Browsing by Subject "Elastic fibres"

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    Electron microscopic observations of elastic fibres in the lung and aorta of tight-skin and beta-aminopropionitrile-fed mice
    (Murcia : F. Hernández, 1992) Masumi Akita; Seong Ho Lee; Katsuji Kaneko
    The lung of the tight-skin (TSK) mouse was characterized by enlargement of the air spaces. Elastin in the alveolar walls of the TSK mouse exhibited fragmentation. The aorta of the TSK mouse was characterized by marked hyperplasia of loose connective tissue in the adventitia. Collagen fibres and ruthenium red-positive materials were markedly increased. Microfibrils surrounding elastin in the adventitia of the aorta were not clear in the TSK mouse. In the lung of the beta-aminopropionitrile (BAPN)-fed mouse. enlargement of the alveolar air spaces was not prominent compared with the TSK mouse. Elastic fibres in the alveolar walls did not show the fragmentation observed in the TSK mouse, and microfibrils surrounding elastin were clearly observed. However. elastic laminae in the media of the BAPNfed mouse aorta were swollen and fragmented. Elastic fibres in the adventitia exhibited a normal appearance and microfibrils surrounding elastin in the adventitia were clearly observed. The results suggest that the mechanism of the connective tissue abnormality in the TSK mouse is different from that of BAPN. which inhibits the activity of lysyl oxidase. The abnormality of elastin and microfibrils surrounding elastin in the TSK mouse probably plays a role in the deformity or degradation of elastic fibres and the structural changes of the lung.
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    Electron microscopic observations on the formation of elastic fibres in cultures of aortic medial cells and adventitial cells
    (Murcia : F. Hernández, 1988) Masumi Akita; Katsuji Kaneko; Merker, H. J.
    The formation of elastic fibres was observed in the cultured cells derived from the tunica media and the tunica adventitia of mouse aorta. Bundles of myofilaments with dense bodies were abundantly observed in the cytoplasm of the cultured media1 cells, and numerous bundles of microfibrillar components were present in the intercellular spaces. Fine granules of approximately 50 nm in diameter were observed in the bundles of microfibrillar components. lt was supposed that these fine granules of elastin fused with each other and formed elastic aggregates and then formed large elastic clumps. Numerous bundles of microfibrillar components were also present in the intercellular spaces of the cultured adventitial cells. Elastic aggregates were scarcely observed in the bundles of microfibrillar components. However, large elastic clumps as observed in the media1 cell culture could not be found in the adventitial cell culture. It is suggested that the formation of large elastic clumps might be related to the sheet structures or lamellae of elastic fibres in the tunica media.
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    Presence of perivenular elastic fibers in nonalcoholic steatohepatitis Fibrosis Stage III
    (Murcia : F. Hernández, 2008) Nakayama, Hirofumi; Itoh, Hiroyuki; Kunita, Satoko; Kuroda, Naoto; Hiroi, Makoto; Matsuura, Hideo; Yasui, Wataru; Enzan, H.
    Elastic fibers appear in extensive old fibrotic foci in general. We examined an association between hepatic fibrosis stage and the presence of perivenular elastic fibers in nonalcoholic steatohepatitis (NASH). A total of 48 liver needle biopsy specimens were used, taken from 48 cases with NASH. Fibrosis Stage (Brunt E, et al. Am. J. Gastroenterol. 1999) of the cases was as follows; six Fibrosis Stage I, twenty-two Fibrosis Stage II, and twenty Fibrosis Stage III. We examined Orcein stain sections in all of the liver needle biopsy specimens. In all twenty Fibrosis Stage III cases, perivenular elastic fiber bundles were observed. In contrast, perivenular elastic fibers were detected only in one of the six Fibrosis Stage I and two of the twenty-two Fibrosis Stage II cases. In liver needle biopsy specimens of NASH, detection of perivenular elastic fibers is useful in deciding Fibrosis Stage III.