Papers by Author: Jin Iida

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Authors: Yasuhito Tanaka, Yoshinori Takakura, K. Kadono, Akira Taniguchi, K. Hayashi, Jin Iida, Koh Ichi Sugimoto, Yasuaki Tohma, Hajime Ohgushi
805
Authors: Jin Iida, Takafumi Yoshikawa, Y. Ueda, Hajime Ohgushi, Toshimasa Uemura, Y. Enomoto, Kunio Ichijima, Yoshinori Takakura, Tetsuya Tateishi
499
Authors: Kazuhide Miyazaki, Takafumi Yoshikawa, Jin Iida, Y. Ueda, M. Koizumi, N. Satoh, Hideki Shigematsu, Y. Dohi, Hajime Ohgushi, Yoshinori Takakura
Abstract: Introduction: Marrow mesenchymal cells contain stem cells and can regenerate tissues. We previously reported the clinical application of autologous cultured bone to regeneration therapy. However, in cases with low numbers of active cells, culture is often unsatisfactory. If frozen marrow cells retain their osteogenic potential, we could clinically use them in regeneration therapy as alternatives to high active cells obtained from youngsters. Here, we examined osteogenic potential of frozen human mesenchymal stem cells in combination with recombinant human bone morphogenetic protein (rhBMP) using biochemical and histological analyses. Method: Marrow fluid was aspirated from the human iliac bone of a 46-year-old man with lumbar canal stenosis during surgery. Two weeks after primary culture in standard medium, bone marrow mesenchymal stem cells (BMSCs) were trypsinized for the preparation of a cell suspension, and cells were concentrated to 106 cells/ml by centrifugation. Cells were kept at – 80 °C until use. To impregnate porous hydroxyapatite (HA) with rhBMP, 1 3g rhBMP/20 3l 0.1 % trifluoroacetic acid was applied on HA, and then desiccated under vacuum. In the present study, we used 4 subgroups: BMSC/rhBMP/HA, BMSC/HA, rhBMP/HA, and HA only. HA constructs from the 4 subgroups were implanted at subcutaneous sites on the back of 5-week-old nude mice (BALB/cA Jcl-nu). Eight weeks after implantation, implanted HA constructs were harvested, and biochemical and histological analyses were performed. Alkaline phosphatase activity (ALP) and human osteocalcin (hOs) levels were measured. Results and Discussion: ALP activity and hOs in the BMSC/BMP/HA subgroup were 2 or 3 times that in the BMSC/HA subgroup. Histological analysis showed that significant bone formation was observed in these two subgroups, and supported biochemical data. However, in the BMP/HA and HA only subgroups, significant bone formation could not be detected histologically nor biochemically. These results indicated that a combination of rhBMP and BMSCs, and only with a minimal amount of 1 3g rhBMP, allowed successful generation of human bone. In the human body, rhBMP in the order of milligrams is necessary for bone formation. However, by combining BMSCs, HA and rhBMP, only a small amount of rhBMP was needed to dramatically enhance osteogenic potential. As we reported here, cryopreserved BMSCs also showed high osteoblastic activity. In conclusion, this study provided histological and biochemical evidence that combination of cryopreserved BMSCs, BMP, and porous HA could enhance osteogenic potential.
1009
Authors: Takafumi Yoshikawa, Tetsuji Ohmura, Yasunori Sen, Jin Iida, Yoshinori Takakura, Iehisa Nonaka, Kunio Ichijima
383
Authors: Takafumi Yoshikawa, Y. Ueda, Takahito Ohmura, Yasunori Sen, Jin Iida, M. Koizumi, K. Kawate, Yoshinori Takakura, Akitaka Nonomura
1075
Authors: Kazuhide Miyazaki, Takafumi Yoshikawa, Koji Hattori, Noriko Okumura, Jin Iida, Yoshinori Takakura
1067
Authors: N. Satoh, Takafumi Yoshikawa, A. Muneyasu, Jin Iida, Akitaka Nonomura, Yoshinori Takakura
745
Authors: Noriko Okumura, Takafumi Yoshikawa, Jin Iida, Akitaka Nonomura, Yoshinori Takakura
Abstract: The effect of genistein, a soybean isoflavone, on new bone formation by bone marrow cells from mature humans was examined. After informed consent was obtained from a 55-year-old woman with osteoporosis and lumbar spondylosis deformans,bone marrow cells were collected from her ilium, cultured in the standard medium of MEM containing fetal calf serum and then cultured with or without the addition of genistein to the bone-forming medium containing dexamethasone etc.. In humans, when genistein was added to the bone-forming medium, genistein (10-7 M and 10-8 M)caused a significant increase in the levels of alkaline phosphatase avtivity and DNA content compared with cells not cultured in genistein. In conclusion,genistein was found to promote bone formation at lower concentrations,and thus may be useful as a bone formation-promoting factor.
667
Authors: Noriko Okumura, Takafumi Yoshikawa, Jin Iida, Akitaka Nonomura, Yoshinori Takakura
1071
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