Comparison of lifetime mortality risk, incidence risk, and DALYs of baseline cancer rates among countries as a benchmark for radiation-related cancer risk

Statistical benchmark data are necessary when considering the basis for radiation protection criteria based on calculated risks. We herein focused on baseline mortality and incidence cancer rates as benchmark data collected from 33 countries. Furthermore, we calculated the lifetime mortality and incidence risks and disability-adjusted life years (DALYs) for all solid cancers, colon cancer, lung cancer, breast cancer, thyroid cancer, and leukemia using the baseline cancer rates and compared them among the countries. The results showed that the lifetime mortality and incidence risks and DALYs for all solid cancers differed among the countries by a factor of 2-4 for males and 2-3 for females; these were low in less-developed countries. Our study proposed that health risk based on baseline cancer rates should be the benchmark for comparing radiation cancer risks.

Temporal changes in cumulative mortality risks of cancer, by occupation, in the working population of Japan from 1995 to 2020: a benchmark for radiation risk comparison

The purpose of this study was to provide benchmark data for discussing the tolerability of cancer risk associated with occupational radiation exposure. It focused on differences in cancer mortality risk by occupation among Japan's working population and examined baseline cancer mortality risks and its variations from 1995 through 2020. Data were collected every five years from national vital statistics sources. By focusing on the same types of cancer among radiation induced effects, cumulative mortality risks were calculated for colorectal, lung, and breast cancer (females only) for those aged 15-74. The average cumulative mortality risk for the working population in Japan has decreased by 30%-60% over the past 25 years. Service workers and male managers were at an average risk, among all workers, while clerical workers and transportation and manufacturing workers had about half the average risk. The risks were higher for professionals and female managers, about 1.5-2 times the average for professionals and up to 5 times the average for female managers. The decrease in the average cancer mortality risk in the working population as a baseline suggests that risk tolerance in society might have changed over time. Since differences in mortality by occupation were confirmed, the usefulness of occupational data as a benchmark needs further investigation, as high-risk/low-risk occupations vary by country and region. The results of this study contribute to put radiation risks into perspective with the background risk of cancer.

Soil dust and bioaerosols as potential sources for resuspended 137Cs occurring near the Fukushima Dai-ichi nuclear power plant

One of the current pathways to radiation exposure, caused by the radionuclides discharged during the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, is the inhalation of resuspended ¹³⁷Cs present in the air. Although wind-induced soil particle resuspension is recognized as a primary resuspension mechanism, studies regarding the aftermath of the FDNPP accident have suggested that bioaerosols can also be a potential source of atmospheric ¹³⁷Cs in rural areas, although the quantitative impact on the atmospheric ¹³⁷Cs concentration is still largely unknown. We propose a model for simulating the ¹³⁷Cs resuspension as soil particles and bioaerosols in the form of fungal spores, which are regarded as a potential candidate for the source of ¹³⁷Cs-bearing bioaerosol emission into the air. We apply the model to the difficult-to-return zone (DRZ) near the FDNPP to characterize the relative importance of the two resuspension mechanisms. Our model calculations show that soil particle resuspension is responsible for the surface-air ¹³⁷Cs observed during winter-spring but could not account for the higher ¹³⁷Cs concentrations observed in summer-autumn. Higher ¹³⁷Cs concentrations are reproduced by the emission of ¹³⁷Cs-bearing bioaerosols (fungal spores) that replenishes the low-level soil particle resuspension in summer-autumn. Our model results show that the accumulation of ¹³⁷Cs in fungal spores and large emissions of spores characteristic of the rural environment are likely responsible for the presence of biogenic ¹³⁷Cs in the air, although the former must be experimentally validated. These findings provide vital information for the assessment of the atmospheric ¹³⁷Cs concentration in the DRZ, as applying the resuspension factor (m^-1) from urban areas, where soil particle resuspension would dominate, can lead to a biased estimate of the surface-air ¹³⁷Cs concentration. Moreover, the influence of bioaerosol ¹³⁷Cs on the atmospheric ¹³⁷Cs concentration would last longer, because undecontaminated forests commonly exist within the DRZ.

Uncertainty and sensitivity analyses for the reduction factor of sheltering for radiation exposures

Sheltering is one of the countermeasures used to mitigate radiation exposure during nuclear power plant accidents. The effectiveness of sheltering for inhalation exposure is often expressed by the reduction factor, which is defined as the ratio of the indoor to the outdoor cumulative radioactivity concentrations or doses. The indoor concentration is mainly controlled by the air exchange rate, penetration factor, and indoor deposition rate. Meanwhile, the air exchange rate depends on surrounding environmental conditions: the wind speed, leakage area normalised by the floor area of the house, and gross building coverage ratio. In this study, the ranges of the uncertainty of the reduction factors for particles and iodine in reactive gas form were investigated under various environmental conditions, and sensitivity analyses were conducted to understand the parameter with the most influence on the uncertainty of the reduction factor. From the results of the uncertainty analyses, the calculated reduction factor was highly variable depending on the environmental condition and the airtightness of the houses. The median and 95th percentile of the reduction factors for the older houses were 0.5 and 0.9 for particles and 0.07 and 0.4 for iodine in reactive gas form, respectively and these ranges were smaller for newer houses. From the results of the sensitivity analyses, the wind speed was the most influential parameter determining the reduction factor. Additionally, the wind speed was less influential for the reduction factor in newer houses.

Assessment of doses in contaminated urban areas: modelling exercise based on Fukushima data

State-of-the-art dose assessment models were applied to estimate doses to the population in urban areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Assessment results were compared among five models, and comparisons of model predictions with actual measurements were also made. Assessments were performed using both probabilistic and deterministic approaches. Predicted dose distributions for indoor and outdoor workers from a probabilistic approach were in good agreement with the actual measurements. In addition, when the models were applied to assess the doses to the representative person, based on a concept recommended by the International Commission on Radiological Protection and in the International Atomic Energy Agency Safety Standards, it was evident that doses to the representative person obtained with a deterministic approach were always higher than those obtained with a probabilistic approach using the same model.

Urban working groups in the IAEA's model testing programmes: overview from the MODARIA I and MODARIA II programmes

The IAEA's model testing programmes have included a series of Working Groups concerned with modelling radioactive contamination in urban environments. These have included the Urban Working Group of Validation of Environmental Model Predictions (1988-1994), the Urban Remediation Working Group of Environmental Modelling for Radiation Safety (EMRAS) (2003-2007), the Urban Areas Working Group of EMRAS II (2009-2011), the Urban Environments Working Group of (Modelling and Data for Radiological Impact Assessments) MODARIA I (2013-2015), and most recently, the Urban Exposures Working Group of MODARIA II (2016-2019). The overarching objective of these Working Groups has been to test and improve the capabilities of computer models used to assess radioactive contamination in urban environments, including dispersion and deposition processes, short-term and long-term redistribution of contaminants following deposition events, and the effectiveness of various countermeasures and other protective actions, including remedial actions, in reducing contamination levels, human exposures, and doses to humans. This paper describes the exercises conducted during the MODARIA I and MODARIA II programmes. These exercises have included short-range and mid-range atmospheric dispersion exercises based on data from field tests or tracer studies, hypothetical urban dispersion exercises, and an exercise based on data collected after the Fukushima Daiichi accident. Improvement of model capabilities will lead to improvements in assessing various contamination scenarios (real or hypothetical), and in turn, to improved decision-making and communication with the public following a nuclear or radiological emergency.

Backward Estimation of Atmospheric Release of 137Cs and 131I Using Total Cumulative Deposition in Terrestrial Areas Following the Fukushima Daiichi Nuclear Power Plant Accident

ABSTRACT

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident caused a significant release of radionuclides into the environment. It is important to explore the timing and amount of radioactive release to terrestrial areas in order to clarify the consequences of the accident, including the dose received by the population living in the areas affected by the accident. In general, backward estimations are performed using air concentrations of radionuclides, but they are difficult to measure when radioactive plumes are passing through, and only spatially and temporally limited measurements are available. Therefore, a new method of backward estimation was developed based on the total cumulative deposition density, which can provide sufficient data in the environment by combining the atmospheric transport, dispersion, and deposition model calculations. Consequently, our estimations show that a major release of 137Cs and 131I occurred on 15, 20, 21, 22, 25, and 30 March 2011, after the accident. The amounts of release estimated by our new method for 137Cs and 131I were 4.9 × 1015 Bq and 120 × 1015 Bq, respectively. These results have no significant contradiction with the estimated results by the previous studies that were based on air concentrations and air dose rates that were measured in terrestrial areas. It was found that our new method is applicable for backward estimation oriented to the dose assessment for the people living in terrestrial areas.

Penetration factor and indoor deposition rate of elementary and particulate iodine in a Japanese house for assessing the effectiveness of sheltering for radiation exposures

Sheltering is one of the countermeasures for protection against radiation exposures in nuclear accidents. The effectiveness of sheltering is often expressed by the reduction factor, that is the ratio of the indoor to the outdoor cumulative radioactivity concentrations or doses. The indoor concentration is mainly controlled by the air exchange rate, penetration factor, and indoor deposition rate. The penetration factor and indoor deposition rate depend on the surface and the materials and structure of windows and doors as it is these openings in the building envelope that control penetration. We investigated experimentally these parameters of I₂and particles. The experiment was performed in two apartment houses, three single-family houses, and chambers. The obtained penetration factor ranged from 0.3 to 1 for particles of 0.3-1μm and 0.15-0.7 for I₂depending on the air exchange rate. The indoor deposition rate for a house room ranged from 0.007 to 0.2 h^-1for particles of 0.3-1μm and 0.2-1.5 h^-1for I₂.

Indoor and outdoor radionuclide distribution in houses after the Fukushima Dai-ichi Nuclear Power Plant accident

An enormous amount of radionuclides was released into the atmosphere following the Fukushima Dai-ichi Nuclear Power Plant accident, with part of it penetrating houses. Information on radionuclide distribution inside and outside houses is useful for indoor external dose assessments. To investigate the radionuclide distribution, we collected both soil samples around the target houses and house material samples (i.e., floor, inner wall, ceiling, outer wall, and roof) in Fukushima Prefecture in 2019. The activity of the samples was measured using a high-purity germanium detector. The surface contamination densities of the floor, inner wall, ceiling, outer wall, and roof relative to the ground were 3 × 10^-3-7 × 10^-2, 6 × 10^-5-4 × 10^-4, 7 × 10^-5-3 × 10^-4, 2 × 10^-3-1 × 10^-2, and 4 × 10^-3-2 × 10^-1, respectively. The relative surface contamination densities varied depending on the surface material, its location, and surface orientation, indicating that these uncertainty factors should be considered in the dose assessment for residents.

Assessment Model of Radiation Doses from External Exposure to the Public after the Fukushima Daiichi Nuclear Power Plant Accident

Radiation exposure is one of most important factors to manage following a nuclear emergency. Actual measurement is the best way to obtain information concerning the dose received by the people in terms of accuracy and reliability. However, in practice, it is difficult to collect measurements from all people affected by nuclear accidents over the whole period of exposure from past to future. Therefore, probabilistic assessment using a model is needed. An assessment model of radiation doses from external exposures was developed based on the actual measurement of individual doses and ambient dose equivalent rates inside and outside houses in Fukushima City. A survey of behavioral patterns was also performed for the same purpose. In addition to our measurement and survey, we took into account the latest insights from the experiences of the Fukushima Daiichi nuclear power plant accident. Comparisons between the assessed and measured results revealed that the time-dependence of doses and the distribution of doses obtained using the developed models agree well with the results of actual measurements. Thus, our probabilistic approach was validated. Based on both our assessment and on our actual measurements, no participants were observed to receive doses in excess of 1 mSv y as of 8 y after the Fukushima Daiichi nuclear power plant accident in Fukushima City.

Development of an External Radiation Dose Estimation Model for Children Returning to Their Homes in Areas Affected by the Fukushima Nuclear Accident

On 1 April 2017, around 6 y after the Fukushima Daiichi nuclear power station accident, evacuation orders for large affected areas were lifted, and areas to which people could return were expanded. In the current study, a dose estimation model based on a probabilistic approach has been developed to estimate the external radiation doses children would receive after returning to these areas. The target groups are children from infants to high school students, and the target areas are nine municipalities including evacuation areas as of 5 September 2015. The estimation period is for 4 y starting 1 April 2017. Validation of the model in an area for which individual personal dosimetry measurements were available showed that it is valid for infants, kindergarteners, 3rd and 4th grade elementary school students, 5th and 6th grade elementary school students, and junior high school students. Considering the statement of the International Commission on Radiological Protection, the estimated radiation doses for these five age groups were taken to be the 95th percentiles of the predicted distributions as an index of conservative judgement. As a result of our estimations, the 95th percentile doses to all age groups were less than 20 mSv y in all periods and in all areas. The 95th percentile doses in some areas were less than 1 mSv y, which is the long-term dosimetric target set by the Japanese government. It should be noted that our results are preliminary, being based on several assumptions and limitations regarding environmental contamination conditions and the behavioral patterns of children. To estimate the children's doses precisely, further considerations for these assumptions and limitations will be needed.

Abstract P3-03-21: Usefulness of sentinel lymph node biopsy by indocyanine green fluorescence method for cN0 breast cancer patients

Background. Indocyanine green (ICG) fluorescence method (ICG-f) has been recently widely used in sentinel lymph node (SLN) detection. The advantages of ICG-f are no radiation exposure, no limitation to use in high-volume medical centers without radioactive facility, and to confirm lymph flow as a real-time image from outside the body. ICG-f identified an average of 2.3-3.4 SLNs and the detection rate was 99%, compared to 1.7-2 SLNs by RI methods. Long-term observation after SNB using ICG-f has not been reported, including arm lymphedema as the complication of this method.We evaluate the usefulness of SLN biopsy (SNB) for cN0 breast cancer patients from data of multicenter cohort study on long-term results after negative SNB by ICG-f.

Methods. Eleven hundred and thirty-two women were enrolled who had histologically proved clinical stage T1-4, pN0, M0 primary invasive breast cancer with SNB using ICG-f (ICG alone or combination of RI/blue dye method) sparing axillary lymph node dissection from May 2007 to December 2015. This study is retrospective, multicenter cohort study conducted at 6 centers in Japan. Primary endpoint is axillary recurrence rate. We analyzed the correlation with the axillary recurrence and adjuvant systemic therapy, adjuvant radiotherapy, and the clinicopathological characteristics. Secondary endpoint is lymphedema.

Results and Discussion. The median follow-up time was 41 (range 21-117) months, and axillary recurrence was found in 6 patients (0.53%). Five out of 6 patients were not received standard adjuvant systemic therapy or adjuvant radiation therapy after breast conserving surgerybecause of patient's preference or old age. Lymphedema was identified only 4 patients in 632 patients. It is reported that axillary recurrence after SNB was 0.3-1.65%, which was consistent with our result. Lymphedema was not frequent in patients received SNB using ICG-f, because SLNs are removed along with lymphatic ducts in the limited area of axillary adipose tissue.

Conclusion.Axillary recurrence after negative SNB using ICG-f was comparable to RI or blue dye method. It might be important to perform appropriate adjuvant medication or radiation therapy for preventing axillary recurrence after SNB using ICG-f.

Next, ICG-f after neoadjuvant chemotherapy is to be investigated, because itis reported that removing more than 2 SLNs were associated with a lower likelihood of false negative ratio in patients with clinically node-positive disease converted to clinically node-negative after chemotherapy, and ICG-f might overcome this issue.

Citation Format: Maeshima Y, Takahara S, Yamauchi A, Yamagami K, Sugie T, Yamashiro H, Kato H, Torii M, Takada M, Torii M. Usefulness of sentinel lymph node biopsy by indocyanine green fluorescence method for cN0 breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-21.

Relationship Between Stress Coping Mechanisms and Depression in Kidney Transplant Recipients

BACKGROUND

It has been reported that transplant recipients are exposed to physical and psychosocial stresses even after transplant surgery and exhibit psychological disorders such as depression.

PURPOSE

In this study, we extracted trends concerning how recipients of kidney transplants cope with stress, and we also examined how they cope with depression and its countermeasures.

METHOD

We administered questionnaire surveys to 109 kidney transplant recipients. These included items on personal attributes, medical information, depression, and stress-coping type scales. Statistical analysis was performed using factor analysis and multiple regression analysis.

RESULTS

Fifteen out of 109 (13.8%) were found to be high-risk patients for depression based on responses to the questionnaire using the depression scale. We extracted 2 factors of stress-coping type, namely Factor 1, "Directly coping with the problem," of patients who try to directly resolve the problem in a positive manner and Factor 2, "Stress-release while avoiding the problem," for those who relieve their feelings in response to the stress without resolving the problem itself. When multiple regression analysis was conducted with the depression scale as the dependent variable and the stress-coping factor as the independent variable, Factor 1 tended to be associated with reduced depression and Factor 2 with increased depression.

CONCLUSIONS

Results showed that to improve the mental health of those who receive kidney transplants, it is necessary to examine the depression and stress-coping types of such patients at an early stage and carry out education on stress-coping, focusing on resolving the actual problem.

A Probabilistic Approach to Assess External Doses to the Public Considering Spatial Variability of Radioactive Contamination and Interpopulation Differences in Behavior Pattern

Dose assessment is an important issue from the viewpoints of protecting people from radiation exposure and managing postaccident situations adequately. However, the radiation doses received by people cannot be determined with complete accuracy because of the uncertainties and the variability associated with any process of defining individual characteristics and in the dose assessment process itself. In this study, a dose assessment model was developed based on measurements and surveys of individual doses and relevant contributors (i.e., ambient dose rates and behavior patterns) in Fukushima City for four population groups: Fukushima City Office staff, Senior Citizens' Club, Contractors' Association, and Agricultural Cooperative. In addition, probabilistic assessments were performed for these population groups by considering the spatial variability of contamination and interpopulation differences resulting from behavior patterns. As a result of comparison with the actual measurements, the assessment results for participants from the Fukushima City Office agreed with the measured values, thereby validating the model and the approach. Although the assessment results obtained for the Senior Citizens' Club and the Agricultural Cooperative differ partly from the measured values, by addressing further considerations in terms of dose reduction effects due to decontamination and the impact of additional exposure sources in agricultural fields, these results can be improved. By contrast, the measurements obtained for the participants from the Contractors' Association were not reproduced well in the present study. To assess the doses to this group, further investigations of association members' work activities and the related dose reduction effects are needed.

Estimation of radiocesium dietary intake from time series data of radiocesium concentrations in sewer sludge

After the Fukushima accident, it became important to determine the quantity of radionuclide ingested by inhabitants. The most common methods currently used to obtain such data are the "market basket" (MB) and "duplicate" (DP) methods. However, it is difficult to conduct monitorings using these methods with sufficient frequency as they are high cost and time-consuming. The present study proposes a new method to estimate the ingestion of radionuclides, based on the time-dependent concentrations of radiocesium in sewer sludge, which addresses the uncertainties of the two common methods. The newly proposed method, which we designate as SL, consists of three steps: (1) the separation of wet weather and dry weather data, (2) determining the mass balance of the wastewater treatment plant (WWTP), and (3) developing a reverse biokinetic model to relate the amount of radionuclides ingested to the amounts contained in the sewer sludge. We tested the new method using the time-dependent radiocesium concentrations in sewer sludge from the WWTP in Fukushima City. The results from the SL method agreed to those from the MB while overestimated those from DP method. The trend lines for all three methods, however, are in good agreement. Sensitivity analyses of SL method indicate further studies on uncertainties of sensitive parameters are deemed necessary to improve the accuracy of the method.

Comparison of Sensitivity of Immunocomplex Capture Fluorescence Analysis for Detecting Donor-specific Anti-HLA Class II Antibodies in Kidney Transplant Patients

BACKGROUND

Immunocomplex capture fluorescence analysis (ICFA) detects donor-specific antihuman leukocyte antigen (HLA) antibodies (DSA), but the detection sensitivity of HLA class II antibodies using conventional ICFA is as low as 57%. The aim of the study was to improve the detection sensitivity of HLA class II antibodies by ICFA, and compare the ICFA results with the Luminex single-antigen bead test.

METHODS

Six DSA-negative kidney transplant donors and recipient pairs and 10 HLA class II DSA-positive pairs were included in the study. The detection sensitivity of modified ICFA was compared with conventional ICFA, and the ICFA results were compared with the Luminex single-antigen bead test.

RESULTS

The index value of modified ICFA was higher than that of conventional ICFA. The cutoff value of conventional ICFA was 30,686 (MFI), which was improved to 19,405 using modified ICFA. Regarding the HLA-DQ antibody, 5 samples found to be positive by Luminex single-antigen bead testing were all negative using modified ICFA. The reason for this discrepancy could be related to: (1) the difference in detection sensitivity; (2) the difference in HLA antigen surface expression between naive lymphocytes and synthetic beads; or (3) the structure of synthetic HLA DQ antigen on the Luminex single-antigen beads.

CONCLUSION

The index value of the modified ICFA was higher than that of conventional ICFA, and the detection sensitivity of HLA class II antibodies was improved by modified ICFA. Further assessment is necessary to clarify the reasons for divergence between ICFA and Luminex single-antigen bead test results.

Altered expression of microRNA during fracture healing in diabetic rats

OBJECTIVES

Diabetes mellitus (DM) is known to impair fracture healing. Increasing evidence suggests that some microRNA (miRNA) is involved in the pathophysiology of diabetes and its complications. We hypothesized that the functions of miRNA and changes to their patterns of expression may be implicated in the pathogenesis of impaired fracture healing in DM.

METHODS

Closed transverse fractures were created in the femurs of 116 rats, with half assigned to the DM group and half assigned to the control group. Rats with DM were induced by a single intraperitoneal injection of streptozotocin. At post-fracture days five, seven, 11, 14, 21, and 28, miRNA was extracted from the newly generated tissue at the fracture site. Microarray analysis was performed with miRNA samples from each group on post-fracture days five and 11. For further analysis, real-time polymerase chain reaction (PCR) analysis was performed at each timepoint.

RESULTS

Microarray analysis showed that there were 14 miRNAs at day five and 17 miRNAs at day 11, with a greater than twofold change in the DM group compared with the control group. Among these types of miRNA, five were selected based on a comparative and extended literature review. Real-time PCR analysis revealed that five types of miRNA (miR-140-3p, miR-140-5p, miR-181a-1-3p, miR-210-3p, and miR-222-3p) were differentially expressed with changing patterns of expression during fracture healing in diabetic rats compared with controls.

CONCLUSIONS

Our findings provide information to further understand the pathology of impaired fracture healing in a diabetic rat model. These results may allow the potential development of molecular therapy using miRNA for the treatment of impaired fracture healing in patients with DM.Cite this article: S. Takahara, S. Y. Lee, T. Iwakura, K. Oe, T. Fukui, E. Okumachi, T. Waki, M. Arakura, Y. Sakai, K. Nishida, R. Kuroda, T. Niikura. Altered expression of microRNA during fracture healing in diabetic rats. Bone Joint Res 2018;7:139-147. DOI: 10.1302/2046-3758.72.BJR-2017-0082.R1.

cis-1 Isomers of tethered bismethano[70]fullerene as electron acceptors in organic photovoltaics

Isomer-controlled [70]fullerene bis-adducts can achieve high performance as electron-acceptors in organic photovoltaics (OPVs) because of their stronger absorption intensities than [60]fullerene derivatives, higher LUMO energy levels than mono-adducts, and less structural and energetic disorder than random isomer mixtures. Especially, attractive are cis-1 isomers that have the closest proximity of addends owing to their plausible more regular close packed structure. In this study, propylene-tethered cis-1 bismethano[70]fullerene with two methyl, ethyl, phenyl, or thienyl groups were rationally designed and prepared for the first time to investigate the OPV performances with an amorphous conjugated polymer donor (PCDTBT). The cis-1 products were found to be a mixture of two regioisomers, α-1-α and α-1-β as major and minor components, respectively. Among them, the cis-1 product with two ethyl groups (Et₂-cis-1-[70]PBC) showed the highest OPV performance, encouraging us to isolate its α-1-α isomer (Et₂-α-1-α-[70]PBC) by high-performance liquid chromatography. OPV devices based on Et₂-cis-1-[70]PBC and Et₂-α-1-α-[70]PBC with PCDTBT showed open-circuit voltages of 0.844 V and 0.864 V, respectively, which were higher than that of a device with typical [70]fullerene mono-adduct, [70]PCBM (0.831 V) with a lower LUMO level. However, the short-circuit current densities and resultant power conversion efficiencies of the devices with Et₂-cis-1-[70]PBC (9.24 mA cm⁻², 4.60%) and Et₂-α-1-α-[70]PBC (6.35 mA cm⁻², 3.25%) were lower than those of the device with [70]PCBM (10.8 mA cm⁻², 5.8%) due to their inferior charge collection efficiencies. The results obtained here reveal that cis-1 [70]fullerene bis-adducts do not guarantee better OPV performance and that further optimization of the substituent structures is necessary.

cis-1 Isomers of [70]fullerene bis-adducts were utilized as electron-acceptors in organic photovoltaic devices for the first time.

Dose-reduction Effects of Vehicles against Gamma Radiation in the Case of a Nuclear Accident

Self-evacuation by a private vehicle is one of the most commonly used methods of public evacuation in the case of a nuclear accident. The aim of this paper is to evaluate the dose-reduction effects of vehicles. To achieve this aim, a model for calculating the dose reduction factor was developed based on the actual shape and weight of Japanese vehicles. This factor is defined as the ratio of dose rate inside a vehicle to that outside. The model was developed based on weight of vehicle to take into account the dose-reduction effects due to not only the steel plate of the vehicle body but also the other assemblies. In addition to model calculation, the dose reduction factors were evaluated by actual measurements in the areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. A comparison between the simulated and the measured results revealed that the dose reduction factors obtained using the developed models were in good agreement with the results of actual measurements. Using this model, we also evaluated the dose reduction factors for cloudshine and groundshine in the case of a nuclear accident. The evaluations were performed for four vehicle models whose weights were 800-1,930 kg. The dose reduction factor for cloudshine with photon energy of 0.4-1.5 MeV was 0.66-0.88, and that for groundshine from Cs was 0.64-0.73. Although these results were obtained under the assumption that Cs is placed only on the ground surface, according to these considerations, if Cs migrated into the ground corresponding to the relaxation mass depth of 10 g cm, the dose reduction factors would be almost 8% less than those for the ground surface.

Bioaccessibility of Fukushima-Accident-Derived Cs in Soils and the Contribution of Soil Ingestion to Radiation Doses in Children

Ingestion of contaminated soil is one potential internal exposure pathway in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Doses from this pathway can be overestimated if the availability of radioactive nuclides in soils for the gastrointestinal tract is not considered. The concept of bioaccessibility has been adopted to evaluate this availability based on in vitro tests. This study evaluated the bioaccessibility of radioactive cesium from soils via the physiologically-based extraction test (PBET) and the extractability of those via an extraction test with 1 mol/L of hydrochloric acid (HCl). The bioaccessibility obtained in the PBET was 5.3% ± 1%, and the extractability in the tests with HCl was 16% ± 3%. The bioaccessibility was strongly correlated with the extractability. This result indicates the possibility that the extractability in HCl can be used as a good predictor of the bioaccessibility with PBET. In addition, we assessed the doses to children from the ingestion of soil via hand-to-mouth activity based on our PBET results using a probabilistic approach considering the spatial distribution of radioactive cesium in Date City in Fukushima Prefecture and the interindividual differences in the surveyed amounts of soil ingestion in Japan. The results of this assessment indicate that even if children were to routinely ingest a large amount of soil with relatively high contamination, the radiation doses from this pathway are negligible compared with doses from external exposure owing to deposited radionuclides in Fukushima Prefecture.

Assessment of residual doses to population after decontamination in Fukushima Prefecture

Large quantities of radioactive materials were released into the environment as a result of the Fukushima Daiichi Nuclear Power Station accident. Many inhabitants residing in the affected areas are now exposed to radiation in their daily lives. In an attempt to manage this radiation dose, an additional radiation dose of 1 mSv/y was adopted as a long-term dosimetric target. An activity level reading of 0.23 μSv/h was then determined as a guidance value to achieve the target by implementing decontamination measures. The objectives of this study are to assess the effects of decontamination based on this guidance value and to predict any possible future problems with the decontamination strategy. Using a probabilistic approach, we assessed the annual effective dose of indoor workers, outdoor workers, and pensioners in the Fukushima Prefecture. Our probabilistic model considers the variabilities in behavioral patterns and Cs-137 surface-activity levels. Five years after the initial contamination, the 95th percentiles of indoor workers and pensioners in 53 of the 59 municipalities were found to receive annual effective doses of below 1 mSv/y (0.026-0.73 mSv/y). However, for outdoor workers in 25 municipalities, the annual doses were over 1 mSv/y (1.0-35 mSv/y). Therefore, the guidance value is effective for indoor workers and pensioners; to determine whether additional countermeasures for outdoor workers should be implemented, a detailed assessment that uses more realistic assumptions is required.

Induction Immunosuppressive Therapy With Everolimus and Low-Dose Tacrolimus Extended-Release Preserves Good Renal Function at 1 Year After Kidney Transplantation

BACKGROUND

Utilization of everolimus (EVR) has been increasing in recent years for patients undergoing renal transplantation to reduce calcineurin inhibitor (CNI) levels. However, an optimum regimen has yet to be established.

METHODS

We retrospectively examined 12 renal transplant recipients who underwent an induction immunosuppressive protocol; the protocol comprises 5 agents, including EVR plus low-dose tacrolimus extended-release (TAC-ER) treatment. We compared those findings from those of 14 patients who underwent a conventional protocol without EVR. Clinical outcome and pathologic changes were assessed by using protocol graft biopsy findings obtained at 3 months and 1 year after transplantation.

RESULTS

The estimated glomerular filtration rate was significantly higher for the EVR group at both 3 months and 1 year compared with the conventional group (P < .01 and P = .03, respectively). TAC-ER trough levels were also significantly lower at 3 months and 1 year (both, P < .01). Histologic findings of the 3-month protocol biopsy samples in the EVR group revealed 4 cases of borderline change and 2 of acute cellular-mediated rejection. The findings from the 1-year biopsy samples revealed 10 cases with normal findings with no evidence of CNI toxicity. Patients in the EVR group developed subclinical borderline change and acute cellular-mediated rejection after 3 months at a significantly higher rate than the conventional group (P = .02).

CONCLUSIONS

Use of the present therapeutic strategy successfully maintained the trough of each drug at a lower level, and it also kept renal function stable up to 1 year after transplantation.

Practices for Supporting and Confirming Decision-Making Involved in Kidney and Liver Donation by Related Living Donors in Japan: A Nationwide Survey

This nationwide survey investigated the actual practices for supporting and confirming the decision-making involved in related living-organ donations in Japan, focusing on organ type and program size differences. Answers to a questionnaire survey were collected from 89 of the 126 (71%) kidney and 30 of the 35 (86%) liver transplantation programs in Japan that were involved in living-donor transplantations in 2013. In 70% of the kidney and 90% of the liver transplantation programs, all donors underwent "third-party" interviews to confirm their voluntariness. The most common third parties were psychiatrists (90% and 83%, respectively). Many programs engaged in practices to support decision-making by donor candidates, including guaranteeing the right to withdraw consent to donate (70% and 100%, respectively) and prescribing a set "cooling-off period" (88% and 100%, respectively). Most donors were offered care by mental health specialists (86% and 93%, respectively). Third parties were designated by more of the larger kidney transplant programs compared with the smaller programs. In conclusion, the actual practices supporting and confirming the decision to donate a living organ varied depending on the organ concerned and the number of patients in the program.

Radiation protection issues on preparedness and response for a severe nuclear accident: experiences of the Fukushima accident

Radiation protection issues on preparedness and response for a severe nuclear accident are discussed in this paper based on the experiences following the accident at Fukushima Daiichi nuclear power plant. The criteria for use in nuclear emergencies in the Japanese emergency preparedness guide were based on the recommendations of International Commission of Radiological Protection (ICRP) Publications 60 and 63. Although the decision-making process for implementing protective actions relied heavily on computer-based predictive models prior to the accident, urgent protective actions, such as evacuation and sheltering, were implemented effectively based on the plant conditions. As there were no recommendations and criteria for long-term protective actions in the emergency preparedness guide, the recommendations of ICRP Publications 103, 109, and 111 were taken into consideration in determining the temporary relocation of inhabitants of heavily contaminated areas. These recommendations were very useful in deciding the emergency protective actions to take in the early stages of the Fukushima accident. However, some suggestions have been made for improving emergency preparedness and response in the early stages of a severe nuclear accident.

Performance of the Japanese glomerular filtration rate equation based on standardized serum cystatin C in potential kidney donors

BACKGROUND

It was reported that the glomerula filtration rate (GFR) equation based on serum creatinine underestimated the GFR in potential kidney donors. Recently, the Japanese GFR equation based on standardized serum cystatin C was reported. Therefore, we assessed the performance of the equation in potential kidney donors.

METHODS

Forty-five potential kidney donors from 2 hospitals were included. GFR was measured (mGFR) using inulin renal clearance. Serum creatinine was measured using the enzymatic method. Serum cystatin C was measured using a nephelometric immunoassay (Siemens) and calibrated to the standardized value traceable to ERM-DA471/IFCC using an equation reported previously. The estimated GFR (eGFR) was calculated using the Japanese GFR equation based on serum creatinine (eGFRcreat) and the Japanese GFR equation based on serum cystatin C (eGFRcys). Bias (mGFR - eGFR) and accuracy (P30) of the equations were evaluated.

RESULTS

Inulin clearance, eGFRcreat, and eGFRcys were 91.0 ± 18.2, 78.5 ± 18.8, and 93.3 ± 16.3 mL/min/1.73 m(2), respectively. Bias of eGFRcreat was 12.4 ± 15.8 mL/min/1.73 m(2) and significantly different from zero, indicating underestimation of GFR. Bias of eGFRcys was -2.3 ± 16.3 mL/min/1.73 m(2) and was not significantly different from zero, suggesting better performance. But, the precision (standard deviation [SD] of bias) and accuracy (P30: Percentage of participants with eGFR within 30% of mGFR) of eGFRcys were not better compared with eGFRcreat. Accuracies (P30) of eGFRcreat and eGFRcys were 87% (95% confidence interval [CI], 74-94) and 82% (95% CI, 69-91), respectively.

CONCLUSION

Bias of eGFRcys was better compared with eGFRcreat. But, the precision (SD of bias) and accuracy of eGFRcys were not superior compared with eGFRcreat in potential kidney donors.

Statistical characterization of radiation doses from external exposures and relevant contributors in Fukushima prefecture

In areas contaminated by radioactive materials, well designed dose assessment is necessary in order to protect people from radiation exposure and manage the exposure situation appropriately. Probabilistic dose assessment is a useful method for providing a more complete characterization of information on dose distributions in the population and requires statistically characterized data on pathway-relevant contributors. The objective of this paper is to determine statistical features of contributors to external exposures, as well as to identify causes of variabilities of individual doses to the populations living in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. To achieve these objectives, measurements of individual doses and ambient dose rates, as well as surveys of behavioral patterns, were performed between February and April 2012. These were made with the cooperation of indoor workers, outdoor workers, and pensioners living in Fukushima prefecture. On the basis of these results, statistical analyses were performed in order to identify variabilities of contributors. In addition, a multi-regression analysis was done to explore a significant relationship between individual doses and relevant contributors. Results showed that the ambient dose equivalent rate also distributed with lognormal form, and it had variabilities attributable to the spatial distribution of deposited radionuclides. The distribution form of time spent outdoors depends on the characteristics of occupation, and the distributions for indoor workers and outdoor workers were lognormal and normal, respectively. Results of a multiple-regression analysis suggested that such variabilities of contributors give rise to significant differences in individual doses among the populations.

Proceedings from an international consensus meeting on posttransplantation diabetes mellitus: recommendations and future directions

A consensus meeting was held in Vienna on September 8-9, 2013, to discuss diagnostic and therapeutic challenges surrounding development of diabetes mellitus after transplantation. The International Expert Panel comprised 24 transplant nephrologists, surgeons, diabetologists and clinical scientists, which met with the aim to review previous guidelines in light of emerging clinical data and research. Recommendations from the consensus discussions are provided in this article. Although the meeting was kidney-centric, reflecting the expertise present, these recommendations are likely to be relevant to other solid organ transplant recipients. Our recommendations include: terminology revision from new-onset diabetes after transplantation to posttransplantation diabetes mellitus (PTDM), exclusion of transient posttransplant hyperglycemia from PTDM diagnosis, expansion of screening strategies (incorporating postprandial glucose and HbA1c) and opinion-based guidance regarding pharmacological therapy in light of recent clinical evidence. Future research in the field was discussed with the aim of establishing collaborative working groups to address unresolved questions. These recommendations are opinion-based and intended to serve as a template for planned guidelines update, based on systematic and graded literature review, on the diagnosis and management of PTDM.

Latent mesangial immunoglobulin A deposition in long-term functioning kidney does not correlate with disease progression and may exhibit fluctuating patterns

BACKGROUND

Latent mesangial immunoglobulin (Ig)A deposition in long-term functioning kidney does not correlate with disease progression and may exhibit fluctuating patterns Mesangial IgA deposition without urinary abnormalities (latent mesangial IgA deposition) is occasionally observed in non-episode biopsies of kidney allografts. However, the histologic features of latent IgA deposition have not been fully characterized.

METHODS

To better identify the clinicopathologic background of subclinical mesangial IgA deposition, we compared the clinical and histologic characteristics of long-term functioning kidney allografts with and without latent IgA deposition.

RESULTS

Among 29 patients with a posttransplant duration of >10 years, 37.9% exhibited latent mesangial IgA deposition. Biopsies indicated that renal function at the time of and 5 years before subclinical mesangial IgA deposition was generally similar. HLA-DR4 and HLA-Bw51 showed a nonsignificant trend to be more frequent in the IgA-positive group. Histologic investigation demonstrated no changes in disease scores based on the Banff 2009 classification between groups. Immunofluorescence revealed co-deposition of C3 at >1+ intensity in 72% IgA-positive patients. Immunohistochemical analysis revealed that IgA deposition per se did not cause notable increases in intraglomerular α-smooth muscle actin (SMA)-positive cells. One patient with subclinical IgA deposition demonstrated a waxing and waning pattern in the amount of IgA deposition.

CONCLUSION

This study suggests that subclinical IgA deposition in long-term functioning kidney allografts is not associated with progressive course in clinical and pathologic findings. Furthermore, the amount of subclinical IgA deposition may exhibit fluctuating patterns in some cases.

Obstacles of non-heart-beating donor kidney transplantation in Japan to date and future perspectives

In Japan, multiple organ retrieval from brain-dead heart-beating donors has been gradually increasing since the law was adopted in 1997 and amended in 2009. However, almost more than 90% of total deceased donor kidney transplantation (DDKT) in Japan are still obtained from non-heart-beating donors (NHBD). The majority of NHBD are Maastricht categories IV and III. In category IV, we usually place a double balloon arterial and a venous drainage catheter via the femoral vessels after the diagnosis of clinical brain death and acquisition of informed consent from the family. After controlled cardiac arrest, the double balloons are inflated and in situ cold perfusion started as soon as possible to minimize warm ischemic time (WIT), seeking to achieve a zero to within a few minutes WIT in most cases. In category III, it is impossible to place the device prior to cardiac arrest. In these cases, after declaration of cardiac death, cardiopulmonary compression is accompanied by systemic heparinization, immediate laparotomy, and insertion of a cold perfusion catheter at the aortic and caval bifurcations to minimize WIT. NHBD kidney retrieval is critical; extirpation must be performed as rapidly as possible. The results of NHBD kidney transplantation in Japan are excellent, according to the advancement and utilization of in situ cannulation, organ perfusion, and sophisticated retrieval techniques. The patient and graft survival rates of DDKT at 1, 3, and 5 years in most recent 2001 to 2007 era were 95.4%, 92.2%, 89.1% (n = 945) and 89.2%, 83.7%, 77.8% (n = 919), respectively.