非破壊的で迅速に骨形成を評価できるマーカーとしての培養液中カルシウム濃度について

Artificial bones made of β-tricalcium phosphate (β-TCP) combined with bone marrow-derived mesenchymal stromal cells (BM-MSCs) are used for effective reconstruction of bone defects caused by genetic defects, traumatic injury, or surgical resection of bone tumors. However, the selection of constructs with high osteogenic potential before implantation is challenging. The purpose of this study was to determine whether the calcium concentration in BM-MSC culture medium can be used as a nondestructive and simple osteogenic marker for selecting tissue-engineered grafts constructed using β-TCP and BM-MSCs. We prepared three cell passages of BM-MSCs derived from three 7-week-old, male Fischer 344 rats; the cells were cultured in osteoinductive medium in the presence of β-TCP for 15 days. The medium was replaced with fresh medium on day 1 in culture and subsequently changed every 48 h; it was collected for measurement of osteocalcin secretion and calcium concentration by enzyme-linked immunosorbent assay and X-ray fluorescence spectrometry, respectively. After cultivation, the constructs were implanted subcutaneously into the backs of recipient rats. Four weeks after implantation, the alkaline phosphatase (ALP) activity and osteocalcin content of the constructs were measured. A strong inverse correlation was observed between the calcium concentration in the medium and the ALP activity and osteocalcin content of the constructs, with Pearson's correlation coefficients of 0.92 and 0.90, respectively. These results indicate that tissue-engineered bone with high osteogenic ability can be selected before implantation based on low calcium content of the culture medium, resulting in successful bone formation after implantation. This nondestructive, simple method shows great promise for assessing the osteogenic ability of tissue-engineered bone.博士（医学）・乙第1411号・平成29年11月24日Copyright © 2017 Cognizant, LLC. The articles contained in the following journals published by Cognizant, LLC are "open access articles" subject to the terms of the Creative Commons Attribution Non-Commercial (CC BY NC) license(https://creativecommons.org/licenses/by-nc/3.0/). That license permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. The articles are therefore free to read, download, cite and share with others

Spectrocolorimetric assessment of cartilage plugs after autologous osteochondral grafting: correlations between color indices and histological findings in a rabbit model

We investigated the use of a commercial spectrocolorimeter and the application of two color models (L* a* b* colorimetric system and spectral reflectance distribution) to describe and quantify cartilage plugs in a rabbit model of osteochondral autografting. Osteochondral plugs were removed and then replaced in their original positions in Japanese white rabbits. The rabbits were sacrificed at 4 or 12 weeks after the operation and cartilage samples were assessed using a spectrocolorimeter. The samples were retrospectively divided into two groups on the basis of the histological findings (group H: hyaline cartilage, successful; group F: fibrous tissue or fibrocartilage, failure) and investigated for possible significant differences in the spectrocolorimetric analyses between the two groups. Moreover, the relationships between the spectrocolorimetric indices and the Mankin histological score were examined. In the L* a* b* colorimetric system, the L* values were significantly lower in group H than in group F (P = 0.02), whereas the a* values were significantly higher in group H than in group F (P = 0.006). Regarding the spectral reflectance distribution, the spectral reflectance percentage 470 (SRP470) values, as a coincidence index for the spectral reflectance distribution (400 to 470 nm in wavelength) of the cartilage plugs with respect to intact cartilage, were 99.8 ± 6.7% in group H and 119.8 ± 10.6% in group F, and the difference between these values was significant (P = 0.005). Furthermore, the a* values were significantly correlated with the histological score (P = 0.004, r = -0.76). The SRP470 values were also significantly correlated with the histological score (P = 0.01, r = 0.67). Our findings demonstrate the ability of spectrocolorimetric measurements to predict the histological findings of cartilage plugs after autologous osteochondral grafting. In particular, the a* values and SRP470 values can be used to judge the surface condition of an osteochondral plug on the basis of objective data. Therefore, spectrocolorimetry may contribute to orthopedics, rheumatology and related research in arthritis, and arthroscopic use of this method may potentially be preferable for in vivo assessment

Nontraumatic tibial polyethylene insert cone fracture in mobile-bearing posterior-stabilized total knee arthroplasty

A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed by the tibial insert cone fracture at the anterior side of the cone, resulting in fracture at the base of the cone. This analysis shows the risk of tibial insert cone fracture due to longitudinal stress in mobile-bearing posterior-stabilized total knee arthroplasty in which an insert is designed to highly conform to the femoral component

Correlations of the histological scores from microscopic findings and the spectrocolorimetric indices

<p><b>Copyright information:</b></p><p>Taken from "Spectrocolorimetric assessment of cartilage plugs after autologous osteochondral grafting: correlations between color indices and histological findings in a rabbit model"</p><p>http://arthritis-research.com/content/9/5/R88</p><p>Arthritis Research & Therapy 2007;9(5):R88-R88.</p><p>Published online 10 Sep 2007</p><p>PMCID:PMC2212560.</p><p></p> The a* values are significantly correlated with the Mankin histological score (= 0.004, r = -0.76). The SRPvalues are significantly correlated with the Mankin histological score (= 0.01, r = 0.67). < 0.05 by non-parametric Spearman's rank-order correlation

Bar graphs representing the spectral reflectance percentages (SRPs) of the cartilage plugs at 4 and 12 weeks (4 w and 12 w, respectively) after transplantation

<p><b>Copyright information:</b></p><p>Taken from "Spectrocolorimetric assessment of cartilage plugs after autologous osteochondral grafting: correlations between color indices and histological findings in a rabbit model"</p><p>http://arthritis-research.com/content/9/5/R88</p><p>Arthritis Research & Therapy 2007;9(5):R88-R88.</p><p>Published online 10 Sep 2007</p><p>PMCID:PMC2212560.</p><p></p> The black bar represents the control cartilage for each group. The SRP values are used as a coincidence index of the spectral reflectance distribution of the repaired cartilage with respect to standard intact cartilage. The SRPvalues of the cartilage plugs are used as a coincidence index between 400 and 700 nm in wavelength (left four bars), while the SRPvalues of the cartilage plugs are used as a coincidence index between 400 and 470 nm in wavelength (right four bars). Error bars represent the standard deviation of each group

Bar graphs representing the spectral reflectance percentages (SRPs) of groups H and F

<p><b>Copyright information:</b></p><p>Taken from "Spectrocolorimetric assessment of cartilage plugs after autologous osteochondral grafting: correlations between color indices and histological findings in a rabbit model"</p><p>http://arthritis-research.com/content/9/5/R88</p><p>Arthritis Research & Therapy 2007;9(5):R88-R88.</p><p>Published online 10 Sep 2007</p><p>PMCID:PMC2212560.</p><p></p> The black bar represents the control cartilage for each group. The SRPvalues of groups H and F (left four bars) and SRPvalues of groups H and F (right four bars) are shown. Error bars represent the standard deviation of each group. *< 0.05, group H versus group F; **P < 0.05, versus the control; non-parametric Mann-Whitney U-test