Publications by authors named "Yoshikawa Hideki"

The Fukushima Daiichi Nuclear Power Plant accident released considerable radionuclides into the environment. Radioactive particles, composed mainly of SiO, emerged as distinctive features, revealing insights into the accident's dynamics. While studies extensively focused on high-volatile radionuclides like Cs, investigations into low-volatile nuclides such as Sr and Pu remain limited.

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Purpose: Dynamic chest radiography (DCR) is a novel imaging technique used to noninvasively evaluate pulmonary perfusion. However, the standard DCR protocol, which is roughly adapted to the patient's body size, occasionally causes over- or underexposure, which could influence clinical evaluation. Therefore, we proposed a refined protocol by increasing the number of patient body mass index (BMI) categories from three to seven groups and verified its usefulness by comparing the image sensitivity indicators (S-values) and entrance surface doses (ESDs) of the conventional protocol with those of our refined protocol.

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Background: Bone morphogenetic protein 2 (BMP2) can enhance posterolateral spinal fusion (PLSF). The minimum effective dose that may stimulate mesenchymal stem cells however remains unknown. Nano-hydroxyapatite (nHAp) polyethylene glycol (PEG)/polylactic acid (PLA) was combined with recombinant human BMP2 (rhBMP2).

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Narrow bandgap inorganic compounds are extremely important in many areas of physics. However, their basic parameter database for surface analysis is incomplete. Electron inelastic mean free paths (IMFPs) are important parameters in surface analysis methods, such as electron spectroscopy and electron microscopy.

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Background While current guidelines require lung ventilation-perfusion (V/Q) scanning as the first step to diagnose chronic pulmonary embolism in pulmonary hypertension (PH), its use may be limited by low availability and/or exposure to ionizing radiation. Purpose To compare the performance of dynamic chest radiography (DCR) and lung V/Q scanning for detection of chronic thromboembolic PH (CTEPH). Materials and Methods Patients with PH who underwent DCR and V/Q scanning in the supine position from December 2019 to July 2021 were retrospectively screened.

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Purpose: To evaluate the utility of vertebral Hounsfield unit (HU) values from computed tomography (CT) in cancer staging as a supplementary screening tool for bone health among prostate cancer (PCa) patients.

Methods: T-scores of bone mineral density (BMD) in each lumbar vertebra (L1-L4) and hip for newly diagnosed PCa patients (N = 139) were measured using dual-energy X-ray absorptiometry (DXA). The degenerative changes in each lumbar vertebra were assessed, and the HU values of trabecular bone in axial CT images of each vertebral body (vertebral CT-HU value) were measured using staging CT.

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Purpose: Recently developed and commercialized dual-layer flat panel detectors (DL-FPDs) with two indirect scintillators are capable of acquiring dual-energy X-ray images. However, in clinical practice, they are utilized to perform conventional radiography using diagnostic X-rays with a wide energy spectrum. The two layers of the DL-FPD may affect the obtained image quality, even when only using one layer for conventional image acquisition, and these effects are yet to be substantiated.

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Article Synopsis
  • The study evaluated the tolerability of a once-yearly infusion of zoledronic acid (ZA) 5 mg for preventing fractures after hip surgery, focusing on side effects like acute-phase reactions (APRs) and calcium levels.
  • Researchers analyzed 84 patients (average age 83) and found APRs in 11.9% of cases, primarily showing symptoms like fever; hypocalcemia occurred in 6% of patients a week after the infusion.
  • Results indicated that increased inflammatory markers post-surgery and higher bone turnover may raise the risks of APRs and low calcium levels, but overall, the infusion was deemed well tolerated with supportive care.
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Background: The risk of osteoporosis in patients with rheumatoid arthritis (RA) is frequently overlooked, and investigating a simple indicator in routine care may be beneficial to motivate osteoporosis examination. The aim of this retrospective, case-controlled study was to identify the correlation between serum albumin concentrations and the prevalence of osteoporosis in postmenopausal patients with RA.

Methods: This study enrolled 197 patients who underwent dual-energy X-ray absorptiometry of lumbar spine (LS) and proximal femur without osteoporosis treatment [mean age, 67.

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Mechanical loading contributes to bone development, growth, and metabolism. However, the mechanisms underlying long bone mineralization changes in loading during the growth period are unclear. The aim of the present study was to investigate the regulatory mechanisms underlying endochondral ossification and endosteal mineralization by developing an organ culture model with cyclic axial mechanical loads.

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Background: The role of local surgery in patients with metastatic soft tissue sarcoma (STS) remains unknown. The study aims to assess the clinical outcomes and impact of surgical resection on survival in patients with metastatic STS and elucidate the survival differences between synchronous and metachronous metastatic groups.

Methods: Among the 272 patients with STS treated between 2000 and 2018, 84 with synchronous or metachronous metastasis were included.

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Effects of high magnetic fields [MFs, ≥ 1 T (T)] on osteoblastic differentiation and the orientation of cells or matrix proteins have been reported. However, the effect of low MFs (< 1 T) on the orientation of bone formation is not well known. This study was performed to verify the effects of low MFs on osteoblastic differentiation, bone formation, and orientation of both cells and newly formed bone.

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Introduction: Glucocorticoids are widely used to treat various diseases including rheumatoid arthritis (RA); however, one of the most frequent and severe adverse effects is glucocorticoid-induced osteoporosis (GIOP). Iguratimod (IGU) is a novel conventional synthetic disease-modifying anti-rheumatic drug developed in Japan. The aim of this study is to investigate the effects of IGU on glucocorticoid-induced disorder of bone metabolism in vitro.

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Background: Efficient bone regeneration using recombinant human bone morphogenetic protein-2 (BMP-2) is needed to reduce side effects caused by high-dose BMP-2 use. The composite material of polylactic acid-polyethene glycol (PLA-PEG) for sustained release and an osteogenic nano-hydroxyapatite (nHAp) can contribute to efficient bone regeneration by BMP-2.

Study Design: An experimental in vitro and in vivo study.

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Synovial mesenchymal stem cell (SMSC) is the promising cell source of cartilage regeneration but has several issues to overcome such as limited cell proliferation and heterogeneity of cartilage regeneration ability. Previous reports demonstrated that basic fibroblast growth factor (bFGF) can promote proliferation and cartilage differentiation potential of MSCs in vitro, although no reports show its beneficial effect in vivo. The purpose of this study is to investigate the promoting effect of bFGF on cartilage regeneration using human SMSC in vivo.

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Purpose: To determine the impact of mechanical stability on the progress of bone ongrowth on the frame surfaces of a titanium-coated polyether ether ketone (TCP) cage and a three-dimensional porous titanium alloy (PTA) cage following posterior lumbar interbody fusion (PLIF) until 1 year postoperatively.

Methods: A total of 59 patients who underwent one- or two-level PLIF for degenerative lumbar disorders since March 2015 were enrolled. Bone ongrowth of all cage frame surfaces (four surfaces per cage: TCP, 288 surfaces and PTA, 284 surfaces) was graded by 6-month and 1-year postoperative computed tomography color mapping (grade 0, 0‒25% of bone ongrowth; grade 1, 26‒50%; grade 2, 51‒75%; and grade 3, 76‒100%).

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Article Synopsis
  • TGF-β and BMP are crucial for bone metabolism, with Smurf proteins like Smurf2 regulating their signaling by tagging molecules for degradation to prevent overactivation.
  • The study investigated Smurf2's role in BMP/Smad signaling using collagen sponges with BMP2 in both wild type (WT) and Smurf2 mice, revealing that Smurf2 mice had greater bone mass and formation.
  • Findings indicate that Smurf2 negatively influences BMP/Smad signaling, as its inhibition enhanced osteogenic differentiation in bone marrow cells, highlighting a new mechanism in bone metabolism.
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Article Synopsis
  • A study compared short-term outcomes of two types of cages used in posterior lumbar interbody fusion (PLIF): titanium-coated poly-ether-ether-ketone (TCP) and three-dimensional porous titanium alloy (PTA).
  • The study involved 63 patients, with analyses focusing on fusion status, cyst formation, cage subsidence, and patient-reported quality of life (QOL) over 6 months and 1 year.
  • Results showed lower cyst formation and cage subsidence in the PTA group, while overall QOL outcomes were similar for both cage types after one year, highlighting concern over the higher cyst occurrence with TCP cages.
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Human synovium-derived stem cells (hSSCs) are an attractive source of cells for cartilage repair. At present, the quality of tissue and techniques used for cartilage regeneration have scope for improvement. A small compound, TD-198946, was reported to enhance chondrogenic induction from hSSCs; however, other applications of TD-198946, such as priming the cell potential of hSSCs, remain unknown.

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Delayed wound healing is one of the severe complications after total ankle arthroplasty (TAA). In particular, once tibialis anterior (TA) tendon is exposed from tendon sheath of extensor retinaculum, wound healing will be critically intractable. We report three cases (mean age: 75.

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We develop an automatic peak fitting algorithm using the Bayesian information criterion (BIC) fitting method with confidence-interval estimation in spectral decomposition. First, spectral decomposition is carried out by adopting the Bayesian exchange Monte Carlo method for various artificial spectral data, and the confidence interval of fitting parameters is evaluated. From the results, an approximated model formula that expresses the confidence interval of parameters and the relationship between the peak-to-peak distance and the signal-to-noise ratio is derived.

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Degeneration of the nucleus pulposus (NP) might serve as a trigger for intervertebral disc degeneration (IDD). A recent drug screening study revealed that the thienoindazole derivative, TD-198946, is a novel drug for the treatment of osteoarthritis. Because of the environmental and functional similarities between articular cartilage and intervertebral disc, TD-198946 is expected to prevent IDD.

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