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At least 433 records · Page 24Linked to original sources
PubMed2005

Direct imaging of meniscus formation in atomic force microscopy using environmental scanning electron microscopy.

Environmental scanning electron microscopy was used to image meniscus formation between an AFM tip and a surface. At high relative humidity, 70%-99%, the meniscus formed is 100 to 1200 nm in height, orders of magnitude larger than predicted by the Kelvin equation using spherical geometry. The height of the meniscus also demonstrates hysteresis associated with increasing or decreasing relative humidity.

Letter↗
PubMed1992

Mammotropes and somatotropes in the adenohypophysis of androgenized female mice: morphological and immunohistochemical studies by light microscopy correlated with routine electron microscopy.

Female mice were divided into androgenized (AF) and control (CF) groups. The AF mice were injected subcutaneously with testosterone propionate (Tp) and the CF mice with sesame oil at 5 days of age. Mammotropes (PRL cells) and somatotropes (GH cells) in the adenohypophyses of these mice when they became adults were studied with immunohistochemistry and morphometry by light microscopy correlated with routine electron microscopy. In CF mice, almost all of the PRL-immunoreactive cells (about 43% of all parenchymal cells) were type I (classical) PRL cells, and almost all of the GH-immunoreactive cells (about 30% of all parenchymal cells) were type I (classical) GH cells. Type II PRL cells accounted for about 0.4% of parenchymal cells, and type II GH cells were about 2.5% of all parenchymal cells. In AF mice, the percentages of PRL and GH cells were not significantly different from those of CF mice. Mammosomatotropes (Ms cells) in both groups were less than 1% of all parenchymal cells. Numbers of all parenchymal, PRL and GH cells, however, were increased significantly in AF mice when compared to those in CF, because the adenohypophysis was increased in volume in AF mice. Type I PRL cells were larger in AF than in CF. The ultrastructure suggested that type I PRL cells may show increased PRL synthesis and secretion in AF mice. Furthermore, AF mice, in which the hypothalamus is masculinized by the neonatal treatment with Tp, retained feminine characteristics in the population and size of PRL cells and GH cells in the adenohypophysis.

Androgens↗
PubMed2004

3-D morphological characterization of the liver parenchyma by atomic force microscopy and by scanning electron microscopy.

A comparative study of atomic force microscopy (AFM) and scanning electron microscopy (SEM) imaging of the healthy human liver parenchyma was carried out to determine the similarities and the differences. In this study, we compared the fine hepatic structures as observed by SEM and AFM. Although AFM revealed such typical hepatic structures as bile canaliculi and hepatocytes, it also showed the location of the nucleus and chromatin granules in rough relief structure, which was not visible by SEM. By contrast, SEM visualized other structures, such as microvilli, the central vein, and collagenous fibers, none of which was visualized by AFM. For better orientation and confirmation of most of the structures imaged by SEM and AFM, Congo Red-stained specimens were also examined. Amyloid deposits in the Disse's spaces were shown especially clearly in these images. The differences between the SEM and AFM images reflected the characteristics of the detection systems and methods used for sample preparation. Our results reveal that more detailed information on hepatic morphology is obtained by exploiting the advantages of both SEM and AFM.

Adult↗
PubMed2005

Three-dimensional morphological characterization of optic nerve fibers by atomic force microscopy and by scanning electron microscopy.

A comparative study of scanning electron microscopy (SEM) and atomic force microscopy (AFM) imaging of the healthy human optic nerve was carried out to determine the similarities and the differences. In this study we compared the fine optic nerve structures as observed by SEM and AFM. The fibers of the right optic nerve of a 61-year-old man show different arrangements in transverse sections taken from the same individual 5 mm central to the optic canal and 5 mm peripheral to the optic chiasma; this difference can be recognized by light microscopy (LM), SEM, and AFM. AFM revealed such typical optic nerve fibers (taken from a point 5 mm central to the optic canal) with annular and longitudinal orientations, which were not visible by SEM in this form. By contrast, LM and SEM visualized other structures, such as pia mater and optic nerve fibers loosely arranged in bundles, none of which was visualized by AFM. The images, however, taken 5 mm peripheral from the optic chiasma show shapeless nerve fibers having a wavy course. Our results reveal that more detailed information on optic nerve morphology is obtained by exploiting the advantages of both SEM and AFM. These are the first SEM and AFM images of healthy human optic nerve fibers, containing clear representations of the three dimensions of the optic nerve.

Aged↗
PubMed1978

Sephadex globules placed as landmarks in combined stereo microscopy, scanning and transmission electron microscopy.

Regions of specific interest in tissue blocks were localized in a stereo microscope and landmarked with Sephadex spheres (10-40 micron in diameter). This procedure made it possible to recognize these regions easily and quickly in the scanning electron microscope. When the tissue was later embedded in Epon the spheres facilitated orientation when sectioning. Thus it was possible with great certainty to determine the level at which ultrathin sections should be cut for transmission electron microscopy to attain an exact correspondence between scanning and transmission electron microscopic observations. The procedure is described and an example of its application is shown in a study of experimental hypertensive endothelial changes.

Angiotensin II↗
PubMed1992

Electron microscopy of bone response to titanium cylindrical screw-type endosseous dental implants.

This study investigated the undecalcified bone and enveloping tissues supporting commercially pure titanium one-stage and two-stage endosseous dental implants placed into the mandibles of adult mongrel dogs. Correlative light microscopy, transmission electron microscopy, and high-voltage transmission electron microscopy demonstrated a dynamic bone interface to the implants. Mineralized tissue was routinely observed within 20 to 50 nm from the implant interface, separated from the implant interface only by an electron-dense deposit. The densely mineralized collagen fiber matrix was oriented parallel to the implant interface, as were osteocytes that were found close to the interface. Osteocytic projections progressed through canaliculi, often directly to the implant interface. Unmineralized areas that appeared to have the potential for mineralization were also identified.

Alveolar Process↗
PubMed1983

Movement of cell surface immunoglobulin (Ig) in guinea pig B cells and lymphocytic leukemia cells as observed by light microscopy and scanning and transmission electron microscopy.

The distribution and regeneration of immunoglobulin (Ig) of guinea pig leukemia cells were investigated through the use of ferritin labeling and scanning electron microscopy. Throughout this work, correlative light microscopy using fluorescein label and transmission electron microscopy using ferritin label were used. The cells used in this study were lymphocytic leukemia cells, an acute (L2C) and a chronic (KSL) form, and normal B cells obtained from Sewall Wright strain 2 guinea pigs. Distinct differences in the movement and regeneration of cell surface Ig were observed when these cells were compared. Both L2C and KSL cells were slower to cap than normal B cells which formed a well-organized single patch. The cells endocytosed the label rapidly and either processed or shed the label within 24 hours except for the L2C cells which had retained internalized label after 24 hours. Regeneration of surface Ig was clearly demonstrated in all three cell types. The apparent similarities between these two lymphocytic guinea pig leukemias and similar reports of human leukemias strongly suggest that the L2C and KSL cells could provide excellent models for future studies of acute and chronic forms of this disease.

Animals↗
PubMed1995

[Angio-architecture of the colon in Crohn disease and ulcerative colitis. Light microscopy and scanning electron microscopy studies with reference to the morphology of the healthy large intestine].

The etiology and the pathogenesis of the chronic inflammatory bowel diseases known as Crohn's disease and ulcerative colitis have not been defined. Therefore, in this study the main emphasis was placed on description of the pathologic anatomy. Disturbed blood supply and vascular disorders have been discussed as etiopathogenetic factors. The results in the literature are frequently contradictory. For this reason, the vascular system of the colon in Crohn's disease and ulcerative colitis was systematically examined by means of various morphological methods in this study. Microvascular corrosion casting and translucent specimens were taken from operative specimens taken from 12 patients with Crohn's disease and 8 with ulcerative colitis. For comparison, tumor-free parts of 6 colon cancer specimens were examined. The evaluation was done by scanning electron- and/or stereoscopic microscopy. In the presence of chronic inflammatory bowel disease dilatation of the submucosal veins, caliber differences in the tunica muscularis and rarefaction of the penetrating blood vessels were found. In summary, an impairment of the blood flow in the tunica muscularis can be postulated. For the first time, the resulting venous stasis has been described, in contrast to the previously described disturbed arterial blood supply.

Adult↗
PubMed1986

Demonstration of calicivirus in human faeces by immunosorbent and immunogold-labelling electron microscopy methods.

Immunosorbent electron microscopy (ISEM) and immuno-gold staining (IGS) electron microscopy methods have been applied to human faeces, shown by direct electron microscopy (EM) to contain calicivirus. Caliciviruses were successfully trapped on grids coated with positive rabbit or human antisera against calicivirus, but not with negative sera. Caliciviruses were specifically labelled with gold particles, when treated with positive rabbit or human antisera against calicivirus followed by protein A-gold and goat anti-rabbit or anti-human IgG gold conjugates in an indirect method in suspension. Goat anti-human IgM gold complexes did not react with the available antisera. Attempts to label caliciviruses trapped on the grids were unsuccessful. No cross-reactions were observed with Norwalk agent-like particles, hepatitis A virus or poliovirus type 3 by any of the methods. The results indicate that ISEM and IGS may be useful techniques for detection and identification of small viruses present in low concentrations in faeces.

Caliciviridae↗
PubMed2004

Surface morphology and chemistry of Prunus laurocerasus L. leaves: a study using X-ray photoelectron spectroscopy, time-of-flight secondary-ion mass spectrometry, atomic-force microscopy and scanning-electron microscopy.

The surface properties of the plant cuticle play a crucial role in plant-pathogen interactions and the retention and penetration of agriculturally important chemicals. This paper describes the use of X-ray photoelectron spectroscopy (XPS), time-of-flight secondary-ion mass spectrometry (ToF-SIMS), tapping-mode atomic force microscopy (TM-AFM) and scanning electron microscopy (SEM) to determine surface-specific chemical and material properties of the adaxial surface of Prunus laurocerasus L. leaves. XPS data, derived from the uppermost few nanometres (< 10 nm) of the leaf surface, were consistent with the wax components and functionality known to be present within the waxes. ToF-SIMS provided molecular speciation from the outermost monolayer of the leaf surface, indicating the importance of a family of acetates with chain lengths ranging from C20 to C34. The presence of alkanes with C29 and C31 chain lengths was also confirmed. SEM and TM-AFM topography images revealed a textured granular surface, while simultaneously recorded AFM phase images revealed heterogeneous material properties at the nanoscale. The relevance of these data to plant cuticle development, allelochemistry and agrochemical delivery is discussed.

Microscopy, Atomic Force↗
PubMed1977

Amalgam tattoos: light and electron microscopy and electron-probe micro-analysis.

A common tattoo occurring in the mouth is caused by the insertion of amalgam filling material into the soft tissues. Fifteen amalgam tattoos were examined. Amalgam or its derivatives were found within macrophages, fibroblasts and multinuclear giant cells. Fine particles were found associated with: the basement-membranes of mucosal epithelium, of striped muscle fibres, and of muscle cells of blood vessels; collagen; elastic tissue; and the connective tissue of nerves. Amalgam consists mainly of mercury, silver and tin. The analytical results suggest that corrosion occurs and that mercury and some tin are lost from the tattoos, leaving silver and tin in macrophages and giant cells, and silver in fibroblasts and in the above-mentioned extracellular sites.

Biopsy↗
PubMed2005

Localization of brain endothelial luminal and abluminal transporters with immunogold electron microscopy.

Immunogold electron microscopy has identified a variety of blood-brain barrier (BBB) proteins with transporter and regulatory functions. For example, isoforms of the glucose transporter, protein kinase C (PKC), and caveolin-1 are BBB specific. Isoform 1 of the facilitative glucose transporter family (GLUT1) is expressed solely in endothelial (and pericyte) domains, and approximately 75% of the protein is membrane-localized in humans. Evidence is presented for a water cotransport function of BBB GLUT1. A shift in transporter polarity characterized by increased luminal membrane GLUT1 is seen when BBB glucose transport is upregulated; but a greater abluminal membrane density is seen in the human BBB when GLUT1 is downregulated. PKC colocalizes with GLUT1 within these endothelial domains during up- and downregulation, suggesting that a PKC-mediated mechanism regulates human BBB glucose transporter expression. Occludin and claudin-5 (like other tight-junctional proteins) exhibit a restricted distribution, and are expressed solely within interendothelial clefts of the BBB. GFAP (glial fibrillary acidic protein) is uniformly expressed throughout the foot-processes and the entire astrocyte. But the microvascular-facing membranes of the glial processes that contact the basal laminae are also polarized, and their transporters may also redistribute within the astrocyte. Monocarboxylic acid transporter and water channel (Aquaporin-4) expression are enriched at the glial foot-process, and both undergo physiological modulation. We suggest that as transcytosis and efflux mechanisms generate interest as potential neurotherapeutic targets, electron microscopic confirmation of their site-specific expression patterns will continue to support the CNS drug discovery process.

Animals↗