PubMed Health⌕ Search

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 1,207 records · Page 67Linked to original sources
PubMed1993

Quantitation of platelet deposition on human arteries: assessment of the disparity between results obtained with 111indium (111In)-labelling versus scanning electron microscopy.

Quantitation techniques for measuring platelet deposition (PD) to vessel surfaces are important to an understanding of thrombogenesis. In previous studies, scanning electron microscopy (SEM) has been shown to indicate a lower extent of PD than platelet 111In-scintigraphy. Part of this disparity may be explained by nonspecific binding of 111In to the vessel surface during perfusion, or loss of adherent 111In-labelled platelets by lysis or dissociation from the surface during specimen preparation for SEM. To assess whether these independent processes occur, we used a previously described human placental artery (HPA) perfusion model to quantify vessel 111In retention. Of the total 111In that bound to the vessel surface during perfusion, 77 +/- 42% (N = 9) was platelet associated 111In (111In-labelled platelets) and 23 +/- 19% (N = 9) was non-platelet associated 111In (nonspecific binding). After specimen fixation, 67 +/- 32% (N = 9) of the initial total surface 111In remained. This decrease is due to dissociation of both adherent 111In-labelled platelets, and nonplatelet associated 111In. After fixation, 57 +/- 34% (N = 9) of the initial total surface 111In remained as 111In-labelled platelets and 10 +/- 13% (N = 9) remained as nonplatelet associated 111In. Fixation caused no measurable lysis of platelets. These data suggest that PD may be overestimated by 111In-scintigraphy because of nonspecific binding of 111In and underestimated by SEM because of dissociation of adherent platelets during specimen preparation for SEM.

Arteries↗
PubMed1995

Morphological and morphometric studies of exfoliated oral squames from chronic inflammatory oral ulcers using light and scanning electron microscopy.

The morphological and morphometric features of exfoliated squames from the margins of chronic oral ulcers were studied by light and scanning electron microscopy. A variety of features consistent with a mixture of degenerative changes and regenerative activity were observed. None was sufficiently reliable to distinguish chronic inflammatory from malignant ulcers.

Carcinoma, Squamous Cell↗
PubMed1998

Morphology of the second- and third-instar larvae of Dermatobia hominis by scanning electron microscopy.

Larvae of Dermatobia hominis 10-27 days old were collected from experimentally infected rats and their morphology was studied by scanning electron microscopy. The moult from the second to third instar occurs at 18 days, with emergence from the host at 30 days post-infection. The second-instar larvae bear on the pseudocephalon, antennae (coeloconic sensilla), and coeloconic and basicoconic sensilla on the maxillary sensory complex. The thoracic segments bear small backwardly-directed spines anteriorly and ventral trichoid and campaniform sensilla. The first four abdominal segments have small and large backwardly-directed spines that are absent on segments five and six. The seventh and eighth abdominal segments have medium-sized forwardly-directed spines. Abdominal segments are encircled by campaniform sensilla. The terminal end of the eighth abdominal segment bears the anus, prominent anal lobes and two spiracular openings on each spiracular plate. Spiracular plates show a radial sun ray pattern. The rear abdomen also bears an ecdysal aperture, several pores and eight coeloconic sensilla. Although there are slight morphological differences, the spines (predominantly flat and thorn-like) and sensilla (campaniform and coeloconic) of the third-instar larvae show a similar arrangement to that of second-instar larvae. Thoracic trichoid sensilla are not seen in third-instar larvae. A perispiracular gland aperture is situated above each posterior spiracular opening. These morphological features are compared with those of other cuterebrid larvae.

Animals↗
PubMed1983

Fine structure of a periciliary ridge complex of frog retinal rod cells revealed by ultrahigh resolution scanning electron microscopy.

We studied the junctional region between rod inner segments (RIS) and outer segments (ROS) in frog retinas by high resolution scanning electron microscopy (SEM). Retinas of dark adapted or light exposed Rana pipiens were critical-point-dried and RIS and ROS were split and coated with ultrathin metal films of niobium and chromium--or decorated with gold--and imaged in a new SE-I imaging mode. The connecting cilium (CC) usually broke at the base of the RIS and remained attached to the ROS. The outer part of the CC plasmalemma expanded to form liplike protrusions beyond which disks evaginated with successively larger diameter until they reached the full width of the ROS. The CC rose out from an invagination of the RIS apical plasma membrane (PM). On the lateral walls of this invagination, a highly ordered complex of nine symmetrically arrayed ridges and grooves rose steeply and extended laterally approximately 0.4-1 micron on the adjacent RIS PM. On the apical plasmalemma, the ridges and grooves formed groups of three to four parallel rows that surrounded the invagination. The grooves were bridged by filaments anchored at the top edges of the ridges. This highly ordered structure we term the periciliary ridge complex (PRC). Its ninefold symmetry apparently reflects the 9 + 0 microtubule organization of the CC axoneme. The three-dimensional structure revealed by SEM was confirmed by transmission electron microscopy (TEM) of sections of Epon-embedded retinas. TEM-immunocytochemistry on thin sections of retinas embedded in glutaraldehyde cross-linked albumin suggested that the PRC and the CC may participate in opsin transport and disk morphogenesis.

Animals↗
PubMed1977

Chronic myelomonocytic leukemia: an ultrastructural study by transmission and scanning electron microscopy.

The hematologic findings in three cases of chronic myelomonocytic leukemia are presented, with results of ultrastructural studies by transmission and scanning electron microscopy on two of the cases. In the peripheral blood there was a dual, non-lymphocytic, markedly increased population of granulocytes and monocytes. The granulocytes showed marked nuclear abnormality and nuclear cytoplasmic organelle asynchrony. In the marrow the majority of the cells appeared granulocytic but atypical forms and intermediate difficult to distinguish from monocyte precursors were evident by electron microscopy. The ultrastructural findings lend some support to the concept that the neoplastic granulocytes and monocytes having a common precursor.

Aged↗
PubMed1980

The stratum corneum xerotic from aging and photochemotherapy (PUVA). A study by scanning electron microscopy.

The relationship between the structure and mechanical properties of the xerotic stratum corneum from aging and photochemotherapy were studied by scanning electron microscopy. Two different types or orthokeratosis were found in these xeroses, from which we infer that the type induced by PUVA does not represent accelerated aging. The orderly architectural pattern of the stratum corneum in xerosis induced by PUVA may be related to the microanatomy of the prominent undulations at the junction between the epidermis and the papillary dermis.

Adult↗
PubMed1989

Examination of mucosal surfaces by scanning electron microscopy before and after removal of debris.

A rapid method is described whereby gastrointestinal biopsy specimen surfaces can be examined by scanning electron microscopy with overlying tract contents (debris) intact, and also re-examined after cleaning to determine the structure of the underlying mucosal surface. The conductive coating of gold is removed using mercury, a non-wetting agent. The specimen surface is suitably cleaned of debris after a brief ultrasonication in absolute ethanol which mixes with the transitional fluid (CO2) used for critical point drying.

Animals↗
PubMed1991

Observations of microvessels in the brain with Alzheimer's disease by the scanning electron microscopy.

Microvessels in the brain with Alzheimer's disease and those of a control group were observed by means of the scanning electron microscopy. There were no morphological differences between the relatively large arteries in Alzheimer's disease and those of the control. Remarkable differences existed in terminal arterioles and capillaries. In Alzheimer's brain, the terminal arterioles frequently had focal constriction and smooth muscle cells with an irregular shape and arrangement, and the capillaries also showed an irregular abluminal surface and irregular constriction and dilatation along their paths. In the control brain, there were no changes such as those observed in Alzheimer's disease. The findings suggest that diffuse neuronal loss in Alzheimer's cerebral cortex might be induced by circulatory disturbance through the changed microvessels.

Aged↗
PubMed1977

Scanning electron microscopy of vaginal colonization.

Changes in the appearance of the vaginal epithelium of rats during the estrous cycle were seen by scanning electron microscopy. Bacterial colonization of this tissue appeared to be influenced by these changes.

Animals↗
PubMed1983

Cytopathogenicity of Naegleria fowleri for rat neuroblastoma cell cultures: scanning electron microscopy study.

Neuroblastoma cells were inoculated with Naegleria fowleri Lee and examined for cytopathology at various periods post-inoculation by scanning electron microscopy. By 18 h post-inoculation, approximately 50% of neuroblastoma cells were nonviable, as evidenced by trypan blue exclusion and light microscopic examination. This cytopathology resulted from piecemeal consumption of target cells mediated by a sucker apparatus extending from the surface of N. fowleri.

Amoeba↗
PubMedDate not supplied

Cochlear hair cell loss in ears with cholesteatomas. Scanning electron microscopy study.

Cochleas from 16 Mongolian gerbils with spontaneous aural cholesteatomas, and four of similar age without cholesteatomas, were examined by scanning electron microscopy to quantify cochlear hair cell loss. Loss of hair cell stereocilia was found in all ears with cholesteatomas and was significantly increased when compared with uninvolved ears from animals of similar age. The hair cell loss associated with gerbilline cholesteatomas appeared to be most marked in the middle turn of the cochlea and increased in severity with increasing size of the cholesteatomas. Outer hair cells were affected more than inner hair cells. Inner and outer hair cell loss was not significantly different in infected cholesteatomas versus sterile cholesteatomas. The greater damage to hair cells at the middle turn compared to the basal turn suggests that these losses may be the result of some agent acting through the cochlear wall rather than through the round window.

Animals↗
PubMed1980

A scanning electron microscopy study of the effect of proteinase inhibitors on mouse uterine morphology.

The luminal uterine surface of mice was examined by scanning electron microscopy after a 24 h treatment with basic pancreatic trypsin inhibitor (BPTI) or L-1-tosylamido-2-phenylethyl chloromethyl ketone (TPCK) administered as a single injection or from a slow release capsule on Day 2 p.c. in doses known to impair fertility. The effect of BPTI was slight, some swelling of cells and loss of microvilli. TPCK, on the other hand, caused disruption of the epithelium through swelling and sloughing of cells, sporadic loss of microvilli, and the presence of red blood cells.

Animals↗
PubMed1992

A new approach to the study of ovarian follicles by scanning electron microscopy and ODO maceration.

The ultrastructure of the follicle-oocyte complex in rodents and humans was revealed by high resolution scanning electron microscopy (SEM) following the Osmium-DMSO-Osmium maceration method (TANAKA and NAGURO, 1981). In primary follicles, the majority of oocyte organelles such as mitochondria and Golgi complex components are concentrated in a juxtanuclear area. In particular, many spherical mitochondria are oriented all around the nucleus. After maceration of the ooplasm matrix, most of these mitochondria appear intermingled with numerous microtubules (MT) and associated with many Golgi vesicles. Such a nuclear polarization of organelles, essential to the oocyte metabolism, might depend upon a MT activity. MT might guide mitochondria to gather in the perinuclear region and further maintain their close associated to the nuclear envelope. A similar relationship among microtubules, vesicular Golgi complex and mitochondria has been also observed when, in maturing oocytes, these organelles migrate and gather in other areas of the ooplasm. A pattern common only to human developing follicles appears in the occurrence of long microvilli projected from follicle cells deep into the oocyte. These unusual microvilli running within the ooplasm are surrounded by several vesicles of the Golgi complex and endoplasmic reticulum, and often end close to the nucleus. In the antral follicle, the microvilli of corona cells, directed toward the oocyte (after their full exposure through the chemical dissolution of the zona pellucida matrix) are extremely numerous (up to 70/cell), long (up to 7/10 microns) and tortuous. They resemble epididymal stereocilia, may be ramified and possess bulbous tips. In contrast, oocyte microvilli are thin and short.(ABSTRACT TRUNCATED AT 250 WORDS)

Dimethyl Sulfoxide↗
PubMed1995

The influence of specimen preparation on artefacts in scanning electron microscopy of respiratory cilia.

The effects of various handling procedures used in preparing specimens of human and pig respiratory mucosa for scanning electron microscopy (SEM) were studied. Using five different washing methods, the percentage area of mucosa covered with extracellular material varied from 1.5 to 53.1%. The best results were achieved when specimens were washed by gently inverting a sample 30 times in a container filled with physiological saline. Fixation and drying of the surface layer caused disorientation of cilia and made examination difficult. Mechanical damage caused loss of cilia and rupture of the cell membrane. For SEM of respiratory cilia it is important to wash the specimen in saline before fixation and to use biopsy forceps as little as possible.

Animals↗
PubMed1987

Examination of intramammary devices from infected and uninfected mammary quarters by scanning electron microscopy.

Polyethylene intramammary devices were removed from six infected and four uninfected mammary quarters of seven lactating cows and examined by scanning electron microscopy. Infecting organisms included Corynebacterium bovis, coagulase-negative staphylococci, and an unidentified fungus. Intramammary devices from infected quarters had amorphous material adhering to large areas of the polyethylene. Large numbers of inflammatory cells and microorganisms were found concentrated within the material. Devices from uninfected quarters had less amorphous material with few adhering inflammatory cells. The amorphous material appeared to be restricted to abraded surfaces of the polyethylene. Milk somatic cell counts in stripping milk of quarters infected with Corynebacterium bovis and coagulase-negative staphylococci before and 3 wk after removal of intramammary device averaged 1.2 X 10(6) and .2 X 10(6)/ml, respectively. Results suggest that increased cell counts of infected quarters containing intramammary devices were associated with microbial colonization of the amorphous material.

Animal Husbandry↗
PubMed1995

Scanning electron microscopy study of the palatine salivary glands of rabbits.

The structure of the palatine salivary glands of rabbits was studied employing scanning electron microscopic methods. The fractured surface of the palatine salivary glands revealed that they were formed of small lobuli separated by interlobular spaces containing numerous bundles of collagen fibers. The NaOH treated specimens showed the organization of the collagen fibrils in their original location. In the interstitial stroma compartment, the collagen fibrils revealed a complex three-dimensional arrangement forming channel-like structures for supporting nerve fibers, small vessels and capillaries. Single groups of acinar cells were clearly demonstrated, and each acinus was enveloped by a characteristic basal lamina showing a sponge-like structure made up of several interconnected meshes of collagen fibrils. Furthermore, taking advantage of the ODO method and field emission scanning electron microscopy, within the cytoplasm of secretory acinar cells numerous organelles were clearly observed in a three-dimensional way such as Golgi complex lamellae, rough endoplasmic reticulum, mitochondria and secretory granules. All these cytoplasmic components revealed their real and microtopographical arrangement in some areas of the acinar cytoplasm clearly suggesting their direct involvement in energetic as well as secretory activities.

Animals↗