| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1985: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
The development of the oral vestibule were observed with light and electron microscopes. Three-dimensional aspects of the rat lip-furrow band obtained with the figurers drown from serial sections of mandibular parts by means of using cosmosone (Nikkon) for image analyser. Examined by light microscope, concurrently with the incisor dental lamina develops, the lip-furrow band forms independently, external to the dental laminas of left and right mandibularparts. Granular substances stained intensely with hematoxilen are clearly observed in the area of central of lip-furrow band on the 17th day of gestation. Subsequently, in those area, undifferential epithelial cells change into light, large and differentiated cells. Later, there are numerous keratohyalin granules in those areas symmetrically. Consequently, keratinized cells take the place of these cells. Finally, these central areas split and thereby the lip becomes separated from the gingiva and jaw. Examined by electron microscopy, varying in form and higher elecron density were nymerously scattered in or between the normal epithelial cells of the areas where the granular substance were observed by light microscopy. They were lost cell junction with neighbouring cells the cytoplasm became condensed and pyknotic nucleus. The split into serveral fragment, in which vacuoles, dilated cisteinae of rough endoplasmic reticulum, mitochondrial changes (swelling, lysis of cristae), dense bodies of irregular shapes were observed. They sere the characteristic feature of the apoptotic bodies. Finally, they were phagocytosed by neighbouring normal epithelial cells. It is assumed that there are relationship between the apoptosis and the cell differentiation.
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