Seiji Otsuka

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The precise biological characteristics of human mesenchymal stem cells (hMSCs), including growth regulatory mechanisms, have not yet been defined. Using 29 strains of hMSCs isolated from bone marrow, we have performed extensive analyses of the growth profiles of hMSCs in vitro. All 29 strains stopped proliferating with a mean population doubling (PD) of 28,(More)
Bone marrow stromal cells (BMSCs) are a mixture of cells differing in differentiation potential including mesenchymal stem cells, and so far no CD antigens were found to be predictable for the differentiation property of each BMSC. Here we attempted to isolate differentiation-associated CD antigens using 100 immortalized human BMSC (ihBMSC) clones. Among 13(More)
The two subunit types of human liver ferritin were purified to homogeneity. Both subunits reassembled in a well-defined manner and formed spherical particles that resembled natural apoferritin in electron micrographs. Affinity chromatography methods were employed to obtain preparations of antibodies that interacted exclusively either with the H or with the(More)
Synovial sarcoma, a soft tissue sarcoma that develops in adults, is pathologically subclassified into monophasic spindle synovial sarcoma and biphasic synovial sarcoma with epithelial components. The molecular mechanism building the epithelial components in biphasic synovial sarcoma is totally unknown. Here we investigated claudins, critical molecules in(More)
STUDY DESIGN Case report. OBJECTIVE To report on a pregnant woman successfully treated with microendoscopic discectomy in the left lateral position under general anesthesia at 24-week gestation. SUMMARY OF BACKGROUND DATA Treatment for lumbar disc herniation in pregnant women poses a particular challenge due to the complexity of the clinical situation.(More)
Mammalian ferritins can be resolved into multiple components by isoelectric focusing, and each tissue contains a characteristic subset of isoferritins. Ferritin isolated from human liver was compared to acidic ferritin isolated from mid-gestational human placenta to define a structural basis for ferritin heterogeneity. Placenta ferritin contained several(More)
Tissue stem cells may serve as progenitors for malignant tumors derived from the same tissue. Here, we report the establishment of immortalized human mesenchymal stem cells (ihMSC) and tested the feasibility of using ihMSC as presarcomatous cells. Immortalization was achieved by introducing the genes for human telomerase reverse transcriptase and Bmi1.(More)
We evaluated the ability of canine bone marrow stromal cells (cBMSCs) to regenerate bone in a cavity of the scapholunate created by curretage and freeze-thawing with liquid nitrogen (LN). Autologous BMSCs were harvested from the iliac crest and expanded in vitro. Their potential to differentiate into osteo-, chondro-, and adipogenic lineages was confirmed(More)
Bone marrow stromal cells (BMSCs) include cells with multidirectional differentiation potential described as mesenchymal stem cells. For clinical use, it is important to develop a way to isolate BMSCs from bone marrow in a closed system without centrifugation. After screening 200 biomaterials, we developed a device containing a nonwoven fabric filter(More)
The expression of the chondromodulin-I (ChM-I) gene, a cartilage-specific gene, is regulated by the binding of Sp3 to the core promoter region, which is inhibited by the methylation of CpG in the target genome in the osteogenic lineage, osteosarcoma (OS) cells. The histone tails associated with the hypermethylated promoter region of the ChM-I gene were(More)