64 research outputs found

    Deficiency of triad junction and contraction in mutant skeletal muscle lacking junctophilin type 1

    Get PDF
    In skeletal muscle excitation–contraction (E–C) coupling, the depolarization signal is converted from the intracellular Ca2+ store into Ca2+ release by functional coupling between the cell surface voltage sensor and the Ca2+ release channel on the sarcoplasmic reticulum (SR). The signal conversion occurs in the junctional membrane complex known as the triad junction, where the invaginated plasma membrane called the transverse-tubule (T-tubule) is pinched from both sides by SR membranes. Previous studies have suggested that junctophilins (JPs) contribute to the formation of the junctional membrane complexes by spanning the intracellular store membrane and interacting with the plasma membrane (PM) in excitable cells. Of the three JP subtypes, both type 1 (JP-1) and type 2 (JP-2) are abundantly expressed in skeletal muscle. To examine the physiological role of JP-1 in skeletal muscle, we generated mutant mice lacking JP-1. The JP-1 knockout mice showed no milk suckling and died shortly after birth. Ultrastructural analysis demonstrated that triad junctions were reduced in number, and that the SR was often structurally abnormal in the skeletal muscles of the mutant mice. The mutant muscle developed less contractile force (evoked by low-frequency electrical stimuli) and showed abnormal sensitivities to extracellular Ca2+. Our results indicate that JP-1 contributes to the construction of triad junctions and that it is essential for the efficiency of signal conversion during E–C coupling in skeletal muscle

    Development of MONSAKUN Touch and Practical Use in Class: Realization of Lesson of Posing of Arithmetical Word Problems

    Get PDF
    和若しくは差で解ける算数文章問題を対象とした単文統合型の作問学習支援システム“モンサクン”は数年に渡り複数の小学校の授業で利用されている.しかしながら,これらの授業では既に対象領域の学習を終えている2年生以上を対象としていたため,付加的な学習としての位置づけになっていた.本研究では,対象領域を学習中である1年生を対象に,単文統合型の作問の実施を目指した.このためにはシステムと授業の融合が必要となるため,(1) システムの通常教室での利用,(2) 作問状況のリアルタイムでの把握,(3) 作問法の教授,が解決すべき課題となった.本論文ではこれらの課題を解決するために行った,(I) モンサクンのタブレット化,(II) 作問状況モニタリングと集計・可視化機能の実現,(III) 作問法の教授法の考案,を述べる.またシステムを用いた9時限に渡る実践を行い,その分析結果から,システムが十分に利用可能であったこと,学習者の問題解決能力や作問能力の向上が見られたことが確認できたので,これを報告する

    Applications of Carbon Nanotubes in Bone Regenerative Medicine

    Get PDF
    Scaffolds are essential for bone regeneration due to their ability to maintain a sustained release of growth factors and to provide a place where cells that form new bone can enter and proliferate. In recent years, scaffolds made of various materials have been developed and evaluated. Functionally effective scaffolds require excellent cell affinity, chemical properties, mechanical properties, and safety. Carbon nanotubes (CNTs) are fibrous nanoparticles with a nano-size diameter and have excellent strength and chemical stability. In the industrial field, they are used as fillers to improve the performance of materials. Because of their excellent physicochemical properties, CNTs are studied for their promising clinical applications as biomaterials. In this review article, we focused on the results of our research on CNT scaffolds for bone regeneration, introduced the promising properties of scaffolds for bone regeneration, and described the potential of CNT scaffolds.ArticleNANOMATERIALS. 10(4):659 (2020)journal articl

    Physico-Chemical, In Vitro, and In Vivo Evaluation of a 3D Unidirectional Porous Hydroxyapatite Scaffold for Bone Regeneration

    Get PDF
    The unidirectional porous hydroxyapatite HAp (UDPHAp) is a scaffold with continuous communicated pore structure in the axial direction. We evaluated and compared the ability of the UDPHAp as a three-dimensional (3D) bone tissue engineering scaffold to the interconnected calcium porous HAp ceramic (IP-CHA). To achieve this, we evaluated in vitro the compressive strength, controlled rhBMP-2 release behavior, adherent cell morphology, cell adhesion manner, and cell attachment of UDPHAp. As a further in vivo experiment, UDPHAp and IP-CHA with rhBMP-2 were transplanted into mouse calvarial defects to evaluate their bone-forming ability. The Results demonstrated that the maximum compressive strengths of the UDPHAp was 7.89 +/- 1.23 MPa and higher than that of IP-CHA (1.92 +/- 0.53 MPa) (p = 0.0039). However, the breaking energies were similar (8.99 +/- 2.72 vs. 13.95 +/- 5.69 mJ, p = 0.055). The UDPHAp released rhBMP-2 more gradually in vivo. Cells on the UDPHAp adhered tightly to the surface, which had grown deeply into the scaffolds. A significant increase in cell number on the UDPHAp was observed compared to the IP-CHA on day 8 (102,479 +/- 34,391 vs. 32,372 +/- 29,061 estimated cells per scaffold, p = 0.0495). In a mouse calvarial defect model, the percentages of new bone area (mature bone + trabecular bone) in the 2x field were 2.514% +/- 1.224% for the IP-CHA group and 7.045% +/- 2.055% for the UDPHAp group, and the percentage was significantly higher in the UDPHAp group (p = 0.0209). While maintaining the same strength as the IP-CHA, the UDPHAp with 84% porosity showed a high cell number, high cell invasiveness, and excellent bone formation. We believe the UDPHAp is an excellent material that can be applied to bone regenerative medicine.ArticleMATERIALS. 10(1):33 (2017)journal articl

    Interactive Learning Environment for Posing 1-step Multiplication Word Problem and Its Experimental Use

    Get PDF
    筆者らはこれまでに,1 回の加減で解決できる算数文章題を対象として,三文構成モデルによる作問学習支援システムを開発している.本研究では,システムを小学校2年生で学習する乗算の領域へと拡張するものであり,システムの拡張から1クラス9時限の実践利用までを行ったので,報告する.結果としては,システムを利用することで問題解決能力はあっても,構造の理解が浅い学習者に対して,構造理解を深められることを示唆する結果が得られた

    Anti-PD-1 antibody decreases tumour-infiltrating regulatory T cells

    Get PDF
    Background There are many types of therapies for cancer. In these days, immunotherapies, especially immune checkpoint inhibitors, are focused on. Though many types of immune checkpoint inhibitors are there, the difference of effect and its mechanism are unclear. Some reports suggest the response rate of anti-PD-1 antibody is superior to that of anti-PD-L1 antibody and could potentially produce different mechanisms of action. On the other hand, Treg also express PD-1; however, their relationship remains unclear. Methods In this study, we used osteosarcoma cell lines in vitro and osteosarcoma mouse model in vivo. In vitro, we analyzed the effect of IFN gamma for expression of PD-L1 on the surface of cell lines by flowcytometry. In vivo, murine osteosarcoma cell line LM8 was subcutaneously transplanted into the dorsum of mice. Mouse anti-PD-1 antibody was intraperitoneally administered. we analysed the effect for survival of anti-PD-1 antibody and proportion of T cells in the tumour by flowcytometry. Results We discovered that IFN gamma increased PD-L1 expression on the surface of osteosarcoma cell lines. In assessing the relationship between anti-PD-1 antibody and Treg, we discovered the administration of anti-PD-1 antibody suppresses increases in tumour volume and prolongs overall survival time. In the tumour microenvironment, we found that the administration of anti-PD-1 antibody decreased Treg within the tumour and increased tumour-infiltrating lymphocytes. Conclusions Here we clarify for the first time an additional mechanism of anti-tumour effect-as exerted by anti-PD-1 antibody decreasing Treg- we anticipate that our findings will lead to the development of new methods for cancer treatment.ArticleBMC CANCER. 20(1):25 (2020)journal articl

    Self-Expandable Metal Stent Placement as a Bridge to Laparoscopic or Open Surgery for Obstructive Colorectal Cancer: Short-Term Outcomes of Nineteen Consecutive Cases

    Get PDF
    Purpose Laparoscopic colorectal resection is a feasible and less invasive procedure with short-term advantages compared with open surgery; however, the evidence for its efficacy for treating obstructive colorectal cancer (CRC) is lacking. In this study, we aimed to determine short-term outcomes of SEMS placement for obstructive CRC followed by laparoscopic colorectal resection.Methods As of August 2013, 51 patients with obstructive CRC underwent stent insertion. Thirty-two patients received palliation therapy not intended for tumor resection. After decompression of the proximal intestine, nine and 10 patients underwent laparoscopic and open surgery, respectively. Clinicopathological, intraoperative, and postoperative data were retrospectively collected.Results There were no differences in resection rates and curabilities between the two groups. All surgeries were performed with a single-stage anastomosis, and no anastomotic leakage was observed. There was one patient with abdominal morbidity in the open group (Open) and none in the Lap group. There was no mortality in either group. Time to flatus (3.4 ± 1.8 days, Lap; 2.6 ± 1.1 days, Open) and time to oral intake (7.9 ± 2.5 days, Lap; 7.7±1.9 days, Open) were similar between the groups. Postoperative hospitalization times for the Lap group were shorter, but the difference was not statistically significant (15.2 ± 3.9 days, Lap; 21 ± 11.7 days, Open, p = 0.21).Conclusion Our findings indicate that laparoscopic surgery combined with preoperative stent placement is feasible as well as safe compared with open surgery for obstructive CRC

    Organ accumulation and carcinogenicity of highly dispersed multi-walled carbon nanotubes administered intravenously in transgenic rasH2 mice

    Get PDF
    Purpose: Multiwalled carbon nanotubes (MWCNTs) have been known to enter the circulatory system via the lungs from inhalation exposure; however, its carcinogenicity and subsequent accumulation in other organs have not been adequately reported in the literature. Moreover, the safety of MWCNTs as a biomaterial has remained a matter of debate, particularly when the material enters the circulatory system. To address these problems, we used carcinogenic rasH2 transgenic mice to intravenously administer highly dispersed MWCNTs and to evaluate their carcinogenicity and accumulation in the organs. Methods: Two types of MWCNTs (thin-and thick-MWCNTs) were intravenously administered at a high dose (approximately 0.7 mg per kg body weight) and low dose (approximately 0.07 mg per kg body weight). Results: MWCNTs showed pancreatic accumulation in 3.2% of mice administered with MWCNTs, but there was no accumulation in other organs. In addition, there was no significant difference in the incidence of tumor among the four MWCNTs-administered groups compared to the vehicle group without MWCNTs administration. Blood tests revealed elevated levels in mean red blood cell volume and mean red blood cell hemoglobin level for the MWCNTs-administered group, in addition to an increase in eotaxin. Conclusion: The present study demonstrated that the use of current technology to sufficiently disperse MWCNTs resulted in minimal organ accumulation with no evidence of carcinogenicity.ArticleINTERNATIONAL JOURNAL OF NANOMEDICINE. 14:6465-6480 (2019)journal articl
    corecore