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Featured Application: Importance of the evaluation of the physician's eye exposure to radiation during 198Au grain brachytherapy, given that the eye dose limit has been reduced drastically from 150 to 20 mSv/year. Brachytherapy is a practical, effective procedure for the local treatment of cancer; it delivers a high radiation dose to a limited tissue volume while sparing the surrounding normal tissues. Although the clinical benefit of brachytherapy is clear, there have been very few studies on the radiation dose received by physicians during the procedure. Furthermore, no study has investigated the eye radiation dose received by physicians performing 198Au grain (seed) brachytherapy, using an eye dosimeter. Recently, the International Commission on Radiological Protection (ICRP) recommended significantly reducing the occupational lens dose limit, from 150 to 20 mSv/yr (100 mSv/5 years). Therefore, it has become essential to evaluate the eye radiation doses of medical workers. We evaluated the eye radiation dose of a brachytherapy physician performing 198Au permanent grain implantation for tongue cancer; this is the first study on this topic. The maximum eye dose was ~0.1 mSv/procedure, suggesting that it is unlikely to exceed the ICRP limit (20 mSv/yr) for the lens, unless many procedures are performed with inappropriate radiation protection. To reduce the dose of radiation received by 198Au grain brachytherapy physicians, it is necessary to use additional lead shielding equipment when preparing the treatment needles, i.e., when loading the grains. This study provides useful information on radiation exposure of physicians conducting 198Au permanent grain brachytherapy. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The International Commission on Radiological Protection has lowered the annual equivalent eye-lens dose to 20 mSv. Although occupational exposure can be high in nuclear medicine (NM) departments, few studies have been conducted regarding eye-lens exposure among NM staff. This study aimed to estimate the annual lens doses of staff in an NM department and identify factors contributing to lens exposure. Four nurses and six radiographers performing positron emission tomography (PET) examinations and four radiographers performing radioisotope (RI) examinations (excluding PET) were recruited for this study. A lens dosimeter was attached near the left eye to measure the 3-mm-dose equivalent; a personal dosimeter was attached to the left side of the neck to measure the 1-cm- and 70-µm-dose equivalents. Measurements were acquired over six months, and the cumulative lens dose was doubled to derive the annual dose. Correlations between the lens and personal-dosimeter doses, between the lens dose and the numbers of procedures, and between the lens dose and the amounts of PET drugs (radiopharmaceuticals) injected were examined. Wilcoxon's signed-rank test was used to compare lens and personal-dosimeter doses. The estimated annual doses were 0.93 ± 0.13 mSv for PET nurses, 0.71 ± 0.41 mSv for PET radiographers, and 1.10 ± 0.53 mSv for RI radiographers. For PET nurses, but not for PET or RI radiographers, there was a positive correlation between the numbers of procedures and lens doses and between amounts injected and lens doses. There was a significant difference between the lens and personal-dosimeter doses of PET nurses. The use of protective measures, such as shielding, should prevent NM staff from receiving lens doses > 20 mSv/year. However, depending on the height of the protective shield, PET nurses may be unable to assess the lens dose accurately using personal dosimeters. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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%. [ABSTRACT FROM AUTHOR]

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 DOSIRISTM. 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, R2 = 0.82 and R2 = 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, R2 = 0.50 and R2 = 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. [ABSTRACT FROM AUTHOR]

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 (R2 = 0.91) and percutaneous coronary intervention (R2 = 0.93). Kerma-area product values may be used for a rough estimation of the eye dose for physicians during routine coronary angiography procedures (R2 = 0.76). For nurses, the neck dose is a good proxy for the eye dose during coronary angiography and percutaneous coronary intervention procedures. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background and Aims In addition to some electronic cigarettes (e-cigarettes), new heat-not-burn tobacco products Ploom and iQOS have recently begun to be sold by tobacco companies. These products are regulated differently in Japan, depending on whether the contents are liquid or tobacco leaf. Our objective was to estimate percentages of awareness and use of e-cigarettes and heat-not-burn tobacco products among the Japanese population, including minors. Design and Setting An internet survey (randomly sampled research agency panellists) with a propensity score adjustment for "being a respondent in an internet survey" using a nationally representative sample in Japan. Participants A total of 8240 respondents aged 15-69 years in 2015 (4084 men and 4156 women). Measurements Adjusted percentages of awareness and use of e-cigarettes (nicotine or non-nicotine e-cigarettes) and heat-not-burn products among total participants; product types and percentages ever used among e-cigarettes ever users. Findings Of respondents in Japan, 48% [95% confidence interval (CI) = 47-49] were aware of e-cigarettes and heat-not-burn tobacco products, 6.6% (95% CI = 6.1-7.1) had ever used, 1.3% (95% CI = 1.0-1.5) had used in the last 30 days and 1.3% (95% CI = 1.1-1.6) had experience of > 50 sessions. Seventy-two per cent (95% CI = 69-76) of ever users used non-nicotine e-cigarettes, while 33% (95% CI = 30-37) of them used nicotine e-cigarettes, which has the majority share world-wide; 7.8% (95% CI = 5.5-10.0) and 8.4% (95% CI = 6.1-10.7) of them used the new devices, Ploom and iQOS, respectively, with a relatively higher percentage among the younger population. Conclusions Approximately half the respondents in a Japanese internet survey were aware of e-cigarettes and heat-not-burn tobacco products, 6.6% had ever used. More than 70% of ever users used non-nicotine e-cigarettes, the sale of which is not legally prohibited, even to minors, in Japan, and 33% of them used nicotine e-cigarettes; 3.5% of never smoking men and 1.3% of never smoking women had ever used e-cigarettes. Corresponding figures for use in the last 30 days were 0.6% and 0.3%, predominantly non-nicotine e-cigarettes. [ABSTRACT FROM AUTHOR]

As the use of diagnostic X-ray equipment with flat panel detectors (FPDs) has increased, so has the importance of proper management of FPD systems. To ensure quality control (QC) of FPD system, an easy method for evaluating FPD imaging performance for both stationary and moving objects is required. Until now, simple rotatable QC phantoms have not been available for the easy evaluation of the performance (spatial resolution and dynamic range) of FPD in imaging moving objects. We developed a QC phantom for this purpose. It consists of three thicknesses of copper and a rotatable test pattern of piano wires of various diameters. Initial tests confirmed its stable performance. Our moving phantom is very useful for QC of FPD images of moving objects because it enables visual evaluation of image performance (spatial resolution and dynamic range) easily. [ABSTRACT FROM AUTHOR]

Objectives: Although the relative risk of lung cancer due to smoking is reported to be lower in Japan than in other countries, few studies have examined the characteristics of Japanese cigarettes or potential differences in smoking patterns among Japanese smokers. Methods: To examine tar, nicotine and carbon monoxide (TNCO) emissions from ten leading cigarettes in Japan, machine smoking tests were conducted using the International Organization for Standardization (ISO) protocol and the Health Canada Intense (HCI) protocol. Smoking topography and tobacco-related biomarkers were collected from 101 Japanese smokers to examine measures of exposure. Results: The findings indicate considerable variability in the smoking behavior of Japanese smokers. On average, puffing behaviors observed among smokers were more similar to the parameters of the HCI protocol, and brands with greater ventilation that yielded lower machine values using the ISO protocol were smoked more intensely than brands with lower levels of ventilation. The smokers of 'ultra-low/low' nicotine-yield cigarettes smoked 2.7-fold more intensively than those of 'medium/high' nicotine-yield cigarette smokers to achieve the same level of salivary cotinine ( p = 0.024). CO levels in expiratory breath samples were associated with puff volume and self-reported smoking intensity, but not with nominal values of nicotine-yield reported on cigarette packages. Conclusions: Japanese smokers engaged in 'compensatory smoking' to achieve their desired nicotine intake, and levels of exposure were greater than those suggested by the nominal value of nicotine and tar yields reported on cigarette packages. [ABSTRACT FROM AUTHOR]

Today, interventional radiology (IR) X-ray units are required for display of doses at an interventional reference point (IRP) for the operator (IR physician). The dose displayed at the IRP (the reference dose) of an X-ray unit has been reported to be helpful for characterizing patient exposure in real time. However, no detailed report has evaluated the accuracy of the reference doses displayed on X-ray equipment. Thus, in this study, we compared the displayed reference dose to the actual measured value in many IR X-ray systems. Although the displayed reference doses of many IR X-ray systems agreed with the measured actual values within approximately 15%, the doses of a few IR units were not close. Furthermore, some X-ray units made in Japan displayed reference doses quite different from the actual measured value, probably because the reference point of these units differs from the International Electrotechnical Commission standard. Thus, IR physicians should pay attention to the location of the IRP of the displayed reference dose in Japan. Furthermore, physicians should be aware of the accuracy of the displayed reference dose of the X-ray system that they use for IR. Thus, regular checks of the displayed reference dose of the X-ray system are important. [ABSTRACT FROM AUTHOR]

A novel separation method of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was developed. The C18and the strong cation-exchange (SCX) columns were employed to separate urinary 8-OHdG. The major interfering substances were removed by the consecutive processes of the C18and the SCX columns. This newly developed procedure allows researchers to quantitatively measure urinary 8-OHdG by high performance liquid chromatography-electrochemical detector (HPLC–ECD) successfully. The newly developed separation method produces the optimized procedure of 8-OHdG measurement, and followed by the evaluation of its basic performance. The optimized measurement was highly reproducible (CV = 2.0–2.9%, n= 10). A correlation was observed between the proposed HPLC–ECD method and the column switching method (r= 0.96). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 × cm2, 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. [ABSTRACT FROM AUTHOR]

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 (R2 = 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]