Three-dimensional structural studies of bone tissues by ion-etching-scanning electron microscopy.

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Three studies were performed in this research project; (1) Three-dimensional structures of the bone tissues of fumerus and alveolar bone and periodontium of mandible of rats were studied with the resin section-ion etching (IE)-scanning electron microscopy (SEM) and energy filter (EF) transmission electron microscope (TEM)-TEM tomography. (2) Immuno histo and cyto-chemistry of rat salivary glands including parotid and von Ebner's gland was performed by using IE-SEM method. (3) Stem cell factors on cultured bone marrow cells which were harvested from mouse tibiae were also examined.In IE-SEM studies, it was suggested that the structure of inner circumferential lamellae was clear, bat arrangement of some collagen fibrils were parallel, some oblique or some crossing as well as osteocytes. On the other hand, in alveolar bone, lamellar structure was absent, and osteocyte arrangement were irregular. In FETEM-TEM tomography study, lamellar structure were clearly observed in the semi-thin secti … More ons of the inner circumferential lamellae in fumerus, but not observed in the alveolar bone. Complicated arrangement of collagen fibrils were alse observed in the semi-thin sections of the periodontium.The ability to apply both light and scanning electron microscopy to immunostained specimens was examined with rat salivary gland. Immunoscanning electron micrographs of the sections which were immunohistochemically stained with anti-amylase and immunogold in association with silver enhancement techniques showed that secretory granules in the secretory terminal portion and intercalated duct cell of the rat parotid gland were immunoreaction positive.In bone marrow microenvironment, various cells are expected to interact each other revulating their functions through mediators and cell-contact Then, the effect of TGF-β1, bFGF, TNF-α, IL-4, and LIF on the stem cell factor (SCF) splice variants expression of bone marrow cells were studied by using flow cytometry and quantitative RT-PCR. Flow cytometry analysis demonstrated that the number of cells expressing membrane-bound SCF increased when the cells were treated with TGF-β1 or bFGF. Quantitative RT-PCR analysis demonstrated that TGF-β 1 recuced both SCF-1 and SCF-2 mRNAs synthesis in a dose dependent manner These results suggest that expressions of stem cell factor splice variants in mouse bone marrow cells were regulated individually under co-stimulation of TGF-β1, bFGF, TNF-α, IL-4, and LIF. Less