CO2 レーザーでアパタイトを溶着させたPEEK ディスク上における、ラット骨髄間葉系細胞の骨形成能に関する培養実験

Background: Polyether-ether-ketone (PEEK) is increasingly being used for spinal applications. However, because of its biologically inactive nature, there are risks of false joint loosening and sinking. PEEK materials are coated with apatite to enhance the osteoconductive properties. In this study, we aimed to evaluate whether strontium apatite stimulate osteogenesis on the surface of PEEK by using the CO2 laser technique. Methods: We prepared non-coated disks, laser-exposed disks without apatite, and four types of apatite-coated by laser PEEK disks (hydroxyapatite (HAP), strontium hydroxyapatite (SrHAP), silicate-substituted strontium apatite (SrSiP), and silicate-zinc-substituted strontium apatite (SrZnSiP)). A part of the study objective was testing various types of apatite coatings. Bone marrow mesenchymal cells (BMSCs) of rats were seeded at a density of 2 × 104/cm2 onto each apatite-coated, non-coated, and laser-irradiated PEEK disks. The disks were then placed in osteogenic medium, and alkaline phosphatase (ALP) staining and Alizarin red staining of BMSCs grown on PEEK disks were performed after 14 days of culture. The concentrations of osteocalcin (OC) and calcium in the culture medium were measured on days 8 and 14 of cell culture. Furthermore, mRNA expression of osteocalcin, ALP, runt-related transcription factor 2 (Runx2), collagen type 1a1 (Col1a1), and collagen type 4a1 (Col4a1) was evaluated by qPCR. Results: The staining for ALP and Alizarin red S was more strongly positive on the apatite-coated PEEK disks compared to that on non-coated or laser-exposed without coating PEEK disks. The concentration of osteocalcin secreted into the medium was also significantly higher in case of the SrHAP, SrSiP, and SrZnSiP disks than that in the case of the non-coated on day14. The calcium concentration in the PEEK disk was significantly lower in all apatite-coated disks than that in the pure PEEK disks on day 14. In qPCR, OC and ALP mRNA expression was significantly higher in the SrZnSiP disks than that in the pure PEEK disks. Conclusions: Our findings demonstrate that laser bonding of apatite-along with trace elements-on the PEEK disk surfaces might provide the material with surface property that enable better osteogenesis.博士（医学）・甲第809号・令和4年3月15日© The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. 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 in a credit line to the data

MIBG Predicts Falls in PD

Background: Falls are associated with poor prognosis in patients with Parkinson's disease (PD). Although several factors related to falls were reported in patients with PD, objective predictors of falls are not identified. We aimed to determine whether 123I-meta-iodobenzylguanidine (MIBG) cardiac scintigraphy could be a useful biomarker to predict falls. Methods: Forty-five patients with PD were enrolled in this study. These subjects were followed up more than 5 years after MIBG scintigraphy and were divided into two groups: one with decreased uptake of MIBG and the other without decreased uptake of MIBG. The cut-off value for the delayed heart-to-mediastinum ratio was 1.8. Kaplan-Meier analysis and a log-rank test were performed to test the predictive power of MIBG cardiac scintigraphy for falls. Univariate analysis was selected because we did not have appropriate data for adjustment, such as motor and cognitive assessment. Results: The group with decreased uptake of MIBG had a significantly higher incidence of falls than that without decreased uptake of MIBG (P = 0.022, log-rank test). Conclusions: Although the limitations of this study were lack of several key factors including motor and cognitive assessment, MIBG cardiac scintigraphy may be used to predict falls in patients with PD

Effectiveness of Photodynamic Therapy and Nd-YAG Laser Treatment for Obstructed Tracheobronchial Malignancies

Since 1980, advanced lung carcinomas were treated with palliative laser therapy for the purpose of opening the endobronchial stenosis and obstruction by either photodynamic therapy (PDT) or Nd-YAG laser treatment at Tokyo Medical University. A total of 258 lesions were treated, 81 by PDT and 177 by Nd-YAG laser treatment. PDT achieved effective results in 61 (75%) of 81 lesions. In the Nd-YAG laser group, 143 (81%) of 177 lesions showed effective results. When the tumor was located in the trachea or main bronchi, effective results were obtained in 73% (19 of 26) of cases treated by PDT and in 93% of cases (64 of 69) treated by Nd-YAG laser. However, in cases in which the tumor was located in lobar or segmental bronchi, the tumor response was effective in 76% (42 of 55) of PDT-treated patients and 73% (79 of 108) of Nd-YAG laser-treated patients. With a mortality rate of 0%, the greatest advantage of PDT over Nd-YAG treatment was safety. Considering complications, PDT seems to be useful for obstruction of lobar and segmental bronchus. Nevertheless, when deciding among alternative therapies, physicians treating patients with advanced lung carcinoma should give careful consideration to the benefit and complications of both laser therapies and decide the most suitable modality

Lung Cancers Treated With Photodynamic Therapy and Surgery

Laser endoscopic surgery, especially the effectiveness of photodynamic therapy (PDT) using Photofrin as a photosensitizer, has now achieved a status as effective treatment modality for lung cancer. Twenty-six lung cancer patients received the preoperative PDT for the purpose of either reducing the extent of resection or increasing operability. Bronchoscopical PDT is performed with topical anesthesia approximately 48 h after the intravenous injection of 2.0 mg/kg body weight of Photofrin. Operation was performed 2–9 weeks after initial PDT. The initial purpose of PDT, i.e. either to reduce the extent of resection or convert inoperable disease to operable status, was achieved in 22 out of 26 patients treated. The survival rate of T3 (main bronchus invasion) cases treated by surgery alone increased significantly from 50.9% to 60.0% with the application of preoperative PDT. This remarkable result may imply that this new option of PDT as preoperative laser irradiation may contribute to the management of advanced lung malignancy

Incidence and Risk Factors for Infections Requiring Hospitalization, Including Pneumocystis Pneumonia, in Japanese Patients with Rheumatoid Arthritis

Objective. Rheumatoid arthritis (RA) may be complicated by different infections, but risk factors for these are not fully elucidated. Here, we assessed the incidence of and risk factors for infections requiring hospitalization (IRH) including pneumocystis pneumonia (PCP) in patients with RA. Methods. We retrospectively surveyed all RA patients treated at our hospital from 2009 to 2013, for whom data were available on demographic features, medications, comorbidities, and severity of RA. Multivariate logistic regression analysis was applied to calculate adjusted odds ratios (ORs) for factors associated with the occurrence of IRH. Results. In a total of 9210 patient-years (2688 patients), there were 373 IRH (3.7/100 patient-years). Respiratory tract infections were most frequent (, and additionally 16 PCP), followed by urinary tract infections (). Significant factors for PCP included higher age (≥70 years; OR 3.5), male sex (6.6), underlying lung disease (3.0), use of corticosteroids (4.8), and use of biologics (5.4). Use of methotrexate (5.7) was positively associated with PCP but negatively with total infections (0.7). Additionally, functional disorders and higher RA disease activity were also related to total infections. Conclusions. Risk factors for infection should be taken into account when deciding treatment for the individual RA patient