High-Resolution Stereo Electron Microscopy of Neurofilaments and Alzheimer Type Paired Helical Filaments

1985 ◽  
Vol 43 ◽  
pp. 730-733
Author(s):  
H.M. Wisniewski ◽  
G.Y. Wen
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Water Surface ◽  
Paired Helical Filaments ◽  
Uranyl Acetate ◽  
Saturated Solution ◽  
New Method ◽  
Alzheimer Type ◽  
Tissue Block ◽  
Ultrathin Sections

To learn about the ultrastructural similarities and dissimilarities between the Alzheimer's paired helical filaments (PHF) and normal neurofilaments, we developed a new method to cut the plastic embedded block. We call the sections cut by this new method supra-ultrathin sections. To obtain supra-ultrathin EM sections, a selected area of the tissue block was first trimmed to a size about 0.25 mm2 to reduce the sectioning pressure between the knife and the tissue block. The tissue was sectioned as thin as possible. The interference color of the sections was almost as transparent as the water surface. The thicker sections with different interference colors were removed by picking up with hair tip so that all of the sections floating on the water were of same or similar thickness. A saturated solution of uranyl acetate in 50% ethanol was used to maximize the contrast of these supra-ultrathin EM sections on uncoated grids.

Platinum Compounds as Stains for Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 230-231
Author(s):  
S. K. Aggarwal ◽  
P. McAllister ◽  
R. W. Wagner ◽  
B. Rosenberg
Keyword(s):  
Electron Microscopy ◽  
Hela Cells ◽  
Uranyl Acetate ◽  
Sarcoma 180 ◽  
Platinum Compounds ◽  
Kb Cells ◽  
En Bloc ◽  
Human Lymphoma ◽  
Ultrathin Sections ◽  
Blue Coloration

Uranyl acetate has been used as an electron stain for en bloc staining as well as for staining ultrathin sections in conjunction with various lead stains (Fig. 1). Present studies reveal that various platinum compounds also show promise as electron stains. Certain platinum compounds have been shown to be effective anti-tumor agents. Of particular interest are the compounds with either uracil or thymine as one of the ligands (cis-Pt(II)-uracil; cis-Pt(II)-thymine). These compounds are amorphous, highly soluble in water and often exhibit an intense blue coloration. These compounds show enough electron density to be used as stains for electron microscopy. Most of the studies are based on various cell lines (human AV, cells, human lymphoma cells, KB cells, Sarcoma-180 ascites cells, chick fibroblasts and HeLa cells) while studies on tissue blocks are in progress.

The Ultrastructure of Lymphocytic Hypophysitis

1981 ◽  
Vol 39 ◽  
pp. 466-467
Author(s):  
S.L. Asa ◽  
K. Kovacs ◽  
J. M. Bilbao ◽  
R. G. Josse ◽  
K. Kreines
Keyword(s):  
Electron Microscopy ◽  
Plasma Cells ◽  
Secretory Granules ◽  
Sella Turcica ◽  
Uranyl Acetate ◽  
Lymphocytic Hypophysitis ◽  
Pituitary Cells ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Mass Lesions

Seven cases of lymphocytic hypophysitis in women have been reported previously in association with various degrees of hypopituitarism. We report two pregnant patients who presented with mass lesions of the sella turcica, clinically mimicking pituitary adenoma. However, pathologic examination revealed extensive infiltration of the anterior pituitary by lymphocytes and plasma cells with destruction of the gland. To our knowledge, the ultrastructural features of lymphocytic hypophysitis have not been studied so far.For transmission electron microscopy, tissue from surgical specimens was fixed in glutaraldehyde, postfixed in OsO4, dehydrated and embedded in epoxy-resin. Ultrathin sections were stained with uranyl acetate and lead citrate and examined with a Philips 300 electron microscope.Electron microscopy revealed adenohypophysial cells of all types exhibiting varying degrees of injury. In the areas of most dense inflammatory cell infiltration pituitary cells contained large lysosomal bodies fusing with secretory granules (Fig. 1), as well as increased numbers of swollen mitochondria, indicating oncocytic transformation (Fig. 2).

scholarly journals FINE STRUCTURES OF INTRACYTOPLASMIC ORGANELLES OF MYCOBACTERIA

1961 ◽  
Vol 9 (3) ◽  
pp. 597-608 ◽  
Author(s):  
Masaatsu Koike ◽  
Kenji Takeya
Keyword(s):  
Electron Microscopy ◽  
Lamellar Structure ◽  
Cytoplasmic Membrane ◽  
Uranyl Acetate ◽  
Low Density ◽  
Nuclear Region ◽  
Unit Membrane ◽  
Veronal Buffer ◽  
Ultrathin Sections ◽  
Fine Structures

The fine structure of the intracytoplasmic organelles of mycobacteria was studied by means of electron microscopy of ultrathin sections. A well-preserved nuclear apparatus was obtained by fixation with OsO4 in acetate-veronal buffer, containing calcium and tryptone, or in collidine-HCl buffer, followed by uranyl-acetate treatment and embedding in araldite. A low density nuclear region was filled with fine fibrils, 30 A in diameter, in parallel or concentric arrangement. A membranous organelle, tentatively designated as "lamellar structure," consists of unit membranes in lamellar arrangement. The thickness of each lamella in this membranous organelle coincides with that of the three-layered cytoplasmic membrane Moreover, the continuity of this unit membrane with the cytoplasmic membrane was demonstrated.

Permeability in the Blood-Brain Barrier in Monkeys Following Exposure to High Altitude

1971 ◽  
Vol 29 ◽  
pp. 328-329
Author(s):  
R.S. Demaree ◽  
L.J. Ackerman ◽  
D. L. Anderson
Keyword(s):  
Electron Microscopy ◽  
Cerebral Edema ◽  
Osmium Tetroxide ◽  
Acute Mountain Sickness ◽  
Cebus Apella ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Limited Evidence ◽  
Ultrathin Sections ◽  
Mountain Sickness

People who rapidly ascend to high terrestrial elevations may experience the “acute mountain sickness” syndrome. Speculation and limited evidence suggest that cerebral edema may play an important role in initiating and perpetuating this condition. We have recently demonstrated by electron microscopy that a mild cerebral edema develops in some Cebus apella monkeys rapidly transported to 14,110 feet. In the present study, Cebus apella monkeys were terminated at 1, 3, or 5 days after being shipped from sea level (160 feet) to 14,110 feet without acclimatization at intermediate altitudes.Thorotrast was administered IV 30 minutes prior to termination by perfusion or guillotine. Cerebral cortex was fixed by either perfusion or immersion in glutaraldehyde, and postfixed in osmium tetroxide. Following fixation, the tissues were dehydrated in ascending concentrations of ethanol followed by propylene oxide and embedded in Epon 812. Ultrathin sections were either not stained or doubly stained with uranyl acetate and lead citrate.

Uranyl Acetate as a Fixative—from pH 2.0 to 8.0

1971 ◽  
Vol 29 ◽  
pp. 490-491
Author(s):  
V. R. Mumaw ◽  
B. L. Munger
Keyword(s):  
Electron Microscopy ◽  
Oxalic Acid ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Tissue Sections ◽  
Normal Rat ◽  
Lead Hydroxide ◽  
Ultrathin Sections ◽  
Rat Tissue

Numerous applications utilizing uranyl acetate as an electron stain for electron microscopy have been described. Uranyl acetate has become a routine stain used in conjunction with lead hydroxide for staining ultrathin sections. En bloc staining with uranyl acetate following osmium tetroxide post-fixation produces undesirable effects on some cytoplasmic components, especially glycogen. Recent studies using uranyl acetate as a fixative and en bloc stain at pH 7.2 before osmification has shown uranyl acetate to have desirable fixation and staining qualities. Tissues treated with uranyl acetate at a pH of 2.0-8.0 were studied. Normal rat tissue was fixed in Karnovsky's paraformaldehyde-glutaraldehyde fixative. The tissue was post-fixed in 0.5% uranyl acetate in water at pH 2.0 and 0.5% uranyl acetate in 0.1M s-collidine with 0.01M oxalic acid at pH 4, pH 6.0, pH 7.2, and pH 8.0 for 1 hour at 4°C. Following several rinses of 0.1M s-collidine buffer, the tissues were treated with 1.33% osmium tetroxide 1 hour at 4°C followed by rapid dehydration in ethanol and embedded in Durcupan ACM. Tissue sections were stained with lead hydroxide.

Organs of a Baikal seal affected by a morbillivirus

1990 ◽  
Vol 48 (3) ◽  
pp. 968-969
Author(s):  
O.I. Belykh ◽  
Ye.V. Likhoshway ◽  
Yu.V. Solodun ◽  
O.A. Goldberg ◽  
V.P. Kumarev
Keyword(s):  
Electron Microscopy ◽  
Measles Virus ◽  
Present Report ◽  
Protein A ◽  
Uranyl Acetate ◽  
Kidney Cells ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Liver And Kidney ◽  
Ultrathin Sections

The population of Baikal seals Phoca sibirica has been plagued in 1987-88 by an unknown disease. Oligonucleotide probing of nucleic acids isolated from tissues of ill and dead animals, as well as immunological evidence and clinical data suggested that seals were infected by a morbillivirus. Morbillivirus antigen has been vizualized in dead seal tissues by immunoelectron microscopy (preembedding technique).The present report gives outline of electron microscopic studies of the tissues of infected Baikal seals. Morbillivirus antigens were vizualized as clusters of gold spheres by postembedding technique with monoclonal antibodies against measles virus and protein A-colloid gold conjugates in nuclei and cytoplasm of liver and kidney cells. Some clusters were associated with virus-like particles having a diameter of 80-100 nm. Electron microscopy of ultrathin sections stained with uranyl acetate revealed nucleocapsides having length of up to 1400 nm, and a diameter of 13-17 nm, morphologically similar to measles and seals distemper virus.

Ultrastructure of Angiosarcoma of Mouse Tail

1980 ◽  
Vol 38 ◽  
pp. 740-741
Author(s):  
White Yvonne ◽  
Winslow Sheldon ◽  
James W. Townsend ◽  
Neil A. Littlefield
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Toluidine Blue ◽  
Female Mouse ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Ultrathin Sections ◽  
Resin Mixture

Spontaneous neoplasms rarely occur on the tails of BALB/cStCrlfC3H/Nctr mice, but the neoplasm most frequently observed is a locally invasive non-metastatic angiosarcoma. In this case a female mouse weighing 33.2 g, 706 days of age, presented a soft, red, irregularly-shaped mass, measuring 18 mm in its greatest dimension, in the subcutis of the base of the tail. A portion of the tail tumor was taken for electron microscopy and the remainder was processed for light microscopy. The tissue processed for electron microscopy was fixed in 4% cacodyl ate-buffered glutaraldehyde, post-fixed in 1% osmium tetroxide, dehydrated in a graded series of ethanol solutions, and embedded in Epon-Araldite resin mixture. Sections of 1 μm were stained with toluidine blue for light microscopy and ultrathin sections of 100 nm were stained with uranyl acetate and lead citrate, then examined with a Philips EM201 electron microscope .

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