PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Microscopy, Electron”

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 19 recordsLinked to original sources
PubMed1987

Minocycline-related cutaneous hyperpigmentation as demonstrated by light microscopy, electron microscopy and X-ray energy spectroscopy.

A 70-year-old patient with a chronic cutaneous ulcer treated by minocycline hydrochloride developed hyperpigmentation of the forearms. Biopsy material was studied by light microscopy, electron microscopy and X-ray energy spectroscopy. Granular gold-brown pigment was found in dermal histiocytes and eccrine myoepithelial cells, which gave positive reaction with Prussian blue and Fontana-Masson stains. Electron microscopy revealed intracytoplasmic granules of dark, homogeneous material and small fine particles. X-ray energy spectroscopy showed iron and other elements in smaller amounts. The different types of minocycline-related hyperpigmentation and the possible pathomechanism are discussed with special regard to the importance of the diagnostic methods.

Aged↗
PubMed1987

Endothelialization of a new Dacron graft in an experimental model: light microscopy, electron microscopy and immunocytochemistry.

Two types of synthetic vascular grafts, Dacron Triaxial and Dacron Gelseal Triaxial, were implanted into both the common carotids of sheep. The animals were sacrificed 1, 2, 8, and 16 weeks after surgery. Multiple specimens, obtained from grafts and anastomoses, were studied by light microscopy, transmission and scanning electron microscopy. A parallel immunocytochemical analysis was performed on some specimens. Dacron Triaxial grafts failed to develop a complete neointimal coverage. Myofibroblasts and fibroblasts were the dominant cells in such synthetic graft. Moreover, focal areas of stripping, platelet deposition, and thrombosis were observed at 8 and 16 weeks. In contrast, a stable endothelial coverage developed on the Gelseal Triaxial grafts after 16 weeks.

Animals↗
PubMed1979

Calcification in a pineal tumour studied by transmission electron microscopy, electron diffraction and x-ray microanalysis.

The calcification in a totally calcified pineal tumour was studied. Transmission electron microscopy indicated that the tumour was a pinealoma. The type of calcification was investigated by bright-field and dark-field transmission electron microscopy in addition to electron diffraction and electron-induced x-ray fluorescence. The calcified material consisted predominantly of amorphous calcium phosphate. The type of calcification differs from the normal calcification present in pineal acervuli which consists of crystalline hydroxypatite.

Brain Neoplasms↗
PubMed1988

Earliest enamel deposits of the rat incisor examined by electron microscopy, electron diffraction, and electron probe microanalysis.

In order to describe initial events in enamel mineralization and to help characterize inorganic-organic interactions in this tissue, the earliest rod and interrod enamel in mandibular incisors from normal young adult (100 gm) rats, perfused with 100% ethylene glycol, has been studied by transmission electron microscopy, selected area electron diffraction, and high-spatial-resolution electron probe microanalysis. Diffraction and probe data were correlated precisely from the same extracellular regions of the tissue. Sites were examined progressively as a function of location a) from the most recently deposited enamel adjacent to ameloblasts toward the dentin-enamel junction and b) from the apical portion of the tooth longitudinally toward its incisal end. Electron diffraction patterns consistent with that of a poorly crystalline hydroxyapatite were generated at all locations. Diffraction characteristics changed only slightly toward that of more crystalline hydroxyapatite at different locations. Earliest apical enamel generated molar Ca/P ratios in a range of 0.99-1.46 (average 1.24 +/- 0.15). Molar Ca/P ratios of the first enamel interrod elements increased from approximately 1.24 at ameloblast-enamel boundaries to approximately 1.40 at the dentin-enamel junction, small changes corresponding to those observed in electron diffraction characteristics.

Animals↗
PubMed1976

Pulmonary mineral dust. A study of ninety patients by electron microscopy, electron microanalysis, and electron microdiffraction.

The results of a study of 90 patients are presented. Intrapulmonary mineral deposits were characterized by electron diffraction and electron probe microanalysis. Using this method, pneumoconioses may be distinguidhed from other pneumopathies. In cases of pneumoconiosis, there exists a specific relationship between the etiology of the dust exposure and the crystallographic characteristics of the intrapulmonary deposits. The nature of the deposits may be indicative of a specific type of pneumoconiosis. This method is particularly useful in differentiating between asbestos bodies and ferruginous bodies. The value of the method in general and its importance in the study of pneumoconiosis are discussed.

Asbestos↗
PubMed1988

Electron microscopy, electron diffraction, and element analysis of wet biological specimens.

Temperature controlled differentially pumped environmental chambers now allow more routine examination of wet specimens in the electron microscope. A sensitive test of their efficiency is the ability to provide high resolution electron diffraction patterns from wet, unfixed protein microcrystals. Fortunately, wet specimens can be prepared with only a few tens of nanometers thickness of remaining water, so extraneous electron scattering by liquid water can be kept to a minimum. It still remains to be determined whether microprobe analysis (X-ray or electron energy-loss spectroscopy) using wet specimens gives better element localization in cells than the current freezing methods. More extensive comparisons are also required of the ultrastructural preservation and visibility of macromolecules immersed in a thin layer of water vs immersion in a thin layer of amorphous ice. However, the recent introduction of commercial forms of the necessary equipment now make these comparisons more feasible.

Freeze Drying↗
PubMed1977

Different types of benign nerve sheath tumors. Light microscopy, electron microscopy and autoradiography.

In a light-, electronmicroscopic and autoradiographic study different types of nerve sheath tumors were classified. Their cellular population was quantitatively evaluated in the electron microscope. In the neurinoma the predominant cell was found to be the Schwann cell, but in the different types of neurofibromata a variable content of connective tissue cells was noted. T-HE DIFFUSE NEUROFIBROMATA SHOWED A QUANTITATIVE CELLULAR COMPOSITION SIMILAR TO NORMAL PERIPHERAL NERVES. In the plexiform neurofibroma a large number of fibroblasts were present and in the argyrophilic neurofibroma high content of perineurial cells was found. In autoradiographic sections the tumors showed in general a low proliferation rate (L.i. 1-3.6%). In the argyrophilic neurofibrom a higher labelling index (9.5%) was found.

Adolescent↗
PubMed1988

[A case of colonic polypoid ganglioneuromatosis--a light microscopy, electron microscopy and immunohistochemical study].

A 68-year-old man with colonic polypoid ganglioneuromatosis is reported. He had manifested no signs and symptoms of von Recklinghausen's disease and/or a multiple endocrine neoplasia syndrome. A single polyp was found by a barium enema and an endoscopic polypectomy was performed. Light microscopy showed the propria mucosa of the polyp was composed of a proliferation of spindle cells with a fibrillar cytoplasma and large cells with a round large nucleus, a prominent nucleolus, and vast cytoplasm. Some crypts were slightly dilated. Random biopsied specimens from the colonic normal mucosa showed focal proliferation of only the spindle cells. Electron microscopically, the spindle cells consisted of Schwann cells forming neurites, and large cells that coincided with the features of ganglion cells. Immunohistochemically, the localization of neuron specific enolase was demonstrated in the cytoplasm of these cells. These findings led to a diagnosis of colonic polypoid ganglioneuromatosis, and the pertinent literature is reviewed.

Aged↗
PubMed1987

Identification of foreign metallic substances inducing hyperpigmentation of skin: light microscopy, electron microscopy and x-ray energy spectroscopic examination.

Identification of foreign metallic substances that induce hyperpigmentation is now possible with the use of x-ray energy spectroscopy (XES), an ultrastructure, nondestructive technique that allows the correlation of the presence of foreign substances with localized tissue and cellular histological changes. This new analytic technique will be an innovative adjunctive technique in the practice of diagnostic pathology and dermatopathology. It is certain that further evaluation of hyperpigmentation will allow for better identification of possible etiological causes, especially in the evaluation of cutaneous hyperpigmentation secondary to metal toxicity.

Adult↗
PubMed1979

Morphological studies on the periostracum of the fresh-water mussel Amblema (Uniondae): light microscopy, transmission electron microscopy, and scanning electron microscopy.

The structure of the periostracum in the fresh-water mussel Amblema has been described using light microscopy, transmission elec;ron microscopy, and scanning electron microscopy. The structure and evolutive course of the periostracum was studied along its entire length, from the periostracal groove until it forms the tough outer covering of the shell. At least five structurally and functionally distinct regions were identified. In addition, the periostracum itself was seen to be a multilayered structure consisting of three major layers which are themselves subdivided into minor layers. From these morphological observations, a regulatory role for the various periostracal layers in mineral trapping, nucleation, and the subsequent formation of the prismatic and nacreous layers of the shell can be postulated.

Animals↗
PubMed1990

Correlative light microscopy, scanning electron microscopy, and transmission electron microscopy of osmium-macerated biological tissues.

A method facilitating correlation of light microscopic (LM), scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images was developed. Rat kidney and heart were initially subjected to the osmium maceration procedure and then embedded in acrylic resin. Semithin sections of the tissue blocks were first provided for LM and then examined by SEM after resin removal. Furthermore, the ultrathin sections adjacent to the semithin sections were observed by TEM. The three-dimensional images of intracellular organelles provided an informative adjunct to LM and TEM.

Animals↗