59 research outputs found

    臨床用CTを用いた上腕骨大結節の領域別骨梁微細構造解析

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    BACKGROUND: In arthroscopic surgery, the suture anchor technique has become popular for rotator cuff repair. Preoperative evaluation of the bone microstructure is of utmost importance because, especially in elderly patients, osteoporotic changes may cause anchor pullout, which results in failure of rotator cuff repair. Many groups have reported humeral microstructural analysis; however, most studies were experiments using porcine specimens or human cadavers. In this study, we used multidetector row computed tomography to successfully perform in vivo evaluation of the bone microstructure of the humeral greater tuberosity in patients with rotator cuff tears. METHODS: Ten patients were examined. Regions of interest were defined in six quadrants of the greater tuberosity (medial, lateral, and far lateral rows of the anterior and posterior areas). The local bone mineral density and the trabecular microstructural parameters, including the mean bone volume to total volume (BV/TV), trabecular thickness, trabecular separation, and structure model index (SMI), were measured using bone analysis software. RESULTS: The BV/TV of the posteromedial region was highest and the SMI of the posteromedial region was lowest. These findings suggest that the bone quality of the posteromedial portion is the highest within the greater tuberosity. CONCLUSION: Because the bone quality may be correlated with the pullout strength of suture anchors, our method can help to understand the individual and regional variance in bone quality and may lead to the creation of personalized surgical protocols.博士(医学)・乙第1360号・平成27年5月28日© 2014 Sakamoto et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

    Interactive Effectiveness of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers or Their Combination on Survival of Hemodialysis Patients

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    Bachground: Does the use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers individually or as a combination confer a survival benefit in hemodialysis patients? The answer to this question is yet unclear. Methods: We performed a case-cohort study using data from the Mineral and Bone Disorder Outcomes Study for Japanese CKD stage 5D patients (MBD-5D), a 3-year multicenter prospective case-cohort study, including 8, 229 hemodialysis patients registered from 86 facilities in Japan. All patients had secondary hyperparathyroidism, a condition defined as a parathyroid hormone level ≥180 pg/mL and/or receiving vitamin D receptor activators. We compared all-cause mortality rates between those receiving ACEI, ARB, and their combination and non-users with interaction testing. We used marginal structural Poisson regression (causal model) to estimate the causal effect and interaction adjusted for possible time-dependent confounding. Cardiovascular mortality was also evaluated. Results: Among 3, 762 randomly sampled subcohort patients, those taking ACEI, ARB, and their combination at baseline accounted for 4.0, 31.6, and 3.8%, respectively. Over 3 years, 1, 226 all-cause and 462 cardiovascular deaths occurred. Compared to non-users, ARB-alone users had a lower all-cause mortality rate (adjusted incident rate ratio [aIRR] 0.62, 95% CI 0.50–0.76), whereas ACEI-alone users showed a statistically similar rate (aIRR 1.01, 95% CI 0.57–1.77). On the contrary, combination users had a greater mortality rate (aIRR 2.56, 95% CI 1.22–5.37), showing significant interaction (p = 0.03). Analysis for cardiovascular mortality showed similar results. Conclusion: Among hemodialysis patients with secondary hyperparathyroidism, unlike ACEI use, ARB use was associated with greater survival than non-use. Conversely, combination use was associated with greater mortality. Controlled trials are warranted to verify the causality factors of these associations

    Usability of detecting delivery errors during treatment of prostate VMAT with a gantry-mounted transmission detector

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    Volumetric‐modulated arc therapy (VMAT) requires highly accurate control of multileaf collimator (MLC) movement, rotation speed of linear accelerator gantry, and monitor units during irradiation. Pretreatment validation and monitoring of these factors during irradiation are necessary for appropriate VMAT treatment. Recently, a gantry mounted transmission detector “Delta4 Discover® (D4D)” was developed to detect errors in delivering doses and dose distribution immediately after treatment. In this study, the performance of D4D was evaluated. Simulation plans, in which the MLC position was displaced by 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm from the clinically used original plans, were created for ten patients who received VMAT treatment for prostate cancer. Dose deviation (DD), distance‐to‐agreement (DTA), and gamma index analysis (GA) for each plan were evaluated by D4D. These results were compared to the results (DD, DTA and GA) measured by Delta4 Phantom + (D4P). We compared the deviations between the planned and measured values of the MLC stop positions A‐side and B‐side in five clinical cases of prostate VMAT during treatment and measured the GA values. For D4D, when the acceptable errors for DD, DTA, and GA were determined to be ≤3%, ≤2 mm, and ≤3%/2 mm, respectively, the minimum detectable errors in the MLC position were 2.0, 1.5, and 1.5 mm based on DD, DTA, and GA respectively. The corresponding minimum detectable MLC position errors were 2.0, 1.0, and 1.5 mm, respectively, for D4P. The deviation between the planned and measured position of MLC stopping point of prostate VMAT during treatment was stable at an average of −0.09 ± 0.05 mm, and all GA values were above 99.86%. In terms of delivering doses and dose distribution of VMAT, error detectability of D4D was comparable to that of D4P. The transmission‐type detector “D4D” is thus suitable for detecting delivery errors during irradiation

    酸化型HMGB-1は間葉系幹細胞/間葉系細胞を介して大腸癌の転移性を促進する

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    High mobility group box-1 (HMGB1) is known to be a chemotactic factor for mesenchymal stem/stromal cells (MSCs), but the effect of post-translational modification on its function is not clear. In this study, we hypothesized that differences in the oxidation state of HMGB1 would lead to differences in the function of MSCs in cancer. In human colorectal cancer, MSCs infiltrating into the stroma were correlated with liver metastasis and serum HMGB1. In animal models, oxidized HMGB1 mobilized three-fold fewer MSCs to subcutaneous tumors compared with reduced HMGB1. Reduced HMGB1 inhibited the proliferation of mouse bone marrow MSCs (BM-MSCs) and induced differentiation into osteoblasts and vascular pericytes, whereas oxidized HMGB1 promoted proliferation and increased stemness, and no differentiation was observed. When BM-MSCs pretreated with oxidized HMGB1 were co-cultured with syngeneic cancer cells, cell proliferation and stemness of cancer cells were increased, and tumorigenesis and drug resistance were promoted. In contrast, co-culture with reduced HMGB1-pretreated BM-MSCs did not enhance stemness. In an animal orthotopic transplantation colorectal cancer model, oxidized HMGB1, but not reduced HMGB1, promoted liver metastasis with intratumoral MSC chemotaxis. Therefore, oxidized HMGB1 reprograms MSCs and promotes cancer malignancy. The oxidized HMGB1–MSC axis may be an important target for cancer therapy.博士(医学)・甲第874号・令和5年3月15

    Photon correlation in GaAs self-assembled quantum dots

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    We report on photon coincidence measurement in a single GaAs self-assembled quantum dot (QD) using a pulsed excitation light source. At low excitation, when a neutral exciton line was present in the photoluminescence (PL) spectrum, we observed nearly perfect single photon emission from an isolated QD at 670 nm wavelength. For higher excitation, multiple PL lines appeared on the spectra, reflecting the formation of exciton complexes. Cross-correlation functions between these lines showed either bunching or antibunching behavior, depending on whether the relevant emission was from a biexciton cascade or a charged exciton recombination.Comment: 5 pages, 3 figure

    A new method for measuring torsional deformity in scoliosis

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    <p>Abstract</p> <p>Background</p> <p>The importance of spinal rotational and torsional deformity in the etiology and the management of scoliosis are well-recognized. For measuring the posterior spinal component rotation, Ho's method was reported to be reliable. However, there is no practical method to measure the anterior spinal component rotation. Moreover, there is also no method to quantify the spinal torsional deformity in scoliosis. The goal of this study is to characterize scoliosis and its deformity to hypothesize the etiology and the development of scoliosis, and to establish a new method for the measurement of the vertebral body rotation and spinal torsional deformity in scoliosis using CT scans.</p> <p>Methods</p> <p>Pre-operative CT scans of 25 non-congenital scoliosis patients were recruited and the apical vertebral rotation was measured by a newly developed method and Ho's method. Ho's method adopts the laminae as the rotational landmark. For a new method to measure the apical vertebral rotation, the posterior point just beneath each pedicle was used as a landmark. For quantifying the spinal torsional deformity angle, the rotational angle difference between the two methods was calculated.</p> <p>Results</p> <p>Intraobserver and interobserver reliability analyses showed both methods to be reliable. Apical vertebral rotation revealed 13.9 ± 6.8 (mean ± standard deviation) degrees by the new method and 7.9 ± 6.3 by Ho's method. Right spinal rotation was assigned a positive value. The discrepancy of rotation (6.1 ± 3.9 degrees), meaning that the anterior component rotated more than the posterior component, was considered to express the spinal torsional deformity to the convex side.</p> <p>Conclusions</p> <p>We have developed an easy, reliable and practical method to measure the rotation of the spinal anterior component using a CT scan. Furthermore, we quantified the spinal torsional deformity to the convex side in scoliosis by comparing the rotation between the anterior and posterior components.</p

    フェムト秒レーザ照射されたCaF_2のTLおよびTSEE

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    A study on thermoluminescence (TL) and thermally stimulated exoelectron emission (TSEE) has been performed for CaF_2 single crystal irradiated by a femtosecond (fs) near-infrared laser. Focused laser pulses with approximately 250 fs duration and with a wavelength of 780 nm have been used to excite the electrons of CaF_2 sample. The result indicates that the intensities of TL and TSEE glow spectra depend on the fs laser beam energy. The CaF_2 sample irradiated with non-thermal processing also shows a TL glow spectrum although the peak intensities are weaker than in the case of thermal processing. It may be suggested that TL glow is attributed to trapped electrons in defects of the CaF_2 crystalline witch is excited by multiphoton absorption and/or multiple-stage reaction

    Development of the Japanese version of the Intensive Care Unit Trigger Tool to detect adverse events in critically ill patients

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    AimThe Intensive Care Unit Trigger Tool (ICUTT) was developed to detect adverse events (AEs) in intensive care unit (ICU) patients. The purpose of this study was to determine the validity and reliability of the Japanese version of the ICUTT (ICUTT-J).MethodsThe translation of ICUTT was carried out based on the guideline for translation of instruments. Subsequently, two review teams independently reviewed 50 patients\u27 medical records using the ICUTT-J, and agreement regarding the presence and number of AEs was evaluated to ensure reliability.ResultsThe ICUTT-J was submitted to the authors of the original ICUTT, who confirmed it as being equivalent to the original version. The item-content validity index and scale-content validity index were 1.00 and 1.00, respectively. Interrater reliability showed moderate agreement of κ = 0.52 in terms of the presence of AEs and linear weighting of κ = 0.49 (95% confidence interval, 0.28, 0.71) in terms of the number of AEs.ConclusionThis study\u27s findings suggest that the ICUTT-J is valid and moderately reliable for use in ICUs

    Frontal wedge deformation near the source region of the 2011 Tohoku-Oki earthquake

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    We report an uplift of 5 m with a horizontal displacement of more than 60 m due to the 2011 Tohoku-Oki earthquake. The uplift was measured by an ocean-bottom pressure gauge installed before the earthquake on a frontal wedge, which formed an uplift system near the Japan Trench. Horizontal displacements of the frontal wedge were measured using local benchmark displacements obtained by acoustic ranging before and after the earthquake. The average displacements at the frontal wedge were 58 m east and 74 m east-southeast. These results strongly suggest a huge coseismic slip beneath the frontal wedge on the plate boundary. The estimated magnitude of the slip along the main fault was 80 m near the trench. Our results suggest that the horizontal and vertical deformations of the frontal wedge due to the slip generated the tremendous tsunami that struck the coastal area of northeastern Japan
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