骨欠損再建における培養細胞シートを併用した培養人工骨移植の有用性

AIM: To determine the effects of transplanting osteogenic matrix cell sheets and beta-tricalcium phosphate (TCP) constructs on bone formation in bone defects. METHODS: Osteogenic matrix cell sheets were prepared from bone marrow stromal cells (BMSCs), and a porous TCP ceramic was used as a scaffold. Three experimental groups were prepared, comprised of TCP scaffolds (1) seeded with BMSCs; (2) wrapped with osteogenic matrix cell sheets; or (3) both. Constructs were implanted into a femoral defect model in rats and bone growth was evaluated by radiography, histology, biochemistry, and mechanical testing after 8 wk. RESULTS: In bone defects, constructs implanted with cell sheets showed callus formation with segmental or continuous bone formation at 8 wk, in contrast to TCP seeded with BMSCs, which resulted in bone non-union. Wrapping TCP constructs with osteogenic matrix cell sheets increased their osteogenic potential and resulting bone formation, compared with conventional bone tissue engineering TCP scaffolds seeded with BMSCs. The compressive stiffness (mean ± SD) values were 225.0 ± 95.7, 30.0 ± 11.5, and 26.3 ± 10.6 MPa for BMSC/TCP/Sheet constructs with continuous bone formation, BMSC/TCP/Sheet constructs with segmental bone formation, and BMSC/TCP constructs, respectively. The compressive stiffness of BMSC/TCP/Sheet constructs with continuous bone formation was significantly higher than those with segmental bone formation and BMSC/TCP constructs. CONCLUSION: This technique is an improvement over current methods, such as TCP substitution, and is useful for hard tissue reconstruction and inducing earlier bone union in defects.博士（医学）・乙第1366号・平成27年11月27日Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved. This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license,which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/ licenses/by-nc/4.0

Assessment of Humeral Retroversion Angle in Baseball Players: A Chronological Study

The objective of this study was to compare the humeral retroversion angles (HRA) between baseball players, including children, and those without a history of playing baseball, clarify the characteristics of the HRA in baseball players, and to determine whether or not chronological changes of the HRA are affected by a throwing motion. We studied 32 young baseball players (Group A), 10 elementary and junior high school students who had never played competitive overhead throwing sports (Group B), 65 adult baseball players who had been playing baseball since childhood in a little league or boy\u27s baseball team (Group C), and 11 adults who had never played competitive overhead throwing sports such as baseball or handball (Group D). Computed tomography of both humeri in these subjects was taken with a 5mm slice thickness. For the measurement of HRA, slices from the center of the humeral head and slices from the humeral epicondyle were examined. In baseball players, the mean HRA on the throwing side was larger than that on the non-throwing side, regardless of age and carrier. The HRAs of the elementary and junior high school baseball players as well as those of adult baseball players were larger on the throwing side. The HRA of the throwing side was significantly greater than that of the non-throwing side in both groups of baseball players. Furthermore, the mean HRA on the throwing side of young baseball players was significantly larger than that of adult baseball players, suggesting that the adaptive bony change of the humerus was caused by throwing stress and might occur in the early formative years of a player\u27s career

Adverse Effects of Personal Protective Equipment Among Intensive Care Unit Healthcare Professionals During the COVID-19 Pandemic: A Scoping Review

IntroductionTo avoid exposure to SARS-COV-2, healthcare professionals use personal protective equipment (PPE) while treating COVID-19 patients. Prior studies have revealed the adverse effects (AEs) of PPE on healthcare workers (HCWs); however, no review has focused on the AEs of PPE on HCWs in intensive care units (ICUs). This review aimed to identify the AEs of PPE on HCWs working in ICUs during the COVID-19 pandemic.MethodsA scoping review was conducted. MEDLINE, CINAHL, the World Health Organization (WHO) global literature on COVID-19, and Igaku-chuo-zasshi (a Japanese medical database), Google Scholar, medRxiv, and Health Research Board (HRB) open research were searched from January 25–28, 2021. The extracted data included author(s) name, year of publication, country, language, article title, journal name, publication type, study methodology, population, outcome, and key findings.ResultsThe initial search identified 691 articles and abstracts. Twenty-five articles were included in the analysis. The analysis comprised four key topics: studies focusing on PPE-related headache, voice disorders, skin manifestations, and miscellaneous AEs of PPE. The majority of AEs for HCWs in ICUs were induced by prolonged use of masks.ConclusionThe AEs of PPE among HCWs in ICUs included heat, headaches, skin injuries, chest discomfort, and dyspnea. Studies with a focus on specific diseases were on skin injuries. Moreover, many AEs were induced by prolonged use of masks

Rh(I)-catalyzed intramolecular [2 + 2 + 1] cycloaddition of allenenes: Construction of bicyclo[4.3.0]nonenones with an angular methyl group and tricyclo[6.4.0.01,5]dodecenone

The [RhCl(CO)dppp]2-catalyzed intramolecular carbonylative [2 + 2 + 1] cycloaddition of allenenes was developed to prepare bicyclo[4.3.0]nonenones possessing a methyl group at the ring junction, which is difficult to achieve by the Pauson–Khand reaction of the corresponding enynes. This method also provided a new procedure for the construction of the tricyclo[6.4.0.01,5]dodecenone framework in a satisfactory yield

Vector transmission of bovine leukemia virus during summer season in Northern Hokkaido

One of the known transmission pathways of bovine leukemia virus (BLV) is bloodsucking insects. Against this background, this study investigated changes in BLV seroconversion in cattle by season on three private farms in Northern Hokkaido. Study results showed that no BLV seroconversion was observed during winter, a season without horse flies, and that all seroconversions occurred during summer. Thus, we collected horse flies which were observed sucking blood on cattle in public grazed fields and performed BLV detection tests in the insects. The tests showed that 75% of the total collected horse flies were BLV-positive. These results suggested the existence of vectors such as horse flies in grazing filed (in summer) was a risk factor of the spread of BLV infection in Northern Hokkaido

Deep Learning for Bone Mineral Density and T-Score Prediction from Chest X-rays: A Multicenter Study

Although the number of patients with osteoporosis is increasing worldwide, diagnosis and treatment are presently inadequate. In this study, we developed a deep learning model to predict bone mineral density (BMD) and T-score from chest X-rays, which are one of the most common, easily accessible, and low-cost medical imaging examination methods. The dataset used in this study contained patients who underwent dual-energy X-ray absorptiometry (DXA) and chest radiography at six hospitals between 2010 and 2021. We trained the deep learning model through ensemble learning of chest X-rays, age, and sex to predict BMD using regression and T-score for multiclass classification. We assessed the following two metrics to evaluate the performance of the deep learning model: (1) correlation between the predicted and true BMDs and (2) consistency in the T-score between the predicted class and true class. The correlation coefficients for BMD prediction were hip = 0.75 and lumbar spine = 0.63. The areas under the curves for the T-score predictions of normal, osteopenia, and osteoporosis diagnoses were 0.89, 0.70, and 0.84, respectively. These results suggest that the proposed deep learning model may be suitable for screening patients with osteoporosis by predicting BMD and T-score from chest X-rays

Effects of micro-porosity and local BMP-2 administration on bioresorption of β-TCP and new bone formation

Abstract Background It has been reported that the microporous structure of calcium phosphate (CaP) ceramics is important to osteoconduction. Bone morphogenetic protein-2 (BMP-2) has been shown to be a promising alternative to bone grafting and a therapeutic agent promoting bone regeneration when delivered locally. The aim of this study was to evaluate the effects of micro-porosity within beta-tricalcium phosphate (β-TCP) cylinders and local BMP-2 administration on β-TCP resorption and new bone formation. Methods Bilateral cylindrical bone defects were created in rabbit distal femora, and the defects were filled with β-TCP. Rabbits were divided into 3 groups; defects were filled with a β-TCP cylinder with a total of approximately 60% porosity (Group A: 13.4% micro- and 46.9% macropore, Group B: 38.5% micro- and 20.3% macropore, Group C: the same micro- and macro-porosity as in group B supplemented with BMP-2). Rabbits were sacrificed 4, 8, 12, and 24 weeks postoperatively. Results The number of TRAP-positive cells and new bone formation in group B were significantly greater than those in group A at every period. The amount of residual β-TCP in group C was less than that in group B at all time periods, resulting in significantly more new bone formation in group C at 8 and 12 weeks. The number of TRAP-positive cells in group C was maximum at 4 weeks. Conclusions These results suggest that the amount of submicron microporous structure and local BMP-2 administration accelerated both osteoclastic resorption of β-TCP and new bone formation, probably through a coupling-like phenomenon between resorption and new bone formation