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東京電力福島第一原子力発電所の廃炉において発生すると考えられる様々な種類の廃棄物は，その汚染レベルに応じて廃棄方法が決定される．様々な放射性物質や核燃料物質のうち，ウランは半減期が非常に長く，放射線計測による検出が難しい場合がある．そこで，本研究では廃棄物表面のウラン汚染レベルを迅速にスクリーニングする方法として，蛍光X 線分析法に基づく手法を提案する．硝酸ウラニル溶液を滴下したろ紙をポリプロピレン製片側粘着テープとマイラ膜で密封し，これをコンクリート固化物，ポリエチレンブロック，ガラス板に重ねたものを，これらの物質の表面がウランに汚染されたもののモデルとした．このモデルの蛍光X 線分析を行った結果，ウラン添加量とU Lα 線の信号強度の相関はどのモデルでもほぼ同じ傾きの直線となった．ただし，コンクリートはウランを含んでいるので，縦軸切片が有意な値を持った．

At TEPCO's Fukushima Daiichi Nuclear Power Station, contaminated water is treated after removing radionuclides. Fuel debris removal, which is commencing soon, may discharge water contaminated with actinides, such as uranium, neptunium, and plutonium, requiring screening prior to treatment. In this paper, we propose an actinide screening method based on X-ray fluorescence (XRF) analysis. In this method, actinides are collected on a chelating disk [1] containing iminodiacetic acid as a chelating agent, and their L-X rays are analyzed using an energy-dispersive XRF device. The Br Kβ, Rb Kα, and Sr Kα peaks overlap with the Lα peaks of U, Np, and Pu, which interferes with the analysis. Of these, the Br Kβ and Rb Kα peaks are located in the lower energy region of the U Lα peak and can be separated by peak fitting [2]. Furthermore, the Sr Kα peak is located between the Np Lα and Pu Lα peaks, hindering its separation by peak fitting owing to the proximity of the peaks. Therefore, before collecting the actinides in the sample solution on the chelating disk, Sr is removed by loading through a Sr Rad Disk [3], which adsorbs Sr well. First, simulated contaminated water containing Sr was mixed with same amount of 4 mol/L nitric acid and a solution containing 200 ng of U, Np, and Pu. This was loaded through a Sr Rad Disk. To the filtrate, 1 mol/L ammonium acetate were added, and pH was adjusted to 5.6. The chelating disk of 22.5 mm diameter was conditioned with methanol, 2 mol/L nitric acid, ultrapure water, and 0.1 mol/L ammonium acetate solution (pH 5.6). Actinides were collected on the disc by loading the sample solution through chelate discs. The XRF measurement of the disc was performed using an Epsilon 4 tabletop XRF spectrometer (PANalytical, Malvern Instruments, Spectris plc, England). The X-ray tube voltage and current were set to 50 kV and 0.3 mA, respectively, and the X-ray accumulation time for each spectral measurement was 300 s. In the measured XRF spectrum, the Lα peaks of U, Np, and Pu were clearly observed. In this presentation, we explain the features and benefits of this technique. This research project was conducted as a regulatory supporting research funded by the Secretariat of Nuclear Regulation Authority (S/NRA/R) in Japan. [1] T. Inui et al., X-ray spectrometry 40, 2011, 301–305. [2] H. Yoshii et al., Spectrochimica Acta B, 189, 2022, 106368. [3] LL. Smith et al., Radiochemical Acta 73, 1996, 165–170., European Conference on X-ray Spectrometry 2022

【緒言】東京電力福島第一原子力発電所の廃炉作業において発生する可能性のある汚染水中のアクチニド (U, Np, Pu) を迅速にスクリーニングする手法が必要とされている．汚染水をキレートディスクに通液して捕集し，蛍光X線分析する方法を検討しているが，Np Lα線やPu Lα線とSr Kα線が重なるので，事前にSrを除去しておくことが望ましい．本研究では，ストロンチウムラドディスクを用いて，事前にSrを除去しておく手法を開発した． 【実験】ストロンチウムラドディスク1)は，試料溶液の硝酸濃度が2 mol/L程度の時にストロンチウムを効率よく吸着する．そこで，模擬汚染水としてのがれき純水浸漬液に等量の4 mol/L硝酸を加えて硝酸濃度を2 mol/Lとし，そこに200 ngのU, Np, Puを添加した．コンディショニングしたストロンチウムラドディスクに通液し，そのろ液を回収した．キレートディスクはpH5.6で通液するのが標準的な手法とされているので2)，液量の10%の1 mol/L酢酸アンモニウム水溶液を緩衝液として加え，pHを5.6に調整してから通液した．ディスクはマイラ膜とポリプロピレン製粘着テープで密封し，卓上型蛍光Ｘ線分析装置Epsilon4 (パナリティカル) で測定した．測定条件は管電圧50 kV，管電流0.3 mA，測定時間3600sである． 【結果と考察】ストロンチウムラドディスク (SrD) とキレートディスク(ChD) の蛍光Ｘ線スペクトルを図1に示す．ストロンチウムラドディスクでSrが完全に除去されているため，キレートディスクにはSr Kα線は表れておらず，明瞭なU Lα線，Np Lα線，Pu Lα線が観測されている．この手法によるU, Np, Puの回収率はそれぞれ99%, 66%, 46%だった． 1)T. Inui et al., X-ray spectrometry 2011, 40, 301–305. 2)古庄義明 et al., 分析化学 2008, 57, 969–989., 日本分析化学会 第82回分析化学討論会

For rapid detection of uranium contamination in wounds at a nuclear fuel handling facility, a technique for XRF analysis of blood collected on small filter paper was developed, and a minimum detectable radioactivity of 0.31 mBq was obtained. This is much smaller than the lower detection limit of 1 Bq of the α-particle survey meter. This very simple and rapid technique has enabled the detection of uranium contamination in wounds with much higher sensitivity.

Uranium, which is used as nuclear fuel, is a radioactive material, and screening for uranium contamination is often performed by radiation measurements. However, a method targeting the number of atoms is more effective than radiation measurements for detecting uranium, which is a long-half-life nuclide with very low specific radioactivity. X-ray fluorescence analysis is one such analytical method that is suitable for screening measurements because of the simple pretreatment required. In this article, the properties of uranium and the superiority of X-ray fluorescence analysis as a screening method for uranium contamination are described first. Furthermore, we provide a comprehensive overview of screening methods based on X-ray fluorescence (XRF) analysis for uranium-contaminated wounds, on the basis of our recent studies. These methods can be used in radiation emergency medicine. In addition, we discuss methods based on total reflection X-ray fluorescence (TXRF) analysis for analyzing uranium-contaminated drainage water which will be found in the decommissioning field of Fukushima Daiichi Nuclear Power Plant.

When workers are wounded at a nuclear fuel handling facility, it is difficult to quantify actinide contamination through α‐particle counting because these particles are shielded by blood. To overcome this problem, we used X‐ray fluorescence (XRF) analysis with a handheld‐type device that is useful in cases where sampling is not allowed, such as in this study. In XRF analysis, a primary X‐ray filter made of metal foil is generally inserted between the X‐ray tube and the sample to attenuate the incident X‐ray at the energy region of the XRF signal for the target element. Doing so can reduce the background signal originating from the scattered radiation of the incident X‐ray. In this study, we aimed to optimize a primary X‐ray filter that facilitates simultaneous high‐sensitivity analysis of uranium and plutonium in a wound. For this purpose, XRF measurements were performed for a needle‐puncture wound model contaminated by U and Pu, and the relationship between the filter material/thickness and the detection limit was investigated. Optimizing the filter material/thickness of a given target element was found to improve the detection limit of the measurement by ~10%.

Personnel working in nuclear fuel handling facilities incur a finite risk of injury and uranium contamination in any resulting wounds. The accidental absorption of uranium from the likes of wounds can lead to a significant degree of internal exposure due to its hazardous nature. Although an appropriate surgical resection of tissue in the contaminated wound is useful for suppressing the additional intake of uranium, the rapid quantification of uranium in the wound is required to avoid unnecessary surgery. For surface contamination, the detection of uranium is usually performed using an α‐particle counting method. However, in the case of wound contamination, most of the α‐particles emitted from the uranium cannot pass through the blood oozing from the wound. Therefore, X‐ray fluorescence (XRF) analysis has been proposed as an alternative means of detecting uranium contamination because X‐rays can pass through several millimeters of blood or soft tissue. In the present study, we developed a new methodology for the rapid detection of uranium in wounds that is based on an XRF analysis of contaminated blood collected on filter paper. With XRF, the detection limit for uranium in blood is 0.45 ppm. This value is lower than those of commercially available α‐survey meters by a factor of ~103. Thus, the proposed method could be adopted for the rapid, on‐site detection of uranium in wounds.

In this study, we proposed a novel methodology based on total reflection X-ray fluorescence (TXRF) analysis for rapid evaluation of uranium radioactivity concentration in water samples, which will be found in the decommissioning field of Fukushima Daiichi Nuclear Power Plant containing various impurities. Sample solutions were prepared by mixing a multi-element standard solution containing uranium and thorium with an immersion liquid of the demolition debris in order to examine the effect of components of the demolition debris. An indium standard solution was added to the samples as an internal standard. Since the Rb Kα peak overlapped with the U Lα and Th Lα peaks, Gaussian fitting was performed to determine the net intensity of the U Lα peak. Moreover, due to the largely different contents of uranium and rubidium, reducing the number of fitting parameter made the Gaussian fitting easier. To determine the widths of the peaks, long-time TXRF measurement of the standard solutions for each element was performed. In the Gaussian fitting, only the peak intensities were considered as fitting parameters because the peak widths and peak energies could be fixed. The relative intensity of the U Lα peak was calculated as the net intensity of the U Lα peak normalized by that of the In Kα peak. The relative intensity was directly proportional to the uranium concentration. The estimated minimum detection limit of uranium with a measurement time of 15 min was significantly lower than the effluent standard value for uranium concentration in drainage water as defined by the Japanese Water Pollution Prevention Law, 20 mBq/cm3. All in all, we believe that this method will be useful in determining the uranium concentration in drainage water in the decommissioning field of Fukushima Daiichi Nuclear Power Plant.

Owing to the strong earthquake and subsequent tsunami in March 2011, the Fukushima Daiichi Nuclear Power Plant was exceedingly damaged and is currently under decommissioning. Herein, we propose a methodology to evaluate the uranium concentration in the drainage water from the decommissioning field. Model sample solutions were prepared by mixing multi-element standard solutions containing uranium with an immersion liquid containing demolition debris. A very small amount (10 μL) of the sample solutions was dropped onto a quartz optical flat directory with or without a chromatography resin separation. The total-reflection X-ray fluorescence (TXRF) spectrometry measurement was performed using a portable device. These measurements showed an overlap of the Rb Kα and U Lα peaks in the TXRF spectrum of the sample solution prepared without chromatography resin separation. By contrast, no overlap was observed in the TXRF spectrum of the sample solution after the separation using a chromatography resin. When the drainage water is composed of 0.04% U-234, 5% U-235, and 94.96% U-238, the measurement times in both methods (i.e., with and without pretreatment) required to attain detection limits lower than the effluent standard value are 15 and 5 min, respectively. Additionally, the detection limits, analysis times, required sample volumes, and procedures of the two methods are compared.

In the event of an accident at a nuclear fuel handling facility, the wounds of affected workers may be contaminated with plutonium. The current approach for identifying plutonium contamination is by detecting α-particles in the blood stream. However, the applicability of this approach is impeded due to the α-particles being easily shielded by the bodily fluid components. In this study, we investigate a contamination testing method for such cases that involves the collection of blood with a small piece of filter paper, sealing the sample with thin films, and performing x-ray fluorescence analysis. Our previous study on collecting uranium-contaminated blood with filter paper and performing x-ray fluorescence analysis revealed that the effects arising from blood components could be completely removed by peak fitting, and thus water instead of blood was used as a solvent here. Samples containing various amounts of plutonium as well as samples with 150 Bq of plutonium and uranium were prepared with a mass ratio of 0 to 500 times greater than that of plutonium. x-ray fluorescence measurements showed a high linearity and reproducibility of the Pu Lα peak intensity and plutonium radioactivity, and it was clarified that the signal intensity of the Pu Lα peak did not depend on the amount of coexisting uranium. This method will allow for the simple and rapid assessment of plutonium contamination in wounds.

Uranium concentrations in drainage water are typically determined by α-spectrometry. However, due to the low specific radioactivity of uranium, the evaporation of large volumes of drainage water, followed by several hours of measurements, is required. Thus, the development of a rapid and simple detection method for uranium in drainage water would enhance the operation efficiency of radiation control workers. We herein propose a novel methodology based on total reflection X-ray fluorescence (TXRF) for the measurement of uranium in contaminated water. TXRF is a particularly desirable method for the rapid and simple evaluation of uranium in contaminated water, as chemical pretreatment of the sample solution is not necessary, measurement times are typically several seconds, and the required sample volume is low. We herein employed sample solutions containing several different concentrations of uranyl acetate with yttrium as an internal standard. The solutions were placed onto sample holders, and were ...

The analysis of uranium in environmental samples, quantified using total reflection X-ray fluorescence (TXRF) analysis, would be adversely affected by the presence of rubidium and strontium in larger amounts than uranium as coexisting elements. This is because the U Lα line at 13.61 keV is close to the Rb Kα line at 13.40 keV and the Sr Kα line at 14.17 keV. Using the U Lβ1 line (instead of the U Lα line), which does not overlap with the peaks of coexisting elements, we will be able to avoid these adverse effects. Since there is no TXRF device that can perform a quantitative analysis of uranium by using the U Lβ1 line, the following modifications were made to the existing device with the intention of rapid on-site analysis. The X-ray tube of the new device has a silver anode instead of a tungsten anode, and the sensitive area of the detector was expanded. In addition, the mechanism for adjusting the position of the sample stage was changed from manual to computerized control. These changes made it possible to screen uranium in environmental samples rapidly on site without chemical separation.

The analysis of uranium in environmental samples, quantified using total reflection X-ray fluorescence (TXRF) analysis, would be adversely affected by the presence of rubidium and strontium in larger amounts than uranium as coexisting elements. This is because the U Lα line at 13.61 keV is close to the Rb Kα line at 13.40 keV and the Sr Kα line at 14.17 keV. Using the U Lβ1 line (instead of the U Lα line), which does not overlap with the peaks of coexisting elements, we will be able to avoid these adverse effects. Since there is no TXRF device that can perform a quantitative analysis of uranium by using the U Lβ1 line, the following modifications were made to the existing device with the intention of rapid on-site analysis. The X-ray tube of the new device has a silver anode instead of a tungsten anode, and the sensitive area of the detector was expanded. In addition, the mechanism for adjusting the position of the sample stage was changed from manual to computerized control. These changes made it possible to screen uranium in environmental samples rapidly on site without chemical separation.

(Objective) We retrospectively investigated the applicability of the Japanese Association for the Surgery of Trauma (JAST) classification version 2008 for renal injuries as predictive factors of the initial treatment for 207 blunt renal injury cases. (Materials and methods) We reviewed 207 patients between 1982 and 2013 who were admitted to our institution with blunt renal trauma. Patients were classified as conservative management group, immediate transcatheter arterial embolization (TAE) group, and immediate nephrectomy group by initial treatment. We retrospectively assessed several parameters including JAST criteria version 2008 type of renal injury (type), severity of hematoma (H factor) and extravasation of urine (U factor), the shock on arrival, associated abdominal injuries, serum hemoglobin levels, and macrohematuria as predicting factors of initial treatment of blunt renal trauma. (Result) TypeIII and PV injuries, H2 factor and associated non-renal abdominal injuries were predictive factors of immediate nephrectomy (p=0.001, p=0.000, p=0.003). TypeIII and PV injuries and H2 factor were predictive factors of immediate TAE. Both of H2 and U2 factors were significant predictors of immediate nephrectomy in patients with typeIII injury. H factor was a significantly predictive factor of immediate TAE in patients with typeI/II injuries (p=0.040). The rate of immediate TAE has been increasing but the rate of partial nephrectomy except for nephrectomy has been decreasing since the year 2007 when TAE was immediately available in our hospital. (Conclusion) The type category and severity of hematoma of JAST classification version 2008 would be predictive factors of initial management of blunt renal injuries. Patients with typeIII injuries and both of H2 and U2 factors, can be adapted to immediate nephrectomy. Patients with typeI/II and H2 factors can be adapted to immediate TAE.

In radiation emergency situations involving persons having plutonium (Pu)-contaminated wounds, rapid assessment of the degree of Pu contamination is required to determine the appropriate course of treatment. Currently, rapid on-site detection of Pu is usually performed by analysis of α-particles emitted from the adhesive tape peeled off the wound. However, the detection of α-particles is difficult, especially in traumatic skin lesions with oozing blood, because of the low permeability of α-particles in blood. Therefore, we focused on x-ray fluorescence (XRF) analysis because x-rays easily pass through several millimetres of blood. In this study, we developed a new methodology for the rapid detection of heavy elements in wounds based on XRF analysis of the contaminated blood collected by gauze patch and filter paper, using stable lead (Pb) as a model contaminant substitute for Pu. Mouse blood samples contaminated with Pb were dropped on gauze patches or absorbed by filter papers and were subjected to XRF measurement. Small pieces of filter paper served as more suitable extraction materials than gauze patches because the entire amount of blood absorbed could be measured. When we used filter paper, the signal intensity of the Pb Lα peak was proportional to the Pb concentration in the blood. With a measurement time of 30 s, the minimum detection limit of Pb in blood collected by filter paper was 2.4 ppm.

Electron Paramagnetic Resonance (EPR) tooth dosimetry is being developed as a device to rapidly assess large populations that were potentially exposed to radiation during a major radiation accident or terrorist event. While most exposures are likely to be due to fallout and therefore involve low linear energy transfer (LET) radiation, there is also a potential for exposures to high LET radiation, for which the effect on teeth has been less well characterized by EPR. Therefore, the aim of this paper is to acquire fundamental response curves for high LET radiation in tooth dosimetry using L band EPR. For this purpose, we exposed human teeth to high energy carbon ions using the heavy ion medical accelerator in Chiba at the National Institute of Radiological Sciences. The primary findings were that EPR signals for carbon ion irradiation were about one-tenth the amplitude of the response to the same dose of 150 kVp X-rays.

In 2011, 2012 and 2013, in the intertidal zones of eastern Japan, we investigated the ecological effects of the severe accident at the Fukushima Daiichi Nuclear Power Plant that accompanied the 2011 Great East Japan Earthquake and Tsunami. The number of intertidal species decreased significantly with decreasing distance from the power plant and no rock shell (Thais clavigera) specimens were collected near the plant, from Hirono to Futaba Beach (a distance of approximately 30 km) in 2012. The collection of rock shell specimens at many other sites hit by the tsunami suggests that the absence of rock shells around the plant in 2012 might have been caused by the nuclear accident in 2011. Quantitative surveys in 2013 showed that the number of species and population densities in the intertidal zones were much lower at sites near, or within several kilometers south of, the plant than at other sites and lower than in 1995, especially in the case of Arthropoda. There is no clear explanation for these findings, but it is evident that the intertidal biota around the power plant has been affected since the nuclear accident.

Carotenoids, natural pigments widely distributed in algae and plants, have a conjugated double bond system. Their excitation energies are correlated with conjugation length. We hypothesized that carotenoids whose energy states are above the singlet excited state of oxygen (singlet oxygen) would possess photosensitizing properties. Here, we demonstrated that human skin melanoma (A375) cells are damaged through the photo-excitation of several carotenoids (neoxanthin, fucoxanthin and siphonaxanthin). In contrast, photo-excitation of carotenoids that possess energy states below that of singlet oxygen, such as -carotene, lutein, loroxanthin and violaxanthin, did not enhance cell death. Production of reactive oxygen species (ROS) by photo-excited fucoxanthin or neoxanthin was confirmed using a reporter assay for ROS production with HeLa Hyper cells, which express a fluorescent indicator protein for intracellular ROS. Fucoxanthin and neoxanthin also showed high cellular penetration and retention. Electron spin resonance spectra using 2,2,6,6-tetramethil-4-piperidone as a singlet oxygen trapping agent demonstrated that singlet oxygen was produced via energy transfer from photo-excited fucoxanthin to oxygen molecules. These results suggest that carotenoids such as fucoxanthin, which are capable of singlet oxygen production through photo-excitation and show good penetration and retention in target cells, are useful as photosensitizers in photodynamic therapy for skin disease.

Two-dimensional (2D) cell cultures are essential for drug development and tumor research. However, the limitations of 2D cultures are widely recognized, and a better technique is needed. Recent studies have indicated that a strong physical contact between cells and 2D substrates induces cellular characteristics that differ from those of tumors growing in vivo. 3D cell cultures using various substrates are then developing; nevertheless, conventional approaches have failed in maintenance of cellular proliferation and viability, uniformity, reproducibility, and/or simplicity of these assays. Here, we developed a 3D culture system with inorganic nanoscale scaffolding using nanoimprinting technology (nano-culture plates), which reproduced the characteristics of tumor cells growing in vivo. Diminished cell-to-substrate physical contact facilitated spontaneous tumor cell migration, intercellular adhesion, and multi-cellular 3D-spheroid formation while maintaining cellular proliferation and viability. The resulting multi-cellular spheroids formed hypoxic core regions similar to tumors growing in vivo. This technology allows creating uniform and highly-reproducible 3D cultures, which is easily applicable for microscopic and spectrophotometric assays, which can be used for high-throughput/high-content screening of anticancer drugs and should accelerate discovery of more effective anticancer therapies.

Introduction 64 Cu-diacetyl-bis ( N 4 -methylthiosemicarbazone) ( 64 Cu-ATSM) is an imaging agent for positron emission tomography (PET) that targets hypoxic tumors. 64 Cu-ATSM is also reported to be a potential agent for internal radiotherapy. In a mouse colon carcinoma (Colon-26) model, we have shown that 64 Cu-ATSM preferentially localizes in intratumoral regions with a high density of CD133 + cells, which show characteristics of cancer stem cells or cancer stem cell-like cells (collectively referred here as CSCs). In this study, we evaluated the therapeutic effect of 64 Cu-ATSM in relation to CD133 expression using this model. Methods Systemic administration of 37 MBq 64 Cu-ATSM or saline was conducted twice within a 1-week interval to mice bearing 1-week-old Colon-26 tumors (days 0–7). At day 19, tumor size measurement, flow cytometry analysis and experimental lung metastatic assay were performed. The therapeutic effect of 64 Cu-ATSM on sorted CD133 + and CD133 − Colon-26 cells was also examined in vitro. Results In vivo studies showed that 64 Cu-ATSM treatment inhibited tumor growth. The percentage of CD133 + cells and metastatic ability in 64 Cu-ATSM treated tumors was decreased compared with that in control animals. In vitro studies demonstrated that 64 Cu-ATSM accumulated in cells under hypoxic conditions and incorporation of 64 Cu-ATSM under hypoxia caused cell death in both CD133 + and CD133 − cells in a similar extent. Conclusions 64 Cu-ATSM administration reduced tumor volume as well as the percentage of CD133 + cells and the metastatic ability of Colon-26 tumors. Together with our data, it is suggested that 64 Cu-ATSM accumulates in regions high in CD133 + highly tumorigenic cells and kills such regions by radiation, resulting in a decrease of the percentage of CD133 + cells.

We aimed to investigate the value of the diameter of the inferior vena cava (IVC) on initial computed tomography (CT) to predict hemodynamic deterioration in patients with blunt torso trauma.We reviewed the initial CT scans, taken after admission to emergency room (ER), of 114 patients with blunt torso trauma who were consecutively admitted during a 24-month period. We measured the maximal anteroposterior and transverse diameters of the IVC at the level of the renal vein. Flat vena cava (FVC) was defined as a maximal transverse to anteroposterior ratio of less than 4:1. According to the hemodynamic status, the patients were categorized into three groups. Patients with hemodynamic deterioration after the CT scans were defined as group D (n = 37). The other patients who remained hemodynamically stable after the CT scans were divided into two groups: patients who were hemodynamically stable on ER arrival were defined as group S (n = 60) and those who were in shock on ER arrival and responded to the fluid resuscitation were defined as group R (n = 17).The anteroposterior diameter of the IVC in group D was significantly smaller than those in groups R and S (7.6 mm ± 4.4 mm, 15.8 mm ± 5.5 mm, and 15.3 mm ± 4.2 mm, respectively; p0.05). Of the 93 patients without FVC, 16 (17%) were in group D, 14 (15%) required blood transfusion, and 8 (9%) required intervention. However, of the 21 patients with FVC, all patients were in group D, 20 (95%) required blood transfusion, and 17 (80%) required intervention. The patients with FVC had higher mortality (52%) than the other patients (2%).In cases of blunt torso trauma, patients with FVC on initial CT may exhibit hemodynamic deterioration, necessitating early blood transfusion and therapeutic intervention.

Introduction 64 Cu-diacetyl-bis ( N 4 -methylthiosemicarbazone) ( 64 Cu-ATSM) is a potential imaging agent of hypoxic tumor for use with PET. Recent literature demonstrated that cancer cells expressing CD133, which is a frequently used marker for so-called cancer stem cells or cancer stem cell-like cells (collectively referred to here as CSCs), contribute to tumor's therapeutic resistance and metastasis ability. Culturing under hypoxia is also reported to enlarge the proportion of CD133 + cells, which would indicate survival advantage of CD133 + cells under hypoxia. Here, we investigated the relationships between 64 Cu-ATSM accumulation and existence of CD133 + cells using mouse colon carcinoma (colon-26) tumor. Methods Intratumor distribution of 64 Cu-ATSM and 18 F-fluorodeoxyglucose ( 18 FDG) was compared with immunohistochemical staining for CD133 with a colon-26 model. In vitro characterization of CD133 + colon-26 cells was also performed. Results In colon-26 tumors, 64 Cu-ATSM localized preferentially in regions with a high density of CD133 + cells. The percentage of CD133 + cells was 11-fold higher in 64 Cu-ATSM high-uptake regions compared with 18 FDG high- (but 64 Cu-ATSM low-) uptake regions. CD133 + colon-26 cells showed characteristics previously linked with CSCs in other cancer cell lines, such as high colony-forming ability, high tumor-initiating ability and enrichment under hypoxic cultivation. The proportion of CD133 + cells was enlarged by culturing under glucose starvation as well as hypoxia, and 64 Cu-ATSM uptake was increased under such conditions. Conclusions Our findings showed that, in colon-26 tumors, 64 Cu-ATSM accumulates in rich regions of CD133 + cells with characteristics of CSCs. Therefore 64 Cu-ATSM could be a potential imaging agent for rich regions of CD133 + cells, associated with CSCs, within tumors.

Introduction [1- 11 C]Acetate positron emission tomography (PET) is used for myocardial studies. In the myocardium, mitochondrial acetyl-CoA synthetase (ACSS1) mainly contributes to the radiopharmaceutical uptake. [1- 11 C]Acetate PET is also used for tumor diagnosis; however, the uptake mechanism of radiolabeled acetate in tumors remains unclear. Our previous study reported that cytosolic acetyl-CoA synthetase (ACSS2) was expressed in tumor cells and up-regulated under hypoxia, whereas expression of ACSS1 was negligible regardless of the oxygen conditions. We also indicated that ACSS2 is a bidirectional enzyme that controls acetyl-CoA/acetate metabolism in tumor cells. In this study, to elucidate the basic mechanism of tumor acetate uptake, we focused on ACSS2 and investigated the role of ACSS2 in the uptake of radiolabeled acetate in tumor cells. Methods [1- 14 C]Acetate uptake and ACSS2 expression were examined in four tumor cell lines under normoxia or hypoxia. An ACSS2 knockdown study was also performed. Results [1- 14 C]Acetate uptake was increased in the tumor cells under hypoxia. This pattern followed that of ACSS2 expression. The incorporated 14 C was mostly distributed in the lipid-soluble fractions, and this tendency increased under hypoxia. ACSS2 knockdown led to a corresponding reduction in [1- 14 C]acetate uptake in all tumor cell lines examined under normoxia and hypoxia. Conclusions ACSS2 plays an important role in the uptake of radiolabeled acetate in tumor cells, which is different from that in the myocardium, which mainly involves ACSS1. The uptake of radiolabeled acetate in tumors increased under hypoxia along with up-regulation of ACSS2 expression. This suggests a possible mechanism for acetate PET for tumors.

The strength of four binary systems NaCl-Na 2 CO 3 , KCl-K 2 CO 3 , KCl-NaCl and K 2 CO 3 -Na 2 CO 3 was investigated in order to develop expendable salt core for high pressure die casting processes. Four point bending test was conducted to determine the strength of specimens made from molten salts by using the permanent mold casting technique. The strength of the system NaCl-Na 2 CO 3 was over 20MPa at the Na 2 CO 3 composition between 20 mol% and 30 mol%, and between 50 mol% and 70 mol%. The highest strength was about 30 MPa at the composition of NaCl-70 mol%Na 2 CO 3 . This strength was 5 times as high as that of commonly used sand cores. The system KCl-K 2 CO 3 also showed 20 MPa in strength. It was observed that there were the primary particles surrounded by the eutectic structure in the solidification structure of the systems NaCl-Na 2 CO 3 and KCl-K 2 CO 3 at the composition where the peak strength was obtained. The presence of the primary particles played an important role to strengthen the structure because the primary particles can prevent or deflect the crack propagation. In contrast to these binary systems, the systems KCl-NaCl and K 2 CO 3 -Na 2 CO 3 were very brittle due to the phase decomposition or other solid-solid phase transformation of the solid solution phase. The strength of these systems was under 6 MPa.

患者は脳梗塞, 高血圧症に対し薬物治療が行われていた76歳の男性で, 前医入院中に誘因なく腹痛を訴え, 腹部CT検査にて腹腔内遊離ガス像を認めたため転院となった. 初診時の腹部所見は板状硬で, 反跳痛, 筋性防禦を認めた. 腹部CT検査上, 腹腔内全体にわたる腹腔内遊離ガス像, ダグラス窩に腹水を認めたため, 消化管穿孔, 汎発性腹膜炎の診断にて緊急開腹手術を施行した. 回盲部から口側50cmの回腸に穿孔部位を認め, 同部位からPTPの角を視認できた. 穿孔部からさらに口側10cmのところにMeckel憩室を認めたため回腸・Meckel憩室合併切除術, 腹腔ドレナージ術を施行した. PTP誤飲による消化管穿孔症例はいまだ散見される. 特に60歳以上の高齢者に多く, PTPを誤飲したことを認識していない症例も少なくない. 高齢者に対する処方の際には, 医療従事者側の薬剤包装に対する配慮が必要であると考えられらた.

症例は43歳の男性で, 発熱, 黄疸, 嚥下困難を主訴に入院した. 高度炎症反応があり, 造影CTで胸部から腹部食道の全周性の壁肥厚と壁内低吸収域を認めた. 上部消化管内視鏡検査では食道壁は全周性に浮腫状であった. 血液培養でKlebsiella pneumoniaeが検出され, 急性食道蜂窩織炎と診断し, 抗菌薬による保存的治療を開始した. 第45病日には全身状態は改善し, 炎症所見もほぼ消退したが, 食道の狭窄, 嚥下痛のため経口摂取は不能であった. さらに, 保存的治療を継続したが, 第100病日経過後も, 食道狭窄, 嚥下痛が改善しなかったため, 第126病日, 右側結腸を用いた食道バイパス術を施行した. 術後経過は順調で術後54日目に軽快退院した. 禁食および広域抗菌薬による保存的治療を行うも狭窄症状と嚥下痛が改善せず, 外科的治療を要した急性食道蜂窩織炎の1例を経験した.

Anti-cancer drug development typically utilizes high-throughput screening with two-dimensional (2D) cell culture. However, 2D culture induces cellular characteristics different from tumors in vivo, resulting in inefficient drug development. Here, we report an innovative high-throughput screening system using nanoimprinting 3D culture to simulate in vivo conditions, thereby facilitating efficient drug development. We demonstrated that cell line-based nanoimprinting 3D screening can more efficiently select drugs that effectively inhibit cancer growth in vivo as compared to 2D culture. Metabolic responses after treatment were assessed using positron emission tomography (PET) probes, and revealed similar characteristics between the 3D spheroids and in vivo tumors. Further, we developed an advanced method to adopt cancer cells from patient tumor tissues for high-throughput drug screening with nanoimprinting 3D culture, which we termed Cancer tissue-Originated Uniformed Spheroid Assay (COUSA). This system identified drugs that were effective in xenografts of the original patient tumors. Nanoimprinting 3D spheroids showed low permeability and formation of hypoxic regions inside, similar to in vivo tumors. Collectively, the nanoimprinting 3D culture provides easy-handling high-throughput drug screening system, which allows for efficient drug development by mimicking the tumor environment. The COUSA system could be a useful platform for drug development with patient cancer cells.

目的:高エネルギー外傷(JATECに基づく)において頭部に外傷を認める患者の頸椎の骨傷に関して検討した報告は少ない。平成16年2月より,高エネルギー外傷で当センター受診された頭部外傷患者全例に頸椎CTもルーチンで施行することとした。われわれは2004年に当学会誌において本研究の速報を発表したが,今回,約1年を経過した時点での成績を報告し,その有用性について改めて検討した。対象と方法:平成16年2月以降,高エネルギー外傷で当センター受診され,当院作成の頸椎クリアランスのプロトコールに従って頭部および頸椎CTを施行したのは83例であった。これらの受傷機転,骨傷の有無などについて検討した。結果:頭部および頸椎CTを施行した83例の内訳は男性56名,女性27名,年齢は13歳～77歳(平均39.5歳)であった。受傷機転は交通事故59件,墜落13件,第三者行為6件,転倒5件であった。83例のうち80例では頸椎単純X線写真上骨傷を同定し得なかった。しかしこのうち12例(15.0%)13頸椎にCT上骨傷を認めた。13例の骨折形態の内訳は,椎体骨折2例,椎弓骨折2例,関節突起骨折5例,横突起骨折1例,棘突起骨折3例であった。受傷高位はC2: 2例,C3: 1例,C4: 1例,C6: 5例,C7: 4例と,下位頸椎に好発する傾向があった。いずれの骨折も保存的に治療した。考察:通常頭部外傷の患者においては,頸椎単純X線写真上骨傷を認めず,また神経学的にも異常を認めない患者であれば頸椎CTを施行することは少ない。しかし今回の結果から,高エネルギー外傷において頭部に外傷を認める場合,頸椎単純X線写真上骨傷を認めなくとも実際は頸椎に骨傷を伴っているケースが高い割合で潜在していることが示された。頭部高エネルギー外傷における頸椎CTのルーチン化は有用であるものと思われた。

Objective. To reevaluate the usefulness of ultrasonography for detecting and classifying solid-organ injuries from blunt abdominal trauma by comparing ultrasonography with computed tomography (CT) and laparotomy. Methods.Six hundred four patients with blunt abdominal trauma were examined by both B-mode ultrasonography and CT for a study period of 14 years. The ultrasonographic examiners were divided into 2 groups depending on their experience with ultrasonography. The ultrasonographic results were then compared with CT and surgical findings. This was a retrospective study. Results. In 198 patients, solid-organ injuries were identified on CT, laparotomy, or both. Sensitivity values in group A (experts) were 87.5% for hepatic injuries, 85.4% for splenic injuries, 77.6% for renal injuries, and 44.4% for pancreatic injuries. Sensitivity values in group B were 46.2% for hepatic injuries, 50.0% for splenic injuries, and 44.1% for renal injuries. The detection rates in group A were 80% to 100% for different types of hepatic injuries except superficial injuries (20%) and 70% to 100% for different types of splenic injuries. The detection rates for renal parenchymal and pancreatic duct injuries were 53.3% and 80%, respectively. The detection rates for injuries requiring intervention were 86.1% in group A and 66.7% in group B. Conclusions. The sensitivity of ultrasonography with the use of CT and surgical findings as reference standards decreased compared with our prior study. However, ultra. sonography was found to enable experienced examiners to detect and classify parenchymal injuries efficiently, despite disadvantages in detecting superficial and vascular injuries. Ultrasonography should be used to explore not only free fluid but also solid-organ injuries.

Chemical modification of the herbicide 1-[2-(benzothiazol-2-yl)isopropyl]-4-methyl-3-phenyl-5H-pyrrolin-2-one (MI-2826) has revealed a new oxazinone herbicide, 3-[2-(7-chlorobenzothiazol-2-yl)isopropyl]-2,3-dihydro-6-methyl-5-phenyl-4H-1,3-oxazin-4-one (MI-3069), for use in paddy fields. In comparing the phyototoxicity of the two herbicides to transplanted rice, the latter was superior to the former and kept the same predominant characteristic to control Echinochloa oryzicola Vasin for a long period of time owing to its long-lasting residual effect.

Threshold photoelectron spectroscopy is a useful tool for measuring vibrational levels of rare gas dimer ions. In this short review, features of threshold photoelectron spectroscopy are introduced. After that, the observed vibra-tional levels of Ar2+ are described in detail. Explanations for the vibrational levels of KrXe+ measured by threshold photoelectron-photoion coincidence technique are also given. In the subsequent study, it is revealed that the II (1/2g) states of Kr2+ and Xe2+ completely dissociate via optical transitions to the repulsive I (1/2g) states, while that of Ail does not dissociate. Precise analysis of the time-of-flight spectrum for the Kr2+ fragment from the Kr2+ II (1/2u) state is also shown. The potential energy curve of the I (1/2g) state and the lifetime of the optical transition from the II (1/2g) state to the I (1/2g) state are obtained from this analysis.

Workers decommissioning the Fukushima-Daiichi nuclear power plant damaged from the Great East Japan Earthquake and resulting tsunami are at risk of injury with possible contamination from radioactive heavy atoms including actinides, such as plutonium. We propose a new methodology for on-site and rapid evaluation of heavy-atom contamination in wounds using a portable X-ray fluorescence (XRF) device. In the present study, stable lead was used as the model contaminant substitute for radioactive heavy atoms. First, the wound model was developed by placing a liquid blood phantom on an epoxy resin wound phantom contaminated with lead. Next, the correlation between the concentration of contaminant and the XRF peak intensity was formulated considering the thickness of blood exiting the wound. Methods to determine the minimum detection limit (MDL) of contaminants at any maximal equivalent dose to the wound by XRF measurement were also established. For example, in this system, at a maximal equivalent dose of 16.5 mSv to the wound and blood thickness of 0.5 mm, the MDL value for lead was 1.2 ppm (3.1 nmol). The radioactivity of 239Pu corresponding to 3.1 nmol is 1.7 kBq, which is lower than the radioactivity of 239Pu contaminating puncture wounds in previous severe accidents. In conclusion, the established methodology could be beneficial for future development of a method to evaluate plutonium contamination in wounds. Highlights: Methodology for evaluation of heavy-atom contamination in a wound was established. A portable X-ray fluorescence device enables on-site, rapid and direct evaluation. This method is expected to be used for evaluation of plutonium contamination in wounds.

外傷性脾損傷にてTAE施行後5日後に, 遅発性破裂を来し脾部分切除を施行した1例を経験したので報告する. 症例は23歳の女性で, 左側腹部の鈍的外傷にて当院救急センター受診した. 腹部CTにてIIIc型脾損傷と診断した. 脾動脈造影にて血管外漏出像を認めたため, 選択的TAEを施行し止血した. TAE後5日目に車椅子で洗髪したところ急激な腹痛が出現した. 腹部CTにて造影剤の血管外漏出と腹腔内出血の増加を認め, 遅発性破裂と診断した. ショック状態が続くため緊急手術を施行した. 上極中心のIIIc型脾損傷であったため部分切除術を施行した. 術後経過は順調で第19病日に退院した. TAE施行後でも遅発性破裂の発症に十分注意した経過観察が重要であると考えられた.