Development of a system for the detection of the inflammatory response induced by airborne fine particulate matter in rat tracheal epithelial cells.

Exposure to airborne particulate matter (PM) is related to the increased risk of several diseases, including chronic and allergic rhinitis. We have previously shown that atmospheric endotoxin level was positively associated with the number of emergency department visits for asthma even after adjusting for meteorological factors, suggestive of the significant association between atmospheric endotoxin level and asthma exacerbation. Whether atmospheric endotoxin level is related to inflammatory response induction is, however, unclear. Here, we established stable cell lines to determine the promoter activity of the genes encoding pro-inflammatory cytokines such as tumor necrosis factor alpha, interleukin 6 (IL6), and IL33 by transfection of each reporter plasmid into rat tracheal epithelial EGV-4 T cells. These cells could measure the inflammatory response induced by endotoxin treatment more easily, rapidly, and sensitively than the conventional system using immunodetection assays. Furthermore, we revealed a relationship between atmospheric endotoxin level and inflammatory response induction. Thus, the system established herein may serve as a promising tool to monitor inflammatory response induced upon PM exposure.

Development of a system for the detection of the inflammatory response induced by airborne fine particulate matter in rat tracheal epithelial cells.

Exposure to airborne particulate matter (PM) is related to the increased risk of several diseases, including chronic and allergic rhinitis. We have previously shown that atmospheric endotoxin level was positively associated with the number of emergency department visits for asthma even after adjusting for meteorological factors, suggestive of the significant association between atmospheric endotoxin level and asthma exacerbation. Whether atmospheric endotoxin level is related to inflammatory response induction is, however, unclear. Here, we established stable cell lines to determine the promoter activity of the genes encoding pro-inflammatory cytokines such as tumor necrosis factor alpha, interleukin 6 (IL6), and IL33 by transfection of each reporter plasmid into rat tracheal epithelial EGV-4 T cells. These cells could measure the inflammatory response induced by endotoxin treatment more easily, rapidly, and sensitively than the conventional system using immunodetection assays. Furthermore, we revealed a relationship between atmospheric endotoxin level and inflammatory response induction. Thus, the system established herein may serve as a promising tool to monitor inflammatory response induced upon PM exposure.

Relationship of Asian Dust Events with Atmospheric Endotoxin and Protein Levels in Sasebo and Kyoto, Japan, in Spring.

Asian dust events are caused by dust storms originating from deserts in Mongolia and northern China, and these events are observed in Japan, mainly in spring. To explore the effect of Asian dust events on atmospheric endotoxin and protein levels, we collected the total suspended particles (TSP) in the spring months (March, April, and May) of 2015 in Sasebo and Kyoto, Japan, and assessed the levels of biological elements at both locations. At both locations, the daily concentrations of TSP, water-soluble Ca2+ (an indicator mineral of soil in dust), endotoxins, and proteins were found to be high during and after Asian dust events recorded by the Japan Meteorological Agency. The concentration of Ca2+ showed a strong positive correlation with the concentrations of TSP and endotoxin, while the concentration of protein was moderately positively correlated with Ca2+ in both Sasebo and Kyoto. There were large concentrations of endotoxins, and the fluctuation ranges were higher in Sasebo than in Kyoto. In contrast, protein concentrations showed low levels of fluctuation, and no major differences were found in the concentration at each location.

Seasonal Fluctuation of Endotoxin and Protein Concentrations in Outdoor Air in Sasebo, Japan.

To determine the levels of endotoxin, which is a major component of outer membrane of Gram-negative bacteria, and protein in the atmosphere in Sasebo, Japan, we measured these biological materials in fine (aerodynamic diameter ≤2.5 µm) and coarse (≥2.5 µm) particles collected for 81 weeks (September 2014 to May 2016). The monthly concentrations (i.e., the mean value of weekly concentrations for each month) of endotoxin were higher in coarse particles than in fine particles. Fluctuations in monthly endotoxin concentrations were large in both fine (0.0005-0.0208 EU/m3) and coarse (0.0032-0.1164 EU/m3) particles. Furthermore, the endotoxin concentrations in coarse particles were highest in October 2014 and 2015 as well as September 2014 (0.0407-0.1164 EU/m3). However, the monthly protein concentrations were higher in fine particles than in coarse particles. Compared to the endotoxin concentrations, the fluctuations in the monthly protein concentrations were smaller in both coarse and fine particles. To our knowledge, this study is the first to report long-term atmospheric concentrations of endotoxin and protein in Japan. Since the endotoxin concentrations in coarse particles were positively associated with the concentrations of Na+ and Cl-, it suggests the involvement of Gram-negative bacteria from seawater to the endotoxin levels in the atmosphere. For fine particles, the protein concentrations were positively associated with the concentrations of particles, NO3- and SO42-. These results suggest that combustion of organic materials, such as biomass burning, may be a contributor to atmospheric protein during this study period.

Nationwide survey on the operational status of electron accelerators for radiation therapy in Japan.

A nationwide survey was conducted on electron accelerators for radiation therapy in Japan for obtaining fundamental data on the actual operational situation of these accelerators. The research subjects were all medical institutions equipped with electron accelerators for radiation therapy (874 accelerators) in Japan. Postcards explaining the purpose and procedure of the survey were sent to each institution. Each institution was requested to download a questionnaire from the website and return it by e-mail. We obtained the following results. Energy: about 90% of the accelerators did not exceed 10 MeV as the permitted maximum energy. Beam intensity: a total of 94% of the accelerators did not exceed 4 Gy/min as the mean exposure dose rate. Beam time: a total of 74% of the accelerators were below half of the permitted maximum beam time. However, 2% of the accelerators exceeded 90% of the permitted maximum time. Cumulative dose: about 10% of institutions obtained permission not to use the maximum beam time, but to use the maximum cumulative dose to secure sufficient beam time. From these results, it became clear that the induced radioactivity based on the maximum beam current and the maximum operating time under an official permit would be overestimated. Therefore, the neutron dose should be assessed by use of a daily operational record, not from an official permit.

[Investigation of actual condition of management and disposal of medical radioactive waste in Korea].

In order to realize the rational management and disposal of radioactive waste like DIS or its clearance as performed in Europe, North America, and Japan, we investigated the situation of medical radioactive waste in Korea and its enforcement. We visited three major Korean facilities in May 2008 and confirmed details of the procedure being used by administering a questionnaire after our visit. From the results, we were able to verify that the governmental agency had established regulations for the clearance of radioactive waste as self-disposal based on the clearance level of IAEA in Korea and that the medical facilities performed suitable management and disposal of radioactive waste based on the regulations and superintendence of a radiation safety officer. The type of nuclear medicine was almost the same as that in Japan, and the half-life of all radiopharmaceuticals was 60 days or less. While performing regulatory adjustment concerning the rational management and disposal of radioactive waste in Korea for reference also in this country, it is important to provide an enforcement procedure with quality assurance in the regulations.

[Bibliographic consideration of proper management of radioactive waste on short-lived period nuclides that are used in nuclear medicine].

A rational clearance system for medical radioactive waste has not yet been established in Japan. As Europe and USA's ways, the establishment of DIS that medical radioactive waste what are kept in storage room for more than decided period each nuclide except from regulation of radiation's control. The purpose of this report is to clarify the problems with the establishment of DIS in Japan through a literature review of the experience in Europe and the USA and previous research that has been reported in Japan. To establish the DIS system, the radiation control system in nuclear medicine should be rebuilt and put into effect.

[Nationwide survey on radioactive waste management related to positron emission tomography in Japan].

BACKGROUND AND PURPOSE: A clearance system for medical radioactive solid waste has not yet been implemented in Japan. Since 2004 new regulations have allowed institutions using positron emission tomography(PET)to handle totally decayed radioactive waste as non-radioactive waste after decay-in-storage. It was expected that this new regulation would mediate the installation of clearance systems in Japan. In order to assess the current situation of radiation safety management in PET institutions, we conducted a nationwide survey. METHODS: The study design was a cross-sectional descriptive study conducted by questionnaire. The subjects of this survey were all the PET institutions in Japan. Among 224 institutes, 128 institutes are equipped with cyclotrons and 96 institutes are not. The number of returned questionnaires was 138. RESULT: Among institutes that are using delivered radiopharmaceuticals, 80% treat their waste as non-radioactive according to the new regulation. The impact of new regulations for reducing radioactive waste in PET institutes without a cyclotron was estimated at about $400 thousand per year. DISCUSSION: The main concern of medical institutes was assessment of the contamination caused by by-products of radioactive nuclides generated in target water during the operation of a cyclotron. It was thought that a rational rule based on scientific risk management should be established because these by-products of radioactive nuclides are negligible for radiation safety. CONCLUSION: New regulation has had a good influence on medical PET institutes, and it is expected that a clearance system for medical radioactive waste will be introduced in the near future, following these recent experiences in PET institutes.

Nationwide survey on the operational status of medical compact cyclotrons in Japan.

The management of induced radioactivity of the cyclotron itself and structures is an important issue in decommissioning of medical compact cyclotrons. To obtain basic data on the actual operational conditions of cyclotrons, we performed nationwide survey. The actual beam current was about half of the maximum beam current indicated in the official permits for cyclotron operation. The actual operating time was about 10% of the maximum operating time indicated in the official permits. The average daily radioactive-nuclide ((18)F) production was only 10% of the allowed maximum quantity. From these results, it became clear that the induced radioactivity of a cyclotron and its concrete structures based on the maximum beam current and the maximum operating time may be overestimated. These basic data are expected to be useful for a realistic evaluation and helpful in establishing a rational regulation in regard to radioactive waste control for decommissioning of medical cyclotrons.

Application of a new bioassay technique using goldfish for assessment of water toxicity.

There are a variety of chemicals in aquatic environment, so it is important to assess the toxicity. The biomarkers such as induction of DNA damage, micronuclei, vitellogenin, and hepatic P450 in fish are known to be effective for monitoring genotoxic and/or estrogenic chemicals. However, there is little study to use these biomarkers in same fish. Goldfish (Carassius auratus) is widely used and is suitable in size to collect blood or organs. In this study, validity of multiple-biomarkers in goldfish was checked using standard chemicals and applied in the river water. Ho River, which flows through the textile dyeing factory in Shizuoka Prefecture, Japan, was reported to show genotoxicity toward Salmonella typhimurium TA98 and YG1024. When the goldfish were exposed to Ho River, DNA damage, estrogenic activity, and CYP1A induction were observed. Through the study, it was assumed that not only mutagens/carcinogens but also endocrine disrupting chemicals and poly aromatic hydrocarbons were present in Ho River. Therefore, chemical identification should be required. We could evaluate both genotoxicity and estrogenic activity simultaneously, so goldfish might be a good experimental model for estimation of chemical contamination levels in aquatic environment.

Measurement of a genotoxic hydrazine, agaritine, and its derivatives by HPLC with fluorescence derivatization in the agaricus mushroom and its products.

Agaricus blazei MURRILL mushroom products are sold as so-called health foods in Japan. However, a part of Agaricus is known to contain hydrazines. A sensitive and specific method for analyzing a genotoxic hydrazine, agaritine, and its derivatives was developed to assess the safety of Agaricus products. beta-N-(gamma-L(+)-Glutamyl)-4-(hydroxymethyl)phenylhydrazine (agaritine, AGT), 4-hydrazinylbenzylalcohol (HMPH), 4-hydrazinylbenzoic acid (CPH), 4-methylphenylhydrazine (MPH) and phenylhydrazine (PH) were converted to their correspond-ing fluorescent derivatives with 3,4-dihydro-6,7 dimethoxy-4-methyl-3-oxoquinoxaline-2-carbonyl chloride (DMEQ-COCl) as the fluorescence derivatization reagent. The detection limits (S/N=3) for CPH, AGT, PH and MPH were 422, 45.3, 16.5 and 138 fmol, respectively, in a 20 microl injection volume. Recoveries, achieved by adding known AGT amounts to the Agaricus sample and Agaricus products, ranged from 92.8 to 102%. By using this method which does not require partial purification of the Agaricus sample, the amounts of AGT in several types of foods were found to be 112-1836 microg/g dry weight.