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Results for “scanning electron microscope”

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At least 253 records · Page 14Linked to original sources

PubMed1975

Scanning electron microscope observations of the rat subcommissural organ.

Under the scanning electron microscope, the rat subcommissural organ (SCO) appears as an oval zone, rich in kinocilia and well delimited from the non-specific ependymal epithelium. This zone surrounds the cranial and posterior part of the mesencephalic canal's entrance. The ependymal cells of the SCO show coniform processes with microvilli and kinocilia. In contact with the apical pole of the peripheric SCO-ependymocytes lie scarce supraependymal axons. The Reissner's fiber is composed by the twining of the fibrillary structures emerging from the area of the SCO.

Animals↗

PubMed2003

Scanning electron microscopic observations of the basement membranes with dithiothreitol separation.

Scanning electron microscopic (SEM) studies of the interstitial surface of the lamina densa can be performed with dithiothreitol separation, which is the only method of exposing this surface. SEM observation revealed the three-dimensional structures of the meshwork in the lamina densa and anchoring fibrils in dithiothreitol-separated specimens. Detection of the components of the basement membrane can be performed by immunoscanning electron microscopy on this exposed surface by comparing the backscattered and the secondary electron images. SEM observation also revealed the fine structure of the lamina fibroreticularis using separated dermis or the lamina propria mucosae.

Animals↗

PubMed1999

Osteogenic potential of rabbit dermal fibroblasts cultured in vitro: a scanning electron microscopic study.

OBJECTIVE: To investigate further into the osteogenic potential of rabbit dermal fibroblasts with scanning electron microscope. METHODS: Split-thickness rabbit skin was processed into small chips that were cultured in vitro and then subjected to scanning electron microscopic study. RESULTS: The fibroblasts swam out from the skin chips and they increased in number rapidly and became confluent. The cells exhibited squamous configuration, possessing arboreal bifurcation and forming multi-layer structure. The fibroblasts then excreted numerous minute granules, heaping up on and around the cells. Thenceforth emerged on the cell surface fine needle-like crystals, that agglomerated with the granules to form nodules. The fibroblasts orientated themselves in a radiating pattern around the large nodules. Neighboring nodules could be linked up into trabecular structures. CONCLUSIONS: Sequence of events of new bone formation by rabbit dermal fibroblasts cultured in vitro is fully depicted and confirmed.

Journal Article↗

PubMed1979

The influence of dexamethasone on subarachnoid fibrosis after subarachnoid haemorrhage. Scanning electron microscopic study in the dog.

The author used the scanning electron microscope (SEM) to study the influence of dexamethasone on subarachnoid fibrosis after experimental subarachnoid haemorrhage (SAH). In the subchronic group of dogs, which were sacrificed three weeks after SAH, an average of 2.82 mg/kg intrathecal dexamethasone seemed to delay the fibrosis somewhat, but statistically showed no significant difference from the control group. In the chronic group, sacrificed three months after SAH, an average of 0.95 mg/kg intrathecal dexamethasone did not prevent the fibrosis, and no significant difference was found from the untreated dogs. The author considers that steroid therapy only delays and does not diminish the inflammatory process. This may also apply to other types of arachnoiditis.

Animals↗

PubMed1993

[Scanning electron microscopic observation of hydrodissected human lens nucleus].

Using a scanning electron microscope, we studied the surface structure of 5 different central nuclei, isolated by repeated hydrodissection during extracapsular cataract extraction. Aside from the damage induced by surgical maneuvers, the surfaces were very smooth, and there was no major disruption of the lamellar structure of the lens. Our studies have shown that hydrodissection, which allows atraumatic separation of the lens fiber layers, can be used to analyze the lamellar structure of the lens. Some of the evaluated specimens showed a distinct suture line and the lens fibers were approximately at right angles to it. These observations were different from those reported previously.

Aged↗

PubMed1979

Prevention of subarachnoid fibrosis after subarachnoid haemorrhage with urokinase. Scanning electron microscopic study in the dog.

The author used the scanning electron microscope (SEM) to study the influence of urokinase on subarachnoid fibrosis after experimental subarachnoid haemorrhage (SAH). In the subchronic group of dogs, which were sacrificed three weeks after SAH, an average of 45--50 IU/kg of intrathecal urokinase diminished the fibrosis. In the chronic group, which was sacrificed three months after SAH, an average of 250 IU/kg of intrathecal urokinase also had considerable reducing effect. The author supposes that fibrinolytic therapy, with lysis of blood clot, contributes to clearance of the blood. We contrast this mechanism with the mechanism and effect of antifibrinolytic therapy. This experiment is the first successful attempt to influence subarachnoid fibrosis, and also the first experiment in which subarachnoid fibrosis could to some extent be prevented.

Animals↗

PubMed1998

Argon laser irradiation effects on sound root surfaces: in vitro scanning electron microscopic observations.

OBJECTIVE: The purpose of this in vitro scanning electron microscopy (SEM) study was to evaluate the effect of low fluence (energy density of 11.5 J/cm2 and 100 J/cm2) argon laser irradiation on the surface morphology of sound root surfaces. SUMMARY BACKGROUND DATA: Previous laboratory investigations have shown that argon laser irradiation of root surfaces provided a protective effect against in vitro cariogenic challenges. METHODS: Root surfaces of extracted human molars were sectioned into treatment quarters: 1) mesiobuccal--no treatment control; 2) mesiolingual--low fluence argon laser irradiation (0.231 Watts, 11.5 J/cm2 for 10 seconds); 3) distobuccal--no treatment control; and 4) distolingual--higher fluence argon laser irradiation (2.0 Watts, 100 J/cm2 for 10 seconds). All surfaces were critical-point dried, coated with platinum and paladium under vacuum, and evaluated qualitatively for intactness, surface morphology, surface deposits, and porosities in a blinded fashion by scanning electron microscope. RESULTS: The argon lased root surfaces demonstrated alterations of root surfaces with creation of surface globular particulate material, microporosities, and depressions. Both low- and high-fluence lased root surfaces showed areas with plaque-like plates with fine punctuate oval particulate material on their surfaces. CONCLUSIONS: Argon laser irradiated root surfaces produce surface granular to globular deposits that may provide readily mobilized tooth mineral, which may become redeposited into the underlying root surface during a cariogenic challenge and enhance resistance to caries formation. In addition, microporosities created by the argon laser may provide a means for bonding fluoride-releasing restorative and preventive materials to root surfaces and further improve the root surfaces' ability to resist cariogenic challenges.

Argon↗

PubMed1989

Quantitative scanning electron microscopic autoradiography of inhaled 239PuO2.

We have applied the scanning electron microscope (SEM) to obtain autoradiographs of particles of 239PuO2 deposited in rat lung. The technique was used to obtain quantitative information on the clearance rates of particles from the alveoli, bronchioles and trachea up to 240 d after exposure. At all times, the concentration of particles on the surface of the bronchioles was an order of magnitude greater than on the tracheal surface. The clearance of Pu from both regions followed a biphasic pattern, similar to that obtained by radiometric analysis of the whole lung. Most of the radiation dose to the bronchiolar epithelium originated from Pu particles in peribronchiolar alveoli in which they were preferentially retained, compared to other alveolar regions. The prolonged retention of particles in the peribronchiolar alveoli may be a significant factor in the induction of lung carcinomas.

Administration, Inhalation↗

PubMed2004

Comparative morphometry and morphology of Anopheles aconitus Form B and C eggs under scanning electron microscope.

Comparative morphometric and morphological studies of eggs under scanning electron microscope (SEM) were undertaken in the three strains of two karyotypic forms of Anopheles aconitus, i.e., Form B (Chiang Mai and Phet Buri strains) and Form C (Chiang Mai and Mae Hong Son strains). Morphometric examination revealed the intraspecific variation with respect to the float width [36.77 +/- 2.30 microm (Form C: Chiang Mai strain) = 38.49 +/- 2.78 microm (Form B: Chiang Mai strain) = 39.06 +/- 2.37 microm (Form B: Phet Buri strain) > 32.40 +/- 3.52 microm (Form C: Mae Hong Son strain)] and number of posterior tubercles on deck [2.40 +/- 0.52 (Form B: Phet Buri strain) = 2.70 +/- 0.82 (Form B: Chiang Mai strain) < 3.10 +/- 0.32 (Form C: Chiang Mai strain) = 3.20 +/- 0.42 (Form C: Mae Hong Son strain)], whereas the surface topography of eggs among the three strains of two karyotypic forms were morphologically similar.

Animals↗

PubMed1989

Scanning electron microscopic studies of the capillaries crossing the scala tympani.

Scanning electron microscopic examinations were carried out on the perilymphatic space bordering the round window in guinea pigs. A number of small vessels were found crossing free through the lumen of the scala tympani in this area. The larger number (5-10) of these capillaries are suspended between the bony cochlear wall and the terminal net of fibrocytes which covers the cochlear opening of the cochlear aqueduct and spreads onto the basal third of the round window membrane. Other capillaries (3-5) cross the lumen of the scala tympani from the outer cochlear wall to the modiolus. All of these capillaries have a thin endothelium and a very thin pericytic covering. These findings suggest that the capillaries crossing the perilymphatic space may give rise to a different chemical composition of the perilymph bordering the round window in comparison with the more upper parts of the scala tympani.

Animals↗

PubMed1984

The scanning electron microscope as a diagnostic tool in liver pathology.

Diagnostic scanning electron microscopic (SEM) investigations can be performed in human liver biopsies after perfusion fixation. For needle and wedge biopsies transparenchymal perfusion techniques have been developed. The perfusion fluid is brought into the tissue through special cannulas and removed by suction. By means of this 'push and pull' method, a directional flow is achieved and the tissue specimens are cleaned of blood. Thus the inner surfaces of the parenchymal tissue are accessible and can be observed with SEM. Vascular changes in different liver diseases, such as sinusoidal stenosis or sinusoidal capillarization, are easily detectable. New aspects are obtained on the morphology, arrangement and the functional role of perisinusoidal cells during mesenchymal reaction. This gives new insights into the pathophysiology of the microcirculation. SEM is also of great significance in diagnosing liver tumours. It may aid in deciding the origin and differentiation of carcinomas or sarcomas. Moreover, for the first time the sinusoidal haemangioendothelioma , consisting of fenestrated sinusoidal cells, could be demonstrated with SEM. Cholestasis can be diagnosed with SEM. However, we were unable to obtain useful information with SEM for the differential diagnosis of intra- and extrahepatic cholestasis.

Biopsy, Needle↗

PubMed2003

Restoration-enamel interface with argon laser and visible light polymerization of compomer and composite resin restorations: a polarized light and scanning electron microscopic in vitro study.

This polarized light (PL) and scanning electron microscopic (SEM) in vitro study investigated the effect of argon laser (AL) and visible light (VL) polymerization on the interfaces between compomer and composite resin restorations and the enamel cavosurfaces. Surface topography by SEM revealed a smooth transition between the restorative materials and adjacent enamel surfaces with no microspaces between the restorations and enamel surfaces. The enamel surfaces showed relatively smooth surface coatings with AL curing compared with exposure of etched prism endings with VL curing. The restoration-enamel interface by PL showed an intimate relationship between the restorative materials and the cavosurface enamel. No differences were found between AL and VL polymerization. With the restoration-enamel interface by SEM, compomers and composite resins were adapted closely to the cavosurface enamel and tags of restorative material protruded into the adjacent cavosurface enamel. Both VL and AL polymerization of compomers and composite resin restorations in vitro produced closely adapted restorations with intimate restoration-enamel interfaces. Such restoration-enamel interfaces may provide a certain degree of resistance against secondary caries formation, and this may be enhanced by the caries protective effect of argon laser irradiation.

Adhesives↗

PubMed1969

Studying neural organization in Aplysia with the scanning electron microscope.

Preliminary attempts have been made to employ the scanning electron microscope in the mapping of a simple nervous system, the abdominal ganglion of Aplysia californica. Early results are encouraging: neuronal fibers have been identified and traced over relatively long distances from their cell bodies to structures tentatively identified as synapses and to structures tentatively identified as electrotonic connections.

Abdomen↗

PubMed1984

[Studies on intestinal trematodes in Korea X. Scanning electron microscopic observation on the tegument of Fibricola seoulensis]

A scanning electron microscopic study was performed to observe the tegumental surface of adult Fibricola seoulensis. The adult worms were collected from the small intestine of mice 5 days to 3 weeks after experimental infection with the metacercariae. The metacercariae were obtained from the viscera of the snakes, Natrix tigrina lateralis, by artificial digestion technique. The results were as follows: The tegument of anterior body was covered with cobblestone-like cytoplasmic processes and that of posterior body showed finger-like processes. The posterior body had 4-5 large transverse wrinklings which formed many discontinued shallow rugae. The entire surface of anterior body was regularly arranged with the spines of which tips diverged into 3 to 4 points. They were densely packed in anterior mid-median portion of dorsal surface where appeared a few spines indented upto 5 points. Farther laterally and posteriorly from this portion, the pointed spines were more sparse and became single tipped and extended to anterior one-third of posterior body. The posterior surface of oral sucker was armed with 50-60 spines having 2-3 tips and ventral sucker also covered with such spines. On anteriormost dorsal surface arranged 60-70 spade-shaped spines. The tribocytic organ was armed with many stout recurved pile-like spines arranged radially. There were 3 types of sensory papillae. The ciliated knob-like (Type I) papillae were almost bilaterally symmetrical in ventral and dorsal surfaces of anterior body, and abundant especially around bases of oral and ventral suckers, tribocytic organ, and in lateral margins of anterior body. About 24 non-ciliated round swellings (Type II) were observed around each lip of oral and ventral suckers. The plate-1ike elevated papilla without cilium (Type III) was found to distribute only in posterior body. These 3 types of papillae seem to be tangoreceptive and/or rheoreceptive in function when their morphology and distributions are considered.

Journal Article↗

PubMed1975

[The surface of nasal polyps in the scanning electron microscope].

23 specimens with endonasal polyposis are examined scanning-electron-microscopically. There is a domination of kinocilia-free epithelium. The latter is bulging out in a dome-shaped manner, extensively loosened, showing transitional forms from cylindrical epithelium to more cube-like and finally squamous epithelium. The cylindrical epithelium is partly closely joined, showing ballon-like bulgings, cytoplasmatic protuberances, filled beaker cells with reduced or missing microvilly and partially granulating surface as well as emptying beaker cells with a thin microvilly edge. The covered surface shows partially normal lawn- and/or bundle-like, long and most parallel kinociliae, and short thin kinociliae in small bundles. All of them have a coordinated direction and a morphologically evident function-phase. In addition there is a network of kinociliae without function-phase and coordinated direction, which may or may not be covered by mucous, as well as damage and reproliferation of kinociliae. By reason of the morphological findings one can come to the conclusion that there is an extensive decrease in function of the mucociliar system in case of polyposis and as a consequence of this bacterial and viral infections might be favoured.

Cilia↗

PubMed1985

The ring of Soemmerring in the rabbit: A scanning electron microscopic study.

The scanning ultrastructure of the remnants of the lens left in the eye after extracapsular lens extraction was investigated in the rabbit. Extracapsular lens extraction was performed in 25 eyes and the development of after-cataract followed by biomicroscopic examination. After survival times varying between 1 week and 12 months, the eyes were enucleated and the rings of Soemmerring treated for light microscopy and transmission and scanning electron microscopy. Soemmerring's ring consisted of the fused remnants of the dissected anterior and posterior lens capsule, enclosing the equatorial part of the former lens, left behind after the operation. The anterior capsule and, to a lesser extent, also the posterior capsule were multilayered and appeared to be thickened. While the remnant of the anterior capsule was lined by a monolayer of epithelial cells, the posterior part of the capsule was only partly lined by irregularly arranged epithelial cells. All epithelial cells were highly vacuolized. In transection the interior part of the ring consisted of normal fibers, irregularly oriented and irregularly shaped fibers, degenerated fibers, and globular amorphous masses. Many of the normal fibers contained cell nuclei. At the equator and at the posterior side of the fusing anterior and posterior capsule as well, the fiber organization resembled the lens bow region of normal lenses. Frequently, islands of epithelial cells were observed in the center of the ring. The vitreal face of the posterior capsule in the center of the ring (in the optic axis of the eye) seemed to be unchanged and on its pupillary surface, fibers of different size as well as fibroblastlike cells were found. However, clear-cut Elschnig's pearls were absent. Our results are compared with the observations summarized in the literature. It can be concluded that the epithelial cells in Soemmerring's ring retain their capacity for division and differentiation. The newly formed fibers seem to be pushed to the center of the ring and to degenerate.

Animals↗

PubMed1993

The sublingua and tongue of Tupaia (Scandentia, Mammalia): a scanning electron microscope study.

The surface morphology of the tongue and the sublingua in Tupaia belangeri was examined both under the dissection microscope and with the scanning electron microscope. Shape and structural differentiation of the sublingua and the anterior ventral part of the tongue are described. Special types of papillae were found on the lingual segment of the keel, along the serrated edges of the sublingua, and at the apex linguae. The findings are discussed with respect to the special conformation of the oral cavity of Tupaia and in relation to the evolutionary and functional significance of the tongue and the sublingua in this species.

Animals↗

PubMed1990

The clinicopathologic, light, and scanning electron microscopic features of eperythrozoonosis in four naturally infected llamas.

The hematologic, biochemical, and light and scanning electron microscopic features of eperythrozoonosis in four llamas are described. One female and three male yearling llamas were presented for evaluation of chronic weight loss. Three of four llamas had historical evidence of chronic inflammatory conditions. On examination, multiple clinical problems were apparent, including poorly to non-regenerative anemia, inflammatory disease, and hypoproteinemia. Coccoid- and ring-shaped basophilic organisms were present on the erythrocytes of all the llamas. On scanning electron microscopy, individual, pairs, and clusters of coccoid-shaped organisms were present on the erythrocytes. The organisms measured 0.4 to 0.6 micron in diameter and caused no marked deformation of the erythrocyte membrane. A rare organism could be found that produced a slight indentation into the erythrocyte membrane. The light and scanning electron microscopic morphologic features suggested that the organism was an Eperythrozoon. Serial evaluation of serum iron concentrations of the llamas showed a decrease serum iron in all animals, with a concurrent decrease in the total iron binding capacity and percent transferrin saturation in two of the llamas. Common abnormalities seen on serum electrophoresis included a decrease in albumin and beta serum fraction in all llamas and a decrease in the gamma globulin fraction of two individuals.

Anemia↗