High-resolution SEM and STEM of adrenocortical endothelium: Molecular resolution of membrane complexes

1993 ◽  
Vol 51 ◽  
pp. 610-611
Author(s):  
Robert P. Apkarian
Keyword(s):  
Fine Structure ◽  
Low Voltage ◽  
Uranyl Acetate ◽  
Correlative Microscopy ◽  
Coated Pits ◽  
Fine Grain ◽  
Structural Identity ◽  
Cellular Pathways ◽  
Steroidogenic Cells ◽  
Cr Film

A multitude of complex ultrastructural features are involved in endothelial cell (EC) gating and sorting of lipid through capillaries and into steroidogenic cells of the adrenal cortex. Correlative microscopy is necessary to distinguish the structural identity of features involved in specific cellular pathways. In addition to diaphragmed fenestrae that frequently appear in clusters, other 60-80 nm openings; plasmalemma vesicles (PV), channels and pockets fitted with diaphragms of the same dimension, coexist on the thin EC surface. Non-diaphragmed coated pits (CP) (100-120 nm) involved in receptor mediated endocytosis were also present on the EC membrane. The present study employed HRSEM of cryofractured and chromium coated specimens and low voltage HRSTEM of 80 nm thick LX-112 embedded sections stained with 2.0% uranyl acetate. Both preparations were imaged at 25 kV with a Topcon DS-130 FESEM equipped with in-lens stage and STEM detector.HRSEM images of the capillary lumen coated with a lnm continuous fine grain Cr film, provided the ability to scan many openings and resolve (SE-I contrast) the fine structure of diaphragm spokes and central densities (Fig. 1).

Simultaneous high-resolution SEM and STEM of organic compounds and biological macromolecules

1993 ◽  
Vol 51 ◽  
pp. 608-609
Author(s):  
R.P. Apkarian ◽  
K.A. Robinson ◽  
Y. Yamasaki ◽  
F.M. Menger
Keyword(s):  
Secondary Electron ◽  
Uranyl Acetate ◽  
Biological Macromolecules ◽  
Polycarbonate Membrane ◽  
Fine Grain ◽  
Transmission Electron ◽  
Contrast Enhanced ◽  
Micelle Solution ◽  
Scanning Transmission ◽  
Cr Film

A simple spray mounting preparation of hydrocarbon based macromolecules onto coated grids or Si chips was employed for secondary electron (HRSEM) or in tandem with scanning transmission electron (STEM) imaging. The grid specimens were staged in the lens of a Topcon DS-130 SEM equipped with a Schottky field emission (SFE) source. A 1 nm probe, created at 25 kV, elicited low radiation damage to the molecules on the formvar support. Molecules on grids were stabilized with heavy metal stains and contrast enhanced by a 1 nm fine-grain Cr film. The strategy was to generate sufficient SE-I electrons for above-lens detection simultaneous with the collection of transmitted electrons by the below specimen STEM detector.The bromine salt of a synthetic amphiphile, N-tetracosanyl-tetraethylenepentaammonium pentabromide was produced as a preliminary micelle solution of [10mM]. After vigorous sonication the solution was diluted to [1mM] with dH2O, filtered through 0.65μm polycarbonate membrane, and mixed vol./vol. with 2% uranyl acetate (freshly prepared and filtered through 0.2μm PC membrane).

Ultrastructure and Staining of Developing Elastic Tissue

1971 ◽  
Vol 29 ◽  
pp. 244-245
Author(s):  
E. N. Albert
Keyword(s):  
Fine Structure ◽  
Phosphotungstic Acid ◽  
Staining Method ◽  
Rat Aorta ◽  
Uranyl Acetate ◽  
The Other ◽  
Elastic Fibers ◽  
Elastic Tissue ◽  
Lead Citrate ◽  
New Born

Silver tetraphenylporphine sulfonate (Ag-TPPS) was synthesized in this laboratory and used as an electron dense stain for elastic tissue (Fig 1). The procedures for the synthesis of tetraphenylporphine sulfonate and the staining method for mature elastic tissue have been described previously.The fine structure of developing elastic tissue was observed in fetal and new born rat aorta using tetraphenylporphine sulfonate, phosphotungstic acid, uranyl acetate and lead citrate. The newly forming elastica consisted of two morphologically distinct components. These were a central amorphous and a peripheral fibrous. The ratio of the central amorphous and the peripheral fibrillar portion changed in favor of the former with increasing age.It was also observed that the staining properties of the two components were entirely different. The peripheral fibrous component stained with uranyl acetate and/or lead citrate while the central amorphous portion demonstrated no affinity for these stains. On the other hand, the central amorphous portion of developing elastic fibers stained vigorously with silver tetraphenylporphine sulfonate, while the fibrillar part did not (compare figs 2, 3, 4). Based upon the above observations it is proposed that developing elastica consists of two components that are morphologically and chemically different.

Fine Structure of Interdental Cells in the Mouse Cochlea

1970 ◽  
Vol 28 ◽  
pp. 140-141
Author(s):  
Roberta M. Bruck
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Young Adult ◽  
Uranyl Acetate ◽  
Ground Substance ◽  
Tectorial Membrane ◽  
Lead Citrate ◽  
Unusual Structure ◽  
Thin Sections ◽  
Collagenous Fibers

An unusual structure in the cochlea is the spiral limbus; this periosteal tissue consists of stellate fibroblasts and collagenous fibers embedded in a translucent ground substance. The collagenous fibers are arranged in vertical columns (the auditory teeth of Haschke). Between the auditory teeth are interdental furrows in which the interdental cells are situated. These epithelial cells supposedly secrete the tectorial membrane.The fine structure of interdental cells in the rat was reported by Iurato (1962). Since the mouse appears to be different, a description of the fine structure of mouse interdental cells' is presented. Young adult C57BL/6J mice were perfused intervascularly with 1% paraformaldehyde/ 1.25% glutaraldehyde in .1M phosphate buffer (pH7.2-7.4). Intact cochlea were decalcified in .1M EDTA by the method of Baird (1967), postosmicated, dehydrated, and embedded in Araldite. Thin sections stained with uranyl acetate and lead citrate were examined in a Phillips EM-200 electron microscope.

Fine Structure of Carotid Body: Normal and Anoxic Cats

1967 ◽  
Vol 25 ◽  
pp. 150-151
Author(s):  
Fadhil Al-Lami ◽  
R.G. Murray
Keyword(s):  
Fine Structure ◽  
Adrenal Medulla ◽  
Carotid Body ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Glomus Cells ◽  
Sustentacular Cells ◽  
Carotid Bodies

Although the fine structure of the carotid body has been described in several recent reports, uncertainties remain, and the morphological effects of anoxia on the carotid body cells of the cat have never been reported. We have, therefore, studied the fine structure of the carotid body both in normal and severely anoxic cats, and to test the specificity of the effects, have compared them with the effects on adrenal medulla, kidney, and liver of the same animals. Carotid bodies of 50 normal and 15 severely anoxic cats (9% oxygen in nitrogen) were studied. Glutaraldehyde followed by OsO4 fixations, Epon 812 embedding, and uranyl acetate and lead citrate staining, were the technics employed.We have called the two types of glomus cells enclosed and enclosing cells. They correspond to those previously designated as chemoreceptor and sustentacular cells respectively (1). The enclosed cells forming the vast majority, are irregular in shape with many processes and occasional peripheral densities (Fig. 1).

SEM analysis of DC magnetron sputtered beryllium films

1988 ◽  
Vol 46 ◽  
pp. 960-961
Author(s):  
E. F. Lindsey ◽  
C. W. Price ◽  
E. L. Pierce ◽  
E. J. Hsieh
Keyword(s):  
Fine Structure ◽  
Electron Emission ◽  
Secondary Electron ◽  
Low Voltage ◽  
Ion Beam ◽  
Secondary Electron Emission ◽  
Sem Analysis ◽  
Fused Silica ◽  
Grain Structure ◽  
Silica Substrate

Columnar structures produced by DC magnetron sputtering can be altered by using RF biased sputtering or by exposing the film to nitrogen pulses during sputtering, and these techniques are being evaluated to refine the grain structure in sputtered beryllium films deposited on fused silica substrates. Beryllium is brittle, and fractures in sputtered beryllium films tend to be intergranular; therefore, a convenient technique to analyze grain structure in these films is to fracture the coated specimens and examine them in an SEM. However, fine structure in sputtered deposits is difficult to image in an SEM, and both the low density and the low secondary electron emission coefficient of beryllium seriously compound this problem. Secondary electron emission can be improved by coating beryllium with Au or Au-Pd, and coating also was required to overcome severe charging of the fused silica substrate even at low voltage. The coating structure can obliterate much of the fine structure in beryllium films, but reasonable results were obtained by using the high-resolution capability of an Hitachi S-800 SEM and either ion-beam coating with Au-Pd or carbon coating by thermal evaporation.

Fine structure of steroidogenic cells of a primate cutaneous organ

1967 ◽  
Vol 121 (2) ◽  
pp. 337-367 ◽  
Author(s):  
Jean Kneeland Sisson ◽  
Wolf H. Fahrenbach
Keyword(s):  
Fine Structure ◽  
Steroidogenic Cells

Fine structure of the bands in the low-temperature spectra of sodium uranyl acetate

1982 ◽  
Vol 37 (5) ◽  
pp. 1277-1281 ◽  
Author(s):  
V. N. Boikov ◽  
A. N. Krasovskii ◽  
D. S. Umreiko
Keyword(s):  
Fine Structure ◽  
Low Temperature ◽  
Uranyl Acetate ◽  
Temperature Spectra

The fine structure of ascus development in Lasiobolus monascus (Pezizales)

1978 ◽  
Vol 56 (7) ◽  
pp. 862-872 ◽  
Author(s):  
James W. Kimbrough ◽  
Gerald L. Benny
Keyword(s):  
Fine Structure ◽  
Uranyl Acetate ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Stalk Cell ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Ultrathin Sections ◽  
Microscopic Inspection ◽  
Physical And Chemical

Ultrastructural and cytochemical studies on the ascus of Lasiobolus monascus are presented. Apothecia in various stages of development were obtained in culture and prepared for both light and electron microscopic observations. Ultrathin sections for electron microscopic inspection were often treated with silver methenamine to enhance wall characteristics. Ascus development was followed from fertilization to maturity.In this species, the ascogonium enlarges after fertilization to become the ascus mother cell. Two pores are present in the young ascus, one connecting it to the antheridium and another between the ascus and stalk cell. The ultrastructural features of these pores in the young and maturing ascus are described. During ascus enlargement, as many as four wall layers are found when poststained with silver methenamine. Only two layers are clearly distinguishable when poststained with uranyl acetate and lead citrate. The apical zone of dehiscence is characterized by a distinct annular swelling which appears during early ascosporogenesis. By spore maturation, this swelling is not evident either at the light or electron microscopic level. Instead, there appear to be both physical and chemical changes in the area of dehiscence. The wall is distinctly thinner and much more electron transparent in the area of dehiscence when treated with silver methanamine.

Postmortem changes of the gill lamellae of fish

1989 ◽  
Vol 47 ◽  
pp. 1080-1081
Author(s):  
K. C. Liu
Keyword(s):  
Fine Structure ◽  
Uranyl Acetate ◽  
Anguilla Japonica ◽  
Gill Lamella ◽  
Postmortem Changes ◽  
Osmic Acid ◽  
Lead Citrate ◽  
Chanos Chanos ◽  
Gill Filaments ◽  
Gill Lamellae

The fine structure of the gill lamellae of fish has been reported for several species. All of them consisted the same types of cells and showed the same characteristics. The structural change of the gill lamellae under natural condition, after death was not reported. This report is to present a study on that event.Gill filaments from cultured Anguilla japonica, Tilapia sp. and Chanos chanos, of marketing size, both fresh and dead for different length of time were studied. The samples were fixed with 3% glutaraldehyde and 1% osmic acid, dehydrated with ethanol, and embedded with Epon and Araldite mixture. Thin section were stained with uranyl acetate and lead citrate. Observations were made with a JEOL 100 CX electron microscpe at 60 KV.The gill lamella of all three species studied showed similar fine stuctural characteristics . They consisted a central raw of pillar cells which formed the blood lumen. A layer of epithelium covered the outer surface . There was a prominent layer of basal limina between those two types of cells (Fig. 1). The epithelium showed degeneration first. It disintegrated and ditached from the basal lamina, and formed debris.

Some aspects of the fine structure of goldfish optic tectum

1978 ◽  
Vol 36 (2) ◽  
pp. 590-591
Author(s):  
Betty I. Roots
Keyword(s):  
Fine Structure ◽  
Optic Tectum ◽  
Phosphate Buffer ◽  
Carassius Auratus ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Goldfish Carassius Auratus ◽  
Laminar Pattern ◽  
The Brain

In teleosts the optic tectum is the major integrative centre in the brain. The cyto- and fibre architecture of the optic tectum have been studied extensively and a well-defined laminar pattern has been described. Here some aspects of the fine structure of the optic tectum of the goldfish, Carassius auratus, will be described and discussed. Goldfish which had been kept at a temperature of 15°C were fixed by perfusion with 2. 5% glutaraldehyde in a phosphate buffer. After fixation pieces of the optic tectum from both dorsal and ventral regions, cut so that their original orientation in the tectum could be determined by their shape, were removed. They were post-fixed in 1% osmium tetroxide in the same buffer for 1 1/2 h, dehydrated, stained in 2% uranyl acetate and embedded in epon. Sections were stained with lead citrate.Lining the ventrical is the ependyma consisting of epithelial-like cells which are 5. 4 μm in diameter, are ciliated, and joined by both desmosomes and tight junctions between their somata.

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