PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Microscopy”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

Morphological studies on the periostracum of the fresh-water mussel Amblema (Uniondae): light microscopy, transmission electron microscopy, and scanning electron microscopy.

The structure of the periostracum in the fresh-water mussel Amblema has been described using light microscopy, transmission elec;ron microscopy, and scanning electron microscopy. The structure and evolutive course of the periostracum was studied along its entire length, from the periostracal groove until it forms the tough outer covering of the shell. At least five structurally and functionally distinct regions were identified. In addition, the periostracum itself was seen to be a multilayered structure consisting of three major layers which are themselves subdivided into minor layers. From these morphological observations, a regulatory role for the various periostracal layers in mineral trapping, nucleation, and the subsequent formation of the prismatic and nacreous layers of the shell can be postulated.

Animals↗
PubMedDate not supplied

Scanning electron microscopy in the study of lung cancer. New technique of comparative studies on the same lung cancer cells by light microscopy and scanning electron microscopy.

A new technique for observing the same lung cancer cells by light microscope and SEM was developed. By this technique it was clarified that the surface ultrastructures of epidermoid carcinoma, adenocarcinoma and oat-cell carcinoma cells are different from each other. Those of adenocarcinoma and mesothelial cells were quite different. This technique might be of use, adding new information into the ordinary cytologic diagnosis of cancer cells.

Adenocarcinoma↗
PubMed1978

Cytoplasmic microtubular images in glutaraldehyde-fixed tissue culture cells by electron microscopy and by immunofluorescence microscopy.

Electron microscopy and indirect immunofluorescence microscopy using monospecific tubulin antibodies were performed in parallel on glutaraldehyde-fixed tissue culture cells without osmium fixation. In order to reduce the excess aldehyde groups of the strongly crosslinked cellular matrix, which normally interfere with subsequent immunofluorescence microscopy, a mild NaBH(4) treatment was introduced during or after the dehydration steps. Cells processed through the NaBH(4) step show, in transmission electron microscopy, normal cytoplasmic microtubules approximately 250 A in diameter. When such cells are subjected to indirect immunofluorescence microscopy using monospecific tubulin antibody they reveal a complex system of unbroken, fine, fluorescent fibers traversing the cytoplasm between the perinuclear space and the plasma membrane. Thin sections of cells processed through the indirect immunofluorescence procedure show antibody-decorated microtubules with a diameter of approximately 600 A. This decoration is not obtained when non-immune IgGs are used instead of monospecific antitubulin IgGs. Thus, a direct comparison of cytoplasmic microtubules in glutaraldehyde-fixed cells by both electron microscopy and immunofluorescence microscopy can be obtained.

Cells, Cultured↗
PubMed1977

[Examination of gallstones on their surface and in fractured cross sections by incident light microscopy and scanning electron microscopy (author's transl)].

Operatively removed gallstones were examined on their surfaces and in fractured cross sections by incident light microscopy and scanning electron microscopy. In addition, micro-bore samples and X-ray crystallography were done. Five gallstone types consisting of three basic structural layers are differentiable by incident light microscopy. The three layers consist of a central nucleus which is always present, a radially structured middle layer, and a fine crystalline outer shell, the presence or absence of the latter two layers differentiating the stone types. Two crystal structures could be differentiated by electron microscopy; a flat and a globular type. The nucleus is always of the globular crystalline type, while the outer layers are flat crystalline. From this we were lead to believe that the conditions in vivo, under which the different layers of a gallstone are built, change. The micro-bore samples lead us to believe that calcium is only secondarily layed down in the gallstone framework. White crystalline deposits, which were formed several seconds after fracture, were discovered on the fractured gallstone cross sections.

Cholelithiasis↗
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↗
PubMed1979

Hormonal influences on the dog prostate--a correlation study with light microscopy, transmission and scanning electron microscopy.

Dog prostates under defined hormonal influences were investigated by light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The normal acinar cell apices exhibited well-developed, densely packed microvilli. TEM demonstrated numerous secretory granules, indicating a high secretory activity. Following castration, the acinar cells of the dog prostate showed rounded apices. Most of the microvilli disappeared and only knob-like protrusions were seen. Castrated dogs following administration of 3 alpha-androstandiol showed fewer microvilli than the controls; however, a well-developed undulating surface could be observed. Castrated dogs given 3 alpha-androstandiol and cyproterone acetate showed almost completely atrophic glandular cells. Prostates of dogs with spontaneous benign prostatic hyperplasia (BPH) were characterized by pleomorphism of cell shapes and surfaces. The different hormonal influences induced changes of the prostatic surface structures and secretory activity.

Androstanols↗
PubMed1977

Effect of pretreatment with ethanol containing fluoride on etched enamel surface as evaluated by scanning electron microscopy, optical microscopy, and tensile bond strength measurement.

The effects of pretreatment with a fluoride-containing ethanol solution on etched enamel surfaces before application of sealant were examined using scanning electron microscopy, optical microscopy, and tensile bond strength determinations. The results suggested that when etched enamel surfaces are treated with ethanol containing no more than 250 ppm fluorine in potassium fluoride, there is no interference with the bonding of the sealant to the treated, etched anamel surface.

Acid Etching, Dental↗
PubMed1979

Combined intravital microscopy and electron microscopy of the blind beginnings of the mesenteric lymphatic capillaries of the rat mesentery. A preliminary report.

The blind beginnings (so-called terminal lymphatics) of the mesenteric lymphatic capillaries have been studied in the rat mesentery by means of intravital microscopy and electron microscopy. Intraluminal objects were observed to move slowly downstream, probably carried by the movement of the lymphatic fluid. No simultaneous changes in capillary lumen could be observed, and the subsequent electron microscope analysis of the same lymphatic capillary demonstrated the absence of smooth muscle cells in the wall of the lymphatic vessel. Interendothelial gaps were present, allowing the uptake of interstitial fluid into the blind ending of the lymphatic capillary.

Animals↗
PubMedDate not supplied

The collagenous architecture of articular cartilage. Correlation of scanning electron microscopy and polarized light microscopy observations.

The localization and directional orientation of collagen fibers in articular cartilage is demonstrated by scanning electron microscopy and polarized light microscopy. Vertical sections of articular cartilage show different directional orientations of collagen fibers through all zones of cartilage depending upon whether the sections are parallel or perpendicular to the cleft pattern produced when the surface of articular cartilage is pierced with a round pointed awl. Sections parallel to the cleft axis show a significant population of oblique collagen fibers which are not seen in sections perpendicular to the clefts. These oblique fiber groups show a progression from nearly radial to nearly tangential orientation from deep to more superficial zones, with the most abrupt directional change seen through the transitional zone. Within the transitional zone there is a narrow band having no vertical or horizontal collagen fibers and in which collagen fibers intersect predominantly at angles ranging between 45 and 135 degrees. The number of chondrocyte lacunae per unit area is greater in sections parallel to the cleft axis compared to perpendicular sections by a factor of approximately 1.6:1. There is therefore a greater relative number of chondrocytes in the plane of section having the greatest abundance of oblique collagen fibers, suggesting a cellular basis for the collagenous architecture observed. The results are consistent with published biophysical data relating tensile and swelling properties of all zones of articular cartilage to the cleft axis.

Animals↗
PubMed1979

Glomerulonephritis induced by high doses of ovalbumin. Studies by electron microscopy, immunofluorescence and immuno-electron microscopy.

Experimental glomerulonephritis was produced in 16 rabbits by intravenous injections of ovalbumin in high doses (0.1 g/day during the first week, 0.2 g x 6/day during the second). The animals were killed on day 14. At that time all animals had 2--4+ proteinuria and a serum C3 level reduced to about 50% of the control level; 11 animals had a significantly raised blood urea level. In all rabbits the antigen had induced severe proliferative glomerulonephritis. Electron microscopy showed that many of the cells accounting for the hypercellularity were monocytes. Surprisingly, electron dense deposits were few and small, mainly on the subendothelial and subepithelial aspects of the glomerular basement membrane. In all the animals ultrastructural immunoperoxidase technique revealed deposits containing ovalbumin, rabbit IgG and C3. With immunofluorescence sparse deposits were occasionally seen. It is concluded that a severe experimental glomerulonephritis can be produced in a state of antigen excess, with the deposition of immune complexes being minimal. Immuno-electron microscopy is essential, however, in detecting even the smallest animals of deposited immune reactants.

Animals↗
PubMed1978

Sephadex globules placed as landmarks in combined stereo microscopy, scanning and transmission electron microscopy.

Regions of specific interest in tissue blocks were localized in a stereo microscope and landmarked with Sephadex spheres (10-40 micron in diameter). This procedure made it possible to recognize these regions easily and quickly in the scanning electron microscope. When the tissue was later embedded in Epon the spheres facilitated orientation when sectioning. Thus it was possible with great certainty to determine the level at which ultrathin sections should be cut for transmission electron microscopy to attain an exact correspondence between scanning and transmission electron microscopic observations. The procedure is described and an example of its application is shown in a study of experimental hypertensive endothelial changes.

Angiotensin II↗
PubMed1979

[Comparative endoscopic, light microscopy and scanning electron microscopy studies of the gastric mucosa in patients with chronic uremia].

Ten patients suffering from chronic uremia were selected for comparison studies of gastric mucosa. With endoscopy erosive gastritis was seen in the corpus and antrum of five patients and in the fundus of two patients. Conventional microscopy (nine patients) revealed chronic gastritis I three times in the fundus and five times in the corpus. Gastritis II was localized once in the corpus and twice in the antrum. Gastritis III was present in the antrum of four patients. Under the scanning electron microscope lesions of gastric mucosa were present in all ten cases. Single cell necrosis (A), mucosal defects involving basal membrane (B), destruction of tunica propria (C), and muscularis mucosae with bleeding (D) were seen. Mucosal lesions A and B are early stages of gastric erosions. The most severe lesions were seen in the antrum mucosa with all three methods.

Chronic Disease↗
PubMed1979

Observations by immunofluorescence microscopy and electron microscopy on the cytopathogenicity of Naegleria fowleri in mouse embryo-cell cultures.

The destruction of secondary mouse-embryo (ME) cells by Naegleria fowleri was studied by indirect immunofluorescence with ME-cell antiserum as a specific label to trace the fate of mammalian-cell cytoplasm. The appearance of naegleria-induced cytopathic effect in the cultures coincided with the accumulation of discrete particles containing granules of ME-cell antigen within the cytoplasm of amoebae, suggesting that the organisms ingested host-cell material. In cultures containing cytochalasin B, a non-lethal inhibitor of phagocytosis by N. fowleri trophozoites failed to acquire any granular fluorescence and were not cytopathogenic. The engulfment of mammalian-cell cytoplasm by the organisms was confirmed when thin sections of naegleria-infected ME-cell cultures were examined by electron microscopy. Amoebae were seen in the process of detaching portions of cytoplasm from whole ME cells by means of distinctive ingesting pseudopodia, and fragments of mammalian-cell cytoplasm were identified within the food vacuoles of trophozoites. There was no evidence for cytotoxic disruption of ME cells before or during engulfment of these fragments. It is concluded that N. fowleri trophozoites attack and destroy cultured ME cells by a phagocytosis-like mechanism alone, without the aid of any amoeba-associated cytotoxic or cytolytic agents. The possible significance of these findings with respect to the in-vivo pathocity of N. fowleri is discussed.

Amoeba↗
PubMed1979

Endothelial cell density determined by specular microscopy and scanning electron microscopy.

Human eyes were photographed with a specular microscope and later examined wit a scanning electron microscope. Corneas from patients undergoing corneal transplantation in whom we were able to obtain preoperative specular micrographs were similarly analyzed. An attempt was made to correlate the counts obtained with both microscopic techniques by determining the amount of shrinkage the cornea undergoes while being processed for SEM. All specimens were counted with a planimeter. We found that the specular microscope adequately analyzes the endothelial cell density in the central and paracentral cornea of a normal eye, but because of its small sampling area specular microscopic counts are subject to significant error when dealing with nonhomogeneous populations such as postoperative cases. We found the peripheral corneal endothelial density to be less than the central endothelial density. Furthermore, we found that we could maximize the accuracy of counting by using a variable frame in a nonhomogeneous population, counting a minimum of four photographs per specimen, analyzing different areas, and analyzing larger areas.

Adolescent↗