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Query: UMLS:C0276640 (TEM)
 20,729 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mammary adenocarcinomas from C3H/HeJ mice carrying the mammary tumor virus were studied by means of light, transmission, and scanning electron microscopy. The histological appearance of the tumors was variable; however, 60% were classified as type B adenocarcinomas, while 20% were type A and 20% were composed of equal regions characteristic of both types. Four populations of tumor cells were observed with the TEM. The most abundant of these, primitive glandular cells, were characterized by large, regular, euchromatic nuclei and cytoplasm containing numerous free ribosomes, little rough endoplasmic reticulum, few mitochondria, small Golgi complex and a variable number of type A virus particles. Specialized glandular cells contained highly pleomorphic nuclei, many lysosomes, lipid droplets, multivesicular bodies, profiles of rough endoplasmic reticulum and granules resembling secretory proteins. Myoepithelial cells and dark glandular cells with abundant organelles, large Golgi complexes, dense cytoplasmic matrix and very heterochromatic nuclei were observed infrequently. The SEM revealed tumor cells to be variable in size, shape and surface characteristics. Most cells were rough in texture, displaying irregular ridges, small blebs and a few short microvilli. The contours of some cells were smooth, and a few cells had short, irregular microvilli on limited regions of their surfaces. Cells lining ducts within the tumor had microvilli on their apical surface, but the number, size, shape and distribution of microvilli varied considerably. Cells lining ducts from non-tumor-bearing animals displayed less variation in size, shape and surface morphology.
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PMID:Fine structure analysis and surface characteristics of mouse mammary gland adenocarcinomas. 633 Aug 78

The rat parotid gland parenchyma consists of four principal components: acini, intercalated ducts, striated ducts, and excretory ducts. Secretory acini are mostly of ellipsoidal to polygonal shapes, exceptionally of typically globular shape. The shape and the size of acini are in a close relation to their localization within the glandular parenchyma. The average acinar size is approximately equal to 35 microns. The structure of the ductal three corresponds with the known description but the surface of the individual segments (especially of striated and excretory ducts) shows some features that are impossible to be discovered when observed with TEM but that are clear by visible when observed with S.E.M. Myoepithelial cells have a typical asteroid shape. The observations with S.E.M. have shown that they overlap with their processes from one acinar cell to another one, or they radiate also over the adjacent intercalated duct.
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PMID:The S.E.M. study of rat parotid gland parenchyma. 664 78

To demonstrate by SEM the topography and cytoarchitecture of the different parenchymal components of human salivary glands, we have employed a number of techniques that allow either the exposure of internal and lateral cell surfaces or, following the removal of connective tissue, the visualization of endpieces, ducts, and myoepithelial cells. Serous glands consist of indented acini attached to the ducts in a grape-like fashion, whereas mucous and mixed glands are made up of smooth tubuli. Myoepithelial cells (mecs), which are abundant on the surfaces of acini, tubuli, and intercalated ducts, are sparse on striated ducts. They are star-shaped on acini, striated ducts, and most of the tubuli. Spindle-shaped mecs are seen, instead, on intercalated ducts and, occasionally, on mucous and mixed tubuli as well. Cells of striated ducts split into a number of large basal portions whose surface is covered by long laminated processes responsible for the striations seen with TEM. Excretory ducts are lined by small cup-shaped basal cells and by tall cylindrical cells, which are completely covered by short processes oriented at random. When observed from below, after removal of the basal lamina, the basal surfaces of cells of excretory ducts exhibit polygonal areas delimited by short reliefs. Those of striated ducts show, instead, long laminar processes arranged radially. Results presented here are discussed and put in relationship to the mechanism of saliva production.
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PMID:3D-structure of cells of human salivary glands as seen by SEM. 821 74