SEARCH · PubMed Health

Results for “Microscopy, Electron, Scanning”

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 1,243 records · Page 69Linked to original sources

PubMed1979

Blood vessels in the tongue of the kitten: scanning electron microscopy of microcorrosion casts.

The subepithelial blood vessels of the dorsal surface of the tongue in young kittens has been studied by scanning electron microscopy of micro-corrosion casts. These vessels entwine the vallate papillae distributed in the pharyngeal part of the tongue, form hairpin loops in association with the small conical papillae along the sides and at the tip of the tongue and establish regularly distributed subpapillary conglomerations over almost its entire oral part. These conglomerations lie directly on veins. Small arterioles reach the vessels surrounding the individual subpapillary conglomerations. By contrast with the arrangement of the superficial vascular bed in the tongue of the dog and some other mammals, no anastomoses between arteries and veins were observed in the kitten between the vessels which supply and drain the subepidermal capillaries.

Animals↗

PubMed1975

Scanning electron microscopy of ascospores of Debaryomyces and Saccharomyces.

Ascospores from species of Debaryomyces and the Torulaspora-group of Saccharomyces were examined by scanning electron microscopy. Ornamentation on ascospores of D. hansenii varied from short to long interconnected ridges or broad based, elongated conical protuberances. A spiral rigde system was detected on the ascospores of D. marama, but wart-like protuberances occurred on those of D. cantarelli, D. castellii, D. coudertii, D. formicarius, D. phaffii, D. vanriji and D. yarrowii. Ascospores of D. halotolerans did not have protuberances and the species appears to be identical with Pichia farinosa. Wart-like protuberances also were found on ascospores of S. delbrueckii, S. microellipsodes, S. rosei, S. inconspicuus, S. fermentati, S. montanus and S. vafer, but the ascospore surface of S. pretoriensis was covered by fine ridges. Short tapered ridges covered the ascospores of S. kloeckerianus.

Cell Wall↗

PubMed2004

New morphological data on Cheilospirura hamulosa (Nematoda, Acuarioidea) by means of bright-field and scanning electron microscopy.

This study reports on the morphology and morphometry of the nematode Cheilospirura hamulosa on the basis of bright-field and scanning electron microscopy. Specimens were recovered after necropsies of 28 Brazilian ring-necked pheasants ( Phasianus colchicus) and 30 domestic chickens ( Gallus g. domesticus) from backyard flocks. Measurements relate to the buccal capsule in the males and the distance of the excretory pore from the anterior end in both sexes, while the vulva and ovijector are studied for the first time. The most important taxonomic characters for the diagnosis of this nematode are the four long, longitudinal cordons which are neither anastomosed nor recurrent. They are composed of a groove with margins formed by cuticular specializations that change in appearance and width backward along the body and which run backward from the cephalic region ending near the posterior end as a cuticular depression. According to their morphology, these cordons could probably have nutritional, attachment and/or sensory functions.

Animals↗

PubMed1981

Scanning electron microscopy of the central nervous system. I. The cerebellum.

The fine structure of the cerebellar cortex has been studied by means of scanning electron microscopy (SEM). The neuropil is revealed by careful tearing of aldehyde-fixed tissue specimens which are prepared by means of dehydration, critical point freeze-drying, and sputter-coating with gold-palladium. Specimens are subsequently viewed at magnifications of up to X 16,000 with capabilities for extension up to about X 40,000. The technique provides remarkable three-dimensional views of neuropil including cell bodies and dendrites, details of presynaptic and postsynaptic morphology, axonal structure, neuroglia, and the microvasculature. It seems particularly powerful in demonstrating relationships between neuropil elements such as the terminal synaptic array on neuron somata and the arrangements of structures on membrane surfaces.

Animals↗

PubMed1994

Cytoskeletal organization of the vestibular sensory epithelia: saponin perfusion method for observing intracellular structures by scanning electron microscopy.

The cytoskeletal organization of the guinea pig vestibular sensory epithelial cells were investigated by the use of saponin perfusion method using scanning electron microscopy. The skeletal framework of a cell is composed of thin (actin or intermediate filaments) and thick filaments (microtubules). The membrane bound organelles such as nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, etc. were also well demonstrated. This made it possible to investigate the three-dimensional structures of cytoskeletons as well as their complex interactions with various membranes bound organelles. It is therefore suspected that this technique may provide us further information about distribution, topographic relationships, and the functional role of cytoskeletons.

Actin Cytoskeleton↗

PubMed1998

Articular cartilage of the rabbit knee after synovectomy: a scanning electron microscopy study.

We sought to study the effect of synovectomy on the surface morphology of articular cartilages of the rabbit knee using scanning electron microscopy (SEM). Fifteen rabbits were surgically synovectomised and allowed to regenerate their synovia during time intervals ranging from 3 to 44 wk. Cartilage specimens were shaved from 5 distinct articular sectors of synovectomised, contralateral and sham-operated knees and prepared for SEM using tannic acid. Applying structural reinforcement by tannic acid was found to secure the in vivo surface morphology of the cartilages and thus production of surface irregularities during preparation was excluded. The surface morphology of cartilages both from the synovectomised and contralateral joints was found to differ from that of intact healthy rabbits. A 'chaotic' nature of the altered cartilaginous morphology persisted as late as 44 wk postsynovectomy. Cartilages from sham-operated joints did not differ detectably from normal cartilages.

Animals↗

PubMed1991

Freeze-substitution techniques for preparing nematodes for scanning electron microscopy.

The effect of different substitution times, temperatures and the incorporation of fixatives on the preservation of three species of nematode for scanning electron microscopy by freeze substitution with methanol, followed by critical point drying, is investigated. Hammerschmidtiella diesingi adults and Trichostrongylus colubriformis infective juveniles were successfully preserved using methanol at 253 K as the substitution medium. Preservation deteriorated with long substitution times, suggesting the extraction of material and that substitution times should be kept as brief as possible. Panagrolaimus davidi was not successfully preserved using pure methanol, but preservation was improved by using fixatives in the substitution medium, the best results being obtained with 1% OsO4/3% glutaraldehyde in methanol. A substitution temperature of 193 K did not give any improvement in preservation. The differences in the quality of preservation between the three species may be due to the relative ability of the cuticle to withstand collapse during critical point drying. Chemical fixation using cold fixative resulted in the retention of a natural posture but poor preservation, whereas hot fixatives resulted in good preservation but the loss of a natural posture. Freeze substitution in methanol may prove useful in the preparation of specimens possessing cuticles or cell walls which have sufficient strength to withstand the drying process (e.g. arthropods, plants, fungi, nematodes). More delicate specimens may require the incorporation of fixatives into the substitution medium or conventional fixation.

Animals↗

PubMed1993

Silver-enhanced colloidal-gold labelling of rabbit kidney collecting-duct cell surfaces imaged by scanning electron microscopy.

The luminal cell surfaces of rabbit kidney cortical collecting-duct cells were labelled with peanut lectin (PNA) and investigated by scanning electron microscopy. Labelling was performed either on 20-microns-thick cryostat sections from prefixed and cryoprotected rabbit kidney tissue or on cultured collecting-duct epithelium using biotinylated PNA and a 6-nm colloidal-gold-coupled antibody against biotin. Colloidal-gold labels were detected at low magnification (2000-4000x) using silver enhancement. Coating with chromium allowed simultaneous imaging of both cell-surface morphology and labelling topography in the backscattered electron imaging mode. Our results show that PNA binding is specific for a subtype of intercalated cells equipped with microvilli on the luminal surface. The presented method promises to be useful for the identification of specific cell types in heterogeneous tissues.

Aging↗

PubMedDate not supplied

Scanning electron microscopy of mechanically isolated seminiferous tubules of the rat testis.

The mechanically isolated seminiferous tubules of the rat testis were studied by scanning electron microscopy. The surface of the tubules is formed by lymphoid endothelial cells. These cells completely surround the seminiferous tubules and form the inner lining of the lymphatic space that lies around the seminiferous tubulus. Between the cells there are groves which correspond to the fenestrations seen in transmission electron microscopy.

Animals↗

PubMed1980

Scanning electron microscopy in the study of normal, inflamed and neoplastic human urothelium.

Seventy-two samples of human urothelium have been examined by scanning electron microscopy (SEM) and the appearances compared with those of conventional light microscopy. Six main SEM cell types were recognised. None was diagnostic of malignancy; in particular, the presence of surface pleomorphic microvilli was not pathognomonic. However, the relation of the SEM appearance to malignancy and the accepted histological grades and clinical stages of malignancy was such as to warrant further examination.

Epithelium↗

PubMed1977

Scanning electron microscopy of budding and metamorphosis in Discophrya collini (Root).

Budding and metamorphosis in the suctorian ciliate, Discophrya collini, have been investigated by scanning electron microscopy. The adult body form, tentacles, stalk, and attachment disk are described. A field of depressions or small pits was observed in the pellicle of adult suctorians in the early stages of bud formation. These pits deepen and coalesce until one large pore, the birth pore, remains. Cilia protrude through the pore, and as eversion of the bud proceeds the meridional arrangement of the larval ciliation is evident. After eversion is completed, a pronounced division furrow is found between the adult and soon-to-be-released swarmer. The stalk-forming region is seen on swarmers. Metamorphosing swarmers produce tentacles upon settling before any indication of ciliary resorption. Resorption of cilia and change in body form occur progressively with the production of the attachment disk and stalk.

Animals↗

PubMed1971

Internal cellular details of Euglena gracilis visualized by scanning electron microscopy.

Simple washing of live Euglena gracilis cleans the pellicle of external coating material. When these cleaned cells are viewed with a scanning electron microscope, organelle outlines can be seen through the thinned pellicle. To view organelles directly, fixed Euglena cells are gently broken first or first frozen and then broken as part of their preparation for scanning electron microscopy. Subsequent viewing at magnifications of x 5,000 to x 21,000 reveals organelles, storage granules, endoplasmic reticulum, and nuclear pores, while retaining great depth of focus.

Chloroplasts↗

PubMed1985

Silicon-containing particles in synovial fluid: scanning electron microscopy coupled with analytical techniques allows an easy identification and differentiation from pathologically relevant crystals.

Silicon-containing particles were observed by scanning electron microscopy (SEM) in synovial fluid samples from patients with crystal-induced or inflammatory synovitis, or both. This material was an artefact produced by the technical procedures, but these particles could be easily differentiated from naturally occurring compounds by their morphology and their composition determined by analytical spectrometry.

Electron Probe Microanalysis↗

PubMed1976

Procedures for obtaining sectional views of fungal fructifications by scanning electron microscopy.

Procedures for sectioning fungal fructifications in host tissues or on artificial media are described, which allow observation of internal structures by scanning electron microscopy. Perithecia of Ceratocystis fimbriata and Phyllachora graminis, and telia of Puccinia xanthii showed excellent preservation of exposed structures in sections which were osmium-coated before being dried. While similar preservation was obtained in sectioned acervuli of Lecanosticta acicola and Marssonia juglandis and in pycnidia of Dothiorella ribis and Phomopsis occulta, the mucilaginous substances produced in these fructifications precluded observation of conidiophores. Extraction of mucilage from these sections was accomplished by periodic acid and dilute KOH treatments, followed by an osmium-coating procedure. In such preparations, mucilage was removed, internal structures were preserved, and pertinent characteristics of conidiogenous cells were resolved.

Agar↗

PubMed1979

Scanning electron microscopy of Acholeplasma colonies on agar.

The colony formation and morphology of Acholeplasma laidlawii and of an Acholeplasma species was studied by scanning electron microscopy. In the colonies of both Acholeplasma spp. large irregularly shaped cells, spherical cells, chains of beads, and long filaments with small bulbous distensions were seen. The membrane of some of the large cells seemed to be perforated, giving the cell a pitted appearance.

Acholeplasma↗

PubMed2007

Effects of dental probing on occlusal surfaces--a scanning electron microscopy evaluation.

The aim of this clinical-morphological study was to investigate the effects of dental probing on occlusal surfaces by scanning electron microscopy (SEM). Twenty sound occlusal surfaces of third molars and 20 teeth with initial carious lesions of 17- to 26-year-old patients (n = 18) were involved. Ten molars of each group were probed with a sharp dental probe (No. 23) before extraction; the other molars served as negative controls. After extraction of the teeth, the crowns were separated and prepared for the SEM study. Probing-related surface defects, enlargements and break-offs of occlusal pits and fissures were observed on all occlusal surfaces with initial carious lesions and on 2 sound surfaces, respectively. No traumatic defects whatsoever were visible on unprobed occlusal surfaces. This investigation confirms findings of light-microscopic studies that using a sharp dental probe for occlusal caries detection causes enamel defects. Therefore, dental probing should be considered as an inappropriate procedure and should be replaced by a meticulous visual inspection. Critical views of tactile caries detection methods with a sharp dental probe as a diagnostic tool seem to be inevitable in undergraduate and postgraduate dental education programmes.

Adolescent↗

PubMed1981

Scanning electron microscopy of rat neurointermediate lobe cells in culture.

Enzymatically dispersed cells of the rat pars nervosa -- pars intermedia (NI) were observed by scanning electron microscopy after 1, 2 and 4 days in culture. The cells attached to the plate slowly, requiring about 3--4 days for the majority to adhere. The epithelial cells became attached singly and in clumps and branched chains, often over a bed of fibroblast-like cells. After the first day in culture, few surface features were evident on the NI cells, but by day 2, the surfaces showed a small number of blebs. In 4-day cultures, the cells revealed extensive areas with blebs and microvilli, and a few structures resembling cilia were observed. The adrenocorticotrophic hormone content of the cells after 4 days in culture was similar to that found in fresh tissue.

Adrenocorticotropic Hormone↗

PubMed1986

Acellular scanning electron microscopy of spicular renal amyloidosis.

Two human renal biopsies containing glomerular amyloid deposits organized into spicular formations (spicular amyloid) were studied by scanning electron microscopy following removal of the cellular components (acellular SEM). Following SEM studies, portions of the same acellular tissue were embedded in paraffin and plastic for light microscopy and transmission electron microscopy, respectively. Spicular deposits by acellular SEM appear as tapering conical formations interconnected by a delicate branching network of fibrils, which imparts a higher degree of organization than previously appreciated by two-dimensional LM and TEM. Silver stains of paraffin- and plastic-embedded acellular tissue showed persistence of argyrophilia in spicular deposits, while acellular TEM showed that the spicules appeared comprised "purely" of amyloid fibrils without visible contaminating material. We conclude that the argyrophilia of spicular amyloid is an inherent feature of the parallel organization of fibrils rather than a result of incorporation of glomerular basement membrane or cell components and that spicular amyloid deposits have a higher degree of organization than is apparent by two-dimensional studies.

Amyloid↗