Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Microscopy, Electron”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources
PubMed1984

A simplified microwell pseudoreplica for the detection of viruses by electron microscopy and immunoelectron microscopy.

Simplified procedures for immunoelectron microscopy (IEM) and electron microscopy (EM) are described. The procedures employ the principle of agar filtration and pseudoreplication. The modification consisted of the use of microwells for storage of gels with or without antiserum (for IEM or EM, respectively) and an array of containers in which pseudoreplication and negative staining were performed. The containers were prepared from 5 ml syringes from which the needle holding parts were cut. This device enabled simultaneous and rapid handling of specimens. With Sindbis virus as a model, our microwell pseudoreplica IEM (MW-PR-IEM) was compared to six other IEM techniques and was found to be the most rapid and sensitive technique. With the MW-PR-IEM technique, the specific minimal detection limit (detection of clumps) was 1.5 x 10(7) virus particles per ml, and the non-specific detection limit (detection of single virions) was 1.8 x 10(6) virus particles per ml.

Antibodies, Viral↗
PubMedDate not supplied

Examination of compact bone microdamage using back-scattered electron microscopy.

A new staining technique using heavy metals (lead-uranyl acetate) has been developed to allow visualization of bone microdamage using both light microscopy and scanning electron microscopy operated in its back-scattered mode (BSE). At the light microscopic level, the number of microcracks counted in sequential sections of human ribs is the same for both the traditional basic fuchsin method of differentially staining microcracks and the new lead-uranyl acetate procedure. With BSE study, however, the number of microcracks observed is significantly reduced in all samples, because of the reduction of projection effect error associated with surface based imaging techniques. Application of the lead-uranyl acetate staining technique to ex vivo-loaded crack propagation specimens showed an extensive ultrastructurally disrupted region associated with the crack path through bone, consistent with the damage process zone around cracks in toughened composite materials.

Adult↗
PubMed1984

Stimulation of wound healing, using brain extract with fibroblast growth factor (FGF) activity. III. Electron microscopy, autoradiography, and ultrastructural autoradiography of granulation tissue.

A bovine brain fraction with FGF activity (fibroblast growth factor) increased the formation of granulation tissue of rats in an experimental wound healing model. It was characterised by intensified formation of new capillaries, stimulation of the synthesis function of fibroblasts and myofibroblasts, and proliferation of freshly developed granulation tissue. The results obtained from light microscopy and autoradiographic electron microscopy with 3H-thymidine suggested significant increase in the labelling of activated, undifferentiated endothelial cells in vascular sprouts and of differentiated endothelial cells in developed capillaries. FGF S3 appeared to speed up the differentiation of freshly formed endothelial cells. Also labelled were pericytes and other fibroblastoid cells, undifferentiated mesenchymal cells, juvenile undifferentiated fibroblasts, mature fibroblasts, myofibroblasts, and macrophages. Pericytes are presumed to be preferential precursors of myofibroblasts, on account of their occurrence in time and similar ultrastructural parameters. Close neighbourhood of lymphocytes and labelled fibroblasts gave rise to the assumption of specific effects, such as stimulation by lymphokines.

Animals↗
PubMed2002

Bidder's organ of Bufo ictericus: a light and electron microscopy analysis.

Male toads of the Bufonidae Family have rudimentary ovaries designated Bidder's organs, and if the testes are removed this organ develops into a functional ovary, representing a morphological strategy for the reproduction of the species. The Bidder's organ of Bufo ictericus was examined using routine and histochemical techniques by light microscopy and transmission electron microscopy. Each Bidder's organ presented a typical ovarian morphology, being composed of a cortex and a medulla. Bidderian follicles in different stages of development were visualized in the cortex, where they are better developed. The germ cells exhibit a large oocyte with a round-shaped nucleus. The Bidderian follicles are supported by a loose net of reticular fibers. In the medullar region, collagen fibers were immersed in the matrix rich in blood vessels that also contained a small quantity of neutral glycoproteins rich in hexose and/or sialic acid and carboxylated polymers with a characteristic distribution of glycosaminoglycans. The oocyte and the follicular cells were separated by a narrow space containing microvilli. The oocyte exhibit a well developed smooth endoplasmic reticulum, a poorly developed Golgi apparatus, and occasional lysosomes. Concentric cisternal complexes are often visualized; however, their morphological significance remains unclear. The peroxisomes display a fine granular matrix without a crystalline core, with a weak 3,3'-diaminobenzidine-reaction. Intimate association between peroxisomes, peroxisomes and lipid inclusions was observed in the oocyte, suggesting its participation in yolk metabolism.

Animals↗
PubMed2002

Scanning electron microscopy of Spinochordodes tellinii (Camerano, 1888), (Gordiacea, Nematomorpha).

There are many species of Nematomorpha which are deficiently described and therefore pose doubts about their actual taxonomic position. This is the case with Spinochordodes tellinii (Comerano, 1888), which was transferred to four different genera and has been recently considered as species incertae sedis. A female of Spinochordodes tellinii is redescribed in this work under light microscopy and Scanning Electron Microscopy. Cuticle details, shapes and areolar distribution and the features as well as the location of spiniform structures are analysed. The systematic position is discussed.

Animals↗
PubMed1989

Visual detection of microencapsulated insecticides with selective staining and scanning electron microscopy.

Selective staining with Sudan IV and methylene blue for light microscopy and scanning electron microscopy (SEM) were investigated to determine their potential for detecting and quantifying microencapsulated insecticides. Penncap-M (microencapsulated methyl parathion), Penncapthrin (microencapsulated permethrin), and Dyfonate (microencapsulated fonofos) were selectively stained with Sudan IV but not with methylene blue. Selective staining was not possible for Altosid SF-10 or SR-20 (microencapsulated methoprene) with either stain. Sudan IV enabled detection of some microencapsulated formulations in the digestive content of selected aquatic invertebrates and prepared contaminated pollen samples. Staining intensity with Sudan IV was greatest with acetone but capsular damage was high. A solvent ratio of 50:50 and 20:80 acetone/xylene minimized capsular collapse and maintained good staining intensity. The use of SEM for capsule identification and quantification depended upon the method of sample preparation: the slide smear method was superior to samples prepared by incision or microtomy. SEM was most suitable for investigation of formulations such as methoprene, for which selective staining was not possible. The chemical basis of staining with Sudan IV and potential application of both identification techniques are discussed.

Aedes↗
PubMed1987

Electron microscopy of biopsies from bronchogenic neoplasms.

Bronchial biopsies were investigated by light microscopy (LM) and electron microscopy (EM) with the aim to evaluate if EM could contribute to the LM tumour type diagnosis. Fourty-three pairs of biopsies were comparable. A histogenetic typing, especially of light microscopically undifferentiated and unclassifiable carcinomas, was possible by EM. However, when considering the therapeutical possibilities, at present time, LM tumour classification must be regarded as fully sufficient.

Biopsy↗
PubMed2003

Scanning transmission X-ray, laser scanning, and transmission electron microscopy mapping of the exopolymeric matrix of microbial biofilms.

Confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and soft X-ray scanning transmission X-ray microscopy (STXM) were used to map the distribution of macromolecular subcomponents (e.g., polysaccharides, proteins, lipids, and nucleic acids) of biofilm cells and matrix. The biofilms were developed from river water supplemented with methanol, and although they comprised a complex microbial community, the biofilms were dominated by heterotrophic bacteria. TEM provided the highest-resolution structural imaging, CLSM provided detailed compositional information when used in conjunction with molecular probes, and STXM provided compositional mapping of macromolecule distributions without the addition of probes. By examining exactly the same region of a sample with combinations of these techniques (STXM with CLSM and STXM with TEM), we demonstrate that this combination of multimicroscopy analysis can be used to create a detailed correlative map of biofilm structure and composition. We are using these correlative techniques to improve our understanding of the biochemical basis for biofilm organization and to assist studies intended to investigate and optimize biofilms for environmental remediation applications.

Bacteria↗
PubMed1978

Positive detection of mycoplasma contamination by the whole-mount preparation of cell cultures for transmission electron microscopy.

Low-level mycoplasma contamination of cell cultures is difficult to recognize with presently available techniques. This report describes the adaptation of the whole-mount technique, usually used for scanning microscopy, for transmission electron microscopy. The differentiation between microvilli and the equal-sized filamentous mycoplasma is based on the differential density obtained by the use of the method described. This method allows positive identification of mycoplasma and reduces the preparation time and the time necessary for scanning the preparation.

Cells, Cultured↗
PubMed1981

Behaviour and pathogenicity of Trichomonas vaginalis in epithelial cell cultures: a study by light and scanning electron microscopy.

The behaviour and pathogenic effects of Trichomonas vaginalis in mammalian cell cultures were studied using light microscopy and scanning electron microscopy. Six hours after inoculation of the parasites into the cell cultures about 10% of the epithelial monolayer was destroyed. The parasites adhered to the epithelial cells, developed an amoeboid morphology, and crawled over and under the monolayer of cells. These observations suggest that the adhesiveness, amoeboid morphology, and motility of T vaginalis may be important mechanisms in the injury caused to the vaginal epithelium.

Animals↗
PubMed1979

Surface characteristics of malignant human urinary bladder epithelium studied with scanning electron microscopy.

Biopsies were obtained from 28 male and seven female patients with cystoscopically and histologically confirmed urinary bladder carcionoma. Tissue specimens for light microscopy and scanning electron microscopy (SEM) were obtained from the tumours as well as from cystoscopically tumour-free mucosa of the dome, the lateral walls and the trigone of the urinary bladder and also from the proximal urethra. Certain surface structural changes, which seem to represent malignancy, present in different regions of the urinary bladder were detected by SEM, although not visible by light microscopy.

Aged↗
PubMed1976

[Pigmented villonodular synovitits of the hip: ultrastructure and aspects on scanning electron microscopy].

The authors studied one case of pigmented, villonodular synovitis (PVNS) of the hip by means of optical microscopy and by transmission and scanning electron microscopy. Scanning electron microscopy showed that the surface of the PVNS is completely different from that of rheumatic synovitis, in particular that of rheumatoid synovitis. The composition and the cellular morphology of the outer layer of the PVNS appear, however, to be similar to those of normal synovial membrane of arthrosic synovial membrane. Clumps of red corpuscles, enclosed in a fibrin network, were visible on the surface of the PVNS in a way that the authors has never seen previously in the 19 other human synovial membranes, normal and pathological, they had studied in this way. The totality of the microscopic findings confirms the importance of the role played by the intra-articular and intra-synovial haemorrhages, and by the macrophage reactions that follow, in the development of the lesions that characterize PVNS.

Adult↗
PubMed2002

[Description of eggs and nymphs of Triatoma jurbergi Carcavallo, Galvão & Lent, 1998 through optical and scanning electron microscopy].

Eggs and nymphs of Triatoma jurbergi were described using optical microscopy and scanning electron microscopy. T. jurbergi is a wild species, found in State of Mato Grosso (15oS and 300 m.a.s.l), Brazil. Eggs showed the operculum and surface with pentagonal and hexagonal cells, with small fractures and punctuations randomly distributed. Differences were found in the five nymphal stages of T. jurbergi, that allow their to be distinguished from the similar species T. guazu. The diagnostic characters most useful for differentiation were the general color of the insect, abdomen shape and its length.

Animals↗
PubMed1992

Review and new case reports on scanning electron microscopy of pili annulati, Monilethrix and Trichothiodystrophy.

Pili annulati, Monilethrix and Trichothiodystrophy are uncommon conditions in which the hair shaft has a distinct appearance as seen by optical microscopy and scanning electron microscopy (SEM). We report several new cases and review the characteristic ultrastructural abnormalities investigated by SEM. Pili annulati: abnormal areas which show a longitudinal, "curtain-like" folding of the cuticular cells, alternating with normal areas. The latter present regularly non-systematized, superficial depressions. Hair specimens of the patient's mother show the same surface irregularities. Monilethrix: most hair shafts show variations in thickness giving a typical nodal appearance. In the isthmus area we noticed longitudinal ridging and cuticular scales that are extended lengthwise in a fish-scale-like pattern. In the nodus area a smooth surface due to a complete loss of cuticular cells, was observed. Trichothiodystrophy: the hair morphology observed by SEM is characterized by severe cuticular and secondary cortical degeneration along the entire length of the flattened hair shaft, with longitudinal ridging, cuticle loss, trichlorrhexis nodosa formation and trichoschisis. SEM observations show morphological abnormalities which are characteristic for each pathological condition described. This method may provide data that add some clarity in the surface changes of the different hair shaft anomalies.

Adult↗
PubMedDate not supplied

A study of primary dental enamel from preterm and full-term children using light and scanning electron microscopy.

PURPOSE: The aim of this study was to examine the enamel thickness of the maxillary primary incisors of preterm children with very low birth weight (< 1,500 g) compared to full-term children with normal birth weight. METHODS: A total of 90 exfoliated maxillary primary central incisors were investigated using light microscopy and scanning electron microscopy (SEM). Three serial buccolingual ground sections of each tooth were examined under light microscopy, and maximum dimensions of the prenatally and postnatally formed enamel were measured. RESULTS: The enamel of preterm teeth was approximately 20% thinner than that for full-term teeth. Most of the reduction was observed in the prenatally formed enamel. This was 5 to 13 times thinner than that for full-term children (P<.001). The "catch-up" thickness of postnatally formed enamel did not compensate fully for the decrease in prenatal enamel (P<.001). Although none of the teeth used in this study had enamel defects visible to the naked eye, 52% of preterm teeth showed enamel hypoplasia under SEM, compared with only 16% found on full-term teeth (P<.001). These defects were present as pits or irregular, shallow areas of missing enamel. CONCLUSIONS: Preterm primary dental enamel is abnormal in surface quality, and is significantly thinner compared to full-term enamel. The thinner enamel is due mainly to reduced prenatal growth and results in smaller dimensions of the primary dentition.

Child, Preschool↗
PubMed1988

Arterial elastin as seen with scanning electron microscopy: a review.

All large arteries contain elastin, collagen, and muscle which can be seen with light microscopy and transmission electron microscopy. Elastin forms an internal elastic lamina (IEL) in all arteries, but also forms multiple fenestrated sheets in the media of the aorta and other large arteries. The fenestrations in the media are larger than those in the IEL. The adventitial elastin is more fibrous and often contains tubular elastin surrounding vasa vasorum when prepared by removing all non-elastin by placing the aorta in 0.1 N NaOH at 70-75 degrees C for five hours. The fenestrations are larger near branches and in an experimentally created poststenotic dilatation. Atherosclerosis appears associated with both new elastin formation in early atherosclerosis and elastolysis in late disease.

Animals↗
PubMedDate not supplied

A method of comparing spermatozoa with light and scanning electron microscopy.

A new method of comparing light microscopy and scanning electron microscopy in the study of small cells, such as spermatozoa, that must be examined under oil immersion is described. A grid is etched on the corner of a microscope glass slide, and its inner edges are incised. Its surface area is calculated as a function f the chamber of the critical-point drying apparatus. This method dispenses with the need for any special coverslip and enables the cells to be observed under oil immersion.

Cytological Techniques↗
PubMed1981

Hyperplastic lesions of the human breast: scanning electron microscopy and a review of current knowledge.

Although the etiology of human breast cancer is unknown, certain epidemiological parameters such as risk of breast cancer development. Concurrent, retrospective and prospective studies have shown that one particular component of benign breast disease -- epithelial hyperplasia, may be responsible for the increase in risk. Several classification have been devised for epithelial hyperplasia of the human breast using light microscopy. By scanning electron microscopy epithelial hyperplasia in ducts has several patterns: focal hyperplasia, simple columnar bridging, complex bridging and solid hyperplasia. Although these patterns may be seen in non-cancerous ducts in both malignant and non-malignant cases, alterations in microvillus structure and number have only been seen to date in malignant cases.

Breast↗