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At least 271 records · Page 15Linked to original sources
PubMed1991

The scanning electron microscope in the pathology of varicose veins.

We studied varices of the lower limb by scanning electron microscope (SEM) in 29 women who had undergone surgery under local anesthesia for symptomatic varicose veins. Their ages ranged between 19 and 42 years (average 30). They were all diagnosed as having incompetence of the valve at the saphenofemoral junction. The surgical procedure was high ligation of the long saphenous vein, excision of the upper portion of the vein and multiple excision of all the varices along the leg through several tiny incisions. Segments of the removed varices and the upper portion of the long saphenous vein were prepared and studied by the Jeol scanning electron microscope (Japan, model 355c). We found no changes in the intima or adventitia and no changes in any of the upper valves of the saphenous vein; however, varying degrees of thinning of the media of the venous wall were seen, which coincided with the areas of varicose dilatation between areas that retained their normal configuration. Our study therefore supports the "weak vein wall" theory concerning the etiology of varicose veins, and confirms that surgery for varicose veins of the lower limb must concentrate on removal of the varices themselves. Since these often lie outside the long saphenous vein, routine stripping is neither advisable nor effective.

Adult↗
PubMed1992

[Clinical and scanning electron microscopic studies on Norwegian scabies infection].

Two typical cases of Norwegian scabies were studied clinically, scanning electron microscopically and histopathologically. Case 1 was a boy with Down's syndrome and case 2 was a man with adult T cell leukemia/lymphoma. Their clinical pictures showed hyperkeratotic plaques and warty crusts on hands, feet, ears, elbows and buttocks. Direct examination of the KOH preparation revealed many embryonated sarcoptic eggs, postpartum egg-shells, fecal pellets, larvae and male and female adult mites. Histopathologic examination showed several burrows inside the thick horny layer. Many sarcoptic egg-shells, mites and fecal pellets were found in the burrows. Psoriasiform hyperplasia and parakeratosis were noted, too. The size and shape of the sarcoptic eggs and the detailed structure of mites and molt were observed by using a scanning electron microscope. Besides, hook-like structures were noted at the tarsi of both forelegs and hindlegs. We suggest that the larvae crawl out from longitudinal openings in the egg-shell by the use of hook-like structures. The mites also used these hook-like structures to make the burrows. Scanning electron microscopy provides a good method to understand the dynamics of these burrowing parasites. It is helpful in illustrating the behavior of the scabies mites in their burrows in Norwegian scabies patients.

Adolescent↗
PubMed1975

A wet stage modification to a scanning electron microscope.

A modification to the vacuum system of a JSM2 scanning electron microscope has enabled hydrated specimens to be placed inside the specimen chamber of the instrument and to be surronded by water vapour at a pressure up to approximately I 3-kPa (10 Torr). The surface topography was observed by detecting the backscattered electrons using a wide angle backscattered electron detector placed close to the specimen. The microscope was operated in the normal scanning mode which allowed the examination of the surface topography of the specimens, whilst still retaining the depth of focus which is a feature of the SEM. This modification has enabled a resolution of approximately 0.2 mum to be obtained from biological specimens partially immersed in water at temperatures just above 0 degrees C.

Microscopy, Electron, Scanning↗
PubMed1993

Effect of ArF-193 nm excimer laser on human dentinal tubules. A scanning electron microscopic study.

The purpose of this study was to evaluate the effects of the ArF-193 nm excimer laser on the dentinal tubules of extracted human teeth under a scanning electron microscope. Fifteen 3 mm thick slices were cut with an electric saw at the cementoenamel junction from 15 extracted human teeth. A diamond bur was used to remove the cementum layer and expose the dentinal tubules. Each slice was scored by a permanent marker into four equal quadrants. The ArF excimer laser was applied for 5 seconds on three of the quadrants with fluences that ranged from 0.2 J/cm2 to 15 J/cm2 and pulse repetition of 25 Hz. The untouched quadrant served as a control. The specimens were mounted on stubs, sputter coated by gold, and examined by a scanning electron microscope. The effects of the ArF excimer laser irradiation varied. Laser fluences of 0.2, 0.5, and 1.0 J/cm2 had no effect. Although fluence of 15 J/cm2 caused significant removal of peritubular dentin, melting and resolidification of the dentinal smear layer was also observed under the scanning electron microscope with a laser fluence of 5 J/cm2.

Argon↗
PubMed1978

[Experimental brain tumors produced transplacentally by ethylnitrosourea (IV): ultrastructure studied by using transmission and scanning electron microscope (author's transl)].

The fine structure of rat gliomas induced transplacentally with a single i.p. dose of 50 mg/kg of Ethylnitrosourea has been studied by using transmission and scanning electron microscope. The subependymal matrix layers of the fetus which was affected by ENU have showed irregular and rough arrangements with expanded extracellular spaces as compared with that of control rats. The cells of subependymal layer seemed to form the microtumor. A so-called "microtumor", which was found in a 8 week old, has been composed of small round cells. The fine structures of these cells have showed the characteristics in primitive oligodendroglioma. The characteristics of the fine structure of astrocytoma cells was identified by both TEM and SEM. The fine structure of subependymal glioma cells was often pleomorphic. These gliomas contained a mixture of primitive oligodendrocytes and ependymal cells together with anaplastic glial cells. With increasing size, the glioma has become more pleomorphic with a mixture of neoplastic oligodendrocytes, astrocytes and ependymal cells, and ependymoma like cells have showed neither cilia nor junctional complex. Abnormal vascular structure in the tumor has been reconfirmed by injection replica scanning electron microscope method. The fine structure of the separated single tumor cell surface was also studied by scanning electron microscope. The differences of the cells surface between that of astrocytoma cell and oligodendroglioma cells were clearly noticed.

Animals↗
PubMed1975

Scanning electron microscopic observations of the human respiratory tract.

As viewed by scanning electron microscopy, the luminal surface of the human trachea at 12 weeks' gestation shows a predominance of microvillous-covered, nonciliated cells, in contrast to the heavily ciliated tracheobronchial surface seen at 34 weeks' gestation. Hyaline membrane disease produces a confluent lining material in the lung periphery that obscures the bronchiolar and alveolar surface architecture. Large saucer-shaped alveoli, numerous alveolar pores, and an abundance of in situ alveolar macrophages are observed in chronic bronchitis and in emphysematous lungs; The scanning electron microscope offers an additional tool for the study of developmental and pathological processes in the human respiratory tract.

Bronchi↗
PubMed1976

Scanning electron microscopic study of chylomicrons incubated with lipoprotein lipase.

The effects of lipolysis on the structure of chylomicrons were studied with the scanning electron microscope using rat chylomicrons incubated with purified bovine milk lipoprotein lipase for 20 minutes at pH 8.1. Since the amount of albumin added to the medium was limited, some of the free fatty acids and partial glycerides formed by lipolysis accumulated in the chylomicrons. Lipolyzed chylomicrons fixed with OSO4 at pH 7.4 appeared in scanning electron micrographs as spheres with multiply idented irregular surfaces, while those fixed at pH 5.5, AS WELL AS CONTROL CHYLOMICRONS FIXED AT BOTH PHs, appeared as spheres with smooth surfaces. Sections of OSO4-fixed specimens, viewed with the transmission electron microscope, showed that the core of lipolyzed chylomicrons fixed at pH 7.4 contained numerous circular electron-lucent areas at the periphery, thus accounting for the indented surfaces observed above, while the core surfaces of the other specimens were circular and smooth. These findings confirm an earlier report that aqueous spaces form in chylomicrons during lipolysis when albumin in the medium is limited, and that the aqueous spaces disappear when specimens are prepared at pH 5.5 for microscopy. Thin sections of specimens that had been prepared for scanning electron microscopy showed that the gold-palladium coating was desposited directly on the indented surface of the lipid core of lipolyzed chylomicrons fixed at pH 7.4. It is concluded that vacuum dehydration during specimen preparation ruptures the outer wall of the aqueous spaces in lipolyzed chylomicrons and thereby exposes the interior of the spaces to gold-palladium coating and viewing with the scanning electron microscope.

Animals↗
PubMed1976

Glycerinated glycol methacrylate mounting medium in highlighting non-coated or glycerin-substituted microsamples under the scanning electron microscope.

Glycol methacrylate hardened with 10-15% glycerin showed no charging and gave dark contrast in the scanning electron microscope with an acceleration voltage of 25kV and a specimen current of 1x10(-10) A. Using human blood cells, it was shown that this conductively treated resin is a useful mounting substrate to highlight the non-coated microsamples or to obtain their highly contrasted images under the scanning electron microscope. It was also demonstrated that the glycerin-substituted blood cells can be scanned with little shrinkage.

Acrylates↗
PubMed1976

[Biological and medical applications of the cathodoluminescence in the scanning electron microscope (author's transl)].

The light emission according to the excitation of solids and molecules by electrons--named cathodoluminescence--extends the analytical field of applications of the scanning electron microscope. This method can be applied in biological and medical research. It can be used for the investigation of marked specimens similar to the fluorescence microscopy. The autoluminescence of some substances can also be used for special applications. The cathodoluminescence in the scanning electron microscope has the advantage that more sensitive detector-systems can be used than with the fluorescence microscope. Moreover, in the scanning microscope it is possible to combine the cathodoluminescence mode with other imaging or analytical equipments.

Beta Particles↗
PubMed1986

Scanning electron microscopic study of the surface of feline gastric epithelium: a simple method of removing the coating material.

Scanning electron microscopic examination of the gastric surface epithelial cells is often hindered by the presence of a coating material. Several methods for removal of coating material on feline gastric mucosa were utilized. The cleansed tissues were evaluated using the scanning electron microscope to assess damage caused by the use of various cleansing methods to surface epithelial cells. The stretched stomach washed several times, including rubbing the mucosal surface with gloved fingers, yielded the best results with no apparent damage to the surface epithelial cells. Flushing unstretched stomachs with saline only did not adequately remove coating material. Flushing unstretched stomachs with saline while stroking the surface with a cotton tipped applicator stick removed debris but damaged the surface epithelium.

Animals↗
PubMed1987

Scanning electron microscopical observations on electrically fused human lymphocytes.

The paper describes scanning electron microscopic observations of electric field induced fusions of human lymphocytes. The cells were fused by application of short-time (20 microseconds) field pulses of 5 kV/cm after dielectrophoretic collection at about 1.2 MHz and 750 V/cm. Electron microscopy clearly demonstrates membrane fusion and the stability of initial stages of fusion.

Cell Fusion↗
PubMed1983

Scanning electron microscopic ultrastructural alterations of the pulmonary alveolus in experimental drowning.

Scanning electron microscopic structural and ultrastructural alterations of alveolar wall in experimental drowning are described. The results obtained confirm the literature's data. Peculiar microlesions affecting Type I alveolar cells, the basement membrane, and sometimes the capillary endothelium could also be observed. Finally, Type II alveolar cells show alterations which could be related with a possible direct action of the drowning liquid.

Animals↗
PubMed1989

A method for visualizing cytoskeletal structures by the scanning electron microscope.

The cytoskeleton of intestinal epithelial cells was observed by scanning electron microscope (SEM). Tissues were treated with Triton X-100, stained to enhance conductivity, and freeze-fractured in liquid nitrogen. With these procedures, not only the localization of core filaments (actin-containing microfilaments) and intermediate filaments but also the relations between fibrous structures and cell organellae were clearly revealed. This conventional method is of great value in interpreting the three-dimensional organization of intracellular fine structures.

Animals↗
PubMed1987

Effect of linear alkyl benzene sulfonate in skin of fish fingerlings (Cirrhina mrigala): observations with scanning electron microscope.

Pathomorphological changes in the skin was noticed under the scanning electron microscope in fish fingerlings (Cirrhina mrigala) exposed to 0.005 ppm (25% of the LC50) concentration to linear alkyl benzene sulfonate. The epithelial cells present in the epidermis of the skin were found to secrete more mucus with linear alkyl benzene sulfonate (LAS) than did controls. The presence or deposition of mucus on the surface of skin indicated likely molecular interaction between constituents of mucus and LAS.

Animals↗
PubMed1981

[The safety of diagnostic continuous wave ultrasonic irradiation-a clinical study serum hemoglobulin level and scanning electron microscopic finding of maternal and cord blood in vitro (author's transl)].

In order to check the safety of diagnostic continuous wave ultrasonic irradiation, a clinical study, serum hemoglobin level and scanning electron microscopic finding of ultrasound irradiated blood were studied. The following results were obtained. 1. Clinical study: Ultrasonic examination were carried out on 6788 pregnant women at the first trimester of gestation. In test group, rate of abortion and premature delivery, fetal malformation and small for date gestation were not significant higher than those of control group. Neither timing of first examination nor number of examinations at the first trimester seemed to increase above mentioned abnormality. 2. Serum hemoglobin level: Blood exposed 2 to 12 hours to low intensity ultrasound (20 mw/cm2) showed significantly higher serum hemoglobin level than that of control group. However, blood exposed 40 to 120 minutes to high intensity ultrasound (2.6 w/cm2) have significant higher hemoglobin level than that of control group. 3. Scanning electron microscopic finding: Erythrocyte exposed 4 to 24 hours to low intensity ultrasound have no significantly different scanning electron microscopic finding when compared to that of control group. However, deformed erythrocytes were significantly higher than those of control group after exposure to 40 to 120 minutes to high intensity ultrasound.

Accident Prevention↗
PubMed1987

Scanning electron microscopic search for peritubular dentine in some early perissodactyls.

A scanning electron microscopic study has shown the presence of a typical layer of peritubular dentine in Hyrachyus. An homogeneous ring-shaped layer in continuity with intertubular dentine and considered as peritubular dentine despite its acid resistant character was observed around the lumens of dentinal tubules in Protungulatum, Tetraclaenodon and Propachynolophus maldani teeth; there is some evidence that the acid solubility of peritubular dentine has been altered during fossilization. No peritubular dentine was found in Phenacodus, Hyracotherium or Homogalax.

Animals↗