetics possible.