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A 66-year-old man underwent multimodal treatment for olfactory neuroblastoma (ONB). When he was 72 years old, a cystic intracranial lesion without accumulation on fluorine-18-fluorodeoxyglucose positron emission tomography was detected. Surgical resection was performed when the patient was 73 years old. The pathological examination revealed recurrence of ONB, and the patient underwent focal irradiation. At age 81, he presented with a second recurrence in the right occipital lobe with radiological and pathological findings similar to the prior recurrence. This case suggests that pathological confirmation should be considered in cases with atypical radiological findings following the treatment of ONB.

The majority of oligodendroglial tumors harbor mutations in the telomerase reverse transcriptase (TERT) gene (TERT) promoter and the isocitrate dehydrogenase 1/2 (IDH1/2) gene (IDH1/2), as well as 1p/19q codeletion. Generally, TERT promoter mutations, C250T and C228T, are mutually exclusive. We present a case of oligodendroglioma harboring both C250T and C228T mutations in TERT promoter. A 38-year-old man presented with grand mal seizures and underwent a resection surgery for a left frontal lobe tumor. He was pathologically diagnosed as having oligodendroglioma and was carefully observed. At 48 years of age, he underwent another resection surgery due to tumor regrowth, with the pathological diagnosis of anaplastic oligodendroglioma. Genetic analysis of the initial tumor specimen revealed IDH1 R132H mutation and both C250T and C228T mutations in TERT promoter. Using mutation-specific primers, two mutations were considered to be distributed in different alleles. In the tumor specimen obtained during the second surgery, IDH1 R132H mutation was detected to be similar to that of the initial specimen; however, only C228T mutation was detected in TERT promoter. The 1p/19q codeletion was detected in both the initial and recurrent tumor specimens. According to the sequencing data from the two tumor specimens, although TERT promoter mutation has been considered to be an early genetic event in the tumorigenesis of oligodendroglial tumors, it is likely that the C250T and C228T mutations in TERT promoter are subclonally distributed in the same tumor specimen of the present case.

A 5-year-old girl presented with headache and vomiting. Head computed tomography and magnetic resonance imaging showed a right frontal lobe tumor with marked calcification. The patient underwent resection surgery with suspicion of anaplastic ependymoma, and the tumor was gross totally removed. Pathological examination revealed areas of dense tumor cells with a high nucleocytoplasmic ratio and myxoid areas consisting of tumor cells with a round-shaped nucleus and eosinophilic cytoplasm. Perivascular pseudorosette, necrosis, circumscribed growth, and microcalcification were also observed. Immunohistochemistry demonstrated negative staining for glial fibrillary protein and epithelial membrane antigen. Diagnosis of a high-grade neuroepithelial tumor (HGNET) with BCL6 corepressor (BCOR) alteration was made based on pathological findings and internal tandem duplication in the exon 15 of BCOR. Although calcification on radiological and pathological examination is not typical, it would be essential to recognize that calcification could appear in HGNET-BCOR.

Purpose F-18-fluoromisonidazole (F-18-FMISO) is the most widely used positron emission tomography (PET) tracer for imaging tumor hypoxia. Previous reports suggested that the time from injection to the scan may affect the assessment of F-18-FMISO uptake. Herein, we directly compared the images at 2 h and 4 h after a single injection of F-18-FMISO. Methods Twenty-three patients with or suspected of having a brain tumor were scanned twice at 2 and 4 h following an intravenous injection of F-18-FMISO. We estimated the mean standardized uptake value (SUV) of the gray matter and white matter and the gray-to-white matter ratio in the background brain tissue from the two scans. We also performed a semi-quantitative analysis using the SUVmax and maximum tumor-to-normal ratio (TNR) for the tumor. Results At 2 h, the SUVmean of gray matter was significantly higher than that of white matter (median 1.23, interquartile range (IQR) 1.10-1.32 vs. 1.04, IQR 0.95-1.16, p < 0.0001), whereas at 4 h, it significantly decreased to approach that of the white matter (1.10, IQR 1.00-1.23 vs. 1.02, IQR 0.93-1.13, p = NS). The gray-to-white matter ratio thus significantly declined from 1.17 (IQR 1.14-1.19) to 1.09 (IQR 1.07-1.10) (p < 0.0001). All 7 patients with glioblastoma showed significant increases in the SUVmax (2.20, IQR 1.67-3.32 at 2 h vs. 2.65, IQR 1.74-4.41 at 4 h, p = 0.016) and the TNR (1.75, IQR 1.40-2.38 at 2 h vs. 2.34, IQR 1.67-3.60 at 4 h, p = 0.016). Conclusion In the assessment of hypoxic tumors, F-18-FMISO PET for hypoxia imaging should be obtained at 4 h rather than 2 h after the injection.

令和3年度宇宙輸送シンポジウム（2022年1月13日-14日. オンライン開催), Space Transportation Symposium FY2021 (January 13-14, 2022. Online Meeting), 資料番号: SA6000173045, STEP-2021-006

令和二年度宇宙輸送シンポジウム（2021年1月14日-15日. オンライン開催), Space Transportation Symposium FY2020 (January 14-15, 2021. Online Meeting), PDF再処理の為、2023年2月27日に差替, 資料番号: SA6000160074, レポート番号: STEP-2020-037

令和元年度宇宙輸送シンポジウム（2020年1月16日-17日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県, Space Transportation Symposium FY2019 (January 16-17, 2020. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000147070, レポート番号: STEP-2019-021

This study noninvasively examined the electrical conductivity (sigma) characteristics of diffuse gliomas using MRI and tested its validity. MRI including a 3D steady-state free precession (3D SSFP) sequence was performed on 30 glioma patients. The sigma maps were reconstructed from the phase images of the 3D SSFP sequence. The sigma histogram metrics were extracted and compared among the contrast-enhanced (CET) and noncontrast-enhanced tumour components (NCET) and normal brain parenchyma (NP). Difference in tumour sigma histogram metrics among tumour grades and correlation of sigma metrics with tumour grades were tested. Validity of sigma measurement using this technique was tested by correlating the mean tumour sigma values measured using MRI with those measured ex vivo using a dielectric probe. Several sigma histogram metrics of CET and NCET of diffuse gliomas were significantly higher than NP (Bonferroni-corrected p ae .045). The maximum sigma of NCET showed a moderate positive correlation with tumour grade (r = .571, Bonferroni-corrected p = .018). The mean tumour sigma measured using MRI showed a moderate positive correlation with the sigma measured ex vivo (r = .518, p = .040). Tissue sigma can be evaluated using MRI, incorporation of which may better characterise diffuse gliomas. aEuro cent This study tested the validity of noninvasive electrical conductivity measurements by MRI. aEuro cent This study also evaluated the electrical conductivity characteristics of diffuse glioma. aEuro cent Gliomas have higher electrical conductivity values than the normal brain parenchyma. aEuro cent Noninvasive electrical conductivity measurement can be helpful for better characterisation of glioma.

平成30年度宇宙輸送シンポジウム（2019年1月17日-18日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県, Space Transportation Symposium FY2018 (January 17-18, 2019. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000136100, レポート番号: STEP-2018-045

FliF is the protein comprising the MS-ring of the bacterial flagellar basal body, which is the base for the assembly of flagellar axial structures. From a fliF mutant that easily releases the rod-hook-filament in viscous environments, more than 400 revertants that recovered their swarming ability in viscous conditions, were isolated. The second-site mutations were determined for approximately 70% of them. There were three regions where the mutations were localized: two in Region I, 112 in Region II, and 71 in Region III including the true reversion. In Region I, second-site mutations were found in FlgC and FlgF of the proximal rod, suggesting that they affect the interaction between the MS-ring and the rod. In Region II, there were 69 and 42 mutations in MotA and MotB, respectively, suggesting that the second-site mutations in MotA and MotB may decrease the rotational speed of the flagellar motor to reduce the probability of releasing the rod under this condition. One exception is a mutation in FlhC that caused a down regulation of the flagellar proteins production but it may directly affect transcription or translation of motA and motB. In Region III, there were 44, 24, and 3 mutations in FliG, FliM, and FliF, respectively. There were no second-site mutations identified in FliN although it is involved in torque generation as a component of the C-ring. Many of the mutations were involved in the motor rotation, and it is suggested that such reduced speeds result in stabilizing the filament attachment to the motor.

第1回ハイブリッドロケットシンポジウム（2018年6月28日-29日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県, 1st Hybrid Rocket Symposium (June 28-29, 2018. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000126018, レポート番号: HR-2018-017

Because it is highly infiltrative, malignant glioma is a cancer with a poor prognosis despite multidisciplinary treatment strategies, such as aggressive surgery and chemoradiotherapy, necessitating new therapeutic approaches to control migration of tumor cells. In our study, we investigated the efficacy of sonodynamic therapy of glioma cells in vitro using porphyrin derivatives, including 5-aminolevulinic acid, protoporphyrin IX and talaporfin sodium, as sonosensitizers. These substances have been known to accumulate in glioma cells and are expected to have cytotoxic effects on sonication. Our study found that the cytotoxicity of sonication of glioma cells is enhanced by each sonosensitizer and that the efficacy of sonodynamic therapy may depend on the degree of intracellular accumulation of sonosensitizer. Also, the study suggests that induction of apoptosis is a major mechanism underlying cell death. Though further investigations are necessary, our preliminary result indicates a potential for sonodynamic therapy with sonosensitizers in glioma treatment.

F-18-FDG PET has become one of the most important methods for studying malignant lymphoma, but its diagnostic role for primary central nervous system lymphoma (PCNSL) has not been established. The aim of this study was to determine the appropriate cut-off values of FDG uptake and to investigate how corticosteroid administration influences PCNSL. We retrospectively reviewed 82 patients with contrast-enhanced brain tumors who underwent an FDG PET scan at onset, including 19 PCNSLs. FDG uptake of the lesion was assessed by the maximum standardized uptake value (SUVmax) and the ratio of tumor to normal contralateral cortex activity (T/N ratio). Receiver operating characteristic (ROC) curves were generated from the SUVmax and T/N ratios. To investigate the influence of corticosteroid application before a FDG PET scan, we evaluated the association between the FDG uptake of the lesion and the cumulative dose of corticosteroid administration on 13 PCNSL patients who had received steroid treatment before an FDG PET examination. The mean FDG SUVmax and T/N ratio of PCNSLs were 22.6 and 2.79, respectively, and these values were significantly higher than those of the other malignant brain tumors. ROC analysis indicated that the evaluation of FDG uptake using the T/N ratio was more reliable than the SUVmax with respect to the differential diagnosis. When PCNSL patients went without steroid application before FDG PET, the accuracy of the T/N ratio with a cut-off point of 2.0 was 91.1 %, the sensitivity was 94.7 %, and the specificity was 87.3 %. Although there are no significant differences in the FDG T/N ratio for PCNSL patients with or without steroid treatment, a negative correlation was found between the T/N ratio and cumulative dose of corticosteroid before PET study (r = -0.71, p = 0.032). We concluded that the T/N ratio was superior to SUVmax for FDG uptake assessment as for distinguishing PCNSLs from other malignant brain tumors; the appropriate T/N ratio cut-off point was 2.0. In addition, FDG uptake could be influenced by cumulative doses of corticosteroid before a PET scan, and thus this fact should be taken into consideration when evaluating FDG PET for PCNSL diagnosis.

ZnO nanomaterials with controlled size, shape and surface chemistry are required for applications in diverse areas, such as optoelectronics, photocatalysis, biomedicine and so on. Here, we report on ZnO nanostructures with rod-like and spherical shapes prepared via laser ablation in liquid using a laser with millisecond-long pulses. By changing laser parameters (such as pulse width and peak power), the size or aspect ratio of such nanostructures could be tuned. The surface chemistry and defects of the products were also strongly affected by applied laser conditions. The preparation of different structures is explained by the intense heating of liquid media caused by millisecond-long pulses and secondary irradiation of already-formed nanostructures.

平成23年度宇宙輸送シンポジウム（2012年1月19日-20日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)（ISAS)）, 相模原市, 神奈川県, Space Transportation Symposium FY2011 (January 19-20, 2012. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000003039, レポート番号: STCP-2011-039

平成25年度 京都大学化学研究所 スーパーコンピュータシステム 利用報告書

Machining characteristics of Fiber Reinforced Plastics (FRPs) using excimer laser have been examined at three wavelengths 193 (ArF), 248 (KrF), and 308 (XeCl) nm in the fluence ranges up to 80 J/cm2. At 308 nm, a maximum removal rate was measured to be as high as 15 micrometers /pulse for the plastics with glass fiber and epoxy matrix (glass/epoxy). Irrespective of fibers and matrix materials, removal rates increased with applying a longer laser wavelength. Complementary studies were also conducted on glass/epoxy at 308 nm to examine the effect of purge gases (He, N2, Ar) to the irradiated area. It was found that Ar and N2 were effective for improvement of the kerf quality and reduction of sooty debris around the irradiated area.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper describes the features of the copper vapor laser developed in IHI Research Center for measurement of high-speed fluid, and the preliminary results of observed measurement on actual fluid flow in a shock tube. The copper vapor laser we have developed selects two different wavelengths (green or yellow) and couples them with an optical fiber. Further, in correspondence with external triggering from a shock tube or other devices, it is possible to freely set the timing for generation of laser pulses. Applying the copper vapor laser for the schlieren light source, we were able to visualize the formation of shock waveforms around an airfoil placed in a shock tube.

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論文タイプ||論説, (一橋大学七十五周年記念号その一 商学 = THE COMMEMORATIVE NUMBER FOR THE 75TH ANNIVERSARY OF THE HITOTSUBASHI UNIVERSITY Commercial Studies)

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