臼蓋形成不全の股関節に行った転子間骨切り術後症例に対するカスタムメイドセメントレスステムの術後10年以上の成績

Background: During fixation of total hip arthroplasty (THA) after osteotomy, it is difficult to obtain a good cement mantle with a cemented stem and to obtain good fit along the medullary canal with a ready-made stem. We developed a CT-based custom stem, which was inserted after osteotomy in THA. Methods: We investigated 32 hips in 28 patients. The mean patient age at surgery was 62 and the mean follow-up period was 13 years. The previous osteotomy was intertrochanteric varus femoral osteotomy in 14 hips, intertrochanteric valgus femoral osteotomy in 17, and Schanz osteotomy in one. CT studies were obtained with a 5 mm slice intervals and 2 mm slice width. We produced stems made of Ti-6Al-4V. The stems did not have collars and the proximal third was coated with a 400-μ. m-thick porous coating covered with 20-μ m-hydroxyapatite (HA) coating. Results: The Harris Hip Score improved from a preoperative mean of 49.9 points to a postoperative mean of 82.7 points. One patient complained of postoperative thigh pain. Fractures occurred in two hips. Dislocation occurred in three patients. To date. no patient has reqired revision of the stem due to aseptic loosening. There was bone-ingrown fixation in all hips. Severe stress shielding was found in 14 hips (44%) Conclusion: Stable fixation was achieved with the proximal press-fit of the custom stem. Although stress shielding was observed in 14 hips, excellent results were obtained over a follow-up period of 10 years with this custom stem system for hips after intertrochanteric femoral osteotomy.博士（医学）・乙第1419号・平成30年6月27

Computer simulation of ion-exchange membrane electrodialysis for salt concentration and reduction of RO discharged brine for salt production and marine environment conservation

The salt discharged from reverse osmosis is concentrated by ion-exchange membrane electrodialysis to produce salt for industrial use and the salt concentration is reduced to seawater level for preventing environmental impact on marine ecosystems. The technology was evaluated experimentally and discussed with a computer simulation program of the electrodialysis system incorporated with U shape cells. The algorithm computes mass transport, energy consumption, electric current leakage, concentrate NaCl purity, pressure drop and limiting current density. The seawater reverse osmosis discharged brine was supplied to the electrodialysis pilot plant and it was operated changing current density and temperature taking benefit of seasoning variations. The computed energy consumption E-Nacl and NaCl concentration in concentrated solutions C-NaCl '' using developing algorithms provided a good description of the experimentally measured values with correlation coefficients of R(r) = 0.9 for E-NaCl and R(r) = 0.6 for C-NaCl ''. Then the reasonability of the developed algorithms is supported by the experimental set of data. The current leakage is nearly 3% for any electric current. The pump driving force is very low. The limiting current density is very high. In order to decrease salt concentration at the outlets of desalting cells to seawater level, it is necessary to increase desalting ratio to 0.5. This technique however increases Emu and decrease C-NaCl ''. In spite of this operating circumstance, E-NaCl and C-NaCl '' are comparable to the data in the salt manufacturing plant operation to produce edible salt. NaCl produced from in the reverse osmosis discharged brine electrodialysis is competitive in the edible salt market. (C) 2015 Elsevier B.V. All rights reserved.Peer ReviewedPostprint (author's final draft

Cardioprotective effects of hyperkalemia during simulated ischemia/reperfusion in neonatal rat cardiomyocytes : Preservation of Na+/K+-ATPase activity

Background : Hyperkalemia has multimodal effects on myocardial protection during ischemia/reperfusion. The preservation of Na+/K+-ATPase activity induced by hyperkalemia may have critical impact on myocardial protection. Methods : To elucidate the roles of hyperkalemia (16 mM) and Na+/K+-ATPase inhibition (100 μMouabain) inmyocardial protection during simulated ischemia (5 mM NaCN and 5.5 mM 2-deoxyglucose)/ reperfusion, we measured loss of membrane integrity and bleb formation using a vital dye calcein AM in cultured neonatal rat cardiomyocytes. The control perfusate was switched to treatment solution for 15 min, followed by reperfusion for 30 min. In a second set of experiments, myocardial excitability and diastolic intracellular calcium ion concentration ([Ca2+]i) were measured during a 45-min treatment using a calcium-sensitive fluorescent dye fluo-4 AM. Results : Simulated ischemia/reperfusion under ouabain treatment induced loss of membrane integrity, which was suppressed by hyperkalemia. Simulated ischemia/reperfusion induced bleb formation, which was accelerated by ouabain. Hyperkalemia delayed and inhibited the increase in diastolic [Ca2+]i induced by simulated ischemia. Furthermore, hyperkalemia almost completely inhibited the effects of ouabain on the diastolic [Ca2+]i during ischemia. Conclusions : These results suggest that hyperkalemia during ischemia is cardioprotective against ischemia/reperfusion insults and that hyperkalemia inhibits the effects of ouabain during ischemia

ケイ酸/亜鉛置換ストロンチウムアパタイトコーティングによるβ-リン酸カルシウムの骨誘導能促進効果

Background: β-Tricalcium phosphate (β-TCP) is a popular synthetic bone graft substitute with excellent osteoconductive properties and bioabsorbability. However, its osteoinductive properties are inferior to those of autologous or allogeneic bone. Trace elements such as strontium (Sr), silica (Si), and zinc (Zn) have been reported to promote osteogenesis in materials. In this study, we aimed to determine whether a Si/Zn-substituted Sr apatite coating of β-TCP could enhance osteoinductive properties. Methods: The apatite-coated β-TCP disks were prepared using nanoparticle suspensions of silicate-substituted Sr apatite (SrSiP) or silicate- and Zn-co-substituted Sr apatite (SrZnSiP). Bone marrow mesenchymal cells (BMSCs) from rat femur were cultured and subsequently seeded at a density of 1.0 × 106/cm2 onto apatite-coated and non-coated β-TCP disks. In vitro, the β-TCP disks were then placed in osteogenic medium, and lactate dehydrogenase (LDH) activity was measured from supernatants after culture for 2 days. Additionally, after culture for 14 days, the mRNA expression of genes encoding osteocalcin (OC), alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was evaluated by qRT-PCR. In vivo, the β-TCP disks were transplanted subcutaneously into rats that were sacrificed after 4 weeks. Then, the harvested disks were evaluated biochemically (ALP activity, OC content, mRNA expression of OC, ALP, BMP-2, and VEGF measured by qRT-PCR), radiologically, and histologically. Results: Significantly higher mRNA expression of almost all evaluated osteogenic and angiogenic genes was observed in the SrZnSiP and SrSiP groups than in the non-coated group, with no significant cytotoxicity elicited by the apatite coating in vitro. Moreover, in vivo, the SrZnSiP and SrSiP groups showed significantly higher osteogenic and angiogenic gene expression and higher ALP activity and OC content than the non-coated group (P < 0.05). Radiological and histopathological findings revealed abundant bone formation in the apatite-coated group. Conclusions: Our findings indicate that apatite coating of β-TCP improves osteoinductive properties without inducing significant cytotoxicity.博士（医学）・甲第805号・令和3年12月21日© 2021. The Author(s).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