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The diagnostic utility and frequency of CD56 expression in plasma cell myeloma
Full text linkPlasma cell myeloma (PCM) is a hematological malignancy characterized by systemic proliferation of neoplastic plasma cells within the bone marrow. Diagnosis requires clinical findings and immunohistochemical staining, including CD138, CD79a, cyclin D1, immunoglobulin κ (Igκ), and λ (Igλ). However, CD79a and cyclin D1 have limited sensitivity and specificity, and Igκ/Igλ assessment is often difficult due to overstaining. Therefore, more reliable antibodies are needed to accurately diagnose PCM. In this study, we examined the diagnostic utility of CD56 expression in PCM. We retrospectively performed immunostaining for CD138, CD56, CD79a, cyclin D1, Igκ, and Igλ in bone marrow samples from 116 patients with PCM.
CD56 expression was observed in 85/116 cases (73.3 %), CD79a was downregulated in 46/116 cases (39.7 %), and cyclin D1 expression was observed in 42/116 cases (36.2 %). The expression of CD56 was significantly higher than that of CD79a and cyclin D1 (both p
These findings highlight CD56 as a helpful marker for PCM diagnosis and support further clinical research.<br
Evaluation of Mycobacterium-derived plasmids for application in oral Actinomyces species
No full textObjectives: Genetic manipulation tools are essential for elucidating the pathogenic mechanisms of microorganisms. Several species of Actinomyces, including A. israelii, are present in the oral cavity and they are the causative agents of actinomycosis. However, efficient gene-editing tools for these species have not yet been developed. In this study, the aim was to evaluate the introduction of foreign genes into Actinomyces using plasmids derived from Mycobacterium, which belong to the same class as Actinomycetes.
Methods: A truncated derivative of pYT923, pYT923S, which contains the replication origin of the M. scrofulaceum plasmid pMSC262 was constructed and introduced into A. israelii by electrotransformation.
Results: pYT923S was successfully introduced into A. israelii. The transformation efficiency of A. israelii was approximately 7–66 CFU/μg of DNA, and all transformed colonies harbored pYT923S. The plasmid recovered from A. israelii replicated in Escherichia coli.
Conclusions: pYT923S was introduced into and maintained within A. israelii. Therefore, the pYT923S vector represents a useful genetic tool for Actinomyces and it is expected to facilitate future studies on the biology and pathogenicity of Actinomyces
Counting-loss correction procedure of X-ray imaging detectors with consideration for the effective atomic number of biological objects
Full text linkIt is necessary to correct counting loss caused by the pulse pile-up effect and dead time when using energy-resolving photon-counting detectors (ERPCDs) under “high-counting-rate” conditions in medical and/or industrial settings. We aimed to develop a novel counting-loss correction procedure in which biological objects having effective atomic numbers (Zeff values) of 6.5–13.0 are measured with polychromatic X-rays. To correct for counting loss, such a procedure must theoretically estimate the count value of an ideal X-ray spectrum without counting loss. In this study, we estimated the ideal X-ray spectrum by focusing on the following two points: (1) the X-ray attenuation in an object (Zeff values of 6.5–13.0) and (2) the detector response. Virtual materials having intermediate atomic numbers between 6.5 and 13.0 were generated by using a mixture of polymethylmethacrylate (PMMA, Zeff = 6.5) and aluminum (Al, Zeff = 13.0). We then constructed an algorithm that can perform the counting-loss correction based on the object’s true Zeff value. To demonstrate the applicability of our procedure, we analyzed investigational objects consisting of PMMA and Al using a prototype ERPCD system. A fresh fish sample was also analyzed. The Zeff values agree with the theoretical values within an accuracy of Zeff ±1. In conclusion, we have developed a highly accurate procedure for correcting counting losses for the quantitative X-ray imaging of biological objects
The influence of lubricant additives and surface roughness and hardness of material on the damage behavior of gears
Full text linkThis study investigates the influence of lubricant additives, surface roughness, and material hardness on gear damage behavior under boundary lubrication conditions. We conducted both the Short-term Test and the Standard Test using an FZG gear test machine to evaluate how lubricant additives and gear surface roughness influence damage progression when the surface roughness exceeds the oil-film thickness. Acid phosphate ester effectively suppressed micropitting through surface smoothing but led to severe damage such as pitting and scuffing during prolonged use. In contrast, sulfurized fatty oil promoted mild wear, delaying catastrophic failures and extending gear life. Higher surface roughness accelerated wear, while increased hardness reduced deformation but it expanded damage areas. The study found that initial surface roughness and its progress during load stages strongly correlate with gear durability. Measurement of arithmetic mean roughness after sufficient running-in under actual load conditions proved useful for predicting long-term performance. These findings highlight the importance of selecting lubricant formulations tailored to specific gear operating environments and damage modes. Understanding the interplay between lubrication chemistry and material properties enables the design of more durable gear systems
SPRED2 controls the severity of cisplatin-induced acute kidney injury by inhibiting ERK activation and TNFα production in mice
No full textCisplatin is an effective chemotherapeutic agent used to treat solid tumors, but its clinical use is limited by acute kidney injury (AKI), in which ERK signaling plays a crucial role. Here, we investigated whether Sprouty-related EVH1 domain-containing protein 2 (SPRED2), an endogenous inhibitor of the Ras/Raf/ERK pathway, protects against cisplatin-induced AKI. Spred2−/− mice showed more severe renal injury and stronger ERK activation than wild-type (WT) mice, whereas pretreatment with the MEK inhibitor U0126 markedly attenuated the injury. In HK-2 cells (proximal tubular cells), SPRED2 knockdown enhanced cisplatin-induced apoptosis and caspase-3 activation, accompanied by decreased Bcl-2 expression. Spred2−/− kidneys displayed increased macrophage infiltration and elevated Tnfα, Il1b, and Ccl2 expression. Neutralization of TNFα with anti-TNFα antibody ameliorated renal injury and reduced the levels of Il1b and Ccl2 mRNA in Spred2−/− mice. In vitro, TNFα slightly decreased the viability of control and SPRED2 knockdown HK-2 cells without cisplatin treatment, but the decreased viability was augmented in SPRED2 knockdown cells by cisplatin. Immunohistochemistry revealed that macrophages were the predominant TNFα-positive cell population. Bone marrow–derived macrophages from Spred2−/− mice produced higher levels of TNFα in response to cisplatin compared with control cells, and this increase was markedly suppressed by U0126.
These findings indicate that endogenous SPRED2 protects kidneys from cisplatin-induced AKI by limiting ERK activation, tubular apoptosis, and TNFα-mediated inflammation
Does innovation-driven policy optimize urban energy consumption? Evidence from China’s innovation-driven city pilot policies
No full textRestructuring energy consumption is essential for promoting green, low-carbon economic and societal development. Innovation-driven policies, particularly those implemented in pilot cities, play a crucial role in this transformation. This study conducts a theoretical analysis to examine how such policies influence urban energy-consumption structures. Using a multitime-point difference-in-differences model, it treats China’s national innovation-driven city pilot policies as a quasi-natural experiment. The results indicate that these policies significantly improve urban energy structures. Mechanism analyses reveal that the improvements occur mainly through green innovation and industrial upgrading. Heterogeneity analysis further indicates that the effects are more pronounced in cities with lower administrative tiers, more challenging geographical conditions, and stronger environmental priorities. These findings provide valuable policy insights for refining innovation-driven strategies, enhancing urban energy-consumption structures, and promoting sustainable economic development in China
Dynamin 2 is involved in osteoblast migration by regulating the organization of F-actin
No full textObjectives: Dynamin, a GTPase that regulates membrane dynamics, has recently been implicated in actin cytoskeletal remodeling. This study aimed to elucidate the role of dynamin in osteoblast migration by examining the effects of dynamin inhibition on the localization and organization of F-actin and dynamin 2 in MC3T3-E1 cells.
Methods: MC3T3-E1 cells were treated with dynamin inhibitors (Dyngo 4a and Dynole 34-2), and cell migration was assessed using a wound-healing assay. Fluorescent staining was performed to analyze the intracellular localization of F-actin and dynamin 2.
Results: Dynamin inhibition significantly reduced the migration of MC3T3-E1 cells. Fluorescence analysis revealed a marked decrease in the accumulation and colocalization of F-actin and dynamin 2 at the protrusion edge. Additionally, dynamin inhibition suppressed the formation of lamellipodia and stress fibers while promoting the appearance of abnormal F-actin clusters in the cytoplasm.
Conclusions: These findings suggest that dynamin plays an essential role in osteoblast migration by regulating actin cytoskeletal remodeling, particularly through the formation of lamellipodia and stress fibers
Helical X-ray tube trajectory estimation via image noise analysis for enhanced CT dosimetry
Full text linkInformation on the helical trajectory of the X-ray tube is necessary for accurate dose evaluation during computed tomography (CT). We aimed to propose a methodology for analyzing the trajectory of the X-ray tube. The novelty of this paper is that the incident direction of X-rays is estimated from the standard deviation (SD) distribution. The X-ray incident direction for each slice was analyzed using a distribution function of SD values, in which the analysis regions were placed in the air region. Then, the helical trajectory of the CT scan was estimated by fitting a three-dimensional helical function to the analyzed data. The robustness of our algorithm was verified through phantom studies: the analyzed X-ray incident directions were compared with instrumental log data, in which cylindrical polyoxymethylene resin phantoms and a whole-body phantom were scanned. Chest CT scanning was mimicked, in which the field of view (FOV) was set at the lung region. The procedure for analyzing the X-ray incident direction was applicable to cylindrical phantoms regardless of the phantom size. In contrast, in the case of the whole-body phantom, although it was possible to apply our procedure to the chest and abdomen regions, the shoulder slices were inappropriate to analyze. Therefore, the helical trajectory was determined based on chest and abdominal CT images. The accuracy in X-ray incident direction analysis was evaluated to be 7.5°. In conclusion, we have developed an algorithm to estimate a three-dimensional helical trajectory that can be used for dose measurements and simulations
放射線治療装置の回転座標系誤差が軸外targetの照射精度に及ぼす影響とTG142のトレランスの評価
No full text【目的】放射線治療装置の回転座標系の誤差が軸外targetの照射精度に及ぼす影響を定量的に評価し，TG142における回転座標系誤差（±1.0°）のトレランスの妥当性を検討する．【方法】Elekta社製放射線治療装置（Elekta, Stockholm, Sweden）とMultiMet-WL QAファントム（Sun Nuclear, Melbourne, FL, USA）を用いて，6個のtargetに対してoff isocenterのWinston–Lutz test（WL test）を実施した．Baselineの測定に加え，意図的にcollimator，gantry，couchに+0.5°, +1.0°回転誤差を加えた6条件で測定を行い，照射野中心とtarget中心のベクトル距離（S値）および各方向（gantry-target: GT, left-right: LR, anterior-posterior: AP）の位置ずれを解析した．【結果】Isocenterからの距離が大きいtargetほど位置ずれが顕著であった．特にcollimator回転誤差の影響が最も大きく，isocenterから7 cm離れたtargetでは0.5°の回転誤差でもS値が最大1.24 mmに達した．次に影響が大きかったのはcouch回転であり，gantry回転はtargetの配置が回転軸に近いものが多く相対的に影響が少なかった．回転座標系の誤差は幾何学的誤差の影響が強く，位置ずれに方向依存性があった．【結語】Collimatorやcouchの影響が大きく，0.5°の誤差でも1 mm以上の位置ずれが生じることがあった．Gantryの影響はtargetの配置依存があり，相対的に小さかった．軸外targetの照射において，TG142の±1.0°のトレランスは放射線治療装置の種類にかかわらず最低限遵守するべき基準であり，targetの配置次第では臨床的に十分なマージンを保証できない可能性が示された．Target配置に応じたより厳格な基準と定期的quality assurance（QA）の重要性が示唆された．Purpose: The aim of this study was to quantitatively evaluate the impact of gantry, collimator, and couch rotational errors in a linear accelerator on the irradiation accuracy of off-isocenter targets, and to assess the validity of the rotational error tolerance (±1.0°) specified in American Association of Physicists in Medicine TG142. Methods: Using an Elekta linear accelerator (Elekta, Stockholm, Sweden) and the MultiMet-WL QA phantom (Sun Nuclear, Melbourne, FL, USA), an off-isocenter Winston–Lutz test was performed on six targets. In addition to baseline measurements, six conditions were evaluated by intentionally introducing rotational errors of +0.5° and +1.0° in the collimator, gantry, and couch. The vector distance (S value) between the field center and the target center, as well as positional deviations in each direction (gantry-target: GT, left-right: LR, anterior-posterior: AP), were analyzed. Results: Targets located farther from the isocenter exhibited more significant positional deviations. The collimator rotation had the greatest impact; at 7 cm from the isocenter, even a 0.5° error resulted in a maximum S value of 1.24 mm. Couch rotation had the next largest effect, while gantry rotation had relatively smaller effects, likely because most targets were located near the gantry’s rotational axis. The rotational errors mainly caused geometric deviations with direction-dependent positional shifts. Conclusion: The effects of the collimator and couch were substantial, with positional deviations exceeding 1 mm even for a 0.5° rotation error. The influence of the gantry was relatively small and dependent on the target configuration. For irradiation of off-axis targets, the TG142 tolerance of ±1.0° should be regarded as a minimum standard that must be strictly observed regardless of the type of linear accelerator. However, depending on the target arrangement, clinically adequate margins may not be ensured. These findings suggest the necessity of applying stricter criteria according to target configuration and emphasize the importance of regular quality assurance
Robust adhesion between solid-state hydroxyapatite and bone tissue through surface demineralization
No full textObjective: Current bone adhesives typically lack adequate mechanical strength, long-term stability, or biocompatibility. To address these limitations, we designed a new adhesion strategy using a solid-state hydroxyapatite (HAp) adhesive in combination with bone surface demineralization.
Methods: Solid-state HAp adhesives were synthesized via wet chemical precipitation and heat treatment. Cortical bone specimens were partially demineralized with phosphoric acid (H3PO4) or ethylenediaminetetraacetic acid (EDTA), and characterized using scanning electron microscopy (SEM) and attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR). Shear adhesion strength of HAp to demineralized bone was measured over time. In vivo fixation was assessed in rats using micro-computed tomography and histology. Statistical analysis used Tukey-Kramer tests after normality and variance checks.
Results: Although the HAp adhesive failed to adhere to non-demineralized bone, effective adhesion was achieved on the surface-demineralized bone tissue. Shear adhesion strength was significantly higher in EDTA-treated samples (238.4 kPa at 10 h) compared to H3PO4-treated samples (102.9 kPa at 1 h), with performance correlating with demineralization depth. ATR-FTIR and SEM analyses revealed that EDTA preserved collagen's triple-helix structure and free water content, both enhancing adhesion. Animal experiments confirmed stable fixation of HAp adhesive to demineralized bone tissue.
Conclusions: Surface demineralization enabled strong adhesion of the solid-state HAp adhesive to bone by exposing collagen swollen with water. Adhesion strength was influenced by structural changes in the demineralized layer, and the adhesive provided stable in vivo fixation, supporting its potential for bone-anchored biomedical applications