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At least 19 recordsLinked to original sources
PubMed1985

Hürthle-cell lesions of the thyroid: a combined study using transmission electron microscopy, scanning electron microscopy, and immunocytochemistry.

Hürthle cell transformation found in 2 nodular goiters, 2 cases of Hashimoto's thyroiditis, 4 follicular adenomas, 3 follicular carcinomas, 2 papillary carcinomas and 1 anaplastic carcinoma were studied by transmission electron microscopy, scanning electron microscopy and immunocytochemistry. Ultrastructural features of Hürthle cells were identical in non-neoplastic and neoplastic lesions. Cells crammed with mitochondria, showing abnormalities in size, shape and content were prominent in most cases. The presence of distinct smooth-surfaced cells interspersed with cells with many microvilli is almost a pathognomonic scanning electron microscopic feature of benign and malignant Hürthle cell lesions. Most Hürthle cells stained positively for thyroglobulin in all cases, but no immunoreactivity for CEA and calcitonin was found.

Adenocarcinoma↗
PubMed1983

Ultrastructural pathology of Crohn's disease: correlated transmission electron microscopy, scanning electron microscopy, and freeze fracture studies.

The mucosa of the ileum or colon from 16 patients with active Crohn's disease was studied using transmission electron microscopy of thin sections, scanning electron microscopy, and freeze fracture electron microscopy. Electron micrographs of diseased tissue, as well as of grossly normal resection margins, were studied. Correlations of mucosal disease, as seen with the various ultrastructural techniques, were made and compared to controls. Alterations of epithelial cell tight junctions in freeze fracture replicas correlated with a decrease in the number of pinpoint contacts between adjacent cells in transmission electron microscopy preparations. Gap junctions in Crohn's disease did not vary with respect to structure or number, when compared to controls. Mucosal microulcerations, affecting 1 to 6 cells, were observed in transmission and scanning electron microscopy preparations. Possible freeze fracture electron microscopy correlates of microulcers consisted of replicas of cells completely devoid of tight junctional structures. "Aphthoid" type ulcers were studied with the various ultrastructural tools and were remarkable for several abnormalities of villi bordering the aphthoid ulcers, as well as surrounding villi. Transmission, scanning, and freeze fracture electron microscopy each provide unique and confirming data that may be used to construct a model for the pathophysiology of Crohn's disease.

Colitis↗
PubMedDate not supplied

Characterization of an oil-degrading Microcoleus consortium by means of confocal scanning microscopy, scanning electron microscopy and transmission electron microscopy.

A consortium of microorganisms with the capacity to degrade crude oil has been characterized by means of confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The analysis using CLSM shows that Microcoleus chthonoplastes is the dominant organism in the consortium. This cyanobacterium forms long filaments that group together in bundles inside a mucopolysaccharide sheath. Scanning electron microscopy and transmission electron microscopy have allowed us to demonstrate that this cyanobacterium forms a consortium primarily with three morphotypes of the heterotrophic microorganisms found in the Microcoleus chthonoplastes sheath. The optimal growth of Microcoleus consortium was obtained in presence of light and crude oil, and under anaerobic conditions. When grown in agar plate, only one type of colony (green and filamentous) was observed.

Cyanobacteria↗
PubMed1993

A light microscopy, scanning electron microscopy, and laser scanning microscopy analysis of retrieved blade implants after 7 to 20 years of clinical function. A report of 3 cases.

The aim of the present study was to evaluate by means of light microscopy, scanning electron microscopy, and laser scanning microscopy the thin ground sections of blade implants retrieved after 7 to 20 years of clinical function. Microscopic examination revealed that most of the implant surface had an intimate contact with compact lamellar bone tissue. Higher magnifications revealed the presence of a gap (1 to 5 mu) interposed between bone and implant. Many osteocytes were near the implant surface and, in many instances, osteocyte canaliculi, running from the lacunae towards the implant surface, were seen. Structures similar to bone reversal lines were observed at the edge of the bone side of the interface. The bone-titanium region is probably an area of dynamic biological activity.

Aged↗
PubMed1975

Red cell surface structure. Stabilization by cholesterol sulfate as evidenced by scanning electron microscopy.

Scanning electron microscopic studies demonstrate that the normal biconcave shape of the human erythrocyte is maintained in hypotonic saline when physiological levels (10 minus 5M) of cholesterol sulfate are added to the solutions. Cholesterol sulfate is a naturally occurring sterol conjugate in plasma and erythrocyte membranes and we propose that it may belong to that class of amphipathic molecules responsible for the maintenance of structure of the erythrocyte by interaction with membrane components.

Cell Membrane↗
PubMed1990

On the varied appearances of the human placental villous surface visualised by scanning electron microscopy.

Scanning electron microscopy enables extensive areas of the human placental villous tree to be viewed at high resolution in a relatively quick and easy manner. It is therefore an invaluable aid to the study of normal placental structure, and may have a potential role to play in pathological diagnosis. However, with increasing experience an awareness of the possible artefacts that may be introduced during fixation and tissue preparation is gradually developing. Some of these artefacts are common to other organs and applications of scanning electron microscopy, whereas others result from the unique structure and three-dimensional configuration of the placenta. Examples of the second category are poorly documented, and yet their occurrence may also significantly influence the appearance of the tissue as seen by light or transmission electron microscopy. This paper illustrates examples of this problem, and emphasises some of the factors that must be considered when interpreting both scanning and transmission electron micrographs of the villous surface.

Chorionic Villi↗
PubMed1986

Pulmonary artery endothelial abnormalities in patients with congenital heart defects and pulmonary hypertension. A correlation of light with scanning electron microscopy and transmission electron microscopy.

Scanning electron microscopy and transmission electron microscopy were applied to lung biopsy specimens from patients with congenital heart defects, and pulmonary artery endothelium was analyzed for alterations in surface characteristics and intracytoplasmic composition which might reflect abnormal function. The patients were divided into four groups distinguished by increasing severity of pulmonary vascular changes on light microscopy graded both morphometrically and by the Heath-Edwards classification; group 1, normal vasculature or only abnormal extension of muscle into peripheral arteries; group 2, medial hypertrophy; group 3, medial hypertrophy +/- decreased artery number + intimal hyperplasia; group 4, decreased artery number + occlusive intimal hyperplasia. On scanning electron microscopy, the pulmonary artery endothelial surface in group 1 patients was "crinkled" or "corduroy-like", i.e., composed of narrow, even ridges; in groups 2 and 3, it was "cable-like", i.e., comprised of deep intertwined ridges; in group 4 it was "chenille" in texture, i.e., high ridges alternated with low, uneven, and twisted ones. There was significant increased density of surface microvilli in groups 2 and 3 patients when compared to groups 1 and 4 (p less than 0.05 for each comparison). On transmission electron microscopy pulmonary artery endothelial cells in groups 2 and 3 patients were also characterized by a significant increase in the volume density of rough endoplasmic reticulum (p less than 0.01) and microfilament bundles (p less than 0.05). The coarse endothelial surface characteristics associated with pulmonary vascular changes may result in abnormal interaction with blood elements and release of vasoactive substances. The increased microvilli, rough endoplasmic reticulum, and microfilament bundles in patients with moderate but not advanced arterial changes suggest a phase where increased endothelial metabolic function and alterations in the cytoskeleton may also contribute to heightened pulmonary vascular reactivity.

Actin Cytoskeleton↗
PubMed1979

[Study of cellular elements in synovial fluid in scanning electron microscopy].

Scanning electron microscopy allows a tridimensional morphological study of the cellular elements of the pathological human synovial fluid. The cells are grouped into two populations: macrophage cells and round cells, whose differentiation is more difficult: polynuclears, lymphocytes and synovial cells. The combination of scanning electron microscopy and X-ray diffraction makes it possible to describe and indentify crystals of sodium urate and of triclinical, dehydrated calcium pyrophosphate.

Arthritis, Rheumatoid↗
PubMed1984

Successive changes in the epimural bacterial community of young lambs as revealed by scanning electron microscopy.

Scanning electron microscopy was used to determine the time of initial colonization of the rumen epithelium of young lambs and successive changes with time in the morphological composition of the epimural community. Tissue samples were obtained from two groups of lambs at 1, 2, 4, 6, 8, and 10 weeks of age. Comparisons were made with the epimural communities observed at 12 well-distributed sites in the rumen of a mature wether. Epimural bacteria were already present on the epithelium at 1 week of age. The morphological composition of the epimural community changed with age, with the pattern of succession being similar in both groups of lambs. A total of 24 morphotypes were distinguished by scanning electron microscopy; 17 were rod shaped, 4 were cocci, 2 were spiral, and 1 was filamentous. These morphotypes were further subdivided into: (i) those persisting after their initial colonization in young lambs and present in the adult (7 morphotypes), (ii) those seen only in the adult (2 morphotypes), and (iii) those present only in young lambs (15 morphotypes). The seven morphotypes present in both the lamb and the adult could be considered indigenous members of the epimural community. Several morphotypes appeared restricted in their colonization to certain regions of the papillae, suggesting the presence of microhabitats within the epithelial habitat. Two rod-shaped bacteria were repeatedly seen specifically attached to one another, suggesting an interspecific association.

Aging↗
PubMedDate not supplied

Blood flow patterns in the rat pancreas: a simulative demonstration by injection replication and scanning electron microscopy.

Scanning electron microscopy of vascular casts prepared by arterial injections of intentionally reduced amounts of resin showed that in the rat pancreas, the casting medium fills blood capillaries in the endocrine islets more promptly than those in the exocrine lobules and secretory ducts. Furthermore, the exocrine lobules containing endocrine islets allowed a more rapid resin flow through the insulo-acinar portal route than those lobules lacking an islet. The capillaries of secretory ducts were the last portions to be filled with resin. Since the resin used in this study was as viscous as blood and injected under a physiological pressure, the microcirculatory patterns demonstrated by the present method reflect the physiological flow pattern of blood in the pancreas.

Animals↗
PubMed1977

Enamel rod formation in the monkey observed by scanning electron microscopy.

Scanning electron microscopy of permanent tooth buds of the monkey confirmed that mineralizing interrod enamel surrounds Tomes' processes on three sides, forming pits that restrict enamel rod formation. The forming face of the enamel rod, which is the floor of the pit, angled toward the tooth surface at the apical edge of the pit, the side nearest the cervical region of the tooth. Consequently, the apical edge of each pit was the only site where both rod and interrod enamel were formed at the nascent tooth surface. The ameloblasts had two secretory surfaces. One was the microvillous surface of the short Tomes' process abutting the forming face of the enamel rod. The other surface, closer to the ameloblast, was between Tomes' processes, abutting the crests of interrod enamel which formed the pits. At each site forming enamel crystallites had specific orientations. Due to the angle of the forming face of the rod and the short Tomes' process, crystallites with both rod and interrod orientation form at the same time and the same plane within the apical (cervical) margin of each rod. It is hypothesized that indistinct boundaries between rod and interrod enamel at the apical margin of each rod are due to both secretory surfaces of ameloblasts secreting at the same time and at the same site.

Ameloblasts↗
PubMed1997

Macromolecular substructure in nuclear pore complexes by in-lens field-emission scanning electron microscopy.

Scanning electron microscopy (SEM) has produced a wealth of novel images that have significantly complemented our perception of biological structure and function, derived initially from transmission electron microscopy (TEM) information. SEM is a surface imaging technology, and its impact at the subcellular level has been restricted by reduced resolution in comparison with TEM. Recently, SEM resolution has been considerably improved by the advent of high-brightness sources used in field-emission instruments (FEISEM) which have produced resolution of around 1 nm, virtually equivalent to TEM "working resolution." Here we review our findings in the use of FEISEM in the imaging of nuclear envelopes and their associated structures, such as nuclear pore complexes, and the relationships of structure and function. FEISEM allows the structurally orientated cell biologist to visualise, directly and in three dimensions, subcellular structure and its modulation with a view to understanding its functional significance.

Animals↗
PubMed1976

Revised seminology of the different mononuclear cells under scanning electron microscopy.

Scanning electron microscopy shows that the thymus cell surface is not smooth but slightly undulated; this type of surface characteristic is found on the cells of several types of T-lymphocyte tumors such as T-cell lymphosarcoma, mycosis fungoides, and T-immunoblastic lymphosarcoma. The cell surface of Frabricius' bursa is covered with numerous short villi. They are found on the cells of several kinds of B-lymphocyte tumors, including B-cell chronic lymphoid leukemia, B-prolymphocytic lymphosarcoma, and B-immunoblastic lymphosarcoma. Mycosis fungoides cells frequently have a characteristic shape. Normal and myeloma plasma cells are similar in shape but their surface is covered with numberous characteristic tiny balls. Immunoblasts are twice the size of so-called small lymphocytes. In the blood and in the lymphocyte population transformed by mitogens, cell surfaces vary from completely smooth (with no undulations as in thymic cells) to villous, with short to very long villi. These variations are visible even when a constant technique and the critical-point drying method are used. Their significance, however, is not known.

Animals↗
PubMed1991

Architecture of myocardial cells in human cardiac ventricles with concentric and eccentric hypertrophy as demonstrated by quantitative scanning electron microscopy.

Scanning electron microscopy (SEM) was used to compare the shapes, size, and connections of cardiocytes in the midwall myofibers in the left ventricles of 5 normal hearts (266 +/- 16 g), 5 hears with concentric hypertrophy (564 +/- 99 g) and 5 with eccentric hypertrophy (651 +/- 114 g), obtained at autopsy and fixed in formalin. In the myofibers from normal and hypertrophied hearts, intercalated discs demarcated cardiocytes which consisted of a cylindrical trunk and one or more series and/or lateral branches; cell connections at the intercalated discs had 6 common basic patterns. The length (L), width (W) and L/W ratio of the cells and the size and number of the series and lateral branches per cell were measured in 50 cells from each heart and averaged for comparison studies. The cells in the concentrically hypertrophied ventricles were much thicker than normal (33.0 +/- 2.8 vs 18.2 +/- 1.4 microns, P less than 0.01) but not significantly longer (81.2 +/- 9.5 vs 71.2 +/- 9.6 microns, NS), so that the L/W ratio was greatly decreased (2.6 +/- 0.3 vs 4.1 +/- 0.7, P less than 0.01). The cells in the eccentrically hypertrophied ventricles were markedly thickened (25.9 +/- 2.4 microns, P less than 0.01) and elongated (4.2 +/- 0.4, NS) remained the same as in normal hearts. In both types of hypertrophy, series and lateral branches were significantly thicker and longer than in normal hearts; the number of series branches per cell was also significantly increased. The number of lateral branches per cell did not differ between the normal and concentrically hypertrophied hearts (2.2 +/- 0.7 vs 2.3 +/- 0.6, NS), but it was decreased by approximately one-half in the eccentrically hypertrophied hearts (1.2 +/- 0.3, P less than 0.05). The potential significance of these differences in SEM findings of cardiocytes is discussed with special reference to the differences in the cause, anatomy, and pathophysiology of concentric and eccentric hypertrophy in adult human hearts.

Adult↗
PubMed1999

Remodeling of cardiomyocytes and their branches in juvenile, adult, and senescent spontaneously hypertensive rats and Wistar Kyoto rats: comparative morphometric analyses by scanning electron microscopy.

Scanning electron microscopy was used to compare the shape, size, and connection of left ventricular (LV) myocytes between spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) at 3, 8, 15, 35, and 63 weeks of age. For either strain at each age, five rats were studied, in which LV myocytes consisted of a cylindrical trunk with series (SB) and/ or lateral branch(es) (LB) and step formations; cell junctions had 12 common basic patterns. The length (L), width (W), and L/W ratio of the myocytes, and various indices for SB, LB, and three selected types of cell junctions were measured in 100 cells from each heart and averaged for comparison studies. In the growing period (3-8 weeks of age), the LV myocytes were similar in shape and width in the two age-matched strains and grew similarly with the same L/W ratio. In adolescent (15-week-old) WKY, LV cells grew with the same L/W ratio as in the younger rats, whereas in adolescent SHR, the cells showed a much greater increase in width than in length (disproportionate hypertrophy), the LB proliferated significantly, and the numbers of step-to-step and side-to-side junctions were diminished. In adult (15-35-week-old) WKY, LV cells continued to grow without much change in SB, LB, and the cell junctions, whereas in adult SHR, LV hypertrophy progressed with enhanced cardiomyocyte hypertrophy, increased number of SB, LB, and step-to-end junctions, and reduction in the number of step-to-step and side-to-side junctions per cell. In aged (63-week-old) WKY and SHR, the indices of LV myocytes, SB, LB, and cell junctions did not differ from those in adult WKY and SHR, except for LB thinning in the WKY and significant LB loss in the SHR. Age-related reductions in side-to-side- and step-to-step junctions, and LB loss with myocardial fibrosis in adult and aged SHR may indicate increased loss of gap junctions which couple the cells for transverse conduction, and contribute to anisotropic discontinuous propagation and potential reentrant LV arrhythmias.

Animals↗
PubMed1985

Erythrocyte morphology in women with severe preeclampsia and eclampsia. Preliminary observations with scanning electron microscopy.

Scanning electron microscopy was used to study the morphologic characteristics of erythrocytes in women with preeclampsia and eclampsia. In nine nulliparous women with eclampsia, the proportion of abnormal red cells (schistocytes, echinocytes, and spherocytes) was significantly greater than in 12 normally pregnant control women (p less than 0.001). Likewise, the proportion of these abnormal erythrocyte forms was significantly greater in 12 nulliparous women with preeclampsia than in 25 normally pregnant control women (p = 0.009). Six women with mild pregnancy-induced hypertension without proteinuria were studied before and after magnesium sulfate therapy had been given, and no differences in the proportion of abnormal erythrocyte forms were found. Evidence for microangiopathic hemolysis, manifest by reticulocytosis and thrombocytopenia, was apparent with eclampsia, although only reticulocytosis was identified in women with preeclampsia. There was evidence for hepatic dysfunction in more than half of the women with eclampsia, and in nearly one third of those with preeclampsia. We speculate that compositional changes in the membrane, induced by plasma/erythrocyte lipid interchanges, which are predisposed by normal pregnancy and amplified by severe preeclampsia, especially in the presence of liver dysfunction, may have participated in the genesis of the red cell abnormalities observed. Furthermore, these abnormalities in the cell membrane may increase erythrocyte susceptibility to microangiopathic hemolysis.

Eclampsia↗