Transfer of 137Cs and 90Sr from soil-to-potato: Interpretation of the association from global fallout in Aomori to accidental release in Fukushima and Chornobyl

Ceasium-137 and 90Sr are major artificial radionuclides that have been released into the environment. Soil-to-plant transfer of radionuclides is an important route to food contamination. The radionuclide activity concentrations in crops must be quantitatively predicted for estimating the internal radiation doses from food ingestion. In this study, soil and potato samples were collected from three study sites contaminated with different sources of 137Cs and 90Sr: Aomori Prefecture (global fallout) and two accidental release areas (Fukushima Prefecture and the Chornobyl exclusion zone). The 137Cs activity concentrations in the soil and potato samples widely ranged from 1.0 to 250,000 and from 0.048 to 200,000 Bq kg-1 dry weight, respectively. The soil-to-potato transfer factor of 137Cs also ranged widely (0.0015-1.1) and decreased with increasing concentration of exchangeable K. Meanwhile, the activity concentrations of 90Sr in the soil and potato samples were 0.50-64,000 and 0.027-18,000 Bq kg-1 dry weight respectively, and the soil-to-potato transfer factor of 90Sr was 0.023-0.74, decreasing with increasing concentration of exchangeable Ca. The specific activity ratios of 137Cs/Cs and 90Sr/Sr in the exchangeable fraction were similar to those in potatoes, with a factor of 3 in the ±95 % confidence intervals over six orders of magnitude and a factor of 2 in the ±95 % confidence intervals over five orders of magnitude, respectively. According to the data, the accuracy of predicting the activity concentrations of 137Cs and 90Sr in potatoes can be improved by applying the specific activity ratios of 137Cs/Cs and 90Sr/Sr in the exchangeable fraction. This approach accounts for variable factors such as the effects of K and Ca fertilization and soil characteristics. It also emphasizes the benefit of determining the stable Cs and Sr concentrations in potatoes and other crops prior to possible future contamination.

Biokinetic model analysis with DTPA administration for a case of accidental inhalation of actinides in Japan

Accidental inhalation intake of plutonium isotopes and 241Am occurred at a Pu research facility in Japan in 2017, and the five workers involved in this accident were treated by the administration of Ca/Zn-diethylenetriaminepentaacetic acid (DTPA). For the worker who was most internally exposed, the therapy was continued over 1 y after the accident. Urinary samples collected before and after each administration were subject to bioassay to evaluate the efficacy of the dose reduction. This study performed numerical analyses using a biokinetic model dealing with 241Am-DTPA with reference to the European Coordinated Network on Radiation Dosimetry approach, which assumes that the complex of actinides and Ca/Zn-DTPA is generated in the designated compartments in the biokinetic model. The results of the model prediction well captured the trend of the observed urinary excretion in the long-term bioassay and would be useful to evaluate the efficacy of the Ca/Zn-DTPA administration for the worker involved in the accident.

Correlation Analysis Between Time Awareness and Morningness-Eveningness Preference

The circadian clock is adjusted by light inputs via the retinohypothalamic tract. Because environmental light is controllable for modern humans at the individual's preference although under social schedules, individual differences in time-related psychology and behavior may be associated with morningness-eveningness preference (M-E preference). To examine this hypothesis, we used the Time Management Scale and Time Anxiety Scale to quantify time-related psychology and behavior. These scales aim to evaluate "awareness of effective time management and utilization" and "anxiety about uncontrollable time schedule and unexpected time-related outcome", respectively. According to our correlation analysis using mid-sleep time as a marker for M-E preference, we obtained results supporting our hypothesis in the correlation between the M-E preference values and the Time Management Scale scores, with larger "time estimation" and "taking each moment as it comes" scores associated with more morningness and eveningness, respectively. Considering that modern humans likely become night owls under artificial light conditions, it appears plausible that lower awareness of time management leads to more eveningness.

A preliminary report on retrospective dose assessment by FISH translocation assay in FDNPP Nuclear Emergency Worker Study (NEWS)

In Japan, a national project of longitudinal health care and epidemiological research (NEWS) was developed in 2014 to analyse the effects of radiation on human health for workers who responded to the Fukushima Dai-ichi nuclear emergency in 2011. In 2018, peripheral blood for chromosome translocation analysis was collected from 62 workers. Retrospective dose assessment was performed with fluorescence in situ hybridisation translocation (FISH-Tr) assay. The range of estimated doses by FISH-Tr assay was 0-635 mGy, in which 22 workers had estimated doses of more than 189 mGy. Biological dose estimates were five times higher in workers with physically measured total exposure recordings above 70 mGy. It is likely that smoking and medical exposure caused the discrepancy between estimated biological and physical total exposure doses. Thus, there is a possibility that retrospective biodosimetry assessment might over-estimate occupational exposures to workers exposed to chronic radiation during nuclear emergency work.

Detection of endogenous circadian rhythms of clock gene mRNA expression in mouse lung tissue using slice cultures

Detection of endogenous circadian rhythms in clock gene mRNA expression requires that mice be sacrificed at regular time intervals over one or more days. This protocol uses culture tissue slices obtained from a single mouse to collect time-course samples. We describe the procedure from preparation of lung slices to rhythmicity analysis of mRNA expression, including details to create handmade culture inserts. This protocol is useful for many mammalian biological clock researchers because it allows a decrease in animal sacrifice. For complete details on the use and execution of this protocol, please refer to Matsumura et al. (2022).¹.

Post COVID-19 condition of the Omicron variant of SARS-CoV-2

Objectives

To investigate the prevalence of post coronavirus disease (COVID-19) condition of the Omicron variant in comparison to other strains.

Study design

A single-center cross-sectional study.

Methods

Patients who recovered from Omicron COVID-19 infection (Omicron group) were interviewed via telephone, and patients infected with other strains (control group) were surveyed via a self-reporting questionnaire. Data on patients’ characteristics, information regarding the acute-phase COVID-19, as well as presence and duration of COVID-19-related symptoms were obtained. Post COVID-19 condition in this study was defined as a symptom that lasted for at least 2 months, within 3 months of COVID-19 onset. We investigated and compared the prevalence of post COVID-19 condition in both groups after performing propensity score matching.

Results

We conducted interviews for 53 out of 128 patients with Omicron and obtained 502 responses in the control group. After matching cases with controls, 18 patients from both groups had improved covariate balance of the factors: older adult, female sex, obesity, and vaccination status. There were no significant differences in the prevalence of each post COVID-19 condition between the two groups. The number of patients with at least one post COVID-19 condition in the Omicron and control groups were 1 (5.6%) and 10 (55.6%) (p = 0.003), respectively.

Conclusions

The prevalence of post Omicron COVID-19 conditions was less than that of the other strains. Further research with a larger sample size is needed to investigate the precise epidemiology of post COVID-19 condition of Omicron, and its impact on health-related quality of life and social productivity.

Metabolic state switches between morning and evening in association with circadian clock in non‐diabetic humans

Aims/Introduction

Understanding morning–evening variation in metabolic state is critical for managing metabolic disorders. We aimed to characterize this variation from the viewpoints of insulin secretion and insulin sensitivity, including their relevance to the circadian rhythm.

Materials and Methods

A total of 14 and 10 people without diabetes were enrolled, and underwent a 75‐g oral glucose tolerance test (OGTT) and hyperinsulinemic‐euglycemic clamp study, respectively. Participants completed the OGTT or hyperinsulinemic‐euglycemic clamp at 08.00 hours and 20.00 hours in random order. Before each study, hair follicles were collected. In mice, phosphorylation levels of protein kinase B were examined in the liver and muscle by western blotting.

Results

Glucose tolerance was better at 08 .00 hours, which was explained by the higher 1‐h insulin secretion on OGTT and increased skeletal muscle insulin sensitivity on hyperinsulinemic‐euglycemic clamp. Hepatic insulin sensitivity, estimated by the hepatic insulin resistance index on OGTT, was better at 20.00 hours. The 1‐h insulin secretion and hepatic insulin resistance index correlated significantly with Per2 messenger ribonucleic acid expression. The change (evening value – morning value) in the glucose infusion rate correlated significantly with the change in non‐esterified fatty acid, but not with clock gene expressions. The change in non‐esterified fatty acid correlated significantly with E4bp4 messenger ribonucleic acid expression and the change in cortisol. In mice, phosphorylation of protein kinase B was decreased in the liver and increased in muscle in the beginning of the active period as, expected from the human study.

Conclusions

Glucose metabolism in each tissue differed between the morning and evening, partly reflecting lipid metabolism, clock genes and cortisol levels. Deeper knowledge of these associations might be useful for ameliorating metabolic disorders.

Medical management of heavily exposed victims: an experience at the Tokaimura criticality accident

A criticality accident occurred at the uranium conversion plant in Tokaimura, Ibaraki Prefecture, Japan on 30 September 1999. When uranyl nitrate was overloaded to a critical mass level, uncontrolled fission reaction occurred. A procedure was carried out according to the JCO manual, although not an officially approved manual. Three workers were heavily exposed to neutrons andγ-rays produced by nuclear fission, and they subsequently developed acute radiation syndrome (ARS). The average doses to the whole body of the three workers were approximately 25, 9, and 3 GyEq (biologically equivalent dose ofγ-exposure), respectively; dose distribution analysis later revealed extreme heterogeneity of these doses in two workers. They were triaged according to the predicted clinical needs. Two of these workers developed severe bone marrow failure and received haematopoietic stem cell transplantation: one with peripheral stem cell transplantation from his Human Leukocyte Antigen compatible sister and the other with umbilical cord blood transplantation. The graft was initially successful in both workers; autologous haematopoietic recovery was observed after donor/recipient mixed chimerism in one of them. Despite of all medical efforts available including haematopoietic stem cell transplantation, investigational drugs, skin graft, two workers died of multiple organ involvement and failure 83 and 211 days after the accident, respectively. Clinically as well as pathologically, the direct cause of death was deemed to be intractable gastrointestinal (GI) bleeding in one, and thoraco-abdominal compartment syndrome due to dermal fibrosis/sclerosis in the other. The third worker also developed bone marrow suppression but was treated with granulocyte colony-stimulating factor. He recovered without major complications and is now under periodical medical follow-up. These experiences suggest that treatment of bone marrow is not a limiting factor for saving the life of ARS victims severely exposed. Successful treatment of other organs such as lungs, skin, and GI tract is also essential. Furthermore, the whole-body dose may not always reflect the prognosis of ARS victims because of the nature of accidental exposure, heterogenous exposure.

Denosumab-related osteonecrosis of the jaw after tooth extraction and the effects of a short drug holiday in cancer patients: a multicenter retrospective study

Pre-existing inflammation, corticosteroid therapy, periapical periodontitis, longer duration of denosumab therapy, and female sex were significantly associated with an increased risk of denosumab-related osteonecrosis of the jaw after tooth extraction in patients with cancer on oncologic doses of denosumab. A short drug holiday did not protect against this complication.

INTRODUCTION

This study retrospectively investigated the relationship between various risk factors, including brief discontinuation of denosumab, and development of denosumab-related osteonecrosis of the jaw (DRONJ) after tooth extraction in patients with cancer who were receiving oncologic doses of this agent.

METHODS

Data were collected on demographic characteristics, duration of denosumab therapy, whether or not denosumab was discontinued before tooth extraction (drug holiday), duration of discontinuation, presence of pre-existing inflammation, and whether or not additional surgical procedures were performed. Risk factors for DRONJ after tooth extraction were evaluated by univariate and multivariate analyses.

RESULTS

A total of 136 dental extractions were performed in 72 patients (31 men, 41 women) with cancer who were receiving oncologic doses of denosumab. Post-extraction DRONJ was diagnosed in 39 teeth (28.7%) in 25 patients. Tooth extraction was significantly associated with development of DRONJ only in patients with pre-existing inflammation (odds ratio [OR] 243.77), those on corticosteroid therapy (OR 73.50), those with periapical periodontitis (OR 14.13), those who had been taking oncologic doses of denosumab for a longer period (OR 4.69), and in women (OR 1.04). There was no significant difference in the occurrence of DRONJ between patients who had a drug holiday before tooth extraction and those who did not.

CONCLUSIONS

These findings suggest that inflamed teeth should be extracted immediately in patients with cancer who are receiving oncologic doses of denosumab. Drug holidays have no significant impact on the risk of DRONJ.

Effects of the chelating agent DTPA on naturally accumulating metals in the body

Diethylenetriaminepentaacetate (DTPA) is the most widely used chelating agent for Pu and Am. Volunteers were assigned to receive intravenous injections or aerosol inhalations of 1 g of DTPA on days 1-4; volunteers received once daily injections of CaDTPA or ZnDTPA, CaDTPA inhalation as an aerosol, or CaDTPA injection on day 1 and ZnDTPA on days 2-4. CaDTPA injection or inhalation increased the excretion rates of Zn in urine with concomitantly reduced levels of serum Zn. Injection of CaDTPA reduced activities of serum alkaline phosphatase (AP) in parallel with the kinetics of Zn, whereas CaDTPA and ZnDTPA injection reduced activities of lactate dehydrogenase (LDH), and reduced activities of creatinine kinase (CK) were observed upon CaDTPA injection and its inhalation. Intravenous administration of CaDTPA and ZnDTPA enhanced excretion rates of Mn in urine, whereas transient reduction of Mn levels in serum was detected only via CaDTPA injection. Both CaDTPA and ZnDTPA transiently reduced levels of Mg in serum without affecting the excretion rates. On the other hand, both DTPAs increased excretion rates of toxic metals such as Pb and Cd, and CaDTPA also increased the rates of Hg. These results suggest that DTPA, and especially CaDTPA, removes essential metals and that the activities of these metalloenzymes are good indicators for the imbalance of essential metals during the DTPA administration. Our results also show that CaDTPA injection is more potent for removing these metals than ZnDTPA and inhalation of CaDTPA, and DTPA may be useful for the treatment of acute heavy metal poisoning with Pb, Cd, or Hg.

The period from prodromal fever onset to rash onset in laboratory-confirmed rubella cases: a cross-sectional study

Background

In resource-limited settings, where rubella is endemic, it is difficult to determine which sporadic case should be tested for rubella. The study aimed to provide useful evidence to help screen rubella cases for real-time reverse transcriptase-polymerase chain reaction (RT-PCR) examination for rubella in resource-limited settings.

Method

Suspected rubella patients identified by a physician and brought to the notice of the Ryugasaki public health center or the Tsuchiura public health center were enrolled from April 2018 through December 2019. The inclusion criterion was a confirmed rubella diagnosis based on laboratory tests. We studied the distribution of the time from the onset of fever until the onset of rash.

Results

The study included 86 cases with simultaneous presentation of fever and rash. Twenty-nine cases had confirmed rubella based on the laboratory diagnosis. Among these, the time from the onset of fever until the onset of rash was limited to − 1 day to 2 days. The number of rubella cases was the highest when the onset of rash was on the following day of the onset of fever. Of the 78 patients who underwent the RT-PCR test, 48% tested positive for rubella among those with a time from the onset of fever to the onset of rash between − 1 day and 2 days (22 out of 46, 95% confidence interval 34–62%); no positive results (0 out of 30, 95% confidence interval - 14%) were seen in patients with a time from fever to rash onset ≥3 days.

Conclusion

The period from the onset of fever to the onset of rash was limited to − 1 day to 2 days among confirmed rubella patients. If the period from onset of fever to the onset of rash was ≥3 days for a patient, the likelihood of rubella was low.

Intake Ratio of 131I to 137CS Derived from Thyroid and Whole-body Doses to Residents of Iwaki City in Japan's Fukushima Prefecture

ABSTRACT

It is very important to determine the precise internal thyroid doses of Fukushima residents involved in the 2011 Fukushima nuclear disaster, particularly for small children. This has been challenging due to the lack of direct human measurements to identify 131I, the biggest contributor to the thyroid doses. We previously used a dataset of late whole-body counter (WBC) measurements targeting 134Cs and 137Cs for the thyroid dose estimation in comparison with the intake ratios of 131I to 137Cs (or 134Cs) derived from thyroid and whole-body doses individually obtained from different subject groups, assuming simultaneous acute intake via inhalation. Herein, we applied the same method to the doses of residents in Iwaki city (located south of the Fukushima Daiichi Nuclear Power Plant) with a relatively high activity ratio (131I/137Cs) for the ground deposition density. Our analyses revealed that the intake ratio (131I/137Cs) for the Iwaki residents was 4.2-4.3, which is relatively consistent with the values obtained in other studies (average 3.0-5.0). No regional difference in the intake ratios from other areas was observed, but further studies are required to determine the accurate intake ratio in the early phase of the accident, in particular focusing on the reasonable interpretation of results of the late WBC measurements to evaluate the actual Cs intake.

Difference in the Cesium Body Contents of Affected Area Residents Depending on the Evacuation Timepoint Following the 2011 Fukushima Nuclear Disaster

Estimating the internal thyroid dose received by residents involved in the 2011 Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has been a challenging task because of the shortage of direct human measurements related to the largest contributing radioisotope to the dose, I. In a previous dose estimation, we used the results of whole-body counter (WBC) measurements targeting Cs and Cs, based on the assumption that these radioisotopes were incorporated at the same time as I in the early phase of the accident. The main purpose of this study was to clarify whether the trace of the early intake remained in the WBC measurements that were started several months after the accident. In the present work, WBC data of 1,639 persons from Namie town, one of the heavily contaminated municipalities, were analyzed together with their evacuation behavior data. The results demonstrated that the cesium detection rate in the WBC results was several times higher in the late evacuees [who evacuated outside the 20-km radius of the FDNPP at 3:00 p.m. (Japanese Local Time) on 12 March or later] compared to the prompt evacuees (who evacuated before 3:00 p.m. on 12 March). Among the adults, the cesium detection rates (and the 90th percentile values of the Cs intake) of the prompt and late evacuees were about 20% (5.4 × 10 Bq) and 60% (1.6 × 10 Bq), respectively. Approximately 20% of the individuals analyzed were categorized as late evacuees. These differences in cesium would be caused by exposure to the radioactive plume in the afternoon on 12 March, which was likely to influence the late evacuees. On the other hand, the intake on 15 March, when the largest release event occurred, was expected to be relatively small for Namie town's residents. In conclusion, the trace of the early intake remained in the WBC measurements, although this would not necessarily be true for all subjects. The results obtained from this study would provide useful information for the reconstruction of the early internal thyroid doses from radioiodine in the future.

Exploration of the characteristics of chronotypes in upper gastrointestinal tract diseases: a multicenter study in Japan

Characteristics of the chronotypes of patients with gastrointestinal disease are unknown. We evaluated chronotypes of patients with upper gastrointestinal diseases with the Munich ChronoType Questionnaire (MCTQ). A total of 2027 subjects from 29 institutions in Japan who had undergone esophagogastroduodenoscopy were asked to answer the MCTQ. The subjects' chronotypes were divided into three groups (early, intermediate, and late chronotype) using the sleep-corrected mid-point of sleep on free days (MSF_SC) values. According to their endoscopic diagnosis and abdominal symptoms, the subjects were divided into the reflux esophagitis (RE) group, gastroduodenal ulcer (GDU) group, upper gastrointestinal carcinoma (CA) group, functional dyspepsia (FD) group, non-FD group, and control group. In total, 1128 subjects were eligible for the analysis. The MSF_SC (average ± standard deviation, clock hours, h) of each disease group was as follows: control group: 02.51 ± 1.22, non-FD group: 02.69 ± 1.14, FD group: 02.91 ± 1.19, RE group: 02.58 ± 1.05, GDU group: 02.47 ± 1.31, and CA group: 02.11 ± 1.08 h. Compared to the control group, the rate of late chronotype of the FD group significantly increased to 33.3%, whereas that of early chronotype of the CA group significantly increased to 38.3% (P = .0177 and 0.0036, respectively). In both the FD and CA groups, chronotype was the independent factor related to the diseases. The adjusted odds ratio of late chronotype to early chronotype was 3.01 [95% CI, 1.23-7.35] in the FD group and 0.44 [95% CI, 0.23-0.85] in the CA group. In conclusion, late chronotype was common in patients with FD, and early chronotype was common in patients with upper gastrointestinal carcinoma.

Ex vivo Culture Assay Using Human Hair Follicles to Study Circadian Characteristics

Ex vivo culture assays of biopsy specimens are advantageous for the experimental evaluation of human circadian characteristics. We developed a simple and non-invasive experimental evaluation method for monitoring the expression of circadian clock genes in an ex vivo culture assay using human hair follicles. This method imposes little burden on subjects. This assay is useful for validating correlations between circadian characteristics in hair follicles and intrinsic characteristics observed in physiological and behavioral studies. While they should be further validated, this ex vivo method constitutes a useful tool for estimating in vivo circadian characteristics.

Bright light improves sleep in patients with Parkinson's disease: possible role of circadian restoration

Parkinson’s disease (PD) is one of the most common neurodegenerative disorders. Among the most common manifestations of PD are sleep problems, which are coupled with the adverse effects of dopaminergic therapies (DT). A non-pharmacological solution for these sleep problems has been sought to avoid additional pharmacological intervention. Here, we show that bright light therapy (BLT) is effective for improving sleep in Japanese PD patients receiving DT. Furthermore, experimental evaluation of peripheral clock gene expression rhythms revealed that most PD patients receiving DT who experienced improved sleep following BLT showed a circadian phase shift, indicating the existence of a correlation between circadian modulation and sleep improvement. Conversely, this result indicates that sleep problems in PD patients receiving DT may arise at least in part as a result of circadian dysfunction. Indeed, we found that chronic dopaminergic stimulation induced a rapid attenuation of autonomous oscillations of clock gene expression in ex vivo cultured mouse suprachiasmatic nucleus (SCN) at the single neuron level. In conclusion, BLT is a promising medical treatment for improving sleep in PD patients receiving DT. This BLT-induced improvement may be due to the restoration of circadian function.

Reassessment of Internal Thyroid Doses to 1,080 Children Examined in a Screening Survey after the 2011 Fukushima Nuclear Disaster

The dose reconstruction of populations potentially affected by the accident at the Fukushima Daiichi nuclear power plant in March 2011 is of great importance. However, it has been difficult to assess internal thyroid doses to Fukushima residents (mainly from their intake of I) due to the lack of direct measurements. For the residents, only about 1,300 data points related to I are available, and 1,080 of the data points were obtained from the screening campaign that was conducted by the Nuclear Emergency Response Local Headquarters at the end of March 2011 in Kawamata Town, Iwaki City, and Iitate Village. Here, we reassessed thyroid doses to 1,080 subjects aged ≤15 y old using new age-specific conversion factors to determine I thyroid contents from net signals of the devices used, with consideration for the possible uncertainty related to the measurements. The results demonstrated that thyroid equivalent doses to the subjects were <30 mSv (excluding outliers). We also demonstrate dose distributions of each age group from the above three municipalities and those of subjects from Minamisoma City and Fukushima City. One of the findings was that the I intake was similar among different age groups in each of the three municipalities. This was consistent with the assumption that ingestion was a dominant route of intake rather than inhalation. The range of thyroid doses to Iitate Village residents was similar to that to Iwaki City residents even though the I concentration in tap water was much higher in Iitate Village than Iwaki City. The range of thyroid doses to Minamisoma City residents was similar to that to Iitate Village and Iwaki City residents, and the range for Fukushima City residents was smallest among the five municipalities. Since the major route of intake has remained unclear, this paper presents the plausible upper and lower thyroid doses, between which the actual doses are thought to mostly exist, based on two intake scenarios: single inhalation and repeated ingestion. Further research is thus necessary to extract useful evidence from the individual evacuation behaviors for improving the present internal thyroid dose assessment.

P1958Baseline glycated hemoglobin level was differently associated with long-term prognosis in peripheral artery disease patients with and without hemodialysis

Introduction

Diabetes (DM) is the leading cause of induction of hemodialysis (HD), and both are major prognostic factors in patients with peripheral artery disease (PAD). However, the prognostic importance of baseline glycated hemoglobin (HbA1c) levels in PAD patients with and without HD is yet to be elucidated.

Purpose

We hypothesized that baseline HbA1c levels had different prognostic impacts after endovascular therapy (EVT) in between PAD patients with and those without regular HD.

Methods

This observational study included 643 consecutive patients who received EVT between 2013 and 2017. Each of 313 HD patients and 330 Non-HD patients was respectively divided into 2 groups by the comorbidity of diabetes, and DM patients were further divided into 3 subgroups depending on HbA1c level at the time of EVT; DM-Low (HbA1c: <6.0%), DM-Mid (6.1–7.0%), and DM-High (>7.1%) groups. The primary endpoint of this study was major amputation-free survival (AFS).

Results

HD group included significantly more patients presenting critical limb ischemia than Non-HD group (46.6% vs. 30.0%, p<0.001). During the observation period after EVT, there were 81 events (25.9%), including 55 death and 26 major amputations in HD group, and 45 events (13.6%), including 30 death and 15 major amputations in Non-HD group. Kaplan-Meier analysis revealed that DM patients had a significantly higher AFS rate in HD group (Log-rank: p=0.003, Figure A). In contrast, in Non-HD group, there was no statistical difference in AFS between DM and Non-DM patients (p=0.36). In Cox regression analysis in HD group, the higher HbA1c-DM group showed the higher hazard ratio (HR) for AFS (p=0.039, Figure B), and DM patients with HbA1c >6.0% had significantly higher HR than Non-DM patients. Whereas, in Non-HD group, HbA1c-DM class adversely associated with HR for AFS (p=0.003), even any classes did not reach statistical differences from Non-DM patients.

Figure 1

Conclusions

Comorbidity of diabetes at the time of EVT worsened long-term prognosis in PAD patients receiving regular HD, but not in those without HD. Additionally, baseline HbA1c levels oppositely affected prognosis in PAD patients with and without HD.

In vivo evaluation of the effect of lithium on peripheral circadian clocks by real-time monitoring of clock gene expression in near-freely moving mice

Lithium has been used as a mood stabilizer to treat human bipolar disorders for over half a century. Several studies have suggested the possibility that the efficacy of lithium treatment results in part from the amelioration of circadian dysfunction. However, the effect of lithium on clock gene expression has not yet been investigated in vivo because continuous measurement of gene expression in organs with high time resolution over a period of several days is difficult. To resolve this issue, we attached a small photo multiplier tube (PMT) tightly to the body surface of transgenic mice carrying a reporter gene such that the photon input window faced target organs such as the liver and kidney and succeeded in long-term continuous measurement of circadian gene expression in semi-freely moving mice over periods of several weeks. Using this simple method, we clearly showed that lithium causes circadian period elongation in peripheral clock gene expression rhythms in vivo. Further development of our detection system to maturity will aid a wide range of research fields in medicine and biology.

Numerical Simulation Based on Individual Voxel Phantoms for a Sophisticated Evaluation of Internal Doses Mainly From 131I in Highly Exposed Workers Involved in the TEPCO Fukushima Daiichi NPP Accident

As a response to the Tokyo Electric Power Company's Fukushima Daiichi nuclear power plant accident in 2011, seven TEPCO workers whose exposure doses were expected to be >250 mSv (a tentative dose limit stipulated by the Japanese central authority) attended Japan's National Institute for Radiological Sciences for additional internal dose measurements. The National Institute for Radiological Sciences examination revealed that these workers' internal doses came mainly from their intake of the radionuclide I during emergency operations. In this study, we performed numerical simulations based on individual volume-pixel (voxel) phantoms of six of the seven workers for a more sophisticated evaluation of their internal doses, taking into account the individual thyroid size and other specific parameters. The voxel phantoms were created from magnetic resonance imaging scan images. As a result, the individual thyroid volumes ranged from 6.5 to 28.2 cm and were considerably smaller than the reference value (~20 cm) adopted in the International Commission on Radiation Protection's dosimetric model for four of the six subjects. Compared to the original estimates of the thyroid absorbed dose, our preliminary evaluation revealed values that were increased by approximately 3-fold or decreased by 30% at maximum. A wide difference in the individual thyroid size would be one of the significant modifiers in the current dose estimation of subjects of the ongoing epidemiological study project. The present simulations also provided evidence that the direct thyroid measurements by the National Institute for Radiological Sciences to determine the workers' I thyroid contents were sufficiently accurate.