229 research outputs found

    Development and verification of control system for heat recovery ground source heat pump system

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    An operation method and control system for heat recovery ground source heat pump (HR-GSHP) systems have been developed. By applying the operation method and control system, the heating and cooling output from the respective GSHP units can be controlled according to the operational condition. This maximizes the energy saving effect by operating the GSHP units without excess temperature change of the heat carrier fluid. In this paper, the outlines of HR-GSHP system and the importance of control system for the HR-GSHP systems were firstly explained. Next, the control system's configuration and the control methodology were explained. In addition, the operation of a HR-GSHP system with the control system, in which the control methodology had been installed, was verified by using the field test apparatus. As the result, it was confirmed that the above control methodologies were applicable

    A study on ensuring the quality and safety of pharmaceuticals and medical devices derived from processing of autologous human induced pluripotent stem(-like) cells

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    As a series of endeavors to establish suitable measures for the sound development of regenerative medicine using human stem cell-based products, we studied scientific principles, concepts, and basic technical elements to ensure the quality and safety of therapeutic products derived from autologous human iPS cells or iPS cell-like cells, taking into consideration scientific and technological advances, ethics, regulatory rationale, and international trends in human stem cell-derived products. This led to the development of the Japanese official Notification No. 0907-4, “Guideline on Ensuring the Quality and Safety of Pharmaceuticals and Medical Devices Derived from the Processing of Autologous Human Induced Pluripotent Stem(-Like) Cells, ” issued by Pharmaceuticals and Food Safety Bureau, Ministry of Health, Labour and Welfare of Japan, on September 7, 2012. The present paper addresses various aspects of products derived from autologous human iPS cells (or iPS cell-like cells), in addition to similar points to consider that are described previously for autologous human stem cell-based products. Major additional points include (1) possible existence of autologous human iPS cell-like cells that are different from iPS cells in terms of specific biological features; (2) the use of autologous human iPS(-like) cells as appropriate starting materials for regenerative medicine, where necessary and significant; (3) establishment of autologous human iPS(-like) cell lines and their characterization; (4) cell banking and/or possible establishment of intermediate cell lines derived from autologous human iPS(-like) cells at appropriate stage(s) of a manufacturing process, if necessary; and (5) concerns about the presence of undifferentiated cells in the final product; such cells may cause ectopic tissue formation and/or tumorigenesis. The ultimate goal of this guidance is to provide suitable medical opportunities as soon as possible to the patients with severe diseases that are difficult to treat with conventional modalities

    Induction of Expandable Tissue-Specific Progenitor Cells from Human Pancreatic Tissue through Transient Expression of Defined Factors

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    We recently demonstrated the generation of mouse induced tissue-specific stem (iTS) cells through transient overexpression of reprogramming factors combined with tissue-specific selection. Here we induced expandable tissue-specific progenitor (iTP) cells from human pancreatic tissue through transient expression of genes encoding the reprogramming factors OCT4 (octamer-binding transcription factor 4), p53 small hairpin RNA (shRNA), SOX2 (sex-determining region Y-box 2), KLF4 (Kruppel-like factor 4), L-MYC, and LIN28. Transfection of episomal plasmid vectors into human pancreatic tissue efficiently generated iTP cells expressing genetic markers of endoderm and pancreatic progenitors. The iTP cells differentiated into insulin-producing cells more efficiently than human induced pluripotent stem cells (iPSCs). iTP cells continued to proliferate faster than pancreatic tissue cells until days 100–120 (passages 15–20). iTP cells subcutaneously inoculated into immunodeficient mice did not form teratomas. Genomic bisulfite nucleotide sequence analysis demonstrated that the OCT4 and NANOG promoters remained partially methylated in iTP cells. We compared the global gene expression profiles of iPSCs, iTP cells, and pancreatic cells (islets >80%). Microarray analyses revealed that the gene expression profiles of iTP cells were similar, but not identical, to those of iPSCs but different from those of pancreatic cells. The generation of human iTP cells may have important implications for the clinical application of stem/progenitor cells
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