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PubMed1987

The fine structure of the human placental villus as revealed by scanning electron microscopy.

Scanning electron microscopy of the placenta has a history of only twenty years. During that time, however, there have been dramatic advances in instrument technology coupled with the refinement of preparative techniques designed to reduce fixation artifacts to a minimum. As a result many of the early claims must be amended or suitably qualified, and this is one aim of the present review. Much new data on the internal structure of the placental villus is also presented. By means of the partial digestion technique it is now possible to describe the three dimensional configuration of the various components of the villous tree. This review will consider these sequentially, starting externally with the gross morphology of the villi and ending with replicas of the fetal vasculature produced by corrosion casting.

Chorionic Villi↗
PubMed1988

[Characteristics of the microstructure of biliary calculi based on data from scanning electron microscopy].

Scanning electron microscopy was employed to study cholelithic microstructure. Irrespective of the chemical composition, the gall-stones demonstrated the presence of a cementing matrix composed of micellar-vesicular particles occurring either in aggregates or regularly spreading along the facets about the surface of crystalloid structures. There appeared to be a close relationship between the latter and the particles which are, viz., vesicles, responsible for the plane and margin epitaxy of the cryslalloid structures. Any cholesterol deposits are lipoprotein-like particles or their derivatives, appearing as micellar-vesicular particles in case of choleliths.

Cholelithiasis↗
PubMed1986

Dissection technique for cochleas prepared for scanning electron microscopy.

Scanning electron microscopy (SEM) permits a three-dimensional study of the surface morphology of the organ of Corti that is very useful in evaluating the condition of the apical end of the hair cells and the stereocilia. However, some laboratories have experienced problems with curling of the basilar membrane during critical point drying of cochlear specimens prepared for SEM evaluation using the Murakami or osmium thiocarbohydrazide-procedures. This curling of the basilar membrane can obstruct the view of the reticular lamina and the ciliary ends of the hair cells. We have used a dissection method, referred to as the anchor technique, to overcome basilar membrane curling. This technique removes all the structures above the reticular lamina but leaves the basilar membrane attached to the spiral ligament and the lateral bone to which the spiral ligament is anchored. Individual cochlear turns are dissected in this manner and mounted on the same examination stub for SEM evaluation. Maintenance of the lateral attachment of the basilar membrane requires additional dissection time but eliminates the problem of curling during critical point drying. An additional benefit is that mounting the individual turns on the same examination stub facilitates evaluation and photomicroscopy of the surface morphology. The anchor technique has been used successfully on the guinea pig and should be appropriate for most mammalian cochleas.

Animals↗
PubMed1986

[Types of mitochondria destruction in the cardiac myocyte (from the data of scanning electron microscopy)].

Scanning electron microscopy has revealed three types of myocardial mitochondria degradation in intact rabbit heart: desquamation of the external membrane, mitochondria swelling with their following destruction, mini-focal ulceration of mitochondrial external membranes. There was a clear-cut daily and seasonal dynamics of the three types of degradation. Mitochondria degradation was much more pronounced in the fibrillating than in intact heart.

Animals↗
PubMed1985

Interaction between glioma cells and normal brain tissue in organ culture studied by scanning electron microscopy.

Scanning electron microscopy was employed to investigate cocultures between normal rat brain fragments and spheroids consisting of rat glioma cells. Lamellipodia were seen to arise from tumor cells at the border between the two structures and touch the surface of the fragment. Cytoplasmic extensions from malignant cells appeared to penetrate into the brain fragment. Leading lamellae were extended from the tumor cells as they migrated along the normal surface and gradually covered the fragment. Tumor cells formed broad foot-plates against the normal surface. No alterations of the brain fragment were observed ahead of the tumor cells. Thus there were specific changes of the surface microarchitecture of the malignant cells, but not of the normal brain tissue.

Animals↗
PubMed1984

[Study of the surface of cytolytic T-lymphocytes by scanning electron microscopy].

Scanning electron microscopy revealed three types of cytolytic T lymphocytes (CTL) interacting with target cells (TC). The type I cells occurred as smooth spherical lymphocytes with single microvilli; the type II rounded or oval cells were uniformly covered with microvilli; the type III cells were marked by an irregular shape, were densely covered with microvilli, while their surface was folded or tuberous. Within the first several minutes after absorption the surface of TC was largely covered by the type I lymphocytes. The proportion of the type III cells rose with the time of interaction. At the beginning it was 8-9%, reaching 30-71% after 30-60 minutes of incubation. It is assumed that the 3 types of the cells described mirror 3 stages of CTL activation. The increase in number of microvilli and appearance of the membranous folds may be a consequence of exocytosis and incorporation of the membrane of secretory granules into the plasma membrane of lymphocytes. The data obtained support the authors' assumption about the secretory mechanism of the action of CTL, whose contact with TC stimulated secretion activation.

Animals↗
PubMed1981

Surface topography and other characteristics of non-transformed and carcinogen transformed C3H/10T 1/2 cells in mitosis, as revealed by quantitative scanning electron microscopy.

Scanning electron microscopy (SEM) has been used for the characterization of the different phases of mitosis in normal and transformed C3H/10T 1/2 cells after the stages had been confirmed by light microscopy. Our findings suggest that it is only possible to separate the different phases of mitosis by SEM after having evaluated a great number of cells and after having established the SEM features for the light microscopically identified mitotic phases (Feulgen staining). The main finding in the study is that both the normal and all three types of transformed cells, type I, II and III, have the same shape in the different stages of mitosis but that transformed cells seem to exhibit a larger number of pleomorphic microvilli than do non-transformed cells. We also found that in contrast to the other mitotic phases, prophase cells have a very low concentration of microvilli in the nuclear area.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1977

The presence of fine elastin fibrils within the elastin fibre observed by scanning electron microscopy.

Scanning electron microscopy of critical point dried, enzymically and chemically purified fetal and adult elastin fibres from bovine ligamentum nuchae has shown that the fibres are composed of fine elastin fibrils (110-130nm diameter). In the fetal tissue the elastin fibres were of relatively uniform thickness and did not bifurcate, but in the adult, much thicker, branching fibres were present. It would appear that, during maturation of the elastin fibre, thickening is the result of the aggregation of many fine fibrils, and bifurcations result form bundles of such fibrils crossing over from one fibre to another.

Animals↗
PubMed1995

Comparison of cell sediment and surface grown "test plaque" using scanning electron microscopy.

Scanning electron microscopy was used to compare the morphology, integrity and distribution of bacterial cells in a test plaque grown on the surface of enamel with that of the cell sediment plaque routinely used in a short-term intraoral caries model. Cultures of S. mutans IB-1600 or S. sobrinus 6715-13 were grown in complex media supplemented with either 2.0% sucrose (glucan plaque) or 0.2% glucose (non-glucan plaque). Cell sediment (CS) plaque was prepared by centrifuging the cultures after incubation, recovering the cell sediment, and spreading it on Metricel membrane filter paper. Surface grown (SG) plaque was prepared by suspending saliva-coated bovine enamel in the culture medium, incubating, and recovering the enamel assembly with bacterial accumulations. Cell morphology and integrity, as well as the appearance of glucan-like material produced by the cells, was similar in both CS and SG test plaques. The cell distribution however, varied in the SG plaque from extremes of all cells to all glucan, whereas the cell sediment plaque was more uniform in cell distribution. A highly standardized test plaque minimizes variability in the intraoral caries model. These findings support the contention that the bacterial cells in a cell sediment plaque are similar in morphology, integrity and glucan production to surface grown plaque, and have the added advantage of uniform distribution, which makes the cell sediment plaque more appropriate for intraoral caries model studies.

Animals↗
PubMed1994

Comparative studies of the same adenocarcinoma cells, macrophages, and mesothelial cells by light microscopy, scanning electron microscopy, and transmission electron microscopy.

The identification of cells in body cavities of cancer patients is sometimes difficult to make. In order to make a definite cytological diagnosis, we observed the same cells by using light microscopy (LM)-scanning electron microscopy (SEM)-transmission electron microscopy (TEM). In this study we first stained cells by the Papanicolaou method after fixation in 1% glutaraldehyde for LM, and then attempted to observe them successively by SEM-TEM after fixation in 1% paraformaldehyde and 1.25% OsO4. Our method and procedures in examining successively one and the same cells in body cavity fluids by using LM, SEM, and TEM ensured accurate discrimination among adenocarcinoma cells, mesothelial cells, and macrophages. The results of this study suggest that LM-SEM-TEM may be of diagnostic value in distinguishing among mesothelial cells, macrophages, and adenocarcinoma cells. This method also succeeded in disclosing differences between the ultrastructure of the cell surfaces, and those of the cytoplasm, and of the nuclei. It is desirable that LM-SEM-TEM observation can be introduced into various aspects in order to obtain an improvement in the diagnosis by cytologic examination, the judgment of therapeutical effects, drug selection, and prognostic presumption.

Adenocarcinoma↗
PubMed1979

Morphological studies of the spleen in idiopathic portal hypertension (so-called Banti's syndrome without liver cirrhosis) using light microscopy, scanning electron microscopy and histometry.

Morphological changes in the spleens of patients with idiopathic portal hypertension (IPH) were studied and compared with the normal spleen. The study used (1) light microscopy with histometry, (2) scanning electron microscopy (SEM) of the splenic tissue with histometry and (3) SEM of the spleen vascular replica. Histometrical studies by light microscopy showed that the volume of red pulp of IPH was increased in a unit area and to a total of 12 times the normal in the whole spleen. The white pulp was scanty of lymphocytes and decreased in a unit area but it was increased in the whole spleen. SEM of the white pulp of IPH demonstrated many channels formed by reticulum cells and running parallel with each other along the central artery. This finding presumably corresponds to periarterial fibrosis in light microscopy. SEM histometry demonstrated that the venous sinuses of IPH were small but increased in number and occupied the same percentage area in a unit red pulp area as in the normal spleen. The Billroth cord of IPH was narrowed and occupied by thickened reticulum cells, which may cause increased pooling and destruction of blood cells in the enlarged spleen (hypersplenism). SEM of the tissue and vascular replica demonstrated open arterial termination in the Billroth cord in the spleen of IPH as well as in the normal spleen. Venous sinuses in the replica of IPH ran parallel with each other forming bundles with fewer intercommunications than normal.

Adult↗
PubMedDate not supplied

[A comparison between phase-contrast optical microscopy and scanning electron microscopy for the analysis of air-borne asbestos fibers in an office environment].

There is no general agreement on the relationship between results obtained by optical microscopy (PCOM) and electron scanning microscopy (SEM) or electron transmission microscopy (TEM) for airborne asbestos fibres. However, a considerable amount of data has been produced in latter years indicating that a general correlation factor, not differing greatly from unity, can be established between the two analytical techniques if counts are limited to fibres longer than 5 microns. A study was made of the relationship between SEM and PCOM when used simultaneously for determination of background concentrations of asbestos in office buildings. Twenty-four couples of samples were collected in parallel for PCOM and SEM in different locations distributed over the various floors of two buildings containing amosite sprayed on structural parts. Asbestos and total fibre counts by SEM were performed following the Verein Deutscher Ingenieure (VDI) method 3492. For total fibre counts the European PCOM method was mainly used. Discrimination of asbestos from non-asbestos fibres was performed using criteria based on birefringence and morphological characteristics of fibres. Counts included only those fibres longer than 5 microns, diameter less than 3 microns and aspect ratio greater than 3. Both total fibres and asbestos fibres were recorded separately by PCOM and SEM. the arithmetic and geometric means of the ratio between PCOM and SEM were 1.3 and 1.1 respectively for total fibres and 1.2 and 1.1 for asbestos fibres (excluding one outlying value). The regression study showed a significant linear correlation (P = 0.01) with correlation coefficients of 0.84 for asbestos fibres and 0.52 for total fibres.

Air Pollution, Indoor↗
PubMed1990

Correlative light microscopy, scanning electron microscopy, and transmission electron microscopy of osmium-macerated biological tissues.

A method facilitating correlation of light microscopic (LM), scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images was developed. Rat kidney and heart were initially subjected to the osmium maceration procedure and then embedded in acrylic resin. Semithin sections of the tissue blocks were first provided for LM and then examined by SEM after resin removal. Furthermore, the ultrathin sections adjacent to the semithin sections were observed by TEM. The three-dimensional images of intracellular organelles provided an informative adjunct to LM and TEM.

Animals↗
PubMed2002

[Morphogenesis of media calcinosis in Mönckeberg disease. Light microscopy, scanning electron microscopy and roentgen microanalysis findings].

OBJECTIVE: In contrast to granular mediacalcinosis of the aorta, Mönckeberg's disease is characterized by the occurrence of sheet-like calcification. It is usually said that the pathogenesis of this calcification is unknown. MATERIAL AND METHODS: To obtain some insight into the mechanism leading to this calcification, we performed light microscopic, scanning electron microscopic and X-ray microanalysis investigations on femoral arteries from autopsies. RESULTS: By light microscopy preferentially sheet-like calcifications of different size appeared. In the alizarin red S stain in the neighborhood of these compact structures calcified globules were observed. By SEM in the neighborhood of the compact areas calcified granules were found; the compact structures themselves consisted of granules sticking one onto the other. X-ray microanalysis exhibited high contents of calcium and phosphorus in the compact calcifications; they also showed a minor content of magnesium. Isolated granules inside the compact calcifications showed a nearly identical composition, while granules outside in the surrounding media consisted preferentially from calcium and phosphorus, but they exhibited a slight higher magnesium content. CONCLUSIONS: It is concluded that Mönckeberg's media calcification is due to dystrophic calcification. Calcified matrix vesicles from necrotic cells, as it is assumed for the pathogenesis of the calcification of arteriosclerotic plaques (31), are interpreted as precursors of the solid calcifications which may develop by confluence and sticking one onto the other of calcified globules.

Aged↗
PubMed1980

Light microscopy, scanning electron microscopy, and microprobe analysis of bone response to zinc and nonzinc amalgam implants.

Freshly mixed, unset zinc-free and zinc-containing analgam was implanted in the right tibia of 32 rats. Half of the specimens were examined by the light microscope and the other half by the scanning electron microscope and x-ray microprobe analysis. It was found that amalgam is well tolerated by the rat osseous tissue, and there were no histologic reaction differences between zinc and zinc free amalgam. The surfaces of the implants were covered by an organic film at 3 weeks and with bone at later intervals. Very little corrosion products containing sulfur were observed on the amalgam surface at all intervals. Bone adjacent to the amalgam contained tin and sulfur irrespective of the presence of zinc in the alloy, indicating outward migration of specific components of the alloy.

Animals↗
PubMed1976

Study on development of Agaricus bisporus by fluorescent microscopy and scanning electron microscopy.

Two strains of Agaricus bisporus have been investigated by fluorescent microscopy and scanning electron microscopy. Somatic nuclei, stained with auramin O and examined by fluorescent microscopy, appear to be randomly distributed, divide asynchronously, and assume a nonclassical or "two-track" configuration during mitotic metaphase. A similar configuration has been observed for nuclei during meiosis, but early meiosis in A. bisporus appears to be classical, usually with nine pairs of chromosomes evident during prophase I. Scanning electron microscopy has been used to document developmental stages in the formation and germination of basidiospores. Two-spored basidia were predominant, but occasionally one- or three-spored forms were observed. Four-spored basidia were absent, and uninucleated basidiospores were exceedingly rare to absent.

Basidiomycota↗