Abstract 853: Investigation of the cumulative number of chromosome aberrations induced by three consecutive CT scans

Purpose The relationship between radiation exposure by CT and the risk of leukemia and brain tumor has been reported in children, in which the risk of leukemia was tripled at a radiation dose of 60 mGy to bone marrow (Pearce MS, Lancet 2012). Therefore, there is a possibility that CT scans induce chromosome aberrations (CAs) causing malignant tumors. When chromosomes are cleaved by radiation, dicentric chromosomes (Dics) and chromosome translocations (Trs) are formed in the same ratio. We have reported that breakage of chromosomes was induced after a single CT scan in adults by Dic assay (DCA) (Scientific Rep 2015). On the other hand, the number of Trs formed also increased after a single CT scan, but, no significant change of the numbers was observed before and after the CT scan (J Rad Res 2016). We then investigated whether cumulative CAs would be observed when an annual CT scan was performed for 3 years.

Methods Peripheral blood samples were collected from 5 patients (4 males and 1 female; age range 51-73 years; mean age, 64 years) 3 times before and after a CT scan at annual examinations. They included 4 patients with malignant lymphoma who had not been treated for more than 3 years after the end of treatment and 1 patient followed due to an abnormal lung shadow without treatment. We performed analysis of Dic and Tr formation by centromere-FISH and painting-FISH using isolated lymphocytes, respectively, and counted the number of CAs equivalent to 2,000 metaphases per sample. The effective radiation dose of a CT scan was calculated by computational dosimetry system (WAZA-ARI).

Results Regardless of CT scans, the number of Trs formed was higher than that of Dics in all patients. The dose of radiation exposure in one CT scan was 22.0 to 73.5 mSv (mean, 42.3 mSv). Both DCA and Tr analyses showed an increase in Dic and Tr formation after all CT scans, except that their number decreased in one patient after the second CT scan. However, the increase in these CAs decreased after about one year, and no cumulative increase in the number of Dics and Trs formed due to three consecutive CT scans was observed.

Conclusion A single CT scan tended to produce both Dic and Tr formation, but there was no cumulative increase in CAs after three consecutive CT scans. The reason that the number of Trs formed was basically higher than that of Dics is considered to be related to such factors as age, smoking status, and past medical radiation exposure especially in adults because Tr is a stable chromosome.

Citation Format: Yu Abe, Hideyoshi Noji, Misaki Sugai, Yumiko Kurosu, Takashi Ohba, Aki Yanagi, Yukari Yanai, Naohiro Tsuyama, Tetsuo Ishikawa, Tomisato Miura, Kenji Kamiya, Mitsuaki A. Yoshida, Akira Sakai. Investigation of the cumulative number of chromosome aberrations induced by three consecutive CT scans [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 853.

Prognostic usefulness of arm circumference and nutritional screening tools in older patients with cardiovascular disease

BACKGROUND AND AIM

Arm circumference (AC) and nutritional screening tools have been shown to have prognostic capability in patients with cardiovascular disease (CVD). This study aimed to compare the prognostic predictive capabilities of AC and nutritional screening tools in older patients with CVD.

METHODS AND RESULTS

The study population consisted of 949 admitted patients ≥60 years old with CVD. Patients underwent AC measurement and nutritional screening before hospital discharge. We used the controlling nutritional status index (CONUT), the geriatric nutritional risk index (GNRI), and the prognostic nutritional index (PNI) as nutritional screening tools. The end point of the study was all-cause mortality. The mean age of the study population was 72.3 ± 7.2 years, and 68.2% of the patients were male. A total of 130 deaths occurred over a median follow-up period of 2.2 years (interquartile range, 1.1-3.8 years). After adjusting for other prognostic factors, AC (hazard ratio [HR]: 0.59; p < 0.001), CONUT (HR: 0.82; p = 0.016), GNRI (HR: 0.77; p = 0.040), and PNI (HR: 0.80; p = 0.014) were significant predictors of mortality. However, adding AC to the multivariate-adjusted model (0.739 vs. 0.714, respectively; p = 0.037), but not CONUT, GNRI, or PNI (0.724, 0.717, and 0.723 vs. 0.714; p = 0.072, p = 0.306, and p = 0.127, respectively), significantly increased the area under the curve on receiver operating characteristic curve.

CONCLUSIONS

AC, but not nutritional screening tools, plays a complementary role to preexisting prognostic factors for predicting prognosis in older patients with CVD.

Associations of disaster-related and psychosocial factors with changes in smoking status after a disaster: a cross-sectional survey after the Great East Japan Earthquake

OBJECTIVE

Few studies have comprehensively examined changes in smoking status and related factors after a disaster. We examined these factors among residents of an evacuation area in Fukushima after the Great East Japan Earthquake.

METHODS

The study participants included 58 755 men and women aged ≥20 years who participated in the Fukushima Health Management Survey in 2012 after the disaster. Smoking status was classified as either current smokers or current non-smokers before and after the disaster. The participants were divided into the following groups: (1) non-smokers both before and after the disaster, (2) non-smokers before and smokers after the disaster, (3) smokers before and non-smokers after the disaster and (4) smokers both before and after the disaster. The adjusted prevalence ratios and 95% CIs of changes in smoking status for demographic, disaster-related and psychosocial factors were tested using logistic regression analysis that was stratified by smoking status before the disaster.

RESULTS

Among the 44 729 participants, who were non-smokers before the disaster, 634 (1.4%) began smoking after the disaster. Among the 14 025 smokers before the disaster, 1564 (11.1%) quit smoking after the disaster, and the proportion of smokers in the evacuation area consequently decreased from 21.2% to 19.6%. In the multivariable model, factors significantly associated with beginning smoking included being a male, being younger, having a lower education, staying in a rental house/apartment, house being damaged, having experienced a tsunami, change jobs and the presence of traumatic symptoms and non-specific psychological distress. On the contrary, factors associated with quitting smoking included being a female, being older, having a higher education and having a stable income.

CONCLUSION

The proportion of smokers slightly decreased among residents in the evacuation area. The changes in smoking statuses were associated with disaster-associated psychosocial factors, particularly changes in living conditions, having experienced a tsunami, change jobs and developing post-traumatic stress disorder.

The Vitamin D3 analogue calcipotriol suppresses CpG-activated TLR9-MyD88 signalling in murine plasmacytoid dendritic cells

BACKGROUND

Plasmacytoid dendritic cells (pDCs) are involved in the pathogenesis of psoriasis by secreting interferon-α. Vitamin D3 analogues are widely used to treat psoriasis, and the representative analogue calcipotriol (CAL) uniquely downregulates the cytokine production and chemotactic activity of pDCs. However, the molecular mechanism of action of CAL is not well understood.

AIM

To investigate effects of CAL on the Toll-like receptor 9-myeloid differentiation primary response gene 88 (TLR9-MyD88) signalling pathway, which induces cytokine production, in murine pDCs.

METHODS

pDCs were isolated from mouse spleen cells by negative selection or were generated from mouse bone-marrow cells, and were stimulated with CpG-oligodeoxynucleotide (ODN) with or without CAL for 24 h. mRNA expression of TLR9 and MyD88 was assessed by real-time PCR, and the amount of TLR9 was measured by western blotting.

RESULTS

CAL suppressed the CpG-ODN-induced increased expression of MyD88 and TLR9 in pDCs.

CONCLUSIONS

CAL may downregulate pDCs by inhibiting TLR9-MyD88 signalling.

Quantification of Turbulent Driving Forces for the Geodesic Acoustic Mode in the JFT-2M Tokamak

We investigate spatial structures of turbulence and turbulent transport modulated by the geodesic acoustic mode (GAM), from which the excitation mechanism of the GAM is discussed. The GAM is found to be predominantly excited through a localized Reynolds stress force, rather than the dynamic shearing force. The evaluated growth rate is larger than the linear damping coefficients and is on the same order of magnitude as the effective growth rate evaluated from time evolution in the GAM kinetic energy.

Dose-response curves for analyzing of dicentric chromosomes and chromosome translocations following doses of 1000 mGy or less, based on irradiated peripheral blood samples from five healthy individuals

In terms of biological dosimetry at the time of radiation exposure, the dicentric chromosome (Dic) assay (DCA) is the gold standard for assessing for the acute phase and chromosome translocation (Tr) analysis is the gold standard for assessing the chronic phase. It is desirable to have individual dose-response curves (DRCs) for each laboratory because the analysis criteria differ between laboratories. We constructed the DRCs for radiation dose estimation (with three methods) using peripheral blood (PB) samples from five healthy individuals. Aliquots were irradiated with one of eight gamma-ray doses (0, 10, 20, 50, 100, 200, 500 or 1000 mGy), then cultured for 48 h. The number of chromosome aberrations (CAs) was analyzed by DCA, using Giemsa staining and centromere-fluorescence in situ hybridization (centromere-FISH) and by chromosome painting (chromosome pairs 1, 2 and 4) for Tr analysis. In DCA, there was large variation between individuals in the frequency of Dics formed, and the slopes of the DRCs were different. In Tr analysis, although variation was observed in the frequency of Tr, the slopes of the DRCs were similar after adjusting the background for age. Good correlation between the irradiation dose and the frequency of CAs formed was observed with these three DRCs. However, performing three different biological dosimetry assays simultaneously on PB from five donors nonetheless results in variation in the frequency of CAs formed, especially at doses of 50 mGy or less, highlighting the difficulty of biological dosimetry using these methods. We conclude that it might be difficult to construct universal DRCs.

Comparative Analysis of the Growth Pattern of Thyroid Cancer in Young Patients Screened by Ultrasonography in Japan After a Nuclear Accident: The Fukushima Health Management Survey

IMPORTANCE

Thyroid cancer generally grows at a very slow rate in adults, and overdiagnosis is a global issue. However, the detection of early-stage thyroid cancer by screening is not well described in young patients. To prevent overdiagnosis, it is essential to understand the natural course of thyroid cancer growth detection by ultrasonography screening in young patients.

OBJECTIVE

To evaluate the natural progression of thyroid cancer in young patients.

DESIGN, SETTING, AND PARTICIPANTS

An observational study evaluated changes in the diameter of malignant or suspected malignant thyroid tumors on 2 occasions. Changes in malignant thyroid tumor diameter were estimated during the observation period between the screening and confirmatory examinations in the first-round thyroid ultrasonography examination of the Fukushima Health Management Survey in patients younger than 21 years after a nuclear accident at a power plant in Fukushima, Japan. In total, 116 patients cytologically diagnosed with or suspected to have thyroid cancer were classified into 3 groups based on a greater than 10% reduction, a change of -10% to +10% in diameter, and a greater than 10% increase in tumor diameter. The association between tumor growth rate and tumor diameter was analyzed. The study was conducted from March 1, 2016, to August 6, 2017.

MAIN OUTCOMES AND MEASURES

Tumor volume changes, the coefficient of growth of thyroid cancer in young patients, and the association between the observation period or tumor diameter and them.

RESULTS

Of 116 patients, 77 were female; the mean age was 16.9 years (median, 17.5 years). The mean observation period was 0.488 (range, 0.077-1.632) years. No significant differences in age, sex, tumor diameter, observation period, or serum levels of thyrotropin and thyroglobulin were observed among the groups. Whereas tumor volume changes were not linearly correlated with the observation period (Pearson R = 0.121; 95% CI, -0.062 to 0.297), the coefficient of growth was significantly and negatively correlated with the tumor diameter in the screening examination (Spearman ρ = -0.183; 95% CI, -0.354 to -0.001), suggesting growth arrest after the initial proliferation phase.

CONCLUSIONS AND RELEVANCE

Ultrasonography screening could reveal asymptomatic thyroid cancer that is falling into a growth arrest pattern in many young patients. Considering the long life expectancy, prevention of overdiagnosis necessitates careful long-term monitoring without immediate diagnosis for suspected noninvasive thyroid cancer.

Simulation of expected childhood and adolescent thyroid cancer cases in Japan using a cancer-progression model based on the National Cancer Registry: Application to the first-round thyroid examination of the Fukushima Health Management Survey

During the 4 years following the nuclear power plant accident of 2011, 39 males and 77 females were diagnosed with or suspected of having cancer based on the first-round thyroid examination of the Fukushima Health Management Survey (FHMS) targeting residents aged <19 years in Fukushima. Prior comparisons between the observed data and Japan's National Cancer Registry (NCR) data suggested that this incidence might be excessive, but such comparisons are problematic because they need not only to adjust index unit (prevalence proportion vs incidence rate), but also examine characteristics (complete enumeration mass screening for the aged 0 to 18 years vs detections in clinical settings for all the residents) and sensitivity of the examinations. The purpose of this study is to build a common model applicable to any region in Japan under nonaccident conditions, and estimate the expected prevalence based on the numbers of subjects surveyed in the FHMS using a simulation of the sensitivity.The cancer-progression model is an extension of Day and Walter's, the parameters of which were estimated by minimizing the weighted root mean squared error between the average age-specific thyroid incident rates from 2001 to 2010 in the NCR and those determined by the model. We estimated expected detectable prevalent cases by the model with their examination-participation proportions and simulated several sensitivities.Median sojourn times were 34 years (males) and 30 years (females) by the model. Simulation results showed that the numbers of observed prevalent cases were within the 95% confidence intervals of the expected prevalent cases with several sensitivities in each gender.We successfully built a cancer-progression model of thyroid cancer based on Japan's NCR data under no accident conditions. It is a tool for comparing the observed prevalence data of examinations and the NCR data, which resolved 3 issues of index unit, the characteristics and sensitivity of the examinations. Simulation results imply that the number of observed thyroid cancer cases can be detected by the FHMS first-round thyroid screening at several sensitivities under no accident conditions.

ATM-mediated mitochondrial damage response triggered by nuclear DNA damage in normal human lung fibroblasts

Ionizing radiation (IR) elevates mitochondrial oxidative phosphorylation (OXPHOS) in response to the energy requirement for DNA damage responses. Reactive oxygen species (ROS) released during mitochondrial OXPHOS may cause oxidative damage to mitochondria in irradiated cells. In this paper, we investigated the association between nuclear DNA damage and mitochondrial damage following IR in normal human lung fibroblasts. In contrast to low-doses of acute single radiation, continuous exposure of chronic radiation or long-term exposure of fractionated radiation (FR) induced persistent Rad51 and γ-H2AX foci at least 24 hours after IR in irradiated cells. Additionally, long-term FR increased mitochondrial ROS accompanied with enhanced mitochondrial membrane potential (ΔΨm) and mitochondrial complex IV (cytochrome c oxidase) activity. Mitochondrial ROS released from the respiratory chain complex I caused oxidative damage to mitochondria. Inhibition of ATM kinase or ATM loss eliminated nuclear DNA damage recognition and mitochondrial radiation responses. Consequently, nuclear DNA damage activates ATM which in turn increases ROS level and subsequently induces mitochondrial damage in irradiated cells. In conclusion, we demonstrated that ATM is essential in the mitochondrial radiation responses in irradiated cells. We further demonstrated that ATM is involved in signal transduction from nucleus to the mitochondria in response to IR.

Turbulent transport reduction induced by transition on radial electric field shear and curvature through amplitude and cross-phase in torus plasma

Spatiotemporal evolutions of radial electric field and turbulence are measured simultaneously in the H-mode transition, which is a prototypical example of turbulence structure formation in high-temperature plasmas. In the dynamical phase where transport barrier is established abruptly, the time-space-frequency-resolved turbulent particle flux is obtained. Here we report the validation of the mechanism of transport barrier formation quantitatively. It is found that the particle flux is suppressed predominantly by reducing density fluctuation amplitude and cross phase between density fluctuation and potential fluctuation. Both radial electric field shear and curvature are responsible for the amplitude suppression as was predicted by theory. Turbulence amplitude reduction immediately responds to the growth of the radial electric field non-uniformity and saturates, while cross phase continuously approaches zero.

Representativeness of individual external doses estimated for one quarter of residents in the Fukushima Prefecture after the nuclear disaster: the Fukushima Health Management Survey

After the Fukushima Dai-ichi Nuclear Power Plant accident, the Fukushima Health Management Survey (FHMS) was launched. The Basic Survey, a component of FHMS, is a questionnaire used to survey residents across the Fukushima Prefecture about their behaviour in the first 4 months after the accident. The questionnaire findings are used to determine individual external doses by linking behaviour data to a computer programme with daily gamma ray dose rate maps, drawn after the accident. Through 30 June 2015, the response rate was only 27.2% (558 550 population), indicating that the findings might not be generalisable because of poor representativeness of the population. The objective of this study was to clarify if the data from the FHMS Basic Survey were representative of the entire population, by conducting a new survey to compare the external doses between non-respondents and respondents in the previous survey. A total of 5350 subjects were randomly selected from 7 local regions of Fukushima Prefecture. An interview survey was conducted with the non-respondents to the FHMS Basic Survey. A total of 990 responses were obtained from the previous non-responders by interview survey. For the regions Kempoku, Kenchu, Kennan, Aizu, Minami-Aizu, Soso, and Iwaki, differences in mean effective dose (95% confidence interval) in mSv between the non-responders and previous responders were 0.12 (0.01-0.23), -0.09 (-0.21-0.03), -0.06 (-0.18-0.07), 0.05 (-0.04-0.14), 0.01 (-0.01-0.02), 0.09 (0.01-0.17), 0.09 (0.00-0.17), respectively. The differences fall neither within the interval (-∞, -0.25) nor within the interval (0.25, ∞). These findings imply that mean effective doses between the previous and new respondents were not different, with a significantly indifferent region of 0.25 mSv according to equivalence tests. The present study indicates that the dose distribution obtained from about one-quarter of Fukushima residents represents the dose distribution for the entire Fukushima Prefecture.

A Chemical Modulator of p53 Transactivation that Acts as a Radioprotective Agonist

Inhibiting p53-dependent apoptosis by inhibitors of p53 is an effective strategy for preventing radiation-induced damage in hematopoietic lineages, while p53 and p21 also play radioprotective roles in the gastrointestinal epithelium. We previously identified some zinc(II) chelators, including 8-quinolinol derivatives, that suppress apoptosis in attempts to discover compounds that target the zinc-binding site in p53. We found that 5-chloro-8-quinolinol (5CHQ) has a unique p53-modulating activity that shifts its transactivation from proapoptotic to protective responses, including enhancing p21 induction and suppressing PUMA induction. This p53-modulating activity also influenced p53 and p53-target gene expression in unirradiated cells without inducing DNA damage. The specificity of 5CHQ for p53 and p21 was demonstrated by silencing the expression of each protein. These effects seem to be attributable to the sequence-specific alteration of p53 DNA-binding, as evaluated by chromatin immunoprecipitation and electrophoretic mobility shift assays. In addition, 5-chloro-8-methoxyquinoline itself had no antiapoptotic activity, indicating that the hydroxyl group at the 8-position is required for its antiapoptotic activity. We applied this remarkable agonistic activity to protecting the hematopoietic and gastrointestinal system in mouse irradiation models. The dose reduction factors of 5CHQ in total-body and abdominally irradiated mice were about 1.2 and 1.3, respectively. 5CHQ effectively protected mouse epithelial stem cells from a lethal dose of abdominal irradiation. Furthermore, the specificity of 5CHQ for p53 in reducing the lethality induced by abdominal irradiation was revealed in Trp53-KO mice. These results indicate that the pharmacologic upregulation of radioprotective p53 target genes is an effective strategy for addressing the gastrointestinal syndrome. Mol Cancer Ther; 17(2); 432-42. ©2017 AACRSee all articles in this MCT Focus section, "Developmental Therapeutics in Radiation Oncology."

Overexpression of Rev1 promotes the development of carcinogen-induced intestinal adenomas via accumulation of point mutation and suppression of apoptosis proportionally to the Rev1 expression level

Cancer development often involves mutagenic replication of damaged DNA by the error-prone translesion synthesis (TLS) pathway. Aberrant activation of this pathway plays a role in tumorigenesis by promoting genetic mutations. Rev1 controls the function of the TLS pathway, and Rev1 expression levels are associated with DNA damage induced cytotoxicity and mutagenicity. However, it remains unclear whether deregulated Rev1 expression triggers or promotes tumorigenesis in vivo. In this study, we generated a novel Rev1-overexpressing transgenic (Tg) mouse and characterized its susceptibility to tumorigenesis. Using a small intestinal tumor model induced by N-methyl-N-nitrosourea (MNU), we found that transgenic expression of Rev1 accelerated intestinal adenoma development in proportion to the Rev1 expression level; however, overexpression of Rev1 alone did not cause spontaneous development of intestinal adenomas. In Rev1 Tg mice, MNU-induced mutagenesis was elevated, whereas apoptosis was suppressed. The effects of hREV1 expression levels on the cytotoxicity and mutagenicity of MNU were confirmed in the human cancer cell line HT1080. These data indicate that dysregulation of cellular Rev1 levels leads to the accumulation of mutations and suppression of cell death, which accelerates the tumorigenic activities of DNA-damaging agents.

Effects of socioeconomic factors on cardiovascular-related symptoms among residents in Fukushima after the Great East Japan Earthquake: a cross-sectional study using data from the Fukushima Health Management Survey

OBJECTIVE

To investigate the association between socioeconomic factors and the exacerbation of cardiovascular symptoms among evacuees after the Great East Japan Earthquake.

METHODS

A sample of 73 433 individuals was included in the Fukushima Health Management Survey. Self-report questionnaires were used to determine the influence of socioeconomic factors including living arrangements, loss of employment and decreased income on the exacerbation of headache, dizziness, palpitations and shortness of breath. Odds ratios (ORs) and 95% CIs of the effect of socioeconomic factors were estimated for each symptom using multiple logistic regression analyses.

RESULTS

Exacerbation of headaches was reported by 1893 individuals, dizziness by 1229, palpitations by 1085 and shortness of breath by 626 individuals. Evacuation accommodation was associated with all of these symptoms. Compared with participants living in their own home (OR=1.00), individuals living in relatives' homes had increased probability of experiencing exacerbation of headache (1.58; 95% CI 1.19 to 2.09) and dizziness (1.42; 95% CI 1.02 to 1.98); those living in rental housing or apartments experienced exacerbation of headache (1.54; 95% CI 1.32 to 1.80), dizziness (1.45; 95% CI 1.20 to 1.75), palpitations (1.25; 95% CI 1.03 to 1.51) and shortness of breath (1.76; 95% CI 1.35 to 2.28); participants living in evacuation shelters experienced exacerbation of headache (1.80; 95% CI 1.09 to 2.96); and refugees living in temporary housing also experienced exacerbation of headache (1.42; 95% CI 1.15 to 1.72), dizziness (1.40; 95% CI 1.09 to 1.79) and shortness of breath (1.49; 95% CI 1.07 to 2.08). Compared with the evacuees who retained their jobs, unemployed individuals showed increased probability of exacerbation of headache (1.28, 95% CI 1.12 to 1.46), dizziness (1.26, 95% CI 1.07 to 1.48) and palpitations (1.21, 95% CI 1.01 to 1.45). Decreased income was associated with exacerbation of headache (1.39, 95% CI 1.22 to 1.60).

CONCLUSION

After the earthquake, living in non-home conditions was more likely to result in exacerbated cardiovascular symptoms among evacuees. Loss of employment was another risk factor related to exacerbated headache and dizziness.

Establishment of induced pluripotent stem cells from normal B cells and inducing AID expression in their differentiation into hematopoietic progenitor cells

B cell derived induced pluripotent stem cells (BiPSCs) were recently established from peripheral blood B cells by the simultaneous transfection of Yamanaka factors (Oct3/4, Sox2, Klf4, c-Myc) and C/EBPα using a Sendai virus vector. Here, using a different method, we established BiPSCs with immunoglobulin heavy chain (IgH) gene rearrangement from normal B cells purified from lymph nodes. The critical points of our method are pre-stimulation of B cells with IL-21 and CD40-ligand (CD40L), followed by consecutive transfection of highly concentrated Yamanaka factors using a retroviral vector. Following each transfection the cells were centrifuged onto a retronectin coated plate and the activated by IL-4, IL-2, and CD40L. Furthermore, we established BiPSCs (BiPSC-A) in which activation-induced cytidine deaminase (AID) could be induced using the doxycycline-controlled. Both the parental BiPSC and BiPSC-A showed the capability of differentiating into hematopoietic progenitor cells (HPCs) based on confirmation of CD34 expression and colony-formation from CD34-positive cells. The findings that BiPSC-A can differentiate into HPCs suggest that there is a possibility that induction of AID expression would result in chromosomal translocations in the process of differentiation from BiPSCs, and therefore that these BiPSCs could be useful in elucidating the tumor origin of abnormal B cells in myelomagenesis.

Metabolomic screening using ESI-FT MS identifies potential radiation-responsive molecules in mouse urine

The demand for establishment of high-throughput biodosimetric methods is increasing. Our aim in this study was to identify low-molecular-weight urinary radiation-responsive molecules using electrospray ionization Fourier transform mass spectrometry (ESI-FT MS), and our final goal was to develop a sensitive biodosimetry technique that can be applied in the early triage of a radiation emergency medical system. We identified nine metabolites by statistical comparison of mouse urine before and 8 h after irradiation. Time-course analysis showed that, of these metabolites, thymidine and either thymine or imidazoleacetic acid were significantly increased dose-dependently 8 h after radiation exposure; these molecules have already been reported as potential radiation biomarkers. Phenyl glucuronide was significantly decreased 8 h after radiation exposure, irrespective of the dose. Histamine and 1-methylhistamine were newly identified by MS/MS and showed significant, dose-dependent increases 72 h after irradiation. Quantification of 1-methylhistamine by enzyme-linked immunosorbent assay (ELISA) analysis also showed a significant increase 72 h after 4 Gy irradiation. These results suggest that urinary metabolomics screening using ESI-FT MS can be a powerful tool for identifying promising radiation-responsive molecules, and that urinary 1-methylhistamine is a potential radiation-responsive molecule for acute, high-dose exposure.

The Relationship Between Functional Independence and Psychological Distress in Elderly Adults Following the Fukushima Daiichi Nuclear Power Plant Accident

This study aimed to explore the relationship between psychological distress and degree of functional independence among elderly adults following the Great East Japan Earthquake. Participants were 20 282 adults aged 65 and older who lived in the Great East Japan Earthquake evacuation zone specified by the government on March 31, 2011. This study is a part of a detailed survey on mental health and lifestyle, the Fukushima Health Management Survey, which was conducted in 2012. Psychological distress was assessed using the Kessler 6 scale. Functional independence in different daily activities was assessed by asking participants whether they could independently perform activities: eating, dressing, toileting, and shopping. According to the multiple logistic regression analysis, psychological distress was significantly associated with independence in all models: without adjustment (Model 1), adjusting for demographic characteristics (Model 2), and adjusting for demographic characteristics and disaster-related factors (Model 3), with an adjusted odds ratio of 2.32 (95% confidence interval = 1.97-2.73). High psychological distress was associated with low functional independence, after controlling for demographic characteristics and disaster-related factors. Thus, using psychological distress as the dependent variable, we examined the relationship between low functional independence and psychological distress among elderly adults who were evacuated.

Academic Responses to Fukushima Disaster

Since radiation accidents, particularly nuclear disasters, are rarer than other types of disasters, a comprehensive radiation disaster medical curriculum for them is currently unavailable. The Fukushima compound disaster has urged the establishment of a new medical curriculum in preparation for any future complex disaster. The medical education will aim to aid decision making on various health risks for workers, vulnerable people, and residents addressing each phase in the disaster. Herein, we introduce 3 novel educational programs that have been initiated to provide students, professionals, and leaders with the knowledge of and skills to elude the social consequences of complex nuclear disasters. The first program concentrates on radiation disaster medicine for medical students at the Fukushima Medical University, together with a science, technology, and society module comprising various topics, such as public risk communication, psychosocial consequences of radiation anxiety, and decision making for radiation disaster. The second program is a Phoenix Leader PhD degree at the Hiroshima University, which aims to develop future leaders who can address the associated scientific, environmental, and social issues. The third program is a Joint Graduate School of Master’s degree in the Division of Disaster and Radiation Medical Sciences at the Nagasaki University and Fukushima Medical University.

Influence of Post-disaster Evacuation on Incidence of Metabolic Syndrome

AIM

After the Great East Japan Earthquake, over 160,000 residents near the Fukushima Daiichi Nuclear Power Plant were forced to evacuate due to a nuclear accident. Health problems in these evacuees have since become major issues. We examined the association between evacuation and incidence of metabolic syndrome (METS) among residents in Fukushima.

METHODS

We conducted a cohort study among residents aged 40-74 years without METS at the time of the disaster in Fukushima. Among 20,269 residents who met the inclusion criteria before the disaster, 8,547 residents (3,697 men and 4,850 women; follow-up proportion: 42.2%) remained available for follow-up examinations after the disaster by the end of March 2013. The main outcome was incidence of METS, defined by guidelines from the Japanese committee, using data from the Comprehensive Health Check before and after the disaster. We divided participants by evacuation status and compared outcomes between groups. Using a logistic regression model, we estimated the odds ratio for incidence of METS, adjusting for potential confounders, age, gender, waist circumference, exercise habit, and alcohol consumption.

RESULTS

Incidence of METS was higher in evacuees (men 19.2%, women 6.6%) than in non-evacuees (men 11.0%, women 4.6%). Evacuees had higher body mass index, waist circumference, triglycerides, and fasting plasma glucose after the disaster than non-evacuees. We found a significant association between evacuation and incidence of METS (adjusted odds ratio 1.72, 95% confidence interval; 1.46-2.02).

CONCLUSION

This is the first study to demonstrate that evacuation after a disaster is associated with increased incidence of METS.

Effect of evacuation on liver function after the Fukushima Daiichi Nuclear Power Plant accident: The Fukushima Health Management Survey

Background

The Great East Japan Earthquake and subsequent Fukushima Daiichi Nuclear Power Plant accident caused residents to switch from their normal lives to lives focused on evacuation. We evaluated liver function before and after this disaster to elucidate the effects of evacuation on liver function.

Methods

This study was a longitudinal survey of 26,006 Japanese men and women living near the Fukushima Daiichi Nuclear Power Plant. This study was undertaken using data from annual health checkups conducted for persons aged 40–90 years between 2008 and 2010. Follow-up examinations were conducted from June 2011 to the end of March 2013, with a mean follow up of 1.6 years. Changes in liver function before and after the disaster were compared among evacuees and non-evacuees. We also assessed groups according to alcohol drinking status.

Results

The prevalence of liver dysfunction significantly increased in all participants from 16.4% before to 19.2% after the disaster. The incidence of liver dysfunction was significantly higher in evacuees than in non-evacuees. Multivariate logistic regression analysis showed that evacuation was significantly associated with liver dysfunction among residents.

Conclusions

This is the first study to show that evacuation due to the Fukushima Daiichi nuclear power plant disaster was associated with an increase in liver dysfunction.

•

Prevalence of liver dysfunction increased after the Great East Japan Earthquake.

•

The change in prevalence of liver dysfunction was greatest in evacuees.

•

Evacuation is one risk factor associated with liver dysfunction.

A comparison of radiation-induced mitochondrial damage between neural progenitor stem cells and differentiated cells

Mitochondria play a key role in maintaining cellular homeostasis during stress responses, and mitochondrial dysfunction contributes to carcinogenesis, aging, and neurologic disease. We here investigated ionizing radiation (IR)-induced mitochondrial damage in human neural progenitor stem cells (NSCs), their differentiated counterparts and human normal fibroblasts. Long-term fractionated radiation (FR) with low doses of X-rays for 31 d enhanced mitochondrial activity as evident by elevated mitochondrial membrane potential (ΔΨm) and mitochondrial complex IV (cytochrome c oxidase) activity to fill the energy demands for the chronic DNA damage response in differentiated cells. Subsequent reduction of the antioxidant glutathione via continuous activation of mitochondrial oxidative phosphorylation caused oxidative stress and genomic instability in differentiated cells exposed to long-term FR. In contrast, long-term FR had no effect on the mitochondrial activity in NSCs. This cell type showed efficient DNA repair, no mitochondrial damage, and resistance to long-term FR. After high doses of acute single radiation (SR) (> 5 Gy), cell cycle arrest at the G2 phase was observed in NSCs and human fibroblasts. Under this condition, increase in mitochondria mass, mitochondrial DNA, and intracellular reactive oxygen species (ROS) levels were observed in the absence of enhanced mitochondrial activity. Consequently, cellular senescence was induced by high doses of SR in differentiated cells. In conclusion, we demonstrated that mitochondrial radiation responses differ according to the extent of DNA damage, duration of radiation exposure, and cell differentiation.

Mitochondrial reactive oxygen species perturb AKT/cyclin D1 cell cycle signaling via oxidative inactivation of PP2A in lowdose irradiated human fibroblasts

Here we investigated the cellular response of normal human fibroblasts to repeated exposure to low-dose radiation. In contrast to acute single radiation, low-dose fractionated radiation (FR) with 0.01 Gy/fraction or 0.05 Gy/fraction for 31 days increased in mitochondrial mass, decreased cellular levels of the antioxidant glutathione and caused persistent accumulation of mitochondrial reactive oxygen species (ROS). Excess ROS promoted oxidative inactivation of protein phosphatase PP2A which in turn led to disruption of normal negative feed-back control of AKT/cyclin D1 signaling in cells treated with long-term FR. The resulting abnormal nuclear accumulation of cyclin D1 causes growth retardation, cellular senescence and genome instability in low-dose irradiated cells. Thus, loss of redox control and subsequently elevated levels of ROS perturb signal transduction as a result of oxidative stress. Our study highlights a specific role of mitochondrial ROS in perturbation of AKT/cyclin D1 cell cycle signaling after low-dose long-term FR. The antioxidants N-acetyl-L-cysteine, TEMPO and mitochondrial-targeted antioxidant Mito-TEMPO provided protection against the harmful cell cycle perturbations induced by low-dose long-term FR.

Evacuation after the Great East Japan Earthquake was associated with poor dietary intake: The Fukushima Health Management Survey

Background

Few studies have investigated the relationship between living arrangements and dietary intake among evacuees after disasters.

Objectives

To examine the relationship between living arrangements and dietary intake using the data of a large-scale cohort survey of evacuees after the Great East Japan Earthquake in 2011.

Methods

73,433 residents in evacuation zones responded to the Fukushima Health Management Survey questionnaire. Subjects were excluded if they did not report their living conditions or were missing more than three pieces of information about dietary intake. The data of 52,314 subjects (23,149 men and 29,165 women ≥15 years old) were used for the analyses. Evacuees' living arrangements were characterized into three categories: evacuation shelters or temporary housing, rental houses or apartments, or a relative's home or their own home. Dietary intake was characterized in terms of grains, fruits and vegetables, meat, soybean products, dairy products, and fish. Daily consumption of the third quartile (Q3) or higher for each food group was defined as ‘high consumption’. Prevalence ratios (PRs) and 95% confidence intervals (CIs) were estimated using modified Poisson regression analyses.

Results

Modified Poisson regression analyses showed that, compared with respondents living in a relative's home or their own home, the PRs and 95% CIs for the people living in rental apartments of high consumption of fruits and vegetables (non-juice), meat, soybean products, and dairy products were 0.69 (95% CI, 0.61–0.77), 0.82 (95% CI, 0.73–0.91), 0.89 (95% CI, 0.83–0.94), and 0.83 (95% CI, 0.74–0.93) respectively. The corresponding PRs and 95% CIs for people living in evacuation shelters or temporary housing were 0.83 (95% CI, 0.78–0.88), 0.90 (95% CI, 0.86–0.95), 0.94 (95% CI, 0.91–0.97), and 0.91 (95% CI, 0.86–0.96) for high consumption of fruits and vegetables (non-juice), meat, soybean products, and dairy products, respectively.

Conclusion

The present study suggests that, after the earthquake, living in non-home conditions was associated with poor dietary intake of fruits and vegetables (non-juice), meat, soybean products, and dairy products, suggesting the need for early improvements in the provision of balanced meals among evacuees living in non-home conditions.

EXTERNAL AND INTERNAL EXPOSURE TO FUKUSHIMA RESIDENTS

The Great East Japan Earthquake of 11 March 2011, caused the Fukushima Daiichi Nuclear Power Plant Accident, which resulted in the release of a large amount of radioactive materials into the environment, and there is a serious concern about the radiation effects on the health of residents living in the affected areas. The evaluation of exposure dose is fundamental for the estimation of health effects, and whenever possible, the exposure dose should be evaluated by actual measurements as opposed to estimations. Here, the outline of the exposure doses of residents estimated from surveys or obtained by measurements is described. Fukushima Health Management Survey reported the results for 460 408 residents during the first 4 months after the accident; 66.3% received doses <1 mSv, 94.9% received <2 mSv, 99.7% received <5 mSv and the maximum dose was 25 mSv. Thus, it was demonstrated that the results from personal dosemeter measurements were comparable to the estimations. The dose assessment of internal exposure of 184 205 residents conducted by Fukushima Prefecture by using whole body counter showed that 99.986% received <1 mSv, with the maximum dose being 3 mSv. Regarding exposure of the thyroid, there is not enough data for the Fukushima accident, but it is presumed that thyroid doses are much lower than those from Chernobyl. The outline of exposure doses of residents in result of the accident is still being clarified, questions and uncertainties in dose assessment remain and further efforts for more accurate dosimetry are required continuously.

Evacuation and Risk of Hypertension After the Great East Japan Earthquake

On March 11, 2011, the Great East Japan Earthquake occurred in Japan, with a nuclear accident subsequently occurring at the Fukushima Daiichi Nuclear Power Plant. The disaster forced many evacuees to change particular aspects of their lifestyles. This study assessed the hypothesis that evacuation may have increased the risk of hypertension among residents in Fukushima. A longitudinal study examined data collected from 31 252 Japanese participants aged 40 to 74 years sourced from general health checkups conducted in 13 communities between 2008 and 2010. Follow-up examinations were conducted from 2011 through 2013. A total of 21 989 participants (follow-up proportion, 70.4%) received follow-up examinations. Mean blood pressure significantly increased in both evacuees and nonevacuees after the disaster, with greater changes in blood pressure among the former. The changes in systolic and diastolic blood pressure among the evacuees and nonevacuees were +5.8/3.4 versus +4.6/2.1 mm Hg ( P <0.01/ P <0.0001) for men and +4.4/2.8 versus +4.1/1.7 mm Hg ( P =0.33/ P <0.0001) for women, respectively. Evacuation was associated with an increased risk of hypertension among men, and the age-adjusted hazard ratios of evacuation for incidence of hypertension were 1.24 (95% confidence interval, 1.11–1.39; P <0.001) for men and 1.05 (95% confidence interval, 0.94–1.17; P =0.37) for women, respectively. For men, after adjustment for confounding variables, the hazard ratio slightly decreased to 1.20, but the association was essentially unchanged. Blood pressure increased among residents, especially evacuees, in the evacuation zone of Fukushima prefecture after the Great East Japan Earthquake. Evacuation may be associated with an increased risk of hypertension among men in the 2 years after the disaster.

Experimental Identification of Electric Field Excitation Mechanisms in a Structural Transition of Tokamak Plasmas

Self-regulation between structure and turbulence, which is a fundamental process in the complex system, has been widely regarded as one of the central issues in modern physics. A typical example of that in magnetically confined plasmas is the Low confinement mode to High confinement mode (L-H) transition, which is intensely studied for more than thirty years since it provides a confinement improvement necessary for the realization of the fusion reactor. An essential issue in the L-H transition physics is the mechanism of the abrupt "radial" electric field generation in toroidal plasmas. To date, several models for the L-H transition have been proposed but the systematic experimental validation is still challenging. Here we report the systematic and quantitative model validations of the radial electric field excitation mechanism for the first time, using a data set of the turbulence and the radial electric field having a high spatiotemporal resolution. Examining time derivative of Poisson's equation, the sum of the loss-cone loss current and the neoclassical bulk viscosity current is found to behave as the experimentally observed radial current that excites the radial electric field within a few factors of magnitude.

Experimental validation of non-uniformity effect of the radial electric field on the edge transport barrier formation in JT-60U H-mode plasmas

The turbulent structure formation, where strongly-inhomogeneous turbulence and global electromagnetic fields are self-organized, is a fundamental mechanism that governs the evolution of high-temperature plasmas in the universe and laboratory (e.g., the generation of edge transport barrier (ETB) of the H-mode in the toroidal plasmas). The roles of inhomogeneities of radial electric field (E_r) are known inevitable. In this mechanism, whether the first derivative of E_r (shear) or the second derivative of E_r (curvature) works most is decisive in determining the class of nontrivial solutions (which describe the barrier structure). Here we report the experimental identification of the essential role of the E_r-curvature on the ETB formation, for the first time, based on the high-spatiotemporal resolution spectroscopic measurement. We found the decisive importance of E_r-curvature on ETB formation during ELM-free phase, but there is only a low correlation with the E_r-shear value at the peak of normalized ion temperature gradient. Furthermore, in the ELMing phase, the effect of curvature is also quantified in terms of the relationship between pedestal width and thickness of the layer of inhomogeneous E_r. This is the fundamental basis to understand the structure of transport barriers in fusion plasmas.

The impact of deformation of an aneurysm model under pulsatile flow on hemodynamic analysis

Hemodynamic analysis of cerebral aneurysms has been widely carried out to clarify the mechanisms of their growth and rupture. In several cases, patient-specific aneurysm models made of transparent polymers have been used. Even though periodic changes in aneurysms due to the pulsation of blood flow could be important, the deformation of the model geometry and its effect on hemodynamic evaluation has not been fully investigated. In addition, the fabrication accuracy of aneurysm models has not been evaluated even though it may affect the hemodynamic parameters to be analyzed. In this study, the fabrication accuracy of a silicone aneurysm model was investigated. Additionally, the deformation of the model under pulsatile flow as well as its correlation with flow behavior was evaluated. Consequently, a fabrication method for an aneurysm model with high accuracy was established and the importance of the wall thickness of the model was also specified.

Analysis of chromosome translocation frequency after a single CT scan in adults

We recently reported an increase in dicentric chromosome (DIC) formation after a single computed tomography (CT) scan (5.78-60.27 mSv: mean 24.24 mSv) and we recommended analysis of 2000 metaphase cells stained with Giemsa and centromere-FISH for dicentric chromosome assay (DCA) in cases of low-dose radiation exposure. In the present study, we analyzed the frequency of chromosome translocations using stored Carnoy's-fixed lymphocyte specimens from the previous study; these specimens were from 12 patients who were subject to chromosome painting of Chromosomes 1, 2 and 4. Chromosomes 1, 2 and 4 were analyzed in ∼5000 cells, which is equivalent to the whole-genome analysis of almost 2000 cells. The frequency of chromosome translocation was higher than the number of DICs formed, both before and after CT scanning. The frequency of chromosome translocations tended to be higher, but not significantly higher, in patients with a treatment history compared with patients without such a history. However, in contrast to the results for DIC formation, the frequency of translocations detected before and after the CT scan did not differ significantly. Therefore, analysis of chromosome translocation may not be a suitable assay for detecting chromosome aberrations in cases of low-dose radiation exposure from a CT scan. A significant increase in the frequency of chromosome translocations was not likely to be detected due to the high baseline before the CT scan; the high and variable frequency of translocations was probably due to multiple confounding factors in adults.

An influential factor for external radiation dose estimation for residents after the Fukushima Daiichi Nuclear Power Plant accident-time spent outdoors for residents in Iitate Village

Many studies have been conducted on radiation doses to residents after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Time spent outdoors is an influential factor for external dose estimation. Since little information was available on actual time spent outdoors for residents, different values of average time spent outdoors per day have been used in dose estimation studies on the FDNPP accident. The most conservative value of 24 h was sometimes used, while 2.4 h was adopted for indoor workers in the UNSCEAR 2013 report. Fukushima Medical University has been estimating individual external doses received by residents as a part of the Fukushima Health Management Survey by collecting information on the records of moves and activities (the Basic Survey) after the accident from each resident. In the present study, these records were analyzed to estimate an average time spent outdoors per day. As an example, in Iitate Village, its arithmetic mean was 2.08 h (95% CI: 1.64-2.51) for a total of 170 persons selected from respondents to the Basic Survey. This is a much smaller value than commonly assumed. When 2.08 h is used for the external dose estimation, the dose is about 25% (23-26% when using the above 95% CI) less compared with the dose estimated for the commonly used value of 8 h.

Comprehensive Survey Results of Childhood Thyroid Ultrasound Examinations in Fukushima in the First Four Years After the Fukushima Daiichi Nuclear Power Plant Accident

BACKGROUND

Thyroid nodules and cancers are rare in children compared with adults. However, after the 1986 Chernobyl Nuclear Power Plant accident, a rapid increase in childhood thyroid cancer was observed. To avoid any confusion and misunderstanding of data obtained in Fukushima after the 2011 nuclear accident, baseline prevalence of thyroid nodules and cancers should be carefully assessed with standardized criteria systematically, and comprehensively applied to the population perceived to be at risk.

AIMS

Under the official framework of the Fukushima Health Management Survey, the thyroids of children in Fukushima were examined using ultrasound, and the results collected in the first four years after the nuclear accident were analyzed in order to establish a baseline prevalence of childhood thyroid abnormalities, especially cancer.

SUBJECTS AND METHODS

Of 367,685 people aged 18 years or younger as of April 1, 2011, who were living in Fukushima Prefecture at the time of the accident, 300,476 underwent thyroid ultrasound screening. Of those, 2108 subjects with thyroid nodules were further examined using an advanced ultrasound instrument, with standardized criteria applied to determine the need for fine-needle aspiration cytology (FNAC). FNAC results determined the need for surgery and histological confirmation of the cytological diagnosis.

RESULTS

Of the 2108 rescreened subjects, 543 underwent FNAC, of whom 113 were diagnosed with malignancy or suspected malignancy. Subsequently, 99 patients underwent surgical resection, revealing 95 cases of papillary thyroid cancer, three poorly differentiated cancers, and one benign nodule. The overall prevalence of childhood thyroid cancer in Fukushima was determined to be 37.3 per 100,000 with no significant differences between evacuated and non-evacuated areas. Thyroid cancer patients had external exposure estimates of <2.2 mSv during the first four months.

CONCLUSIONS

The high prevalence of childhood thyroid cancer detected in this four-year study in Fukushima can be attributed to mass screening. It clearly exceeds what is found incidentally anywhere else. Direct comparisons with any other results, even those from cancer registries, are not meaningful because of differences in methodology.

Effect of Evacuation on Body Weight After the Great East Japan Earthquake

INTRODUCTION

The Great East Japan Earthquake occurred on March 11, 2011, with a nuclear accident subsequently occurring at the Fukushima Daiichi Nuclear Power Plant. The government ordered a mandatory evacuation from the high radioactive concentration area in Fukushima, which might have forced many evacuees to change particular aspects of their lifestyles. This study assessed the hypothesis that mean body weight and the proportion of overweight/obese individuals would increase among evacuees after versus before the disaster.

METHODS

A longitudinal study examined data collected from 41,633 Japanese participants (mean age, 67 years) sourced from general health checkups conducted in 13 communities between 2008 and 2010. Follow-up examinations were conducted from June 2011 through March 2013.

RESULTS

A total of 27,486 participants (12,432 men and 15,054 women; follow-up proportion, 66%) received follow-up examinations after the disaster, with an average follow-up of 1.6 years. Mean body weight significantly increased in both evacuees (n=9,671) and non-evacuees (n=17,815) after the disaster, with greater changes in body weight among evacuees than non-evacuees (+1.2 kg vs +0.3 kg, p<0.001). The proportion of overweight/obese people also increased among evacuees after the disaster, and evacuation was associated with an increased risk of being overweight, despite adjustments for confounding variables. The proportions of overweight evacuees before and after the disaster were 31.8% and 39.4%, respectively, whereas proportions among non-evacuees were 28.3% and 30.3%, respectively.

CONCLUSIONS

Body weight and the proportion of overweight/obese people increased among residents, especially evacuees, in the evacuation zone of Fukushima prefecture after the Great East Japan Earthquake.

Hepcidin-2 in mouse urine as a candidate radiation-responsive molecule

We used high-performance liquid chromatography to separate urine obtained from whole-body gamma-irradiated mice (4 Gy) before analyzing each fraction with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry to identify radiation-responsive molecules. We identified two candidates: hepcidin antimicrobial peptide 2 (hepcidin-2) and peptide fragments of kidney androgen-regulated protein (KAP). We observed that peak increases of hepcidin-2 in urine were delayed in a dose-dependent manner (1 Gy and above); however, the amount of KAP peptide fragments showed no correlation with radiation dose. In addition, an increase in hepcidin-2 after exposure to relatively low radiation doses (0.25 and 0.5 Gy, respectively) was biphasic (at 8-48 h and 120-168 h, respectively, after irradiation). The increase in hepcidin-2 paralleled an increase in hepcidin-2 gene (Hamp2) mRNA levels in the liver. These results suggest that radiation exposure directly or indirectly induces urinary excretion of hepcidin-2 at least in part by the upregulation of Hamp2 mRNA in the liver.

Hypo-high-density Lipoprotein Cholesterolemia Caused by Evacuation after the Fukushima Daiichi Nuclear Power Plant Accident: Results from the Fukushima Health Management Survey

Objective The Great East Japan Earthquake and the Fukushima Daiichi nuclear disaster forced the evacuation of residents and led to many changes in the lifestyle of the evacuees. A comprehensive health check was implemented to support the prevention of lifestyle-related disease, and we analyzed changes in lipid metabolism before and after these disasters. Methods Subjects included Japanese men and women living near the Fukushima Daiichi nuclear power plant in Fukushima Prefecture. Annual health checkups, focusing on metabolic syndromes, were conducted for persons ≥40 years of age by the Heath Care Insures. Results A total of 27,486 subjects underwent a follow-up examination after the disaster, with a mean follow-up of 1.6 years. Following the disaster, the prevalence of hypo-high-density lipoprotein (HDL) cholesterolemia increased significantly from 6.0% to 7.2%. In the hypo-HDL cholesterolemia group, the body mass index (BMI), blood pressure, and LDL-C level increased significantly in men after the disaster. On the other hand, in the normal HDL-C level group, the BMI, blood pressure, glucose and lipid metabolism, and liver function were adversely affected. The decrease in HDL-C was significantly greater in evacuees than non-evacuees in the normal HDL-C level group. Furthermore, a multivariate logistic regression analysis showed that the evacuation was significantly associated with the incidence of hypo-HDL cholesterolemia. Conclusion This is the first study to evaluate how the evacuation affected the incidence of hypo-HDL cholesterolemia and led to an increase in cardiovascular disease. This information may be important in the follow-up and lifestyle change recommendations for evacuees.

Prevalence of Renal Dysfunction among Evacuees and Non-evacuees after the Great East Earthquake: Results from the Fukushima Health Management Survey

Objective We conducted the present study to evaluate the prevalence of chronic kidney disease (CKD) and CKD complications among evacuees and non-evacuees after the Great East Japan Earthquake and Fukushima Daiichi nuclear disaster. Methods Twenty-seven thousand and eighty-eight subjects who were living near the Fukushima Daiichi Nuclear Power Plant in Fukushima Prefecture in Japan, aged ≥40 years by the Heath Care Insures, were included in the analyses. Metabolic factors were compared between the evacuees and non-evacuees stratified by the eGFR and proteinuria grades. Results The prevalence of CKD with a low eGFR (<60 mL/min/1.73 m(2)) and proteinuria were 21.59% and 1.85%, respectively. The risk of CKD complications was classified into four grades according to the eGFR and proteinuria grades. The prevalence of diabetes, hypertension, and dyslipidemia were significantly higher in the very high risk group than in the low risk group. The prevalence of diabetes and dyslipidemia were significantly higher in evacuees than in non-evacuees in only the low risk group. However, a multivariate logistic regression analysis showed that evacuation was not significantly associated with the risk of a low eGFR or proteinuria. Conclusion This study did not reach the definitive conclusion that evacuation elevated the risk of CKD complication, although evacuation might lead to increased CKD complications in the future. We believe that this information is important for follow-up and lifestyle change recommendations for evacuees.

The protocol and preliminary baseline survey results of the thyroid ultrasound examination in Fukushima [Rapid Communication]

After the Fukushima nuclear power plant accident on March 11, 2011, the public of Japan became particularly concerned about the possibility of an increased risk of childhood thyroid cancer, similar to what was observed after the Chernobyl's accident. Due to serious public health perception, there was an urgency to evaluate the baseline levels of childhood thyroid status in Fukushima prefecture. Therefore we have commenced a thyroid ultrasound examination (TUE) survey of the approximately 360,000 pediatric inhabitants (0 to 18 years of age) who lived in Fukushima at the time of the accident in October 2011. The subjects were divided into three categories according to the standardized diagnostic criteria of ultrasound findings. Category A contained the subjects whose TUE findings were intact or benign. Category B were recommended a confirmatory TUE. Category C was recommended an immediate confirmatory TUE.

RESULTS

The survey of 40,302 subjects in the first year was completed in March, 2013. There were 40,097 (99.5%), 205 (0.50%) and 0 subjects in categories A, B and C, respectively. Of the 82 category B subjects who underwent fine needle aspiration cytology (FNAC), 12 were diagnosed with a malignant tumor or were suspected to have malignancy. The 12 subjects received thyroid surgery and 11 thyroid cancers and one benign nodule were confirmed histologically after surgery. This is the first large-scaled TUE survey to employ sophisticated ultrasound screening and aim to evaluate the baseline frequency of childhood thyroid nodules and cysts. The results will become the golden standard of future comparative TUE in Fukushima, Japan.