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PubMed2001

Atomic Force Microscopy and Scanning Electron Microscopy Reveal Genome-dependent Ultrastructure of Seed Surface.

Both scanning electron microscopy (SEM) and contact mode imaging via atomic force microscopy (AFM) have been utilized to elucidate the ultrastructure of mung bean seed surfaces. The results indicate: 1) that AFM is useful in the examination of seed surface ultrastructure ex-vaccuo without the need for additional complex preparative procedures; and 2) that both the cotyledon and seed coat of different strains of mung beans bear specific ultrastructural details unique to each strain. To our knowledge, these are the first AFM images of seed surfaces.

Journal Article↗
PubMed1999

Discrimination of morphological findings in dentine from osteogenesis imperfecta patients using combinations of polarized light microscopy, microradiography and scanning electron microscopy.

OBJECTIVES: The aim of this study was to investigate the morphological appearance of dentine in teeth from individuals with osteogenesis imperfecta type I, III and IV using different histological techniques, and to correlate morphological findings to different types of osteogenesis imperfecta. SAMPLE AND METHODS: Extracted or exfoliated primary and permanent teeth were collected from 15 patients with the osteogenesis imperfecta diagnoses I, III or IV, with or without the additional diagnosis dentinogenesis imperfecta. Ground and decalcified sections were prepared from the teeth. Histo-morphological studies of the dentine were performed utilizing light and polarized light microscopy, microradiography and scanning electron microscopy. RESULTS: Characteristic findings were irregular tubules, remnants of capillary inclusions and obliterated pulps. All types of osteogenesis imperfecta exhibited similar types of dentine aberrations, but patients with type III or IV had a higher frequency of aberrations when compared to type I. CONCLUSIONS: The combination of either polarized light microscopy or micro-radiography, together with scanning electron microscopy, gave the most amount of morphological information from dentine samples. In addition, aberrations in dentine structure were more clearly observable. Light microscopy was not critical for the analyses.

Adolescent↗
PubMed1980

The immotile cilia syndrome: phase contrast light microscopy, scanning and transmission electron microscopy.

In the immotile cilia syndrome, transmission electron microscopy of the cilia shows abnormalities in the arrangement of the central pairs of tubules and in the dynein arms of the peripheral tubules, or in the radial spokes, We studied four nonrelated children, 9/12, 5, 6, and 6 years old, with situs inversus and a history of chronic sinusitis and bronchitis (Kartagener's syndrome) and four children in the same age group and with the same history, but without situs inversus. Under the phase contrast microscope no motile cilia were seen in the four patients with Kartagener's syndrome and in two of the four other children. Transmission electron microscopy showed aberrations in the cilia (absence of dyneim arms, random orientation of central tubules) in the patients with Kartagener's syndrome. Scanning electron microscopy revealed differences in morphology and arrangement of cilia between patients and controls. In the patients much more mucus was present on the mucosal surface. Furthermore, the cilia were in a state of disorder, with a multidirectional orientation instead of the parallel orientation seen in controls.

Child↗
PubMed1992

Absence of ovicidal effects of fenoxycarb in the tick Ixodes dammini as observed by light, scanning, and transmission electron microscopy.

Freshly oviposited eggs from fed females of the northern deer tick Ixodes dammini were divided into two groups--untreated controls and fenoxycarb-exposed ova. The level of fenoxycarb exposure in the experimental group was equal to a concentration that proved 100% lethal in the cat flea, Ctenocephalides felis (Marchiondo et al. 1990). Both groups were allowed to develop with samples taken at 48 and 144 h for examination by light microscopy, scanning electron microscopy, and transmission electron microscopy. No disruption of the stages of tick embryological development was observed when specimens were examined by these methods. Eggs not sampled for light microscopy or scanning or transmission electron microscopy during development were allowed to hatch. The resulting larvae were fully developed and motile in both the control and experimental conditions, further supporting the conclusion that embryological development of I. dammini is not disrupted by concentrations of fenoxycarb which would be practical in the field.

Animals↗
PubMed1980

Electron microscopy: a method for the diagnosis of inherited metabolic storage diseases. Electron microscopy in diagnosis.

In the diagnosis of inherited metabolic diseases, electron microscopy has become an important method complementary to clinical, histological and biochemical assays. The characteristic ultrastructure of stored material as well as the site of accumulation in the cell are shown in a number of metabolic disorders. The most prominent advantages of electron microscopical techniques as compared to alternative techniques are discussed. One of the advantages is the fact that ultrastructural investigation requires only tissue samples of very small size, and another that its results may be obtained within two days. Moreover, transmission electron microscopy permits new and promising analytical methods such as quantitative estimation of organellar changes (morphometry) and energy dispersive X-ray elemental analysis (EDX).

Fabry Disease↗
PubMed1983

Analytical scanning and transmission electron microscopy and x-ray microdiffractometry of calcium pyrophosphate dihydrate crystal deposits in tissues.

This paper reviews current methods and applications for the detection and identification of calcium pyrophosphate dihydrate (CPPD) crystals. Methods reviewed include compensated polarized light microscopy, scanning electron microscopy, transmission electron microscopy, x-ray energy-dispersive elemental analysis, x-ray powder microdiffractometry, and selected area electron diffractometry. Although compensated polarized light microscopy is the best technique for crystal detection in pathologic fluids and tissues, because of crystal size this technique cannot discriminate easily between CPPD(M) and CPPD(T) polymorphs. To determine the presence and relative concentration of CPPD(M) and CPPD(T), x-ray or electron microdiffractometry is required. Analytical scanning and transmission electron microscopy are needed to localize crystals ultrastructurally and to determine the relationship of the crystal deposits to tissue components. The correlative application of multiple techniques on the same sample or adjacent samples provides more precise localization and identification than any single technique.

Calcium Pyrophosphate↗
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↗
PubMed1991

Imaging friction tracks at diamond surfaces using reflection electron microscopy.

Reflection electron microscopy (REM) is applied to image the structure of polished natural diamond (001) surfaces (of 5 x 4 mm size) after friction experiments under a pressure below the critical value. Friction tracks marked by a diamond needle after a single pass movement under a pressure of 13 GPa can be seen in REM images and show non-uniform contrast. The surface shows relatively dark image contrast at the light contacted area, which is possibly due to the structural modification at the top atomic layer. The high local contacting pressure pushes part of the needle into the surface which causes fracture, resulting in the formation of grooves at the surface. It is possible to have plastic deformation in this process, but no evidence has been found for the presence of cracking. The observations support the adhesion frictional mechanism rather than the micro-cleavage model.

Carbon↗
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↗
PubMed1985

Both electrical and chemical transmission between the 'lobula giant movement detector' and the 'descending contralateral movement detector' neurons of locusts are supported by electron microscopy.

Conventional electron microscopy combined with cobalt staining techniques has revealed chemical synapses and gap junction-like areas denoting specific regions of contact between two large, uniquely identifiable visual interneurons in the brain of the locust Schistocerca gregaria. The morphological demonstration of chemical synapses suggests that one of the two neurons, the 'descending contralateral movement detector', receives a chemically mediated input from its main presynaptic element, the 'lobula giant movement detector'. This observation supports recent electrophysiological studies demonstrating synaptic delays between the two cells, characteristic of chemical synapses. However, regions with the appearance of gap junctions are also observed. This corroborates earlier work which suggested that these two neurons are coupled electrically.

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↗
PubMed1984

Heterogeneity of endothelium in human aorta. A quantitative analysis by scanning electron microscopy.

Scanning electron microscopy was used to characterize a silver-stained endothelial surface of human aorta and iliac artery. The autopsy material was taken 1-3 h after death from two age groups: group A (0-7 yr) and group B (40-75 yr). The mean cell density per 1 mm2 in the arteries of group A was significantly higher than in the arteries of group B which lie outside ostia, fatty streaks and plaques. In adult arteries the cell density over the plaque was significantly lower than in the regions overlying a fatty streak or uninvolved surface. The luminal surface of child arteries outside high hemodynamic stress zones is a homogeneous sheet covered with exceptionally small (less than 400 micron2) and medium (400-800 micron2) cells. Large (800-1200 micron2) and giant (1200-8000 micron2) endothelial cells emerge only in fatty streaks of child arteries. The luminal surface of adult arteries is a heterogeneous monolayer covered with polymorphic cells both in regions unaffected by atherosclerosis and over the fatty streak and plaque. Giant and large endothelial cells account for 25-41% of the total cell population of adult arteries, occupying more than 40% of the surface in the latter.

Adult↗
PubMed1982

The effect of EDTAC and the variation of its working time analyzed with scanning electron microscopy.

Scanning electron microscopy was used in an in vitro evaluation of EDTAC's effect on the dentinal wall of the root canal. The effects produced by varying its working time were observed. This analysis was done on twenty-four sections of roots in longitudinal and transversal cuts. After 5 minutes a certain cleansing effect on the dentinal wall as compared with the control was observed. the strongest effect was detected at 15 minutes, with no variations after 30 minutes.

Chelating Agents↗