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We quantified the level of backscatter radiation generated from physicians' heads using a phantom. We also evaluated the shielding rate of the protective eyewear and optimal placement of the eye-dedicated dosimeter (skin surface or behind the Pb-eyewear). We performed diagnostic X-rays of two head phantoms: Styrofoam (negligible backscatter radiation) and anthropomorphic (included backscatter radiation). Radiophotoluminescence glass dosimeters were used to measure the eye-lens dose, with or without 0.07-mm Pb-equivalent protective eyewear. We used tube voltages of 50, 65 and 80 kV because the scattered radiation has a lower mean energy than the primary X-ray beam. The backscatter radiation accounted for 17.3-22.3% of the eye-lens dose, with the percentage increasing with increasing tube voltage. Furthermore, the shielding rate of the protective eyewear was overestimated, and the eye-lens dose was underestimated when the eye-dedicated dosimeter was placed behind the protective eyewear. We quantified the backscatter radiation generated from physicians' heads. To account for the effect of backscatter radiation, an anthropomorphic, rather than Styrofoam, phantom should be used. Close contact of the dosimeter with the skin surface is essential for accurate evaluation of backscatter radiation from physician's own heads. To assess the eye-lens dose accurately, the dosimeter should be placed near the eye. If the dosimeter is placed behind the lens of the protective eyewear, we recommend using a backscatter radiation calibration factor of 1.2-1.3., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Given the new recommendations for occupational eye lens doses, various lead glasses have been used to reduce irradiation of interventional radiologists. However, the protection afforded by lead glasses over prescription glasses (thus over-glasses-type eyewear) has not been considered in detail. We used a phantom to compare the protective effects of such eyewear and regular eyewear of 0.07 mm lead-equivalent thickness. The shielding rates behind the eyewear and on the surface of the left eye of an anthropomorphic phantom were calculated. The left eye of the phantom was irradiated at various angles and the shielding effects were evaluated. We measured the radiation dose to the left side of the phantom using RPLDs attached to the left eye and to the surface/back of the left eyewear. Over-glasses-type eyewear afforded good protection against x-rays from the left and below; the average shielding rates on the surface of the left eye ranged from 0.70-0.72. In clinical settings, scattered radiation is incident on physicians' eyes from the left and below, and through any gap in lead glasses. Over-glasses-type eyewear afforded better protection than regular eyewear of the same lead-equivalent thickness at the irradiation angles of concern in clinical settings. Although clinical evaluation is needed, we suggest over-glasses-type Pb eyewear even for physicians who do not wear prescription glasses., (© 2024 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved.)

After the Fukushima nuclear power plant accident in 2011, many types of survey meters were used, including Geiger-Müller (GM) survey meters, which have long been used to measure β-rays. Recently, however, a novel radiation survey meter that uses a plastic-scintillation sensor has been developed. Although manufacturers' catalog data are available for these survey meters, there have been no user reports on performance. In addition, the performance of commercial plastic-scintillation survey meters has not been evaluated. In this study, we experimentally compared the performance of a plastic-scintillation survey meter with that of a GM survey meter. The results show that the two instruments performed very similarly in most respects. The GM survey meter exhibited count losses when the radiation count rate was high, whereas the plastic-scintillation survey meter remained accurate under such circumstances, with almost no count loss at high radiation rates. For measurements at background rates (i.e., low counting rates), the counting rates of the plastic-scintillation and GM survey meters were similar. Therefore, an advantage of plastic-scintillation survey meters is that they are less affected by count loss than GM survey meters. We conclude that the plastic-scintillation survey meter is a useful β-ray measuring/monitoring instrument.

Purpose: The objective of this study was to compare the temperature dependence of a scintillation survey meter with and without the temperature compensation function. Investigation of temperature dependence is important to make precise measurements in various environments., Method: The experiment was conducted using the NaI (Tl) scintillation survey meter with the temperature compensation function (TCS-1172) and the NaI (Tl) and CsI (Tl) scintillation survey meters without the temperature compensation function (TCS-171, PDR-111). In all, 1 cm dose equivalent rate (µSv/h) was measured by changing the room temperature from 10 to 40 degree Celsius., Result: The results showed that the scintillation survey meter with the temperature compensation function had almost no change in the measured values with changes in room temperature, whereas the 1 cm dose equivalent rate of the scintillation survey meter without the temperature compensation function changed by a maximum of -7.2 (%/10°C) as temperature increased., Conclusion: This study confirms that the scintillation survey meter with the temperature compensation function was less dependent on temperature, and stable measurement was possible. However, it was suggested that the scintillation survey meter without the temperature compensation function might cause a drop in the measured value as the temperature rises.

Background: Plastic additives have adverse effects on human health. Children frequently use toys that contain various substances found in paints, plasticizers, and other materials, which heighten the risk of specific chemical exposure. Infants are particularly prone to chemical exposure through the "mouthing" behavior because of the possibility of placing toys in their mouths. Thus, this vulnerability should be considered during risk assessments of chemical exposure., Methods: This study performed a comprehensive analysis of the chemical components in various 84 plastic toys including "designated toys" (toys that may be harmful to infant health if in contact with their mouths: Article 78 of the Enforcement Regulations of the Food Sanitation Law by the Minister of Health, Labor and Welfare) such as dolls, balls, blocks, bathing toys, toy vehicles, pacifiers, and household items, purchased in the Japanese market by nontargeted and targeted analysis., Results: Plasticizers, flame retardants, and fragrances were the main compounds in almost all the toy products. The results showed that plastic products made in China tended to contain high levels of phthalate esters. In particular, hazardous plasticizers, such as diisodecyl, di-n-octyl, and diisononyl phthalates were detected above the regulatory limit (0.1%) in used products manufactured before regulations were passed in Japan. Furthermore, we detected alternative plasticizers, such as acetyl tributyl citrate (ATBC; 52%), diisononyl adipate (DINA; 50%), and di(2-ethylhexyl) terephthalate (DEHT; 40%). ATBC was detected at high concentrations in numerous toy products. Thus, infants with free access to indoor plastic toys might be exposed to these chemicals., Conclusions: This study observed that the chemical profiles of toy products were dependent on the year of manufacture. Furthermore, the detection of currently regulated plasticizers in secondhand products manufactured before regulations were enforced, along with the increasing trend of using alternative substances to regulated phthalate esters in products, suggests the potential exposure of infants to these plasticizers through the use of toys. Therefore, regular fact-finding surveys should continue to be conducted for the risk assessment and safety management of domestic toy products.

A moment magnitude (Mw) 7.5 earthquake (the Global IDentifire (GLIDE) number: # Q-2024-000001-JPN) struck the Noto Peninsula of Ishikawa Prefecture on 1 January 2024 at 16:10 (Japan Standard Time). The reversed fault, 150 km in length and subducting beneath the peninsula, resulted in maximum seismic intensity 7 shaking, triggered the tsunami, destroyed over 43 thousand buildings, and disrupted roads and lifelines. The disaster claimed 236 deaths, including 15 indirect disaster deaths as of Jan. 28, 2024. There were Disaster Base Hospitals (DBHs) in the region, which survived structurally but suffered from impaired functions and the surge of medical needs of affected people. The disaster medical system of Japan immediately responded and coordinated the hundreds of emergency medical teams (EMTs), i.e., the Japan Disaster Medical Assistance Team (DMAT), from all over the country. Tohoku University Hospital, which had the experience of the 2011 Great East Japan Earthquake (GEJE), joined the coordinated response, dispatching a chain of DMATs, which helped the medical and public health coordination in Wajima City. The medical and public health needs included injuries, non-communicable diseases, infectious diseases, mental health issues, and maternal and child health issues, which were similar in the affected communities in GEJE. Although the actual damage far exceeded expectations, the structural retrofitting and business continuity plans of DBHs and the coordinated response of the national disaster medical system enhanced the effectiveness of medical and public health response.

The diagnostic reference level (DRL) is an effective tool for optimising protection in medical exposures to patients. However regarding air kerma at the patient entrance reference point ( K a,r ), one of the DRL quantities for endoscopic retrograde cholangiopancreatography (ERCP), manufacturers use a variety of the International Electrotechnical Commission and their own specific definitions of the reference point. The research question for this study was whether K a,r is appropriate as a DRL quantity for ERCP. The purpose of this study was to evaluate the difference between K a,r and air kerma incident on the patient's skin surface ( K a,e ) at the different height of the patient couch for a C-arm system. Fluoroscopy and radiography were performed using a C-arm system (Ultimax-i, Canon Medical Systems, Japan) and a over-couch tube system (CUREVISTA Open, Fujifilm Healthcare, Japan). K a,e was measured by an ion chamber placed on the entrance surface of the phantom. Kerma-area product ( P KA ) and K a,r were measured by a built-in P KA meter and displayed on the fluoroscopy system. K a,e decreased while K a,r increased as the patient couch moved away from the focal spot. The uncertainty of the K a,e / K a,r ratio due to the different height of the patient couch was estimated to be 75%-94%. K a,r may not accurately represent K a,e . P KA was a robust DRL quantity that was independent of the patient couch height. We cautioned against optimising patient doses in ERCP with DRLs set in terms of K a,r without considering the patient couch height of the C-arm system. Therefore, we recommend that K a,r is an inappropriate DRL quantity in ERCP using the C-arm system., (© 2023 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved.)

The purpose of this study was to estimate the internal dose of radiation in Japanese macaques (aka Nihonzaru or snow monkey) due to the Fukushima nuclear power plant accident. Images of a male Japanese macaque weighing ~10 kg were acquired using a multi-slice computed tomography (CT) scan with a 64-row segment detector. The CT images were used to create voxel phantoms of the bones, bone marrow, brain, eyes, heart, lungs, stomach, liver, spleen, pancreas, kidneys, intestines, bladder, testes, thyroid and miscellaneous tissue. The Particle and Heavy Ion Transport System (PHITS) Monte Carlo code was used to calculate the internal exposure rate conversion factors for 134Cs, 137Cs and 131I isotopes for the created voxel phantoms with a statistical precision higher than 1%. The PHITS-calculated energy deposits were compared with those for rhesus monkeys. The results showed that the fractions of energy deposits for β-radiation in different organs were almost identical between the two species. For γ-radiation, there was excellent agreement in the self-absorption rate with the approximate curve of the Japanese macaque, with an average deviation of 2%. The maximum deviation of 12% was for the kidney, which has two organs, so the error with the approximate curve is slightly larger due to the energy loss created between organs., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Although interventional radiology (IVR) is preferred over surgical procedures because it is less invasive, it results in increased radiation exposure due to long fluoroscopy times and the need for frequent imaging. Nurses engaged in cardiac IVR receive the highest lens radiation doses among medical workers, after physicians. Hence, it is important to measure the lens exposure of IVR nurses accurately. Very few studies have evaluated IVR nurse lens doses using direct dosimeters. This study was conducted using direct eye dosimeters to determine the occupational eye dose of nurses engaged in cardiac IVR, and to identify simple and accurate methods to evaluate the lens dose received by nurses. Over 6 months, in a catheterization laboratory, we measured the occupational dose to the eyes (3 mm dose equivalent) and neck (0.07 mm dose equivalent) of nurses on the right and left sides. We investigated the relationship between lens and neck doses, and found a significant correlation. Hence, it may be possible to estimate the lens dose from the neck badge dose. We also evaluated the appropriate position (left or right) of eye dosimeters for IVR nurses. Although there was little difference between the mean doses to the right and left eyes, that to the right eye was slightly higher. In addition, we investigated whether it is possible to estimate doses received by IVR nurses from patient dose parameters. There were significant correlations between the measured doses to the neck and lens, and the patient dose parameters (fluoroscopy time and air kerma), implying that these parameters could be used to estimate the lens dose. However, it may be difficult to determine the lens dose of IVR nurses accurately from neck badges or patient dose parameters because of variation in the behaviors of nurses and the procedure type. Therefore, neck doses and patient dose parameters do not correlate well with the radiation eye doses of individual IVR nurses measured by personal eye dosimeters. For IVR nurses with higher eye doses, more accurate measurement of the radiation doses is required. We recommend that a lens dosimeter be worn near the eyes to measure the lens dose to IVR nurses accurately, especially those exposed to relatively high doses.

Objectives: To explore the impact of modernization on oxidative stress during a momentous health transition process, we investigated differences in oxidative stress among the indigenous populations of villages in northern Laos with different levels of modernization., Methods: We conducted a cross-sectional study of 380 adults in three villages with different levels of modernization. Three biomarkers related to oxidative stress were measured: urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane concentrations (both measured by liquid chromatography-tandem mass spectrometry), and blood telomere length (measured with qPCR). We examined associations between village-level modernization and oxidative stress-related biomarkers in a multilevel analysis including a random effect and covariates., Results: The geometric means of urinary 8-OHdG and 8-isoprostane concentrations were 2.92 and 0.700 μg/g creatinine, respectively, in our study population. Higher urinary 8-OHdG concentrations and shorter telomeres were observed in participants from the more modernized villages, whereas urinary 8-isoprostane concentrations did not differ significantly among villages., Conclusions: Our findings imply that modernization-induced changes in lifestyle may increase oxidative DNA damage. Baseline levels of oxidative lipid damage are expected to be high in the indigenous populations of northern Laos. Assessments of oxidative stress may provide valuable insights into the mechanisms of health transition in specific populations., (© 2023 The Authors. American Journal of Biological Anthropology published by Wiley Periodicals LLC.)

Objectives: To investigate determinants of oxidative stress in an indigenous population, we examined associations of trace element exposures and dietary patterns with three oxidative stress-related biomarkers among indigenous populations in Northern Laos., Methods: This cross-sectional study included 341 adults from three villages with different levels of modernization. We used three oxidative stress-related biomarkers: urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane concentrations, which were measured using liquid chromatography-tandem mass spectrometry, and blood telomere lengths, which were measured using a quantitative polymerase chain reaction method. We used multilevel analysis to examine associations of urinary arsenic, cadmium, and selenium concentrations, their interaction terms, and wild-plant-food scores (principal component scores calculated from food consumption frequencies) with oxidative stress-related biomarkers., Results: Urinary arsenic and cadmium concentrations were positively associated with urinary 8-isoprostane concentrations. Urinary selenium concentrations were positively associated with urinary 8-OHdG concentrations. Interaction terms ([arsenic or cadmium] × selenium) showed negative associations with urinary 8-OHdG and 8-isoprostane concentrations, respectively. Urinary cadmium concentrations were negatively associated with telomere lengths. Wild-plant-food scores did not exhibit associations with oxidative stress-related biomarkers., Conclusion: Our findings imply that exposure to arsenic and cadmium is associated with greater oxidative lipid damage, whereas selenium may attenuate arsenic-induced oxidative DNA damage and cadmium-induced oxidative lipid damage. Cadmium exposure may accelerate telomere attrition. Trace element exposure may be a determinant of oxidative stress among indigenous populations in Northern Laos., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Mobile radiography allows for the diagnostic imaging of patients who cannot move to the X-ray examination room. Therefore, mobile X-ray equipment is useful for patients who have difficulty with movement. However, staff are exposed to scattered radiation from the patient, and they can receive potentially harmful radiation doses during radiography. We estimated occupational exposure during mobile radiography using phantom measurements. Scattered radiation distribution during mobile radiography was investigated using a radiation survey meter. The efficacy of radiation-reducing methods for mobile radiography was also evaluated. The dose decreased as the distance from the X-ray center increased. When the distance was more than 150 cm, the dose decreased to less than 1 μSv. It is extremely important for radiological technologists (RTs) to maintain a sufficient distance from the patient to reduce radiation exposure. The spatial dose at eye-lens height increases when the bed height is high, and when the RT is short in stature and abdominal imaging is performed. Maintaining sufficient distance from the patient is also particularly effective in limiting radiation exposure of the eye lens. Our results suggest that the doses of radiation received by staff during mobile radiography are not significant when appropriate radiation protection is used. To reduce exposure, it is important to maintain a sufficient distance from the patient. Therefore, RTs should bear this is mind during mobile radiography.

In 2011, the International Commission on Radiological Protection (ICRP) recommended a significant reduction in the lens-equivalent radiation dose limit, thus from an average of 150 to 20 mSv/year over 5 years. In recent years, the occupational dose has been rising with the increased sophistication of interventional radiology (IVR); management of IVR staff radiation doses has become more important, making real-time radiation monitoring of such staff desirable. Recently, the i3 real-time occupational exposure monitoring system (based on RaySafeTM) has replaced the conventional i2 system. Here, we compared the i2 and i3 systems in terms of sensitivity (batch uniformity), tube-voltage dependency, dose linearity, dose-rate dependency, and angle dependency. The sensitivity difference (batch uniformity) was approximately 5%, and the tube-voltage dependency was <±20% between 50 and 110 kV. Dose linearity was good (R2 = 1.00); a slight dose-rate dependency (~20%) was evident at very high dose rates (250 mGy/h). The i3 dosimeter showed better performance for the lower radiation detection limit compared with the i2 system. The horizontal and vertical angle dependencies of i3 were superior to those of i2. Thus, i3 sensitivity was higher over a wider angle range compared with i2, aiding the measurement of scattered radiation. Unlike the i2 sensor, the influence of backscattered radiation (i.e., radiation from an angle of 180°) was negligible. Therefore, the i3 system may be more appropriate in areas affected by backscatter. In the future, i3 will facilitate real-time dosimetry and dose management during IVR and other applications.

In the present study, we evaluated the acute response of mice exposed to IQOS aerosol, a brand-name heated tobacco product (HTP), in the lung tissue. First, the thiobarbituric acid-reactive substances (TBA-RS) value was measured as an index to assess oxidative stress, and a significant increase was observed after exposure, followed by a significant increase in the total lung GSH concentration. The stress responses induced by IQOS aerosols was then analyzed by focusing on the changes in Nrf2 and ATF4, which are transcription factors that induce the expression of genes involved in GSH biosynthesis or metabolism. Although Nrf2 activation was not observed, significant accumulation of ATF4 in the nuclear fraction was noted three hours after exposure to IQOS aerosols. Upon an examination of changes in factors in the GSH biosynthetic system, a significant increase in cystine concentration in the lung tissue was measured, and an increase in xCT expression level was observed in the cell membrane fraction three-six hours after IQOS exposure. Furthermore, characteristic changes in HO-1, a stress-response protein regulated by ATF4, was discovered six hours after IQOS exposure. Moreover, analysis of the upstream ATF4 regulatory system revealed that phosphorylation of eIF2α was enhanced in the lung cytoplasmic fraction three hours after exposure to IQOS aerosols. These findings suggest that ER stress might be induced as an early response to IQOS aerosol exposure, accompanied by the activation of the eIF2α-ATF4 axis. These intracellular changes have also been reported after exposure to combustible cigarette smoke. Thus, the acute response found in the lungs of mice in the present study demonstrate that the inhalation of aerosols from IQOS elicits a biological response similar to that of combustible cigarette smoke. In conclusion, our results provide evidence that the biological effects of HTPs, such as IQOS, cannot be ignored in the lungs.

Purpose: Skin injury in patients due to radiation exposure has been a complication in percutaneous coronary intervention (PCI) for a long time. To the best of our knowledge, there have been no reports comparing radiation dose by treatment area with diagnostic reference levels (DRLs) 2020, although the radiation dose varies by treatment area in PCI., Methods: In this study, the treatment areas were classified into four segments (i.e., AHA #1-3, AHA #4, AHA #5-10, and AHA #11-15), and each segment was compared with DRLs 2020. This retrospective study included 984 consecutive patients with single-vessel disease and non-chronic total occlusion. PCI was performed on a single device., Results: The median radiation dose was 1640.8 mGy, and the radiation dose for AHA #4 was 2732.0 mGy, which was significantly higher than the other treatment areas (p<0.001). In AHA #4, the radiation dose increased due to the heavy use of the left cranial view, and the patient background contributed to the increased lesion complexity. Therefore, it was challenging to evaluate AHA #4 and the other treatment areas with a uniform DRL value., Conclusion: Establishing a subdivided index for each treatment area is crucial if DRLs are used as a reference during procedures and as a guide for dose optimization.

The exact profiles of the clinical symptoms related to the SARS-CoV-2 Omicron variant (B.1.1.529) remain largely uncertain. Therefore, this study aimed to clarify the clinical manifestations of infection with this variant. We enrolled individuals who were tested by quantitative nasopharyngeal swab reverse transcription-polymerase chain reaction (RT-PCR) test at a large screening center in a city of Japan during the B.1.1.529 Omicron variant wave between January and May 2022, after contact with COVID-19 patients. Swab tests were planned to be performed approximately 4-5 days after contact. The presence of COVID-19-related symptoms was assessed at the swab test site. Among the 2,507 enrolled individuals, 943 (37.6%) were RT-PCR test-positive and 1,564 (62.4%) were test-negative. Among the 943 PCR test-positive participants, the prevalence of the symptoms was as follows: 47.3% with cough, 32.9% with sore throat, 18.4% with fatigability, 12.7% with fever of ≥ 37.5℃, 9.9% with dyspnea, 2.1% with dysosmia, and 1.4% with dysgeusia. The prevalence of cough, sore throat, dyspnea, and fatigability was higher among adults aged ≥ 18 years than among children and adolescents. The prevalence of dysosmia and dysgeusia remarkably decreased during the Omicron wave (1-3%) compared to during the pre-Omicron variant waves (15-25%). In summary, common COVID-19-related symptoms during the Omicron variant wave included cough and sore throat, followed by fatigability, fever, and dyspnea. The prevalence of most of these symptoms was higher in adults than in non-adults. The prevalence of dysosmia and dysgeusia remarkably decreased with the Omicron variant than with pre-Omicron variants.

The administration of a third booster dose of messenger ribonucleic acid (mRNA) vaccines against coronavirus disease 2019 (COVID-19) has progressed worldwide. Since January 2022, Japan has faced a nationwide outbreak caused by the Omicron variant, which occurred simultaneously with the progression of mass vaccination with the third booster dose. Therefore, this study evaluated the effectiveness of the third dose of vaccine by reverse transcription-polymerase chain reaction (RT-PCR) test using nasopharyngeal swab samples from adults aged ≥ 18 years tested after having close contact with COVID-19 cases between January and May 2022. Participants who completed only one dose were excluded from the study. Among the 928 enrolled participants, 139 had never been vaccinated, 609 had completed two doses, 180 had completed three doses before the swab test, and the overall RT-PCR test positivity rate in each group was 48.9%, 46.0%, and 32.2%, respectively. The vaccine effectiveness of the third dose to prevent infection after close contact was approximately 40% (95% confidence interval: 20-60%), which was the highest at 10-70 days after receiving the third dose. In conclusion, the effectiveness of the three-dose mRNA COVID-19 vaccine after close contact during the Omicron outbreak is approximately 40%., (© 2022. The Author(s).)

Although the amount of chemicals in heated tobacco products (HTPs) aerosols is reduced compared to conventional combustible cigarette smoke, the association between HTPs and reduced health effects remains unclear. In this study, we hypothesized that exposure to IQOS, an HTP, would increase oxidative stress and affect the secretion of inflammatory cytokines. First, C57BL/6 mice exposed to IQOS aerosols were evaluated to determine the adverse effects of IQOS exposure. IQOS exposure significantly decreased the concentration of GSH in alveolar macrophages in a dose-dependent manner and increased the percentage of GSSG in lung tissues. These results indicate that IQOS exposure increases oxidative stress, and GSH is consumed to remove oxidative stress. In addition, foamy alveolar macrophages were observed in the bronchial alveolar lavage fluid after IQOS exposure. Although the concentration of inflammatory cytokines, IL-6, and GM-CSF, in the plasma increased significantly after IQOS exposure, there were no significant changes in other cytokines. These results indicate that short-term exposure to IQOS aerosols may increase oxidative stress and induce the secretion of inflammatory cytokines. Lastly, the longer-term effects of IQOS aerosols exposure should be evaluated in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Heated tobacco products (HTPs) have become increasingly popular among smokers, especially among young adults in Japan in recent years. Assessments of secondhand tobacco smoke (SHS) exposure due to HTPs are scarce. The present study aimed to assess the urinary levels of total nicotine metabolites (TNMs) of non-smoking spouses and their children following SHS exposure due to their fathers' use of HTPs. A total of 41 families including 129 participants were recruited between 2018 and 2021. The number of non-smoking spouses and children of the fathers who smoke combustion cigarettes, the fathers who use HTPs, and the fathers who are non-users or have never smoked was 27, 66, and 36, respectively. The urinary levels of TNMs, including cotinine (Cot) and 3'-hydroxycotinine (3-OHCot), were measured using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The spouses and children of fathers who use HTPs had significantly higher levels of TNMs in their urine compared to those with fathers who were non-smokers or non-users. The current study is the first to assess SHS exposure due to HTP use, and to suggest the importance of strategies to prevent exposure to SHS from HTP use in public places and educational strategies to protect non-smokers from secondhand HTP aerosol exposure in households and other private places.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remained a major global health concern in 2021. To suppress the spread of infection, mass vaccinations have been performed across countries worldwide. In Japan, vaccinations of the first and second doses for most of the nation were performed during the nationwide outbreak of the B.1.617.2 (Delta) variant with the L452R spike protein mutation, and the effectiveness of the vaccinations to suppress the spread of COVID-19 among the people in Japan remains uncertain. In this study, adults aged ≥18 years, who were in contact with patients with COVID-19 and underwent nasopharyngeal swab reverse transcription-polymerase chain reaction (RT-PCR) tests during August and September 2021 at a mass screening test center in Japan, were enrolled. In this period, more than 95% of the COVID-19 infections were reportedly caused by the Delta variant. As a result, a total of 784 adults with recent contact history, including 231 (29.5%) RT-PCR test-positive cases, were enrolled. The test positivity rate was lower in individuals who had been vaccinated twice than in unvaccinated individuals (12.5% vs. 39.0%, p < 0.0001), with the risk ratio of 0.32 (95% confidence interval 0.23-0.46). The vaccine effectiveness was the highest between 7-90 days after the second vaccine dose. In conclusion, two doses of mRNA COVID-19 vaccines effectively suppressed transmission in Japan during the nationwide pandemic of the Delta variant, estimated to have prevented 50-80% of the infection.

Occupational eye dose monitoring during interventional radiology and interventional cardiology is important to avoid radiation-induced cataracts. The aim of this study was to assess the eye dose correlation with neck dose and patient-related quantities for interventional cardiology physicians and nurses. The originality of this study lies in obtaining correlations between the location of the dosimeter and eye dose radiation readings among different procedures and practitioners. The doses were measured for each procedure (18 procedures of coronary angiography and 16 procedures of percutaneous coronary intervention) using an active personal dosimeter. The eye dose for physicians was not correlated with the neck dose. The eye dose for nurses had a good correlation with the neck dose during both coronary angiography (R 2  = 0.91) and percutaneous coronary intervention (R 2  = 0.93). Kerma-area product values may be used for a rough estimation of the eye dose for physicians during routine coronary angiography procedures (R 2  = 0.76). For nurses, the neck dose is a good proxy for the eye dose during coronary angiography and percutaneous coronary intervention procedures., (© 2022. Japanese Society of Radiological Technology and Japan Society of Medical Physics.)

It is important to evaluate the radiation eye dose (3 mm dose equivalent, Hp (3)) received by physicians during computed tomography fluoroscopy (CTF)-guided biopsy, as physicians are close to the source of scattered radiation. In this study, we measured the radiation eye dose in Hp (3) received by one physician during CTF in a timeframe of 18 months using a direct eye dosimeter, the DOSIRIS TM . The physician placed eye dosimeters above and under their lead (Pb) eyeglasses. We recorded the occupational radiation dose received using a neck dosimeter, gathered CT dose-related parameters (e.g., CT-fluoroscopic acquisition number, CT-fluoroscopic time, and CT-fluoroscopic mAs), and performed a total of 95 procedures during CTF-guided biopsies. We also estimated the eye dose (Hp (3)) received using neck personal dosimeters and CT dose-related parameters. The physician eye doses (right and left side) received in terms of Hp (3) without the use of Pb eyeglasses for 18 months were 2.25 and 2.06 mSv, respectively. The protective effect of the Pb eyeglasses (0.5 mm Pb) on the right and left sides during CTF procedures was 27.8 and 37.5%, respectively. This study proved the existence of significant correlations between the eye and neck dose measurement (right and left sides, R 2 = 0.82 and R 2 = 0.55, respectively) in physicians. In addition, we found significant correlations between CT-related parameters, such as CT-fluoroscopy mAs, and radiation eye doses (right and left sides, R 2 = 0.50 and R 2 = 0.52, respectively). The eye dose of Hp (3) received in CTF was underestimated when evaluated using neck dosimeters. Therefore, we suggest that the physician involved in CTF use a direct eye dosimeter such as the DOSIRIS for the accurate evaluation of their eye lens dose.

Ionizing radiation exposure affects the redox state in vivo. Recently, whole-blood antioxidant capacity (WBAC) has been reported to decrease in a dose-dependent manner after acute total body irradiation (TBI). However, changes in WBAC after localized and chronic irradiations have not been reported. This study analyzed changes to WBAC in mice after either localized irradiation (irradiation of the left hind leg only) or chronic TBI using the i-STrap method. Leg-localized irradiation exerted limited effects on WBAC, while WBAC decreased in a dose rate-dependent manner after TBI. Further, the WBAC reached the minimum value in a shorter period at a smaller dose rate. Our results suggest that changes in WBAC do not directly reflect absorbed dose, but may reflect radiation-induced biological damage at the systemic level. This study will contribute to the understanding of radiation-induced injuries and diseases, and will facilitate the establishment of biomarkers for radiation exposure., (© The Author(s) 2021. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Introduction: There is no standardized aerosol exposure apparatus to deliver heated tobacco products (HTPs) for in vivo experiments. Therefore, we developed a novel HTPs aerosol exposure apparatus for mice and demonstrated that nicotine and other chemicals in HTPs aerosol generated by the apparatus can be delivered to mice which replicate human smoke., Aims and Methods: The amounts of nicotine, tar, and carbon monoxide (CO) in IQOS (Marlboro Regular HeatSticks) aerosol generated by two types of apparatuses were determined. C57BL/6N mice were exposed to IQOS aerosol, followed by determination of the urinary nicotine metabolites. Further, the skin surface temperature of mice was monitored to confirm the vasoconstriction action of nicotine., Results: The amount of chemicals in IQOS aerosol by the novel air push-in inhalation apparatus for HTPs (APIA) was equivalent to that of the analytical vaping machine (LM4E) (1.60 ± 0.08 [APIA] vs. 1.46 ± 0.07 mg/stick [LM4E] in nicotine and 0.55 ± 0.04 [APIA] vs. 0.45 ± 0.01 mg/stick [LM4E] in CO). After mice were exposed to IQOS aerosol by APIA, the urinary nicotine metabolite levels were determined; peak values in cotinine and 3-hydroxycotinine (3-HC) were 6.82 μg/mg creatinine at 1 hour after exposure and 32.9 μg/mg creatinine at 2 hours after exposure, respectively. The skin surface temperature decreased and was lower (33.5°C ± 0.5°C) at 30 minutes than before exposure (37.6°C ± 0.8°C)., Conclusions: The new apparatus for HTPs aerosol exposure to mice showed good performances in terms of both chemical analysis of collected aerosol and fluctuations in the urinary nicotine metabolites., Implications: The APIA reported in this study can expose small animals to HTPs aerosol, including nicotine and other chemical substances as same amounts as LM4E and replicate actual human smoking process by in vivo experiments. Therefore, the experiments using APIA can provide evidence to assess the health risks of HTPs use., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved.For permissions, please e-mail: journals.permissions@oup.com.)

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global public health concern in 2021. However, the risk of attending schools during the pandemic remains unevaluated. This study estimated the secondary transmission rate at schools using the results of a real-time reverse transcription-polymerase chain reaction (RT-PCR) screening test performed between July 2020 and April 2021, before starting the nationwide mass vaccination. A total of 1,924 students (20 RT-PCR-positive; 1.0%) from 52 schools or preschools were evaluated, together with 1,379 non-adults (95 RT-PCR-positive; 6.9%) exposed to SARS-CoV-2 in non-school environments. Assuming that the infectious index cases were asymptomatic and the transmission at schools followed a Bernoulli process, we estimated the probability of transmission after each contact at school as approximately 0.005 (0.5% per contact) with the current infection prevention measures at schools in Japan (i.e., hand hygiene, physical distancing, wearing masks, and effective ventilation). Furthermore, assuming that all children are capable of carrying the infection, then contact between an index case and 20-30 students per day at schools would yield the expected value for secondary cases of ≥ 1.0, during the 10 days of the infectious period. In conclusion, with the current infection prevention measures at schools in Japan, secondary transmission at schools would occur in approximately every 200 contacts. When considering this rate, compliance with the current infection prevention measures at schools and early detection and quarantine of the index cases would be effective in preventing the spread of COVID-19 at schools.

Objective Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), remains the world's largest public health concern in 2021. A history of close contact with infectious patients is a factor that predicts a positive SARS-CoV-2 test result. Meanwhile, the precise predictive value of symptoms suggestive of COVID-19 has not been fully elucidated. This study aimed to clarify the predictive and discriminatory value of each clinical symptom suggestive of COVID-19. Methods This study enrolled participants who were tested for SARS-CoV-2 by reverse transcription polymerase chain reaction using a nasopharyngeal swab between November 2020 and January 2021. All enrolled patients were evaluated for data regarding the presence and closeness of contact with infectious patients and comprehensive clinical features (i.e., fever, cough, dyspnea, fatigue, dysosmia, and dysgeusia). Results Among the 1,744 tested participants, 144 tested positive for SARS-CoV-2. In the test-positive group, self-reported cough, fatigue, dysosmia, and dysgeusia were significant predictors of COVID-19, independent from a history of close contact. In particular, the presence of dysosmia was the strongest predictor of COVID-19 in both univariate and multivariate analyses. Among the 42 patients with self-reported dysosmia, 25 (59.5%) were SARS-CoV-2 test-positive. Self-reported dysosmia was reported by 25 (17.4%) of the 144 patients who tested positive for SARS-CoV-2, and 15 (60.0%) of the 25 COVID-19 patients with dysosmia had accompanying dysgeusia. Conclusion The presence of dysosmia was reported by 10-25% of patients with COVID-19, and is a significant predictor of COVID-19 infection, independent from a history of close contact.

Background: In recent years, heated tobacco products (HTPs), which are widely used in Japan, have been sold by various brands using additives such as flavors. It has been reported that the components of mainstream smoke are different from those of conventional cigarettes. In this study, we established an analytical method for furans and pyridines in the mainstream smoke, which are characteristic of HTPs and particularly harmful among the generated components, and investigated the amount of component to which the smokers are exposed., Methods: We established a simple analytical method for simultaneous analysis of gaseous and particulate compounds in the mainstream smoke of HTPs (IQOS, glo, ploom S) in Japan by combining a sorbent cartridge and glass fiber filter (Cambridge filter pad (CFP)). Both the sorbent cartridge and CFP were extracted using 2-propanol and analyzed via GC-MS/MS to determine the concentration of furans and pyridines generated from each HTP., Results: The results showed that the levels of target furans such as furfural, 2-furanmethanol, 2(5H)-furanone, and 5-methylfurfural tended to be higher in the mainstream smoke of glo than in standard cigarettes (3R4F). Pyridine, which is generated at a high level in 3R4F as a combustion component, and 4-ethenylpyridine (EP), which is a known marker of environmental tobacco smoke, were detected. Among these components, 2-furanmethanol and pyridine are classified as Group 2B (possibly carcinogenic to humans) by the International Agency for Research on Cancer (IARC). Therefore, it is possible that they will contribute to the health effects caused by use of HTPs., Conclusions: Using the new collection and analytical method for furans and pyridines in the mainstream smoke of HTPs, the level of each compound to which smokers are exposed could be clarified. By comprehensively combining information on the amount of ingredients and toxicity, it will be possible to perform a more detailed calculation of the health risks of using HTPs. In addition, the components detected in this study may be the causative substances of indoor pollution through exhaled smoke and sidestream smoke; therefore, environmental research on the chemicals generated from HTPs would be warranted in future studies., (© 2021. The Author(s).)

Radiation protection/evaluation during interventional radiology (IVR) poses a very important problem. Although IVR physicians should wear protective aprons, the IVR physician may not tolerate wearing one for long procedures because protective aprons are generally heavy. In fact, orthopedic problems are increasingly reported in IVR physicians due to the strain of wearing heavy protective aprons during IVR. In recent years, non-Pb protective aprons (lighter weight, composite materials) have been developed. Although non-Pb protective aprons are more expensive than Pb protective aprons, the former aprons weigh less. However, whether the protective performance of non-Pb aprons is sufficient in the IVR clinical setting is unclear. This study compared the ability of non-Pb and Pb protective aprons (0.25- and 0.35-mm Pb-equivalents) to protect physicians from scatter radiation in a clinical setting (IVR, cardiac catheterizations, including percutaneous coronary intervention) using an electric personal dosimeter (EPD). For radiation measurements, physicians wore EPDs: One inside a personal protective apron at the chest, and one outside a personal protective apron at the chest. Physician comfort levels in each apron during procedures were also evaluated. As a result, performance (both the shielding effect (98.5%) and comfort (good)) of the non-Pb 0.35-mm-Pb-equivalent protective apron was good in the clinical setting. The radiation-shielding effects of the non-Pb 0.35-mm and Pb 0.35-mm-Pb-equivalent protective aprons were very similar. Therefore, non-Pb 0.35-mm Pb-equivalent protective aprons may be more suitable for providing radiation protection for IVR physicians because the shielding effect and comfort are both good in the clinical IVR setting. As non-Pb protective aprons are nontoxic and weigh less than Pb protective aprons, non-Pb protective aprons will be the preferred type for radiation protection of IVR staff, especially physicians.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the world's largest public health concern in 2021. This study evaluated the associations of the prevalence of airway symptoms among the tested individuals and data regarding the natural environmental factors with the weekly number of newly diagnosed COVID-19 patients in Sendai City (N t ). For the derivatives of the screening test results, data from individuals with a contact history who underwent nasopharyngeal swab reverse transcription-polymerase chain reaction (RT-PCR) testing between July 2020 and April 2021 (6,156 participants, including 550 test-positive patients) were used. The value of N t correlated with the weekly RT-PCR test-positive rate after close contact, prevalence of cough symptoms in test-positive individuals or in test-negative individuals, lower air temperature, lower air humidity, and higher wind speed. The weekly test-positive rate correlated with lower air humidity and higher wind speed. In cross-correlation analyses, natural environmental factors correlated with the regional epidemic status on a scale of months, whereas the airway symptoms among non-COVID-19 population affected on a scale of weeks. When applying an autoregression model to the serial data of N t , large-scale movements of people were suggested to be another factor to influence the local epidemics on a scale of days. In conclusion, the prevalence of cough symptoms in the local population, lower air humidity or higher wind speed, and large-scale movements of people in the locality would jointly influence the local epidemic status of COVID-19.

The new recommendation of the International Commission on Radiological Protection for occupational eye dose is an equivalent dose limit to the eye of 20 mSv year-1, averaged over a 5-year period. This recommendation is a drastic reduction from the previous limit of 150 mSv year-1. Hence, it is important to protect physicians' eyes from X-ray radiation. Particularly in interventional radiology (IVR) procedures, many physicians use protective lead (Pb) glasses to reduce their occupational exposure. This study assessed the shielding effects of novel 0.07 mm Pb glasses. The novel glasses (XR-700) have Pb-acrylic lens molded in three dimensions. We studied the novel type of 0.07 mm Pb glasses over a period of seven consecutive months. The eye dose occupational radiation exposure of seven IVR physicians was evaluated during various procedures. All IVR physicians wore eye dosimeters (DOSIRIS™) close to the left side of the left eye. To calculate the shielding effects of the glasses, this same type of eye dosimeter was worn both inside and outside of the Pb lenses. The average shielding effect of the novel glasses across the seven physicians was 61.4%. Our results suggest an improved shielding effect for IVR physicians that use these glasses. No physician complained that the new glasses were uncomfortable; therefore comfort is not a problem. The lightweight glasses were acceptable to IVR physicians, who often must perform long procedures. Thus, the novel glasses are comfortable and reasonably protective. Based on the results of this study, we recommend that IVR physicians use these novel 0.07 mm Pb glasses to reduce their exposure., (© The Author(s) 2021. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

In computed tomography (CT)-guided interventions (CTIs), physicians are close to a source of scattered radiation. The physician and staff are at high risk of radiation-induced injury (cataracts). Thus, dose-reducing measures for physicians are important. However, few previous reports have examined radiation doses to physicians in CTIs. This study evaluated the radiation dose to the physician and medical staff using multi detector (MD)CT-fluoroscopy, and attempted to understand radiation-protection and -reduction methods. The procedures were performed using an interventional radiology (IVR)-CT system. We measured the occupational radiation dose (physician and nurse) using a personal dosimeter in real-time, gathered CT-related parameters (fluoroscopy time, mAs, CT dose index (CTDI), and dose length product (DLP)), and performed consecutive 232 procedures in CT-guided biopsy. Physician doses (eye lens, neck, and hand; μSv, average ± SD) in our CTIs were 39.1 ± 36.3, 23.1 ± 23.7, and 28.6 ± 31.0, respectively. Nurse doses (neck and chest) were lower (2.3 ± 5.0 and 2.4 ± 4.4, respectively) than the physician doses. There were significant correlations between the physician doses (eye and neck) and related factors, such as CT-fluoroscopy mAs (eye dose: r = 0.90 and neck dose: r = 0.83). We need to understand the importance of reducing/optimizing the dose to the physician and medical staff in CTIs. Our study suggests that physician and staff doses were not significant when the procedures were performed with the appropriate radiation protection and low-dose techniques.

Ionizing radiation exposure may not only cause acute radiation syndrome, but also an increased risk of late effects. It has been hypothesized that induction of chronic oxidative stress mediates the late effects of ionizing radiation. However, only a few reports have analyzed changes in long-term antioxidant capacity after irradiation in vivo. Our previous study demonstrated changes in whole-blood antioxidant capacity and red blood cell (RBC) glutathione levels within 50 days after total body irradiation (TBI). In this study, seven-week-old, male, C57BL/6J mice exposed to total body irradiation by X-ray and changes in whole-blood antioxidant capacity and RBC glutathione levels at ≥ 100 days after TBI were investigated. Whole-blood antioxidant capacity was chronically decreased in the 5-Gy group. The RBC reduced glutathione (GSH) level and the GSH/oxidative glutathione (GSSG) ratio were chronically decreased after ≥ 1 Gy of TBI. Interestingly, the complete blood counts (CBC) changed less with 1-Gy exposure, suggesting that GSH and the GSH/GSSG ratio were more sensitive radiation exposure markers than whole-blood antioxidant capacity and CBC counts. It has been reported that GSH depletion is one of the triggers leading to cataracts, hypertension, and atherosclerosis, and these diseases are also known as radiation-induced late effects. The present findings further suggest that chronic antioxidant reduction may contribute to the pathogenesis of late radiation effects.

In response to the COVID-19 pandemic caused by SARS-CoV-2 in 2020, we conducted drive-through nasopharyngeal swab testing for COVID-19 in Sendai city, Japan, since April 2020. All tested individuals were judged in advance by public health centers for the necessity of undergoing the test with possible contact history and/or symptoms suggestive of COVID-19. In this study, to identify the predictors of SARS-CoV-2 test positivity for more efficient and evidenced selection of suspected individuals, we enrolled 3,540 consecutive individuals, tested in the first 7 months of the testing program, with data regarding to the history of close contact with COVID-19 patients, including those involved in cluster outbreaks. This cohort included 284 foreign students (257 males and 27 females) from a vocational school involved in the largest cluster outbreak in the area. Close contact history was present in 952 (26.9%) of the participants. The reverse transcription-polymerase chain reaction (RT-PCR) test results showed that 164 participants (4.6%) were positive and 3,376 participants (95.4%) were negative for the SARS-CoV-2 nucleocapsid gene (N2). In the univariate and multivariate analyses, history of close contact with COVID-19 patients, higher age, cough symptoms, and non-native ethnicity were predictors for SARS-CoV-2 test positivity. However, the significance of age and foreign nationality disappeared or declined upon excluding the foreign students from the aforementioned largest cluster outbreak. In conclusion, a history of close contact with COVID-19 patients and the presence of cough symptoms are significant predictors of SARS-CoV-2 test positivity.

In recent years, endovascular treatment of aortic aneurysms has attracted considerable attention as a promising alternative to traditional surgery. Hybrid operating room systems (HORSs) are increasingly being used to perform endovascular procedures. The clinical benefits of endovascular treatments using HORSs are very clear, and these procedures are increasing in number. In procedures such as thoracic endovascular aortic repair (TEVAR) and endovascular aortic repair (EVAR), wires and catheters are used to deliver and deploy the stent graft in the thoracic/abdominal aorta under fluoroscopic control, including DSA. Thus, the radiation dose to the patient is an important issue. We determined radiation dose indicators (the dose-area product (DAP) and air karma (AK) parameters) associated with endovascular treatments (EVAR and TEVAR) using a HORS. As a result, the mean ± standard deviation (SD) DAPs of TEVAR and EVAR were 323.7 ± 161.0 and 371.3 ± 186.0 Gy x cm 2 , respectively. The mean ± SD AKs of TEVAR and EVAR were 0.92 ± 0.44 and 1.11 ± 0.54 Gy, respectively. The mean ± SD fluoroscopy times of TEVAR and EVAR were 13.4 ± 7.1 and 23.2 ± 11.7 min, respectively. Patient radiation dose results in this study of endovascular treatments using HORSs showed no deterministic radiation effects, such as skin injuries. However, radiation exposure during TEVAR and EVAR cannot be ignored. The radiation dose should be evaluated in HORSs during endovascular treatments. Reducing/optimizing the radiation dose to the patient in HORSs is important.

Radiation exposure during interventional radiology (IR) procedures is a critical issue. We have developed a wireless real-time dosimeter for IR patients that use nontoxic phosphor (four sensors). We evaluated the basic performance parameters (such as dose linearity, batch uniformity, reproducibility, and wireless-communication conditions) of the developed system using an IR X-ray system. Further, we investigated the influence of noise from other medical equipment on our wireless real-time dosimeter in the IR X-ray room. Overall, our wireless system exhibited excellent performance in terms of uniformity, reproducibility, and linearity; moreover, the wireless communication performance was better. The developed system enabled real-time visualization of patient radiation dose, without noise contamination from other medical equipment. In addition, the wireless system can be easily installed in a location where the PC screen (display) can be readily viewed by the IR physician. Hence, we developed a wireless system that can display the patient radiation dose data in real time; the system performed satisfactorily upon application in radiation dosimetry. Therefore, our wireless system will facilitate the real-time monitoring/management of patient radiation dose during IR.

Radiation-related tissue injuries after medical radiation procedures, such as fluoroscopically guided intervention (FGI), have been reported in patients. Real-time monitoring of medical radiation exposure administered to patients during FGI is important to avoid such tissue injuries. In our previous study, we reported a novel (prototype) real-time radiation system for FGI. However, the prototype sensor indicated low sensitivity to radiation exposure from the side and back, although it had high-quality fundamental characteristics. Therefore, we developed a novel 4-channel sensor with modified shape and size than the previous sensor, and evaluated the basic performance (i.e., measured the energy, dose linearity, dose rate, and angular dependence) of the novel and previous sensors. Both sensors of our real-time dosimeter system demonstrated the low energy dependence, excellent dose linearity (R 2 = 1.0000), and good dose rate dependence (i.e., within 5% statistical difference). Besides, the sensitivity of 0° ± 180° in the horizontal and vertical directions was almost 100% sensitivity for the new sensor, which significantly improved the angular dependence. Moreover, the novel dosimeter exerted less influence on X-ray images (fluoroscopy) than other sensors because of modifying a small shape and size. Therefore, the developed dosimeter system is expected to be useful for measuring the exposure of patients to radiation doses during FGI procedures.

An electronic cigarette (e-cigarette) is a product used to smoke aerosol by heating a solution of "e-liquid" that consists of propylene glycol (PG) and glycerol (GLY) containing nicotine and flavors. In this study, thermal decomposition products generated from three brands of e-cigarettes were determined at various electric power levels. When using neat PG or GLY instead of e-liquid, propylene oxide was detected only in the gas phase from PG and not detected from GLY. In contrast, glycidol was detected only from GLY and not from PG. Almost all of the glyoxal and acrolein was detected from GLY, but formaldehyde and methyl glyoxal were detected from both PG and GLY. Using commercially available e-liquids, the same results were obtained. Nearly all chemical compounds generated from e-cigarettes have a carbon number of 3 or less except for nicotine and flavors. We measured chemical compounds generated from e-cigarettes at various electric power levels (1-85 W). At an electric power of 10 W, the generation of chemical compounds was very low; however, when the electric power exceeded 40 W, it increased exponentially. As thermal decomposition products of e-liquid, acetaldehyde, acrolein, and propylene oxide mainly occur as gaseous matter, while glyoxal, methylglyoxal, and glycidol mainly occur as particulate matter. Formaldehyde exits in both gaseous and particulate matter forms. Thermal decomposition products can be divided into three groups: thermal decomposition products originating from PG and GLY, those originating from other sources, and those directly generated. Concentrations of these thermal decomposition products were mostly higher than those in traditional cigarettes. In particular, thermal decomposition products generated from one of the studied e-cigarettes were very high; e.g., formaldehyde reached 4400 μg/15 puffs at 50 W. E-cigarette users must know that hazardous substances are generated even within the recommended electric power limits.

Biodosimetry is a useful method for estimating personal exposure doses to ionizing radiation. Studies have identified metabolites in non-cellular biofluids that can be used as markers in biodosimetry. Levels of metabolites in blood cells may reflect health status or environmental stresses differentially. Here, we report changes in the levels of murine blood cell metabolites following exposure to X-rays in vivo. Levels of blood cell metabolites were measured by capillary electrophoresis time-of-flight mass spectrometry. The levels of 100 metabolites were altered substantially following exposure. We identified 2-aminobutyric acid, 2'-deoxycytidine, and choline as potentially useful markers of radiation exposure and established a potential prediction panel of the exposure dose using stepwise regression. Levels of blood cell metabolites may be useful biomarkers in estimating exposure doses during unexpected radiation incidents.

Monitoring and protecting of occupational eye doses in interventional radiology (IR) are very important matters. DOSIRIS™ is the useful solution to estimate the 3 mm dose-equivalent (Hp(3)), and it can be worn behind lead glasses. And DOSIRIS™, adjustable according to 3 axes, it is ideally placed as close to the eye and in contact with the skin. So, DOSIRIS™ will be suitable eye lens dosimeter. However, the fundamental characteristics of the DOSIRIS™ in the diagnostic x-ray energy domain (including that of IR x-ray systems) remain unclear. Here, we evaluated the performance of the dosimeter in that energy range. As a result, the DOSIRIS™ has good fundamental characteristics (batch uniformity, dose linearity, energy dependence, and angular dependence) in the diagnostic x-ray energy domain. We conclude that the DOSIRIS™ has satisfactory basic performance for occupational eye dosimetry in diagnostic x-ray energy settings (including IR x-ray systems).

Although several experimental studies have reported that oxidative stress levels decrease during smoking cessation, how they change among general smokers has yet to be completely elucidated. In the present study, a total of 23 smokers who underwent smoking cessation treatment were observed for two-week changes in their levels of 8-OHdG and 8-isoprostane. Physical and nutritional characteristics were measured at the initial patient visit, and casual urine samples were collected at the initial visit and at a follow-up visit two weeks later. Oxidative stress was measured by a high performance liquid chromatography electrochemical detector, and the two-week difference in the levels of oxidative stress was assessed according to demographic and nutrient factors. Neither the urinary level of 8-OHdG nor that of 8-isoprostane decreased, although the cotinine level was decreased at two weeks. A Two-way repeated ANOVA revealed a significant interaction for fat intake by time for the change in the 8-OHdG level (P=0.03) and significant interactions for α-tocopherol intake (P=0.03), iron intake, and carbohydrate intake (P=0.03), all of which were time-dependent for the change in the 8-isoprostane level. The 8-OHdG level decreased among smokers with a high fat intake and was increased with a low fat intake. The 8-isoprostane levels were decreased among smokers with a high carbohydrate intake and increased with a low carbohydrate intake, decreased with a low iron intake and increased with a high iron intake and decreased with a low α-tocopherol intake and increased with a high α-tocopherol intake. Although the present study failed to observe a decrease in oxidative stress levels during the two-week smoking cessation period, we hypothesize that the intake levels of specific nutrients when initiating smoking cessation treatment may predict any subsequent changes in the oxidative stress levels.

Radiation dose management is important in interventional radiology (IR) procedures, such as percutaneous coronary intervention, to prevent radiation-induced injuries. Therefore, radiation dose should be monitored in real time during IR. This study evaluated the fundamental characteristics of a novel real-time skin dosimeter (RTSD) developed at our institution. In addition, we compared the performance of our new and old radiation sensors and that of a skin dose monitor (SDM), with ion chamber reference values. We evaluated the fundamental characteristics (e.g., energy dependence, dose dependence, and angular dependence) of the RTSD developed by us in the diagnostic X-ray energy range. The performance of our RTSD was similar to that of the SDM. In particular, the new radiation sensor of our RTSD demonstrated better dose rate dependence compared to the old sensor. In addition, the new sensor had the advantage of being small in size and thus minimally affecting the X-ray images compared to the old sensor. Therefore, the developed skin dosimeter and radiation sensor may be useful in real-time measurement of patients' exposure to and multi-channel monitoring of radiation in IR procedures. The new dosimeter system can be recommended for visualization and management of the radiation dose to which the patients' skin is exposed.

As a new form of cigarettes, heated tobacco products (HTPs) have been rapidly distributed worldwide. In this study, an improved method for analyzing gaseous and particulate compounds generated from HTPs is described. Smoke is collected using a GF-CX572 sorbent cartridge with 300 mg of carbon molecular sieves, that is, Carboxen 572 (CX572), and a 9 mm glass-fiber filter (GF). After collection, the CX572 particles from the cartridge are transferred along with the GF and deposited into a vial containing two phases of carbon disulfide and methanol. The CX572 particles settle into the lower carbon disulfide phase, while nonpolar compounds are desorbed. After the sample is allowed to stand, the solution is slowly stirred. The two-phase mixture of carbon disulfide and methanol is combined into a homogeneous solution. Polar compounds are then desorbed, while the desorbed nonpolar compounds remain in solution. For the analysis of carbonyl compounds, an enriched 2,4-dinitrophenylhydrazine solution is added to a portion of the combined solution for derivatization and subsequent high-performance liquid chromatography analysis. For the analysis of volatile organic compounds and water, a portion of the combined solution is analyzed by gas chromatography-mass spectrometry or equipped with a thermal conductivity detector. By applying the proposed GF-CX572 one-cartridge method to the analysis of the mainstream smoke generated from HTPs and traditional cigarettes, several chemical compounds are detected, and the chemical composition of smoke is revealed. The GF-CX572 one-cartridge method can analyze gaseous and particulate chemical compounds from the HTP smoke by utilizing not only the entire puff volume but also one puff volume because the GF-CX-572 cartridge can be replaced with a new cartridge within 3 s. An overview of the chemicals generated from HTPs is obtained in detail by one-puff volume sampling. In addition, the generated chemical compounds strongly depend on the temperature of tobacco leaves in HTPs.

Many reports have demonstrated that radiation stimulates reactive oxygen species (ROS) production by mitochondria for a few hours to a few days after irradiation. However, these studies were performed using cell lines, and there is a lack of information about redox homeostasis in irradiated animals and humans. Blood redox homeostasis reflects the body condition well and can be used as a diagnostic marker. However, most redox homeostasis studies have focused on plasma or serum, and the anti-oxidant capacity of whole blood has scarcely been investigated. Here, we report changes in the anti-oxidant capacity of whole blood after X-ray irradiation using C57BL/6 J mice. Whole-blood anti-oxidant capacity was measured by electron spin resonance (ESR) spin trapping using a novel spin-trapping agent, 2-diphenylphosphinoyl-2-methyl-3,4-dihydro-2H-pyrrole N-oxide (DPhPMPO). We found that whole-blood anti-oxidant capacity decreased in a dose-dependent manner (correlation factor, r > 0.9; P < 0.05) from 2 to 24 days after irradiation with 0.5-3 Gy. We further found that the red blood cell (RBC) glutathione level decreased and lipid peroxidation level increased in a dose-dependent manner from 2 to 6 days after irradiation. These findings suggest that blood redox state may be a useful biomarker for estimating exposure doses during nuclear and/or radiation accidents.

Background: The ammonia contained in tobacco fillers and mainstream and sidestream cigarette smoke accelerates nicotine dependence in cigarette smokers. Ammonia has been included in the non-exhaustive priority list of 39 tobacco components and emissions of cigarette published by the World Health Organization (WHO) Study Group on Tobacco Product Regulation. The development of a simple ammonia detection method will contribute to the establishment of tobacco product regulation under tobacco control policies and allow surveys to be conducted, even by laboratories with small research budgets., Methods: We developed a simple colorimetric method based on the salicylate-chlorine reaction and absorption spectrometry with two reagents (sodium nitroprusside and sodium dichloroisocyanurate). To compare this method to conventional ion chromatography, we analyzed the ammonia levels in tobacco fillers extracted from 35 Japanese commercially marketed cigarette brands manufactured by four tobacco companies (Japan Tobacco (JT) Inc., British American Tobacco (BAT), Philip Morris Japan, and Natural American Spirit). We also analyzed the ammonia levels in the sidestream smoke from cigarettes of the brands that were found to contain high or low tobacco filler ammonia levels., Results: The ammonia levels in the reference cigarette (3R4F) measured by our method and ion chromatography were similar and comparable to previously reported levels. The ammonia levels in tobacco fillers extracted from 35 cigarette brands ranged from 0.25 to 1.58 mg/g. The mean ammonia level of JT cigarette brands was significantly higher (0.83 ± 0.28 mg/g) than that of Natural American Spirit cigarette brands (0.30 ± 0.08 mg/g) and lower than those in the other two cigarette brands (1.11 ± 0.19 mg/g for BAT and 1.24 ± 0.15 mg/g for Philip Morris) (p < 0.001 by Bonferroni test). The ammonia levels in the sidestream smoke of CABIN, Marlboro Black Menthol, American Spirit Light, and Seven Stars were 5.89 ± 0.28, 5.23 ± 0.12, 6.92 ± 0.56, and 4.14 ± 0.19 mg/cigarette, respectively. The ammonia levels were higher in sidestream smoke than in tobacco filler., Conclusions: Our simple colorimetric could be used to analyze ammonia in tobacco fillers and sidestream smoke. There were significant differences between the ammonia levels of the 35 commercially marketed cigarette brands in Japan manufactured by four tobacco manufacturers. Over 90% of the ammonia in sidestream smoke was in gaseous phase.

There are no feasible real-time and direct skin dosimeters for interventional radiology. One would be available if there were x-ray phosphors that had no brightness change caused by x-ray irradiation, but the emission of the Y 2 O 3 :Eu, (Y, Gd, Eu)BO 3 , and YVO 4 :Eu phosphors investigated in our previous study was reduced by x-ray irradiation. We found that the brightness of those phosphors recovered, and the purpose of this study is to investigate their recovery phenomena. It is expected that more kinds of phosphors could be used in x-ray dosimeters if the brightness changes caused by x-rays are elucidated and prevented. Three kinds of phosphors-Y 2 O 3 :Eu, (Y, Gd, Eu)BO 3 , and YVO 4 :Eu-were irradiated by x-rays (2 Gy) to reduce their brightness. After the irradiation, brightness changes occurring at room temperature and at 80 °C were investigated. The irradiation reduced the brightness of all the phosphors by 5%-10%, but the brightness of each recovered immediately both at room temperature and at 80 °C. The recovery at 80 °C was faster than that at room temperature, and at both temperatures the recovered brightness remained at 95%-98% of the brightness before the x-ray irradiation. The brightness recovery phenomena of Y 2 O 3 :Eu, (Y, Gd, Eu)BO 3 , and YVO 4 :Eu phosphors occurring after brightness deterioration due to x-ray irradiation were found to be more significant at 80 °C than at room temperature. More kinds of phosphors could be used in x-ray scintillation dosimeters if the reasons for the brightness changes caused by x-rays were elucidated.

Because of the health effects of secondhand smoke, the Japanese government is trying to establish an effective law for total avoidance of secondhand smoke in indoor environments for tobacco-free Tokyo Olympic and Paralympic games 2020, as requested by the International Olympic Committee (IOC) and the World Health Organization (WHO). Meanwhile, Philip Morris International has begun selling a new heat-not-burn tobacco, iQOS, which it claims is designed not to produce secondhand smoke. There is little scientific data, however, of the hazards and toxicity of iQOS. In this study, we evaluated several harmful compounds (nicotine, tar, carbon monoxide (CO) and tobacco-specific nitrosamines (TSNAs)) in the mainstream smoke and fillers of iQOS, and compared their concentrations with those from conventional combustion cigarettes. The concentrations of nicotine in tobacco fillers and the mainstream smoke of iQOS were almost the same as those of conventional combustion cigarettes, while the concentration of TSNAs was one fifth and CO was one hundredth of those of conventional combustion cigarettes. These toxic compounds are not completely removed from the mainstream smoke of iQOS, making it necessary to consider the health effects and regulation of iQOS.

There is currently no effective real-time patient dosimeter available for use in interventional radiology (IR). We conducted a feasibility study in a clinical setting to investigate the use of the new dosimeter using photoluminescence sensors during procedures. Reference dosimeters were set at almost the same position of the prototype dosimeter sensors. We found excellent correlations between the reference measurements and those of the prototype dosimeter (r 2 =0.950). The sensor of the new dosimeter does not interfere with the IR procedure. The new dosimeter will be an effective tool for the real-time measurement of patient skin doses during IR., (Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

Japan Network for Research and Information on Medical Exposures (J-RIME) released the primary diagnostic reference levels (DRLs 2015) to optimize/manage the radiation dose for interventional radiology (IVR) on June 7, 2015 in Japan. However, this DRLs 2015 has a wide range of selection bias for only certified IVR technologists' dates. Therefore, it is important to know the radiation dose including non-certified IVR technologists' facilities. In this study, we verified the fluoroscopy radiation dose rates for many IVR systems in the present situation. This study was conducted at 13 cardiac catheterization laboratories (18 X-ray systems) around Sendai. We measured the entrance doses at the patient entrance reference point (interventional reference point) using a 20-cm-thick acrylic plate and skin-dose monitor. Although the DRLs 2015 of IVR is 20 mGy/min, the result of a fluoroscopy radiation dose in 18 X-ray systems was median (inter quartile range: IQR), 24.4 (16.3, 35.5) mGy/min. The optimization/managing the radiation dose of IVR X-ray systems is an important issue. In addition, it is necessary to intensify the activities to raise awareness for DRLs 2015.

There are case reports of injuries caused by the radiation from interventional radiology (IVR) X-ray systems. Therefore, the management of radiation doses in IVR is important. However, no detailed report has evaluated image quality for a large number of IVR X-ray systems. As a result, it is unclear whether the image quality of the X-ray equipment currently used in IVR procedures is optimal. We compared the entrance surface doses and image quality of multiple IVR X-ray systems. This study was conducted in 2014 at 13 medical facilities using 18 IVR X-ray systems. We evaluated image quality and simultaneously measured the radiation dose. Entrance surface doses for fluoroscopy (duration, 1 min) and cineradiography (duration, 10 s) are measured using a 20-cm-thick acrylic plate and skin dose monitor. The image quality (such as spatial resolution and low-contrast detectability) of both fluoroscopy and cineradiography was evaluated using a QC phantom. For fluoroscopy, the average entrance surface dose using the 20-cm-thick acrylic plate was 13.9 (range 2.1-28.2) mGy/min. For cineradiography, the average entrance surface dose was 24.6 (range 5.1-49.3) mGy/10 s. We found positive correlations between radiation doses and image quality scores, in general, especially for fluoroscopy. The differences in surface dose among the 18 IVR X-ray systems were high (max/min, 9.7-fold for cineradiography; 13.4-fold for fluoroscopy). The differences in image quality scores (spatial resolution, low-contrast detectability, and dynamic range) were also very large. In general, there tended to be a correlation between radiation dose and image quality. Periodical measurements of the radiation dose and image quality of the X-ray equipment used for cineradiography and fluoroscopy in IVR are necessary. The need to minimize patient exposure requires that the dose be reduced to the minimum level that will generate an image with an acceptable degree of noise.

Purpose: The increasing amounts of evidence with abnormal aging process have been involved in the pathogenesis of chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). Mice with deficient protein L-isoaspartate (D-aspartate) O-methyl transferase 1 (PCMT1) expression reveal acceleration of aging and result in the increased proportion of D-aspartate (D-Asp) residues and dysfunction in proteins. Furthermore, mitochondrial morphology and functions are associated with COPD and IPF pathogenesis. The purpose of the current study was to investigate the role of PCMT1 on mitochondrial morphology using A549 cells., Materials and Methods: We investigated PCMT1, prohibitin1 (PHB1), mitochondrial membrane proteins expression, mitochondrial morphology, and the proportion of D-Asp residues in PHB1 in A549 cells with (PCMT1-KD) and without the context of decreased PCMT1 expression (PCMT1-Cont) using electron microscopy, fluorescence staining, Western blot analysis, and the ATP content per cells. To investigate the effects of the PCMT1-KD cells, we developed double-transfected cell lines containing either the cytosolic or the endoplasmic isoform of PCMT1., Results: We found a significantly higher proportion of D-Asp residues in PHB1 in PCMT1-KD cells than that in PCMT1-Cont cells. The PCMT1-KD cells without cigarette smoke extract exposure were characterized by a significantly increased proportion of the D-Asp residues in PHB1, damaged mitochondrial ultrastructure, and a tendency toward the fission direction of the mitochondrial dynamics followed by a significant decrease in the cellular ATP content., Conclusions: The increased proportion of the D-Asp residues may contribute to COPD pathogenesis, via irreversible protein conformational changes, followed by mitochondrial dysfunction.