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PubMed1976

The effects of ophthalmic drugs, vehicles, and preservatives on corneal epithelium: a scanning electron microscope study.

Scanning electron microscopy was found to be of considerable use in evaluating the effects of various commonly used drugs, vehicles, and preservatives on the corneal surface. Of the preparations tested 0.3 per cent gentamicin caused many central cellular microvilli to stand up prominently. Moderate losses of peripheral microvilli, with mild superficial cellular desquamation was noted with 0.25 per cent phospholine iodide, 2 per cent pilocarpine, 2 per cent fluorescein, and Fluor-I-Strip. The top layer of epithelial cells desquamated with 4 per cent cocaine or neopolycin treatment. The top two layers of cells were lost when 0.01 per cent benzalkonium chloride was instilled. When cell death occurred severe membrane disruption was accompanied by loss of microvilli and rupture of intercellular tight junctions. These studies show that the cytotoxicity of topical ocular preparations can be tested in an in vivo model and evaluated by scanning electron microscopy.

Anesthetics, Local↗
PubMed1979

Surface configuration of mesothelial cells in effusions. A comparative light microscopic and scanning electron microscopic study.

Surface configuration of mesothelial cells identified by light microscopy (LM) has been studied by scanning electron microscopy (SEM). It has been shown that mesothelial cells may have a variable SEM appearance. The surfaces of a small proportion of mesothelial cells are covered by regular microvilli (MV) and show openings of the pinocytotic vesicles. The surfaces of the majority of these cells are covered by vesicles or blebs. An intermediate population of mesothelial cells, i.e., cells displaying side-by-side blebs and MV, has also been observed. The latter cells no longer display pinocytotic vesicles. Occasional mesothelial cells have smooth surfaces. It has been shown by LM and transmission electron microscopy that cells with blebs are viable and capable of mitotic activity. It is concluded that mesothelial cells, detached from their epithelial setting, lose microvilli and pinocytotic vesicles and acquire surface blebs. The possible relationship between mesothelial cells and macrophages based on surface features has been discussed.

Animals↗
PubMed1979

Crohn's disease: a scanning electron microscopic study.

A scanning electron microscopic study of Crohn's disease was done using surgically resected specimens. Grossly normal resection margins as well as nonulcerated portions from diseased areas were selected for study. Scanning electron microscopic findings in Crohn's disease included changes in villous size and shape, villous fusion and epithelial bridge formation, goblet cell hypertrophy and hyperplasia, and increased secretion of mucus. These changes were marked in involved areas, and many were also present in six of seven margins of resection available for study in the ileal group. The abnormalities found in grossly normal margins of resection suggest a more widespread involvement than can be appreciated by gross and light microscopic examination of the specimen. Formation of the increased coat of mucus observed may be stimulated by a number of agents and could contribute to an enhanced barrier function in areas of early involvement in Crohn's disease, thereby decreasing the uptake of toxic or antigenic macromolecules. A decrease in bacterial superinfections would also be facilitated. Later lesions, with severe villous changes and hypersecretion of mucus, may favor the uptake of toxic and antigenic macromolecules as well as aid in the establishment of bacterial superinfections.

Adolescent↗
PubMed1977

The vascularization of the neural stalk and the pars nervosa of the hypophysis in the toad, Bufo bufo (L.) (amphibia, anura). A comparative light microscopical and scanning electron microscopical study.

The angioarchitecture of the neural stalk and the encephaloposthypophysial portal system of the hypophysis of the toad, Bufo bufo (L.), was studied using three different methods. The neural stalk is mainly supplied by branches of the arteria infundibularis superficialis which form a widemeshed vascular network. Dorsally this network continues into the plexus of the pars nervosa. The vascularization of the pars nervosa is made up of the encephalo-posthypophysial portal system. This portal system consists of a hypothalamic branch (=portion), a mesencephalic and a mesencephalicbulbar branch (=portion). The hypothalamic branch was found to drain the pars ventralis of the tuber cinereum as well as more dorsal regions of the diencephalon. The mesencephalic-bulbar trunk enters the hypothalamic branch. The resulting common stem of the encephalo-posthypophysial portal vein the curves around the retroinfundibular communicating artery, crosses its ventral side and runs caudally. The secondary capillary plexus of the pars nervosa is characterized by well defined capillary plexus of the pars nervosa is characterized by well defined capillary networks which are located at the periphery of the parenchyma of the pars nervosa, thus forming a rostral, dorsal and ventro-caudal net. The central region of the parenchyma of the pars nervosa is supplied only by main branches of the encephalo-postpophysial portal vein. The venous drainage of the pars nervosa is via the vena hypophysea transversa.

Animals↗
PubMed1975

[The enamel-dentin membrane in the scanning electron microscope].

In the scanning electron microscope in detailed structure of the dentino-enamel membrane can be investigated. This membrane is mineralized. After partial demineralization it covers the bottom of prism margins and enables their firm anchoring on the surface of dentin. Here the prism bundles are anchored in dishlike formations, on the bottom of which a network of fibers is found, covered by the dentin-enamel membrane. Through artificial fissures in the membrane the above mentioned network of fibers can be seen.

Bicuspid↗
PubMed1976

Fine structure of schistosome eggs as seen through the scanning electron microscope.

Through a scanning electron microscope the eggs of Schistosoma japonicum were observed to have microvili-like chitinous projections densely distributed and entangled on the surface, each more than 3 mu in length and 0.05 to 0.08 mu in diameter. The microspines of eggs of S. mansoni and S. haematobium were found to be thicker, shorter, and less widespread than were those of S. japonicum eggs, and not entangled. It is noteworthy that such small projections on the surface of schistosome eggs remain erect in the critical point drying procedure.

Female↗
PubMed1975

Preclotting of knitted Dacron prosthesis. A scanning electron microscope study.

A scanning electron microscope study of preclotting on knitted Dacron prosthesis is reported. Five steps of the interaction are well identified: (1) before any blood contact (virgin Dacron), (2) during the first 3 minutes (fibrin and platelet aggregates), (3) fifth minute of contact (clotting), (4) 15 minutes of contact with heparinized blood (thin fibrin network), and (5) the following minutes (invasion of fibrin, which enmeshes blood cells).

Adult↗
PubMed1977

Modified tannin-osmium conductive staining method for non-coated scanning electron microscope specimens. Its application to microdissection scanning electron microscopy of the spleen.

Supplement of guanidine hydrochloride to the original tannic acid solution of MURAKAMI (1973) eliminated, without debilitating the conductivity effect, the vexatious treatment with different amino-acids and sucrose in the previous method (MURAKAMI, 1974). The procedures and advantages of this simplified modification are described using human spleen samples; attempt was made to elucidate the structure of arterial terminals by dissecting the specimens under the scanning electron microscope.

Dissection↗
PubMed1979

[Root canal filling materials (electron scanning microscope comparison of root canal adaptation to 3 endodontic filling products)].

The main characteristics required of a good endodontic fillingsmaterial are its perfectly hermetic sealing of the root canal, the eventual secondary canals, and the dentine canals, against bacteria. 48 root canals, sealed respectively with A H 26, Endomethazone and N 2, have been checked by means of the Scanning Electron Microscope in order to discover to what extent these products conform to the qualifications mentioned. 842 photographs have been taken. The results of the investigation are discussed judging from some photographs chosen at random.

Dental Pulp Cavity↗
PubMed1975

The bronchiolar epithelium in cigarette smokers. Observations with the scanning electron microscope.

Observations with the scanning electron microscope were made on the bronchiolar epithelium of 25 lungs removed at surgery. In all but 3 cases, the lungs were removed for a malignant tumor. Abundant ciliated cells were present in all lung specimens. In lungs obtained from nonsmokers, numerous Clara cells were present in the small bronchioles, whereas goblet cells were seen, and in most cases, the Clara cells were infrequent or absent. The evidence for the secretory nature of the Clara cells is discussed as is the possible effect on lung function of alteration in the type of secretory cell in the bronchioles.

Adult↗
PubMed1978

Microanatomy of the human amniotic membranes. A light microscopic, transmission, and scanning electron microscopic study.

The human amnion was examined by means of light microscopy and scanning and transmission electron microscopy. The surface shows apart from microvilli a particular structure, called "blebs"; the intercellular junction is formed by desmosomes and a labyrinthine channel system, and at the base pedicels extend into the basement membrane. Cell shedding uncovers the basement membrane which seems to play a primordial role in preserving the intact amniotic cavity. These data underline the complex structure and the multiple role the amnion performs during gestation.

Amnion↗
PubMed1978

Murine macrophage-lymphocyte interactions: scanning electron microscopic study.

Light and scanning electron microscopic observations revealed murine macrophage-lymphocyte interactions involving the initial contact of peritoneal, spleen, or thymus lymphocytes with peritoneal macrophage processes or microprocesses followed by clustering of lymphocytes over the central nuclear area of the macrophages. Lymphocyte-lymphocyte clustering was not observed in the absence of macrophages. Attachment and subsequent clustering appeared not to require the presence of serum or antigen; the attachment of allogeneic or xenogeneic lymphocytes was comparable to that seen in the syngeneic system, but central clustering of these lymphocytes failed to occur. No attachment or clustering was observed when thymic lymphocytes were cultured with thymus derived fibroblasts rather than with peritoneal macrophages. Lymphocyte attachment to immune, antigen-activated, syngeneic macrophages occurred more rapidly than that to normal unstimulated syngeneic macrophages; however, lymphocytes attached to the "activated" macrophages appeared to be killed by a nonphagocytic mechanism. A similar increase in the rate of lymphocyte attachment to macrophages occurred in the presence of migration inhibitory factor. Subsequent lymphocyte clustering on macrophages was observed in the migration inhibitory factor-stimulated cultures. In addition, lymphocyte-macrophage interactions similar to those in vitro were observed to occur in vivo on intraperitoneally implanted cover slips.

Animals↗
PubMed1978

Mucosa of the Heister valve in cholelithiasis: transmission and scanning electron microscopic study.

Light, transmission, and scanning electron microscopic studies were performed on 24 gallbladders with thin walls, without inflammation, extirpated by cholecystectomy because of gallstones and on five, free from biliary diseases, obtained by autopsies. Examination of gallbladders and epithelium covering the valvula spiralis (Heister) of the ductus cysticus showed the surface structure of the epithelium covering the Heister valve to be mulberry-like and characteristically pleated, similar to the epithelial lining of the gallbladder. In cases of cholelithiasis, several denuded areas were detectable on the valves. The epithelial lining of the gallbladder was intact. As a new observation, we describe the appearance of worm-like processes on the lateral surface of detached epithelial cells, seen during the course of scanning electron microscopic study. These probably correspond to interdigitating cell junctions observed by transmission electron microscopy.

Cholelithiasis↗
PubMed1975

The morphology of growth cartilage using the scanning electron microscope.

The authors undertook a scanning electron microscopic study of the layers of the growth cartilage in the distal end of the rabbit femur in longitudinal and transverse fractures. The relationships between the various morphological structures were determined. The three-dimensional spatial depiction facilitates the better understanding of some mutual relationships between various growth cartilage components. Especially interesting are the regressive processes in both the cells and the matrix which explain the reduction of mechanical strength in the zone of the hypertrophic cells. Also interesting is the way in which the cells are placed and fixed in the lucunae. Moreover, the spatial picture of the terminal plate shows an unexpectedly compact structure.

Animals↗
PubMed1979

Morphogenesis of rod cells in the retina of the albino rat: a scanning electron microscopic study.

This study presents scanning electron microscopic (SEM) observations of topographical changes that occur during morphogenesis of rod cells in the albino rat. Correlative transmission electron microscopy (TEM) was also utilized. Albino rats ranging in age from birth to three weeks were used for the study. Tissues were prepared by conventional methods for SEM and TEM. At birth, numerous irregularly arranged inner segments extend from the external surface of the sensory retina. They are spherical, smooth surfaced and possess a randomly oriented cilium. The internal morphology of these immature inner segments is comparable to that observed in other vertebrate species. Statistical analysis reveals a rapid increse in the number of rod cells during the first week. This period is characterized by the elongation of inner segments and their associated cilia. Microvilli project from the apices of Müller cells, but not from adjacent inner segments. By day 5, cilia occasionally display small bulbous outer segments. They are more numerous by day 8 and are usually eccentrically positioned at the tips of cilia. By day 11, outer segments are abundant and frequently obscure from view the underlying inner segments and associated cilia. Elongated cylindrical outer segments are present within the posterior retina at the end of the second week. However, rod cell morphogenesis lags in the peripheral retina. Topographical variations between developing photoreceptor cells in mammalian and non-mammalian retinas are discussed.

Aging↗