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Radiocesium released by the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident still exists in the environment in two forms: adsorbed species on mineral particles in the soil and microparticles containing radiocesium mainly composed of silicate glass (CsMPs). CsMPs are dispersed not only around the FDNPP but also over a wide area of the Kanto region. The behavior and characteristics of CsMPs must be investigated to evaluate the impact of the FDNPP accident. Deposited particles including radiocesium were wiped from metal handrails on balconies and car hoods using tissue papers at six locations in the Kanto region (Tokai village, Ushiku City, Abiko City, Chiba City, Kawaguchi City, and Arakawa Ward) between March 15 and 21, 2011. CsMPs were isolated from the samples, and their characteristics were investigated. In total, 106 CsMPs derived from Unit 2 were successfully separated from 13 tissue paper samples. The radiation images of the two types of CsMPs discovered in Ushiku City demonstrate that CsMPs can easily become susceptible to fragmentation over time, even in the absence of weathering effects., (© 2023. The Author(s).)

Abstract: The plume from Fukushima Dai-ichi Nuclear Power Plant (FDNPP) Unit 2, which reached the Tokyo metropolitan area on 15 March 2011 immediately after the FDNPP disaster, contained insoluble radiocesium-bearing microparticles (CsMPs). This study aimed to reanalyze a mask worn during the disaster to determine the ratio of CsMPs to radiocesium that directly arrived in the Tokyo metropolitan area as a plume immediately after the disaster. CsMPs were isolated from the non-woven masks worn at the Hongo Campus of the University of Tokyo from 15-16 March 2011 that trapped radioactive material from the accident. Twenty-two CsMPs with diameters in the range of 1.9-3.6 μm were found in the mask worn outdoors by one person. The CsMP radioactive ratio to overall radiocesium content of the mask was 9.9%. The CsMPs were collected more efficiently by the mask than by a suspended particulate matter filter. A face mask might trap CsMPs in a plume more efficiently than a suspended particulate matter filter. Determining the amount of CsMPs led to a reassessment of the internal dose by CsMPs that were inhaled by the public immediately after the FDNPP accident., (Copyright © 2023 Health Physics Society.)

A decade has passed since the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident on March 11, 2011. However, radioactive particles have recently been detected in the indoor air of some residences near the FDNPP. Following the recommendations of previous research, we determined the presence of radiocesium-bearing microparticles (CsMPs) and measured the radioactivity of radiocesium that adhered on non-woven face masks worn by six persons during the indoor cleaning of 59 residences in Namie, Futaba, Okuma, and Tomioka towns in Fukushima Prefecture. Of the 284 masks worn in this study, significant 137 Cs radioactivity was detected in 268, and 44 new CsMPs were discovered in 28. The results of this study also suggest the presence of highly concentrated soluble radiocesium particles or soluble radioactive cesium aerosols adhered to house dust. This implies that the CsMPs constituted a large proportion of radioactivity in the indoor air contamination for particles in the 1.0-2.5 µm size range due to the radioactive radiocesium particles. It is desirable to wear masks during cleaning to prevent inhalation of CsMPs., (© 2023. The Author(s).)

Dementia with Lewy bodies (DLB) is the second most common form of neurodegenerative dementia in elderly people, following Alzheimer's disease. Only three genes, SNCA (α-synuclein), APOE (apolipoprotein E), and GBA (glucosylceramidase), have been convincingly demonstrated to be associated with DLB. Here, we applied whole-genome sequencing to blood samples from 61 DLB patients and 45 cognitively normal controls. We used accumulation of candidate mutations to detect novel DLB-associated genes. Subsequent single nucleotide polymorphism (SNP) genotyping and association studies in a large number of samples from Japanese individuals revealed novel heterozygous variants in MFSD3 (rs143475431, c.888T>A:p.C296*; n = 5,421, p = 0.00063) and MRPL43 (chr10:102746730, c.241A>C:p.N81H; n = 4,782, p = 0.0029). We further found that the MFSD3 variant increased plasma levels of butyrylcholinesterase (n = 1,206, p = 0.029). We believe that our findings will contribute to the understanding of DLB and provide insight into its pathogenic mechanism for future studies., (© 2022 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics published by Wiley Periodicals LLC.)

MicroRNAs (miRNAs) are small non-coding RNAs shown to regulate gene expression by binding to complementary transcripts. Genetic variants, including single-nucleotide polymorphisms and short insertions/deletions, contribute to traits and diseases by influencing miRNA expression. However, the association between genetic variation and miRNA expression remains to be elucidated. Here, by using genotype data and miRNA expression data from 3448 Japanese serum samples, we developed a computational pipeline to systematically identify genome-wide miRNA expression quantitative trait loci (miR-eQTLs). Not only did we identify a total of 2487 cis-miR-eQTLs and 3 155 773 trans-miR-eQTLs at a false discovery rate of <0.05 in six dementia types (Alzheimer's disease, dementia with Lewy bodies, vascular dementia, frontotemporal lobar degeneration, normal-pressure hydrocephalus and mild cognitive impairment) and all samples, including those from patients with other types of dementia, but also we examined the commonality and specificity of miR-eQTLs among dementia types. To enable data searching and downloading of these cis- and trans-eQTLs, we developed a user-friendly database named JAMIR-eQTL, publicly available at https://www.jamir-eqtl.org/. This is the first miR-eQTL database designed for dementia types. Our integrative and comprehensive resource will contribute to understanding the genetic basis of miRNA expression as well as to the discovery of deleterious mutations, particularly in dementia studies. Database URL: https://www.jamir-eqtl.org/., (© The Author(s) 2021. Published by Oxford University Press.)

Alzheimer's disease (AD) has no cure, but early detection and risk prediction could allow earlier intervention. Genetic risk factors may differ between ethnic populations. To discover novel susceptibility loci of AD in the Japanese population, we conducted a genome-wide association study (GWAS) with 3962 AD cases and 4074 controls. Out of 4,852,957 genetic markers that passed stringent quality control filters, 134 in nine loci, including APOE and SORL1, were convincingly associated with AD. Lead SNPs located in seven novel loci were genotyped in an independent Japanese AD case-control cohort. The novel locus FAM47E reached genome-wide significance in a meta-analysis of association results. This is the first report associating the FAM47E locus with AD in the Japanese population. A trans-ethnic meta-analysis combining the results of the Japanese data sets with summary statistics from stage 1 data of the International Genomics of Alzheimer's Project identified an additional novel susceptibility locus in OR2B2. Our data highlight the importance of performing GWAS in non-European populations.

The distribution of radiocesium was examined in bamboo shoots, Phyllostachys pubescens, collected from 10 sites located some 41 to 1140 km from the Fukushima Daiichi nuclear power plant, Japan, in the Spring of 2012, 1 year after the Fukushima nuclear accident. Maximum activity concentrations for radiocesium ¹³⁴Cs and ¹³⁷Cs in the edible bamboo shoot parts, 41 km away from the Fukushima Daiichi plant, were in excess of 15.3 and 21.8 kBq/kg (dry weight basis; 1.34 and 1.92 kBq/kg, fresh weight), respectively. In the radiocesium-contaminated samples, the radiocesium activities were higher in the inner tip parts, including the upper edible parts and the apical culm sheath, than in the hardened culm sheath and underground basal parts. The radiocesium/potassium ratios also tended to be higher in the inner tip parts. The radiocesium activities increased with bamboo shoot length in another bamboo species, Phyllostachys bambusoides, suggesting that radiocesium accumulated in the inner tip parts during growth of the shoots.

An application of sequential automated SPE separation equipment coupled to the quadrupole-based ICPMS instrumentation with a dynamic reaction cell such as a screening test system of (90)Sr and Pu isotopes in environmental samples was developed in this work. So far, during the course of a large number of reports as to various specific radioactivities in environmental samples surveyed at radioactive contaminated area around the Fukushima Daiichi Nuclear Power Plants (FDNPP), there is a much smaller number of reports on (90)Sr and Pu isotopes than that of (134)Cs and (137)Cs since the FDNPP accident, and then it would be expected to develop the simple analysis method of these isotopes instead of radiation measurements currently in use. In particular, a screening for (90)Sr in environmental samples has been accomplished using an isotopic ratio measurement mode in comparison with the characterization on the Solid Phase Elution (SPE) separation between strontium and zirconium isotopes around the mass-90 fraction. As a result, for a trial analysis of environmental samples of a muddy snow water and a soil which were collected at Fukushima, it was found that the present developed system makes it applicable for achieving up to the specific activity levels of several hundreds Bq/kg ((90)Sr) and about 1-2Bq/kg (Pu isotopes) as the screening test system., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

We succeeded to establish cell lines from endemic fish species Honmoroko Gnathopogon caerulescens, which inhabits Lake Biwa, the third oldest lake in the world. Two cell lines designated as RMT1 and RMO1 were established from testis and ovary of G. caerulescens, respectively. These cell lines were initially cultured in Leibovitz's L-15 medium supplemented with fetal bovine serum (FBS), fish embryo extract, epidermal growth factor, and basic fibroblast growth factor. Further addition of forskolin and β-mercaptoethanol was required to establish and maintain these cell lines for more than 60 passages. RMT1 and RMO1 cells showed fibroblast- and epithelial-like morphology, respectively. From immunocytochemical staining and gene expression patterns, RMT1 cells showed a characteristic of testicular Sertoli cells and RMO1 cells did that of ovarian theca cells. Both RMT1 and RMO1 cells multiplied well in the medium supplemented with 10 % FBS at 28 °C and their minimum population doubling times were 24.4 and 28.8 h, respectively. At the 45th passage, most of the RMT1 and RMO1 cells had a hyperploid set of chromosomes (67.3 and 96.1 %, respectively). Cells with normal diploid chromosome set were not observed. RMT1 cells were transfected with an enhanced green fluorescent protein (EGFP) expression vector and human elongation factor 1 α promoter worked efficiently to express EGFP. In addition, EGFP-expressing cell lines were also established, suggesting that the cell lines could be utilized as an in vitro monitor system (biosensor) for the evaluation of endocrine disruptors which might affect gonadal function.

In response to contamination from the recent Fukushima nuclear accident, we conducted radionuclide analysis on bamboos sampled from six sites within a 25 to 980 km radius of the Fukushima Daiichi nuclear power plant. Maximum activity concentrations of radiocesium (134)Cs and (137)Cs in samples from Fukushima city, 65 km away from the Fukushima Daiichi plant, were in excess of 71 and 79 kBq/kg, dry weight (DW), respectively. In Kashiwa city, 195 km away from the Fukushima Daiichi, the sample concentrations were in excess of 3.4 and 4.3 kBq/kg DW, respectively. In Toyohashi city, 440 km away from the Fukushima Daiichi, the concentrations were below the measurable limits of up to 4.5 Bq/kg DW. In the radiocesium contaminated samples, the radiocesium activity was higher in mature and fallen leaves than in young leaves, branches and culms.

Rainwater was contaminated by a large release of radionuclides into the environment during the Fukushima Daiichi nuclear disaster. It became a matter of concern for Japan when several water purification plants detected ¹³¹I contamination in the drinking water. In the present study, the decontamination efficiency of two easily obtainable commercial water purifiers were examined for rainwater contaminated with ¹³¹I, ¹³⁴Cs and ¹³⁷Cs. The water purifiers removed 94.2-97.8% of the ¹³¹I and 84.2-91.5% of the ¹³⁴Cs and ¹³⁷Cs after one filtration. Seven filtrations removed 98.2-99.6% of the ¹³¹I and over 98.0% of the ¹³⁴Cs and ¹³⁷Cs. From a practical perspective, over the fourth filtrations were not needed because of no significant improvements after the third filtration.

Background: Light-emitting diodes (LEDs) are being used for a variety of new uses because of their cost-effectiveness and durability. We therefore considered using white LEDs as a light source for GI endoscopes to simplify the endoscopic system., Objective: To assess the feasibility and safety of an LED-illuminated colonoscope., Design: Pilot study of the LED colonoscope in healthy human volunteers and patients with colorectal lesions., Setting: Yamaguchi University Hospital, Ube, Japan., Interventions: We performed a total colonoscopy for 2 healthy volunteers and a sigmoidoscopy for 15 patients with colorectal lesions by using both LED and conventional colonoscopes. We assessed the feasibility and safety of the LED colonoscope by using a 5-grade scale. The 30 images of 15 colorectal lesions obtained by using each endoscope were evaluated in a blind, randomized order by 2 endoscopists., Main Outcome Measurements: The mean scores of the LED colonoscope for the operability, ease of manipulation, image quality, and safety., Results: We manufactured a prototype LED colonoscope with white LEDs on its tip. The LED colonoscope did not require an external light source or light-guide fiber bundle. The operability and ease of manipulation of the LED colonoscope were evaluated as similar to those of the conventional colonoscope. The color of the colonic mucosa and the vascular pattern were clearly visualized in the volunteers. For the 15 colorectal lesions, the mean score for image quality was not significantly different between the colonoscopes. The study was performed safely without any incident., Limitations: Single-center, small number of patients., Conclusions: The use of an LED colonoscope is feasible, and LED illumination may simplify the endoscope system., (Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

It is generally accepted that Clostridium perfringens strains associated with food poisoning carry their enterotoxin gene, cpe, on the chromosome, while C. perfringens strains isolated from non-food-borne diseases, such as antibiotic-associated diarrhea and sporadic diarrhea, carry cpe on the plasmid. However, we recently encountered a food poisoning outbreak caused by C. perfringens bearing a plasmid cpe. We therefore investigated a total of 31 clinical and non-clinical C. perfringens strains to locate the cpe gene by PCR. The cpe of nine heat-sensitive (100 degrees C for 10min) strains isolated from three outbreaks of food poisoning were located on the plasmid, while those of six heat-resistant strains from other food poisoning outbreaks were located on the chromosome. Moreover, the cpe of 5 heat-sensitive strains isolated from healthy human feces and those of 11 heat-sensitive soil strains were also located on the plasmid. These findings indicate that heat-sensitive, cpe-plasmid-borne C. perfringens strains should not be disregarded as causative agents of food poisoning.

Background: Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine and has been shown to be involved in the development of chronic murine colitis. In the +173 G/C polymorphism of the MIF gene, the presence of C creates the binding motif of activator protein 4. This study explored the association of this polymorphism with ulcerative colitis (UC)., Methods: Genotyping was carried out, with a tetra-primer polymerase chain reaction (PCR) method, for 659 DNA specimens from 438 healthy volunteers and 221 patients with UC. Genotype distribution between cases and controls and the association of patients' genotypes with clinical parameters were statistically evaluated., Results: No significant difference in genotype distribution was found between UC patients and healthy controls. However, when the relation of the C/C genotype to clinical parameters in UC patients was evaluated by Fisher's exact test, it was found that the frequency of the C/C genotype was higher in patients with pancolitis type than in those with other types restricted to the distal or left-sided colon (odds ratio [OR], 10.781; 95% confidence interval [CI], 1.342-86.619; P = 0.0074)., Conclusions: These data suggest that the MIF -173 G/C polymorphism may be related to the extent of disease in UC in a Japanese population.

Background: Ulcerative colitis (UC) is a chronic disorder of undetermined etiology, but a genetic predisposition to UC is well recognized. Among cytokines induced in UC, interleukin 1 (IL-1) appears to have a central role because of its immunological upregulatory and proinflammatory activities. The aim of this study was to assess whether UC is associated with polymorphisms of the IL-1beta gene and three additional genes inducible with IL-1beta in Japanese subjects., Methods: A total of 96 patients with UC and 106 ethnically matched controls were genotyped at polymorphic sites in IL-1beta, matrix metalloproteinase 1 (MMP-1), matrix metalloproteinase 3 (MMP-3), and inducible nitric oxide synthase (iNOS) genes, using polymerase chain reaction (PCR)-based methods., Results: There was no significant difference in genotype distributions of IL-1beta, MMP-1, MMP-3, and iNOS genes between controls and UC patients in a Japanese population. Also, no significant association of those polymorphisms with various clinical parameters of the patients was found. However, concerning association of age at onset with clinical factors in UC, the frequency of pancolitis was significantly higher in UC patients with age at onset being less than 30 years than in those more than 30 years of age (P = 0.049)., Conclusions: No association of the IL-1beta and three IL-1beta-inducible gene polymorphisms with UC was observed in a Japanese population.