Chuichiro Hayashi

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We introduce the notions of Heegaard splittings and thin multiple Heegaard splittings of 1-submanifolds in compact orientable 3-manifolds, which are generalizations of those of bridge decompositions and thin positions. We show that either a thin multiple Heegaard splitting of 1-submanifold T is also a Heegaard splitting with minimal complexity or the(More)
Both connective tissue mast cells and mast cells grown in vitro are derived from multipotential hematopoietic stem cells, but these two mast cell populations exhibit many differences in morphology, biochemistry, and function. We investigated whether the phenotype of cultured mast cells or their progeny was altered when the cells were transferred into(More)
Concentration of mast-cell precursors in hematopoietic tissues of mouse embryos was evaluated by a limiting dilution method. Cells from yolk sacs, livers, and bodies of (WB x C57BL/6)F1 (hereafter called WBB6F1)- +/+ embryos were injected directly into the skin of adult WBB6F1-W/Wv mice which were genetically depleted of tissue mast cells. Concentration of(More)
How many Reidemeister moves do we need for unknotting a given diagram of the trivial knot? Hass and Lagarias gave an upper bound. We give an upper bound for deforming a diagram of a split link to be disconnected. On the other hand, the absolute value of the writhe gives a lower bound of the number of Reidemeister I moves for unknotting. That of a complexity(More)
Mice of mutant genotypes were used to investigate the differentiation process of connective tissue mast cells. Mast cell precursors, which are a progeny of the multipotential hematopoietic stem cell, leave the bone marrow, migrate in the bloodstream and enter into connective tissues where they proliferate and differentiate into mast cells. A portion of(More)
Concentration of mast-cell precursors in the skin and liver of mouse embryos was evaluated by the limiting dilution analysis. The concentration of mast-cell precursors in the liver of (WB X C57BL/6)F1 (hereafter WBB6F1)-+/+ embryos reached the maximum level at Day 15 of the pregnancy, whereas the concentration in the skin at Day 17. The concentration of(More)
From *The Institute for Cancer Research and the Departments of*Pharmacology, §Internal Medicine, and 1Dermatology, Osaka University Medical School, Osaka 530, Japan; the IShizuoka Laboratory Animal Center, Hamamatsu 435, Japan; and the **Department of Pathology, Beth Israel Hospital and Harvard Medical School, and the Charles A. Dana Research Institute,(More)
Presence of mast cell precursors in the mouse peritoneal cavity was demonstrated, and the precursors were characterized. When a cell suspension, containing mast cell precursor(s), was directly injected into the skin of genetically mast cell-deficient WBB6F1 (WB X C57BL/6)-W/Wv mice, a cluster composed of approximately 2,000 mast cells appeared at the(More)