Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0568
    Keywords: Key words Alpha-smooth muscle actin ; Calponin ; Keratin ; S-100 protein ; Vimentin ; Glial fibrillary acidic protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Using a battery of monoclonal antibodies specific for rat proteins, immunohistochemistry was carried out on the developing myoepithelial cells (MECs) of the rat major salivary glands. The proteins examined were α-smooth muscle actin (αSMA), h1-calponin (calponin), keratin 14 (K14), β subunit of S-100 protein (S-100β), vimentin and glial fibrillary acidic protein (GFAP). The MECs exhibited immunoreactivity for αSMA, calponin and K14, but not that for S-100β, vimentin and GFAP. Immunoreactivity for αSMA appeared in the MECs from the time when the microfilaments were initially deposited in these cells, i.e., at 20 days in utero in the sublingual and submandibular glands and at birth in the parotid gland. Calponin immunoreactivity was seen 1 day earlier than αSMA. The appearance was almost at the same time as the onset of the MEC differentiation in each gland. A small number of the MECs expressed weak K14 immunoreactivity from the time when the acinus-intercalated duct structure was established, i.e., at 21 days in utero in the sublingual gland, at 5 days after birth in the perotid gland and after 5 weeks post-natally in the submandibular gland. In addition, K14 immunoreactivity was observed in the basal cells of the striated and excretory ducts. The first appearance of K14 in these cells again coincided with the emergence of the duct system in each gland, i.e., at 20 days in utero in the sublingual gland, at 21 days in utero in the submandibular gland and at 3 days after birth in the parotid gland. Finally, the MECs in all the glands were found to redistribute as the acini matured. As the acini grew rapidly during the weaning period in the parotid and the sublingual glands, the MECs ceased to surround the acini. Thereafter, they disappeared from the acini in the parotid gland, whereas they reappeared in the sublingual gland. In the submandibular gland, the MECs were confined to the terminal tubules until 4 weeks after birth. Thereafter, the acini were established and invested by the MECs. In conclusion, immunohistochemistry of calponin and αSMA is a useful tool for identification of the MEC during its earliest differentiation, which has hitherto been possible only electron microscopically. In addition, it is suggested that the MEC is heterogeneous and the functionally differentiated MEC appears after weaning around acini of the mucous and seromucous glands.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2307
    Keywords: Key words Salivary gland tumor ; Keratin ; Alpha- smooth muscle actin ; Calponin ; Caldesmon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Our recent study of developing myoepithelial cells (MECs) in rat salivary glands demonstrated that developing MECs begin to express α-smooth muscle actin (αSMA) first and, thereafter, keratin 14. Therefore, it is unlikely that duct basal cells expressing keratin 14 alone are immature or undifferentiated MECs. In this study we carried out immunohistochemistry of pleomorphic adenomas and adenoid cystic carcinomas including normal salivary glands using monoclonal antibodies to keratin 14, smooth muscle proteins and keratin 19. The smooth muscle proteins examined included αSMA, h-caldesmon and h1-calponin; h1-calponin was observed in keratinocytes and nerve fibers, indicating that the protein is not specific to smooth muscle, whereas αSMA and h-caldesmon turned out to be highly specific markers for smooth muscle cells in normal tissues. In normal glands, MECs were positive for both keratin 14 and smooth muscle proteins (αSMA and h-caldesmon). Non-MEC cells were essentially devoid of smooth muscle proteins. Non-MEC duct basal cells expressed keratin 14 with or without keratin 19, and luminal cells keratin 19 with or without keratin 14. This suggests that the keratin 14-positive, smooth muscle proteins-negative duct basal cells are luminal cell progenitors. Luminal cells in tubular structures of both tumors were positive for keratin 19 with or without keratin 14. Nonluminal peripheral cells of pleomorphic adenomas were mostly positive for keratin 14, and a small fraction of them expressed smooth muscle proteins. Conversely, peripheral cells of adenoid cystic carcinomas were mostly positive for smooth muscle proteins, and some of them expressed keratin 14. These results strongly suggest (1) that the luminal cell progenitors transform into major constituents of pleomorphic adenoma cells with keratin 14 but not smooth muscle proteins, and (2) that the peripheral cells of adenoid cystic carcinoma are derived from undifferentiated MECs. Solid structures of pleomorphic adenomas were formed by proliferation of the peripheral cells. MECs were observed only occasionally in the periphery. Solid and cribriform structures of adenoid cystic carcinomas were formed by proliferation of the luminal cells. MECs were observed in the periphery and around the pseudocyst.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...