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

Plastic coverslips made of polymethylpentene serve as excellent substrates for growth of bovine endothelial cells, and are easily processed for both transmission (TEM) and scanning (SEM) electron microscopy. Portions of the same coverslip (monolayer) are used for both SEM and TEM examination and are fixed, postfixed, and dehydrated as a single entity. The portion of the coverslip for SEM is then excised, critical point dried, and mounted for sputter coating prior to viewing. The remaining piece of coverslip used for TEM is Epon-Araldite embedded, polymerized, separated from the coverslip by liquid nitrogen immersion, and sectioned either "en face" or in cross section for viewing. Coated glass coverslips are not required and organic solvents such as propylene oxide, acetone, and amyl acetate can be used for dehydration and infiltration. Furthermore, specimens do not require re-embedding or blocks to be glued onto blank capsules before sectioning. The number of cells needed to achieve a monolayer is significantly reduced compared to the usual culture flasks, but are abundant enough to assess ultrastructural changes accurately. Support films may be required to prevent folding of the ultrathin section which can obstruct viewing of cells located on the edge of the section.
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PMID:Transmission and scanning electron microscopy of cell monolayers grown on polymethylpentene coverslips. 49 32

A developmental study of intraventricular macrophages was carried out from 11 days post-conception up to 90 days post-natum, using semithin sections, transmission electron microscopy and scanning electron microscopy. In semithin sections and in the TEM three main morphological types (and some transitional forms) were identified and are described as circular, irregular and flattened, respectively. In the SEM three corresponding types were identified, a relatively smooth spherical type, a highly ruffled type and a fairly smooth flattened type. A fourth, multi-blebbed type, was occasionally seen in late prenatal and early postnatal mice. It seemed most likely that these cells were mitotic. The likely sequence of development is that the spherical or circular type is the most primitive, although capable of phagocytosis; and that this differentiates into the ruffled or irregular variety, which in turn differentiates into the flattened type, which is by far the most common type found after birth.
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PMID:A semithin light microscopic, transmission electron microscopic and scanning electron microscopic study of macrophages in the lateral ventricle of mice from embryonic to adult life. 51 69

Morphologic responses of neoplastic human prostate to long-term explant culture were monitored at serial intervals by LM, TEM and SEM, and compared to normal prostate. Explants were cultured at 37 degrees C in CMRL-1066 supplemented with fetal calf serum and antibiotics. At 0-time culture, normal prostate of young adult males obtained at immediate autopsy, consisted of glandular spaces and ducts lined by columnar to cuboidal secretory epithelial cells and basal cells embedded in fibromuscular stroma. Neoplastic tissue was obtained surgically by transurethral resection (TUR), and consisted of stroma widely infiltrated by well-to moderately-differentiated tumor cells arranged in variable sized, gland-like structures. Secretory activity was evident; basal cells were absent in these glands. During early periods of culture up to several weeks, secretory cells of normal prostate became necrotic. Basal cells remained viable, repopulated acinar structures and epithelialized explant surfaces. At these sites, basal cells, or their derivatives, formed a multicellular epithelium. Exaggerated intercellular spaces separated cells, and synthesis of mucus-like material was seen. Epithelial characteristics included microvilli, junctional complexes, and basal lamina. In marked contrast, tumor cells covered explant surfaces forming an irregular, disorganized layer of squamous-like cells with elongated nuclei and prominent nucleoli. Microvilli, junctional complexes, and basal lamina were poorly developed or absent. Intercellular attachments appeared tenous. Some tumor cells accumulated lipid; synthesis of mucus-like material was not seen. At later intervals of culture up to 10 weeks, synthesis of mucus-like material by basal cells, or their derivatives, declined. Surface cells of neoplastic prostate gradually became more anaplastic in appearance; cells contacted neighboring cells with pseudopodia and filopodia.
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PMID:Studies on carcinogenesis of human prostate. IV. Comparison of normal and neoplastic prostate during long-term explant culture. 52 30

The morphology of canine thoracic duct and peripheral collecting lymphatics was determined using light microscopy together with scanning and transmission electron microscopy (SEM and TEM). The thoracic duct was compared to the thoracic aorta and to the vena cava. Luminal surface detail was determined using the secondary imaging mode of the SEM. Subsurface nuclear and connective tissue detail was determined using back-scattered electron imagining combined with Willard's modification of Gomori's Methenamine Silver Stain. Central and peripheral lymphatic vessels have surface morphology distinct from either arteries or veins. The endothelial cell density in lymphatic vessels is less than in arteries or veins. The nuclear chromatin of lymphatic endothelial cells is coarsely granular and evenly distributed. This contrasts with nuclei from arteries or veins in which the chromatin is segmented. The distribution and orientation of lymphatic subsurface connective tissue fibers also differs from that seen in arteries and veins. It is concluded that canine lymphatic vessels have a unique surface and subsurface morphology and can be unequivocally identified by SEM.
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PMID:Scanning electron microscopy of collecting lymphatic vessels and their comparison to arteries and veins. 52 42

The migration of myogenic stem cells into the leg anlagen of chick embryos between stages 16--20 of Hamburger and Hamilton was examined. SEM and TEM studies reveal that cell migration starts at stage 16 from the just-formed somites 26-28. The migrating myogenic cells are elongated and oriented in a medio-lateral direction. The leading ends branch into filopodia which contact a fibrillar network. At first, single cells migrate; later on the cells leaving the ventro-lateral edge of the dermatome migrate in strands and have specialized contacts between them. After reaction with ruthenium red and concanavalin A the migrating cells show a thick surface coat to which ruthenium red-positive particles are attached. The surface coat may be important in the interactions among the migrating cells as well as between the cells and the substrate. The migration of myogenic stem cells was found to take place in a matrix of collagenous fibrils and ruthenium red-positive particles, probably containing glycosaminoglycans. At the onset of migration the fibrillar network exhibits a preferred medio-lateral orientation. Therefore, it may be concluded that this alignment of the fibrils influences the direction of cell migration.
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PMID:The migration of myogenic cells from the somites into the leg region of avian embryos. An ultrastructural study. 52 19

The pathologic morphology of osteoarthrosis (arthrosis deformans) is illustrated macroscopically, histologically, and electron microscopically TEM and SEM). The morphologic hallmark of the lesions is the association of destructive and inadequate reparative processes in the articular cartilage and reactive bone growth, often leading to grotesque deformity of the joints with characteristic osteophytosis. The fundamental morphologic alterations involving chondrocytes and matrix are similar in all arthroses, irrespective of their topography.
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PMID:[Pathomorphology of human arthroses]. 53 87

The oocyst wall of Isospora lacazei from sparrows was studied with scanning (SEM) and transmission (TEM) electron microscopy. In TEM, the oocyst wall consisted of four distinct layers (L1-4). The innermost layer, L1, was moderately electron-lucent and 240--285 nm thick; L2 was electron-dense and 210--240 nm thick; L3 was moderately electron-lucent and 15--150 nm thick; L4, the outer most layer, was discontinuous and consisted of electron-dense discoid bodies which measured 180--220 nm x 320--840 nm. The discoid bodies of L4 as seen by TEM appeared spheroid in shape when observed by SEM. One or two membranes were situated on or between various layers of the oocyst wall. One such membrane occurred on the inner margin of L1, two closely applied membranes were interposed between L1 and L2, one membrane occurred between L2 and L3, and one membrane on the outer margin of L3.
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PMID:Scanning and transmission electron microscopy of the oocyst wall of Isospora lacazei. 53 68

Certain differences were found in the histochemistry and fine structure of an active bladder tegument of an infective larva of M. endothoracicus and a regressively changing bladder of an aging larva of this species. The bladder tegument of an aging larva contained an accumulation of acid mucosubstances and phospholipids, that of a younger larva neutral mucosubstances, and it reacted less strongly than the former to tyrosine, cystine and tryptophane. Evidence was obtained with the scanning (SEM) and transmission (TEM) microscope for regressive changes in the bladder of an aging larva: its microtriches were more slender, less tightly packed and fibrously interconnected, and there were spherical formations adhering to the microthrix border. Sometimes, the vacuolation of rod-shaped bodies was so much advanced that these bodies looked like vacuoles arising to the surface of the distal cytoplasm. Another sign of bladder regression was the formation of vacuoles in the cytoplasm of subtegumental cells with contents of a granular to crystalline structure.
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PMID:Histochemistry and fine structure of the bladder tegument of a larval Multiceps endothoracicus. 56 13

An electron-microscopical study was made on morphological changes in which T-Tbp would undergo during clotting and fibrinolytic process. Morphological appearance of concentrically arranged membrane structure in T-Tbp remained nearly intact during blood coagulation process. T-Tbp, which existed in the sediments following dissolution of fibrin clot by the application of UK, showed an appearance of fine granules adhering to the surface of aggregates of particles through SEM. Through TEM, T-Tbp in the sediments was found to have retained its concentrically arranged membrane structures in most places, while, in some other places the appearance of fused membranes, smaller single vesicles and long sheets of membranes, and the formation of "blebs" etc. were observed. Various morphological changes caused by fibrinolytic substances accompanied the loss in coagulation activities. Our results showed that coagulation activities of T-Tbp must be completely dependent upon the presence of the membrane structures.
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PMID:Studies on the tissue thromboplastin during the coagulation-fibrinolytic process--ultrastructural changes. 57 34

The epithelium of the vocal cord from children and adults is analysed with SEM and TEM. Scanning micrographs show that the apical cell membrane is furnished with microvilli and microridges of various patterns. The function of microridges is discussed in relation to the distribution and retention of mucus on the vocal cord.
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PMID:The human vocal cord surface. 59 46


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