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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Four of the five kinds of cells constituting the walls of thyroid cysts can be identified in the SEM. These are cuboidal cells, mucous cells, cells with large granules and ciliated cells. A correlation between SEM and TEM observations is attempted.
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PMID:The luminal surface of thyroid cysts in SEM. 62 58

TEM, SEM and X-ray diffraction analysis demonstrate the heterogeneity of the dentinal tissue on Anarhichas lupus, a vascular osteodentine. The disordered aspect of collagen fibres, incompletely mineralized (the periodical striation being still visible), explains the scattered distribution of crystallites since they are responsible for their arrangement. The low degree of mineralization revealed by the visible collagen striation is confirmed by X-ray diffraction analysis (the crystallinity of vascular osteodentine being much lower than that of the peripheral dental tissue) as well as by high resolution TEM, since no lattice planes could be observed. Osteodentine, supporting bone and proper bone have in common a mineral phase, more or less organized, different from the apatite system.
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PMID:Osteodentine and vascular osteodentine of Anarhichas lupus (L.). 63 May 86

Scanning (SEM) and transmission (TEM) electron microscopic studies in the legumen of Phaseolus vulgaris var. nanus L. (kidney beans) were carried out. In this work emphasis was laid on the analysis of the morphological structure of the parenchyma tissue, being the chief component of the pod at edible maturity. The leaf character of the pod becomes especially evident by the occurence of stomata, trichomes, and typical cuticle structures on the outside of the pod (SEM). The cells of the mesophyll-like parenchyma tissue are distinguished by a great range of variation of their plastids (chloroplasts--chloroamyloplasts--amyloplasts) and some special cytological features such as a strongly developed rough ER, big nuclei, and numerous plasmodesmata (TEM).
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PMID:Electron microscopic studies in cultivated plants. I. Green pods of Phaseolus vulgaris var. nanus L. 63 61

Scanning (SEM) and transmission (TEM) electron microscopic studies in fresh and stored roots (4 months at an average temperature of +8 degrees C) of Daucus carota L. (carrots) were carried out. Chief stress was laid on the analysis of the histological and cytological structure of the secondary phloem parenchyma cell. SEM images show the three-dimensional histological arrangement of the cells. Moreover, the outlines of lipid droplets, mitochondria, starch grains, and carotin pigment crystals are visible within the parietal cytoplasmic layer. In TEM, besides the usual cell organelles (mitochondria, golgi-apparatus, ER, etc.) nuclei with several nuclear bodies can be recognised. The morphological structure of the chromoplasts shows a remarkable diversity. Within stored carrots a strong reduction of lipid droplets and starch grains within the chromoplasts takes place.
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PMID:Electron microscopic studies in cultivated plants. II. Fresh and stored roots of Daucus carota L. 63 62

Bundles of collagen fibrils, elastic fibres and fibroblasts are organized into a network that lies in the plane of a large portion of the bat wing. By ultrastructural (TEM and SEM) and biochemical analyses it was found that individual bundles of the net are similar to elastic ligaments. Although elastic fibres predominate, they are integrated and aligned in parallel with small bundles of collagen. A reticulum of fibroblasts, joined by focal junctions, forms a cellular framework throughout each bundle. Because of the unique features of the fibre bundles of the bat's wing, in particular their accessibility, and the parallel alignment of the collagen fibrils and elastic fibres in each easily isolatable fibre bundle, they should prove a most valuable model for connective tissue studies, particularly for the study of collagen-elastin interactions.
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PMID:A collagen and elastic network in the wing of the bat. 64

A supraependymal cluster of neuronal cells and processes consistently present on the floor of the hamster third ventricle was identified and characterized by means of correlative scanning (SEM) and transmission (TEM) electron microscopy. SEM revealed each cluster to be ovoid with the majority of its surface covered by dome-shaped protrusions and fine beaded fibers. A number of processes traveling individually or in groups also entered or exited from the cluster at its base. As these processes passed over the ventricular surface, they contributed to an extensive network on the floor and ventral aspect of the ventricular wall. Some processes terminated on the ependymal surface in bulbous endings while others penetrated the ependyma. The neuronal nature of these clusters and their associated processes was confirmed at the TEM level. The dome-shaped protrusions visible on the surface of the cluster in SEM corresponded to apical surfaces of neurons confined to the peripheral aspect of a core of loosely arranged processes. These cells exhibited a prominent nucleolus, stacks of rough endoplasmic reticulum (RER), polyribosomes, Golgi cisternae, mitochondria and microtubules (MT) and gave rise to dendritic processes which extended into the core. These dendrites gave off branches at acute angles and contained polyribosomes, single cisternae of RER and evenly spaced MT. Other profiles of processes within the core shared these characteristics, suggesting that they also were branches of the peripheral cells. Axons present within the core and on the cluster's surface exhibited vesicle-filled varicosities which frequently established synaptic contact with the peripheral cells and their processes. The presence of an intraventricular cluster of neurons which potentially communicates with centers extrinsic to the ventricle may have important implications in the hypothesized role of cerebrospinal fluid and tanycytic ependyma in the neuroendocrine regulation of anterior pituitary function.
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PMID:Electron microscopic demonstration of a supraependymal cluster of neuronal cells and processes in the hamster third ventricle. 64 88

The use of both SEM and TEM techniques in studying the alterations of the columnar ciliated epithelium of the whole respiratory tract of ferrets enables the authors to find a significant discrepancy between tracheal and nasal mucosa destructions. This discrepancy is not a function of the anatomical location of virus instillation. Theoretical and pratical meanings are discussed.
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PMID:Scanning and transmission electron microscopy study of ferret respiratory mucosa infected with influenza A virus. 67 15

An unusual example of the invasion of one tissue by another occurs during gastrulation in the chick embryo when the definitive endoblast becomes inserted into the hypoblast. The two tissues were examined morphologically by SEM and TEM. They resemble each other in being of an epithelial type, though neither possesses a basal lamina. The definitive endoblast cells are flatter than the hypoblast cells and more closely attached to one another. When they were explanted in hanging drop cultures, the two tissues were found to exhibit differences in their behaviour. In comparison with the definitive endoblast, the hypoblast cells attached more readily to the glass, produced larger ruffle membranes, moved more rapidly, showed poorer contact-inhibition of locomotion and showed a greater tendency to break away from the main explant. When a hypoblast explant was confronted with a definitive endoblast explant, the hypoblast cells became displaced by the definitive endoblast. The hypoblast explant tended to fragment into smaller groups of cells, many of which migrated around the definitive endoblast, thus mimicking the situation in vivo. Control experiments comprised confronting hypoblast with hypoblast, hypoblast with somites, definitive endoblast with definitive endoblast, and definitive endoblast with somites. The hypoblast explants behaved in a consistent manner, always fragmenting when coming into contact with cells from a confronting explant. The definitive endoblast explants showed more contact inhibition of locomotion when confronted with definitive endoblast or with somites than when confronted with hypoblast. It is suggested therefore that the ability of the hypoblast cells to separate from one another may play an important role in the penetration of the hypoblast by the definitive endoblast both in vitro and in vivo.
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PMID:In vivo and in vitro studies on the hypoblast and definitive endoblast of avian embryos. 70 30

The inner ears of 35 adult chickens were studied by TEM, SEM and light microscopy. Two well differentiated hair cell/nerve ending units were present: tall hair cells with small vesiculated nerve endings were located on the attached part of the basilar membrane; short hair cells with large vesiculated nerve endings were located on the free basilar membrane except for the distal tip. In this respect the chicken ear is similar to that of the pigeon. The chickens examined did have some unique features. Sensory cells of lenticular and hemispheric shape were also present at the proximal end. Bundles of long dense tubules were seen frequently within the sensory cell cytoplasm. Kinocilia were absent from the hair bundles of many of the sensory cells. The internal structure of the kinocilia which were present was atypical and consisted of a variable number of doublets. Eight peripheral plus one central doublet were found most frequently.
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PMID:Structure of the chicken's inner ear: SEM and TEM study. 70 16

The fine structure of rat gliomas induced transplacentally with a single i.p. dose of 50 mg/kg of Ethylnitrosourea has been studied by using transmission and scanning electron microscope. The subependymal matrix layers of the fetus which was affected by ENU have showed irregular and rough arrangements with expanded extracellular spaces as compared with that of control rats. The cells of subependymal layer seemed to form the microtumor. A so-called "microtumor", which was found in a 8 week old, has been composed of small round cells. The fine structures of these cells have showed the characteristics in primitive oligodendroglioma. The characteristics of the fine structure of astrocytoma cells was identified by both TEM and SEM. The fine structure of subependymal glioma cells was often pleomorphic. These gliomas contained a mixture of primitive oligodendrocytes and ependymal cells together with anaplastic glial cells. With increasing size, the glioma has become more pleomorphic with a mixture of neoplastic oligodendrocytes, astrocytes and ependymal cells, and ependymoma like cells have showed neither cilia nor junctional complex. Abnormal vascular structure in the tumor has been reconfirmed by injection replica scanning electron microscope method. The fine structure of the separated single tumor cell surface was also studied by scanning electron microscope. The differences of the cells surface between that of astrocytoma cell and oligodendroglioma cells were clearly noticed.
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PMID:[Experimental brain tumors produced transplacentally by ethylnitrosourea (IV): ultrastructure studied by using transmission and scanning electron microscope (author's transl)]. 70 10


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