PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “scanning electron microscope”

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 145 records · Page 8Linked to original sources
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↗
PubMedDate not supplied

Scanning electron microscope imaging of onychomycosis.

Although scanning electron microscope technology has been used for more than 60 years in many fields of medical research, no studies have focused on obtaining high-resolution microscopic images of onychomycosis of the toenail caused by Trichophyton rubrum in a geriatric population. To provide new insight into the intricate structure and behavior of chronic toenail onychomycosis, we produced three-dimensional images of onychomycosis obtained from two geriatric patients with confirmed growth of T rubrum. The photomicrographs illustrate the pervasive integration and penetration of the fungus hyphal elements, underscoring the clinical difficulty of obtaining rapid treatment of fungal infections in the distal and lateral subungual space of the human toenail. Although the scanning electron microscope may not be a practical diagnostic tool for most physicians, it remains invaluable for the researcher to obtain insight into the spatial orientation, behavior, and appearance of onychomycosis.

Aged↗
PubMed1997

[Histological findings in aneurysm treated with IDC: scanning electron microscopical study].

We reported the scanning electron microscopic findings of an aneurysm embolized with interlocking detachable coils (IDC). A 78-year-old man was referred to our hospital because of left hemiparesis and dysphagia. CT scan showed multiple lacunar infarction in the bilateral corona radiata. Angiography demonstrated a small incidental aneurysm of the right internal carotid artery (IC-PC junction). The left hemiparesis gradually improved and 2 weeks after admission the aneurysm was treated with IDC. Three coils were placed in the aneurysm and post-operative angiography demonstrated complete embolization. Dysphagia caused by the pseudobulbar pulse did not improve and, 4 weeks after endovascular surgery, the patient died of aspiration pneumonia. An autopsy was performed and the scanning electron microscopical findings of the aneurysm showed development of endothelial cells on the coil surface. Many clinical reports supported the usefulness of Guglielmi detachable coils (GDC) and several experimental reports demonstrated the intimal proliferation in aneurysms embolized with coils. However, pathological changes of the aneurysms treated with coils have been reported in only four clinical cases. There was no evidence of endothelialization in any of these cases. To our knowledge, our case is the first report describing the endothelial proliferation over the coils. It is necessary to accumulate histopathological data and long-term follow-up in humans treated with coils.

Aged↗
PubMed1982

The environmental scanning electron microscope and its applications.

An environmental scanning electron microscope can be made by incorporating a pressure limiting aperture at some distance below the objective aperture of an SEM, and by providing independent pumping between these two apertures. Tilting of the pressure limiting aperture with respect to the axis of the electron optics column redirects the gas jet which develops above the pressure limiting aperture and which otherwise would inject excessive gas through the objective aperture into the column. The detection of backscattered and multiple-backscattered electrons is achieved below the pressure limiting aperture in the region confined by the sample, the detector and the aperture grid. Wet specimens can be examined in the environmental scanning electron microscope at 7kV and TV rates by placing them at a sufficiently close distance to the pressure limiting aperture. Live seedlings and ants have been observed in this way. Wet (fresh) rat tissues, wool fibers subjected to various treatments, crystallization and rewetting of salts, and some radiation effects have been observed and recorded under the environmental scanning electron microscope. Examination of specimens in the full pressure range, 0-1013 mbar, is possible. A detector-aperture system which will allow the signal originating from the sample to be detected simultaneously both below and above the aperture is under construction. Further development of environmental scanning electron microscopy now depends upon close co-ordination between microscope manufacturers and research groups involved in such fields as biology, fiber technology, radiation and physical chemistry.

Animals↗
PubMed1988

Silver accumulations in periapical granulomas: report of five cases using the scanning electron microscope, the electron microprobe, and other complementary methods.

A series of cytologic imprints obtained from periapical granulomas were studied with the conventional light microscope, the scanning electron microscope, and the electron microprobe to analyze the chemical composition of several black deposits that were randomly observed near or in the cytoplasm of macrophages and multinucleated giant cells. These granulomas had been removed from endodontically treated human teeth in which the root canals had been obturated with silver cones and Grossman's sealer 3 to 5 years previously. To investigate whether corrosion had occurred on the silver cones, the cones were also examined with the scanning electron microscope and the electron microprobe. Our observations revealed that all the examined silver cones showed different degrees of corrosion on their surfaces, whereas different concentrations of silver, sulfur, and chlorine were detected at the same sites in the cytologic imprints. However, it is impossible to determine from this study whether the presence of corrosive by-products in the periapical tissues is responsible for the development of a pathologic reaction at these sites.

Adolescent↗
PubMed1993

[Origin of bone hyperplasia in osteoarthritic femoral head: a scanning electron microscopic study].

Total hip replacement was carried out in 7 Patients suffering from osteoarthritis of the hip joint. They were given tetracycline preoperatively to label the newly formed bone tissues. The excised femoral heads were processed into undecalcified specimens, which were subjected to fluorescence microscopic and scanning electron microscopic studies. Narrow ribbon-shaped golden fluorescence could be observed along the trabeculae, reflecting newly formed bone by the cambium layer of the periosteum, while in the intertrabecular space both reticular and particulate and ball-shaped fluorescence could be detected, implying newly deposited bone by the marrow stromal cells. Under scanning electron microscope, the reticular new bone produced the new secondary trabeculae. The particulate and ball-shaped new bone tissues were deposited on the surface of the trabecular periosteum and filled up the inter-trabecular space. All these new bone tissues accounted for the bone hyperplasia or the osteoarthritic femoral head.

Femur Head↗
PubMed1991

Ultrastructure of the perineurial cell of the sciatic nerve in rats--a transmission and scanning electron microscopic study.

The perineurial cells of the sciatic nerve of mature albino rats were investigated by using light microscope (LM), transmission electron microscope (TEM) and scanning electron microscope (SEM). The perineurium of the sciatic nerve was composed of several lamellae of thin perineurial cells which were held together by the zonula occludens and also by the zonula adherens. The TEM view of the perineurium revealed that the plasmalemma of the perineurial cells presented numerous caveolae similar to those described in the endothelial cells of blood capillaries. By SEM, the perineurial cells were very thin, flattened out with various shapes from rectangular to hexagonal, and arranged closely to each other in the fashion of a stone pavement around the nerve fascicles. It was possible to isolate the perineurium from the nerve and to demonstrate the cellular border of the perineurial cells by silver impregnation method. The SEM observation of the perineurial cells ascertained the figure of the cells which were seen in the silver-impregnated specimen under LM. The present authors have interest in the fact that shape and arrangement of the perineurial cells of spinal nerves resemble closely those of the myoid cells in the limiting lamina of the seminiferous tubules of the mammalian testes. The meaning and significance of the similarity between these two types of cells was discussed.

Animals↗
PubMed1982

Birefringence and mineral content of the first stage of artificial carious lesion formation (a combined polarizing microscopic, microradiographic and scanning electron microscopic investigation).

Artificial carious lesions were made using acetic buffer solutions of pH 6.0 containing calcium and phosphate. The solutions were highly undersaturated with respect to hydroxyapatite. Out of 72 lesions 51 showed subsurface demineralization, whereas in 21 only a superficial demineralization occurred. These superficial lesions were examined using polarized light microscopy, microradiography and scanning electron microscopy. This superficial breakdown of enamel material, considered as the initial demineralization of the enamel, appeared to occur at the prism junctions. This was indicated by the polarizing microscope technique and was made clearly visible using scanning electron microscopy. Quantitative polarizing microscopy and microradiography revealed results which correlated very well. From this it is probable that the initial superficial demineralization of the enamel is--under the described conditions--a simple dissolution reaction.

Birefringence↗
PubMed1995

Scanning electron microscopic evaluation of two compaction techniques using a composite resin as a root canal filling material.

The canals of 20 human dental roots were instrumented using a a step- back technique. The smear layer was removed, and the canals were obturated with composite resin. Two different techniques of compaction were used: either vertical or lateral motions were used to condense composite resin inside the root canal that was then photopolymerized layer by layer using the argon laser (488 nm). The beam was delivered into the root canal by means of an optical fiber 320 micrometers in diameter. Longitudinal and cross-sections of the samples and resin replicas of the root canals were examined using a light and scanning electron microscope. Scanning electron microscopic examination revealed that laterally compacted resin fillings showed fewer voids than those obtained by vertical compaction. In both experimental groups, adhesion of the resin to the dentin walls, pulled-out resin tags, microfailure, and resin fracture, leaving a layer of resin associated with the wall surface were observed.

Argon↗
PubMed1999

Two in-office bleaching systems: a scanning electron microscope study.

The purpose of this investigation was to analyze by scanning electron microscopy the effects of heated and light-absorbing bleaching agents on enamel surface morphology. Twelve freshly extracted human anterior teeth were selected for this study. The teeth were randomly divided into four equal groups: Group I (control), Group II (teeth treated with Opalescence Quick, a heated bleaching agent), Group III (teeth treated with Opalescence Xtra, a light-absorbing bleaching agent), Group IV (teeth treated with Ultra-Etch 35% phosphoric acid etchant). After receiving a prophylaxis with a slurry of pumice, the bleaching materials were applied to the facial enamel surfaces following the manufacturer's specifications. The teeth in Group IV were etched for 15 to 20 seconds, washed, and air-dried. All specimens were prepared for scanning electron microscope evaluations. Scanning electron microscope micrographs indicated that only those specimens etched with phosphoric acid (Group IV) exhibited an etching pattern on the enamel surface. No differences in enamel surface morphology were observed between the untreated control specimens and the specimens treated with the bleaching materials.

Carbamide Peroxide↗
PubMed1998

Visualization of bacterial glycocalyx with a scanning electron microscope.

Using a new technique for scanning electron microscopic preparation, bacterial glycocalyx is seen in its natural, highly hydrated state for the first time. Visual images of the glycocalyx obtained from these preparations are a marked departure from the visual images of glycocalyx obtained previously with conventional scanning electron microscopic analysis. The dominating presence of glycocalyx visualized in its naturally hydrated state gives credence to the role of bacterial glycocalyx as a mechanical barrier to host defenses and antibiotics and supports the role of glycocalyx as a significant factor in bacterial virulence.

Animals↗
PubMed1980

A correlative light microscopic, transmission and scanning electron microscopic study of the dorsum of human tongue.

The dorsum of the human tongue has three types of papillae, filiform, fungiform and circumvallate. Some investigators have studied these by light and transmission electron microscopy. Since knowledge of the morphology through studies by scanning of the morphology through studies by scanning electron microscopy (SEM) is scant, this investigation was started with the purpose of studying human tongues at different ages. One fetal tongue and portions of three tongues from newborns were removed. Additional specimens were biopsied from the anterior region of three adult tongues. Samples were processed routinely for light microscopy, transmission electron microscoy (TEM) and scanning electron microscopy (SEM). Two distinct features were evident on the fetal tongue. The first was that the surface epithelial layer of the tongue appeared to be periderm. The second was that fungiform papillae began their development earlier than filiform. At birth, the putative periderm had disappeared and a few filiform papillae were observed. On the adult tongue, filiform papillae were numerous and were comprised of two cell populations. One cell population contained numerous keratohyalin granules (KHG). The KHG were two types, eosinophilic and basophilic. Ultrastructurally, the eosinophilic granules were less electron dense and larger in size than the basophilic KHG.

Adult↗
PubMed1982

The comparison scanning electron microscope within the field of forensic science.

A brief historical view of the origin, development, and application of the light comparison microscope is given. Problems emanating from restricted depth of focus in light-microscopical techniques are eliminated by utilizing the scanning electron microscope. Various attempts have been made to use the scanning electron microscope suitable for comparison microscopy: videotape, image storage tube, split field scan. In 1980 another way of performing scanning electron comparison microscopy was contrived: the coupling of two instruments. Both instruments are equipped with several electron detection systems, which produce special contrast effects. For applications with the comparison scanning electron microscope in forensic science a number of interchangeable specimen holders, were designed.

Forensic Medicine↗
PubMed1980

Scanning electron microscope studies of solar elastosis.

Scanning electron microscope findings of solar elastosis were compared with those of normal dermis in specimens digested by hyaluronidase and by autoclaving. Solar elastosis showed amorphous masses and broad fibres with irregular shapes and sizes in specimens digested by hyaluronidase, while it showed only fibrous structures in those after autoclaving. It is suggested that the origin of solar elastosis is elastic tissue.

Aged↗
PubMed1995

Scanning electron microscopic analysis of breast aspirates.

Scanning electron microscopic analysis (SEM) of 50 pre-selected breast aspirates was performed after light microscopy and cytomorphological evaluation. SEM analysis of these aspirates revealed the presence of microvilli (mv), microprojections, blebs and irregular contours in malignant cells. Benign cells were regular, globular and smooth. SEM provided additional morphologic data which if used in conjunction with light microscopy can assist in reaching a correct diagnosis.

Adolescent↗