scholarly journals AN ELECTRON MICROSCOPIC STUDY OF NUCLEAR ELIMINATION FROM THE LATE ERYTHROBLAST

1967 ◽  
Vol 33 (3) ◽  
pp. 625-635 ◽  
Author(s):  
Ehud Skutelsky ◽  
David Danon
Keyword(s):  
Bone Marrow ◽  
Osmium Tetroxide ◽  
Mitotic Division ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Whole Process ◽  
Narrow Passage ◽  
Rounded Form

The process of expulsion of the nucleus during the transformation of the late erythroblast to reticulocyte is described. Erythroid clones taken from the spleen of lethally irradiated mice transplanted with syngeneic bone marrow were used. 10–12-day old isolated clones were fixed in glutaraldehyde, then in osmium tetroxide. Ultra-thin sections were stained with uranyl acetate and/or lead citrate before examination. Late (orthochromatic) erythroblasts develop pseudopod-like cytoplasmic protrusions into one of which the nucleus gradually penetrates, being deformed by the extrusion through the relatively narrow passage. During the whole process, mitochondria and vesicular and membranous elements are concentrated in the cytoplasm. Once outside the cell, the nucleus reassumes its rounded form. It is surrounded by a narrow rim of cytoplasm and structurally altered plasma membrane and is connected to the rest of the cell by a bridge. Elongated vacuoles appear within this bridge, with a resulting release of the enveloped nucleus which is soon phagocytized by macrophages; this leaves behind the newly formed reticulocyte. During this process, the cytoplasmic protrusions, the agglomeration of mitochondria, and the mode of separation of the nucleus from the rest of the cell are similar to those occurring in mitotic division.

An Electron Microscopic Investigation of the Pathogenesis of Hemorrhage Induced by Rattlesnake Venom

1974 ◽  
Vol 32 ◽  
pp. 56-57
Author(s):  
Charlotte L. Ownby ◽  
Robert A. Kainer ◽  
Anthony T. Tu
Keyword(s):  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Rattlesnake Venom ◽  
Diamondback Rattlesnake

One of the significant changes induced by the injection of rattlesnake (Crotalidae) venom is hemorrhage. Since crotaline antivenin does not prevent such local tissue damage, a more effective treatment of snakebite is needed. To aid in the development of such a treatment the pathogenesis of venom-induced hemorrhae was investigated.Swiss-Webster white mice were injected intramuscularly with Western diamondback rattlesnake (Crotalus atrox) venom. Two minutes after the injection, muscle tissue was obtained by bioosy from the thigh and fixed in 6% glutaraldehyde in Milloniq's phosphate buffer (DH 7.4, 2 hrs., 4°C). After post-fixation in 2% osmium tetroxide in Milloniq's phosphate buffer (pH 7.4, 1hr., 4°C) the tissue was dehydrated routinely in ethanol and embedded in Epon 812. The thin sections were stained with uranyl acetate in methanol and lead citrate then observed with either a Zeiss EM 9A or an Hitachi HS-8 electron microscope.

Membranous alterations in the cytoplasm and nucleus in a primitive neuroectodermal tumor of the brain

1978 ◽  
Vol 36 (2) ◽  
pp. 628-629
Author(s):  
C. N. Sun ◽  
C. Araoz ◽  
H. J. White
Keyword(s):  
Nuclear Envelope ◽  
Tumor Cells ◽  
Osmium Tetroxide ◽  
Primitive Neuroectodermal Tumor ◽  
Uranyl Acetate ◽  
Neuroectodermal Tumor ◽  
Annulate Lamellae ◽  
Lead Citrate ◽  
Thin Sections ◽  
The Brain

The ultrastructure of a cerebral primitive neuroectodermal tumor has been reported previously. In the present case, we will present some unusual previously unreported membranous structures and alterations in the cytoplasm and nucleus of the tumor cells.Specimens were cut into small pieces about 1 mm3 and immediately fixed in 4% glutaraldehyde in phosphate buffer for two hours, then post-fixed in 1% buffered osmium tetroxide for one hour. After dehydration, tissues were embedded in Epon 812. Thin sections were stained with uranyl acetate and lead citrate.In the cytoplasm of the tumor cells, we found paired cisternae (Fig. 1) and annulate lamellae (Fig. 2) noting that the annulate lamellae were sometimes associated with the outer nuclear envelope (Fig. 3). These membranous structures have been reported in other tumor cells. In our case, mitochondrial to nuclear envelope fusions were often noted (Fig. 4). Although this phenomenon was reported in an oncocytoma, their frequency in the present study is quite striking.

A Modified Technic of Staining Elastic Tissue for Electron Microscopic Study

1975 ◽  
Vol 33 ◽  
pp. 626-627
Author(s):  
J.A. Nordquist ◽  
K. Chrysant ◽  
A.K. Mandal
Keyword(s):  
Electron Microscopy ◽  
Osmium Tetroxide ◽  
Renal Tissue ◽  
Uranyl Acetate ◽  
Elastic Tissue ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Modified Method ◽  
Tetraphenyl Porphyrin ◽  
Normal Rat

By electron microscopy elastic tissue appear electrolucent in osmium fixed unstained grids as well as grids stained with uranyl acetate and lead citrate (UA + LC). Albert and Fleischer have studied aorta of mice with metalloporphyrins imparting conspicuous electron density to the elastic tissue. We are reporting here a modified method of electron microscopic (EM) study of the elastic tissue using metalloporhyrin, silver tetraphenyl porphyrin sulfonate (STPPS).We have studied the renal arterioles of rats and human in normal and diseased states. Elastic tissue of the aorta from young normal rat served as control for this study. Renal and aortic tissues were fixed in 4 percent glutaraldehyde, post fixed in 1 percent osmium tetroxide and embedded in spurr (blocks). From the blocks of renal tissue, 0.5 μ sections were cut, stained with methylene blue and azure II and studied by light microscopy.

scholarly journals Electron microscopic immunoperoxidase staining of insulin using 4-chloro-1-naphthol after osmium fixation.

1982 ◽  
Vol 30 (7) ◽  
pp. 710-712 ◽  
Author(s):  
D G Baskin ◽  
H Mar ◽  
K C Gorray ◽  
W Y Fujimoto
Keyword(s):  
Osmium Tetroxide ◽  
Ultrastructural Localization ◽  
Uranyl Acetate ◽  
Immunoperoxidase Staining ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Specific Staining ◽  
Fixed Tissue ◽  
Substrate Solution ◽  
Peptide Antigens

Ultrastructural localization of insulin in B cells of guinea pig pancreas was accomplished after osmium fixation with an immunoperoxidase procedure that utilized 4-chloro-1-naphthol (CN) in the substrate solution. The principal features of this protocol were: a) osmium tetroxide postfixation; b) omission of hydrogen peroxide "etching"; c) use of CN instead of diaminobenzidine in the substrate solution; d) elimination of osmium tetroxide after the substrate reaction; e) uranyl acetate and lead citrate counterstaining. This procedure produces intense specific staining with low background using highly dilute antiserum, and appears to be useful for postembedding immunoperoxidase staining of a variety of peptide antigens in osmium-fixed tissue.

Electron microscopic evidence for a double hair-like nap appearing at low frequency on Bacillus anthracis Sterne spores

1969 ◽  
Vol 15 (10) ◽  
pp. 1247-1248 ◽  
Author(s):  
M. J. Kramer ◽  
Ivan L. Roth
Keyword(s):  
Bacillus Anthracis ◽  
Microscopic Examination ◽  
Low Frequency ◽  
Electron Microscopic Examination ◽  
Uranyl Acetate ◽  
Spore Coat ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Very Low Frequency

Electron microscopic examination of thin sections of Bacillus anthracis Sterne spores triply poststained with KMnO4, uranyl acetate, and lead citrate has indicated an unusual morphological variant. These spores are seen at very low frequency and have, in addition to the hair-like nap normally associated with the exosporium a second hairy layer which appears to originate in the spore coat complex.

Intracisternal microtubules in proximal tubule cells of duck kidney: A serendipitous finding

1987 ◽  
Vol 45 ◽  
pp. 898-899
Author(s):  
M.K. Bhatnagar ◽  
S.M. Snelgrove-Hobson ◽  
P.V.V. Prasada Rao
Keyword(s):  
Electron Microscope ◽  
Proximal Tubule ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Kidney Cortex ◽  
Lead Citrate ◽  
Cell Organelles ◽  
Thin Sections ◽  
Proximal Tubule Cells ◽  
Tubule Cells

Cytpplasmic microtubules, ubiquitous cell organelles, lie free in the cytosol without being compartmented off by membranes. In rare instances, however, intracisternal microtubules (ICM) have been reported in ganglionic neurons of aging dogs and in the proximal tubule cells (PTC) of rabbit kidneys. We report here the presence of ICM in the PTC of the kidneys of Peking ducks (Anas platyrhynhos).A total of 106 Peking ducks (24 males and 24 females of 9 months, 48 females of 15 months, 6 males of 30 months and 2 males and 2 females of 48 months of age) were anesthetized and exsanguinated. Pieces of kidney cortex were fixed in 4% glutaraldehyde in 0.5M phosphate buffer (pH 7.3) at 29°C for four hours. Samples were post fixed in 2% osmium tetroxide for two hours. One micron sections of Epon-embedded cortices were stained with toluidine blue and thin sections (70-70 nm) contrasted with uranyl acetate and lead citrate were examined with a JEOL 100-S electron microscope at 80 kV.

scholarly journals EVIDENCE FOR CHANGES IN PROTEIN POLYSACCHARIDE ASSOCIATED WITH THE ONSET OF CALCIFICATION IN CARTILAGE

1968 ◽  
Vol 39 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Victor J. Matukas ◽  
George A. Krikos
Keyword(s):  
Electron Microscopy ◽  
Osmium Tetroxide ◽  
Marked Decrease ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Calcified Cartilage ◽  
The Matrix ◽  
Microscopic Studies ◽  
Matrix Components

Past work has suggested that protein polysaccharide may play a role in the calcification of cartilage. Recent electron microscopic studies on noncalcified cartilage have indicated that protein polysaccharide in cartilage matrix is represented by granules associated with collagen fibers. The present work has been designed for comparison of the matrix of noncalcified cartilage to that of calcified cartilage, with particular reference to these granules. Small blocks of tibia from 16-day embryos were fixed in cacodylate-buffered glutaraldehyde and postfixed in either phosphate- or Veronal-buffered osmium tetroxide. Special care was taken to maintain the pH above 7.0 at all times. For electron microscopy the tissues were dehydrated, embedded in Epon 812, sectioned, and stained with uranyl acetate or lead citrate. A marked decrease in the size of granules in the matrix of calcified cartilage compared to noncalcified cartilage was noted. Associated with the decrease in the size of granules was a condensation of matrix components and the presence of an amorphous electron-opaque material that was not seen in noncalcified areas. These results are interpreted to represent either a drop in concentration or a change in state of protein polysaccharide with the onset of calcification in cartilage.

Intracellular and Extracellular Acid Hydrolase Activity in the Drosophila Melanogaster Ovary

1982 ◽  
Vol 40 ◽  
pp. 242-243
Author(s):  
Lawrence G. Altman ◽  
R. Witkus ◽  
G. M. Vernon
Keyword(s):  
Drosophila Melanogaster ◽  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Acid Hydrolase ◽  
Lead Citrate ◽  
Wild Type ◽  
Thin Sections

Ovaries from wild type Drosophila melanogaster were incubated for acid phosphatase activity (pH 5). Following fixation in either 3.0% or 6.0% glutaraldehyde prepared in 0.1M cacodyiate buffer. Post-fixation was done in 1.0% osmium tetroxide and tissues were subjected to a graded series of acetone and infiltrated with Epon-Araldite. Control tissues were incubated without the substrate, in this case Bglycerophosphate. Ultrastructural integrity was checked against tissue prepared by omitting the incubation period completely. Thin and semi-thin sections were cut on an LKB ultramicrotome. In some instances, observations were recorded without uranyl acetate and lead citrate counterstaining.

Neural Degeneration in the Spiral Ganglia of C57BL/6 Mice

1988 ◽  
Vol 46 ◽  
pp. 136-137
Author(s):  
Glenn M. Cohen ◽  
Joseph S. Grasso
Keyword(s):  
Osmium Tetroxide ◽  
Initial Study ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Thin Sections ◽  
Neural Degeneration ◽  
Age Related ◽  
Sensory Hair Cell ◽  
Spiral Ganglia ◽  
Old Mice

C57BL/6 mice, along with several other mouse genotypes, have served as models for human presbycusis (age-related hearing losses). C57BL/6 mice and their genetic substrain C57/bl6 show progressively severe hearing losses, starting as early as 30 days postnatally. The hearing losses result from sweeping sensory (hair cell) and neural degeneration that begins in the basal end and advances apically. For the initial study of the spiral ganglia C57BL/6 mice, our two objectives were to develop criteria for identifying the different degenerative stages and determine Whether the same degenerative stages repeat themselves in both young and old mice.Female C57BL/6 mice of seven ages, ranging from 1 1/2 to 32 months, were examined. The ears were exposed to the fixative (3.5% glutaraldehyde [GA]) within cne min after sacrifice. The cochleae were decalcified in 5% EDTA in 3.5% GA, postfixed in 1% osmium tetroxide, and embedded in Araldite 502 epoxy. Semithin (1μ) sections were stained with toluidine blue or p-phenylenediamine; thin sections were stained with uranyl acetate and lead citrate.

Cystoid Degeneration of Mouse Pituitary – Ultrastructural Study

1980 ◽  
Vol 38 ◽  
pp. 462-463
Author(s):  
Annette M. Andrews ◽  
Alex M. Cameron ◽  
James W. Townsend ◽  
Winslow G. Sheldon
Keyword(s):  
Electron Microscope ◽  
Toluidine Blue ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Pars Intermedia ◽  
Lead Citrate ◽  
Thin Sections ◽  
Resin Mixture ◽  
Mouse Pituitary ◽  
Two Sides

Pituitaries of 6 C3H/HEJ MTV+ mice about 660 days of age were fixed by immersion in cacodylate-buffered 4% glutaraldehyde, post-fixed in 1% osmium tetroxide, stained en block with aqueous uranyl acetate, dehydrated in a graded series of ethanol solutions, cleared in acetone, and embedded in an Epon-Araldite resin mixture. Semi-thin (1 μm) sections were taken of the entire face of the block, and stained with toluidine blue. Subsequently, thin sections (100 nm) were prepared from mesas of the two sides of the pars distal is and one mesa of the pars intermedia. Thin sections were stained with ethanolic uranyl acetate followed by Sato's lead citrate (1), then examined on a Philips EM201 electron microscope.

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