scholarly journals WOUND HEALING AND COLLAGEN FORMATION

1962 ◽  
Vol 15 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Russell Ross ◽  
Earl P. Benditt
Keyword(s):  
Osmium Tetroxide ◽  
Unit Area ◽  
Modified Technique ◽  
Electron Microscopic ◽  
Collagen Formation ◽  
Fibrillar Material ◽  
Nuclear Track Emulsion ◽  
Microscopic Studies ◽  
Healing Wounds ◽  
Collagenous Material

The sequence of incorporation and utilization of tritium-labeled proline has been examined in healing wounds from normal and scorbutic guinea pigs. Linear incisions in the skin of the animals were allowed to heal for 7 days. Each animal was given proline-H3, and the wounds were excised 30 minutes, 1 and 4 hours, 1, 3 and 7 days after proline administration. The tissues were fixed in osmium tetroxide, fixed again in neutral buffered formalin, embedded in epoxy resin, and sectioned at 1 micron thickness. The sections were coated with nuclear track emulsion, exposed, developed, and stained. The results of grain counts were quantitated as the number of counts per unit area overlying cells, fibers, etc. In both groups the proline reaches a maximum over the fibroblasts within 4 hours and subsequently disappears from the cells. Concomitantly, the proline reaches a maximum over the collagen (in normal animals) and extracellular fibrillar material (in scorbutic animals) by 4 hours, where it remains. The modified technique of radioautography used in this study allows not only resolution of approximately 1 micron, but also minimal background, decreased artifact, and a clear separation of the randomly situated elements within the wounds so that grain counting is facilitated. The results correlated with previous electron microscopic studies are consistent with the utilization of proline by the fibroblasts and its incorporation into collagen (in normal animals) and into the extracellular, fibrillar, non-collagenous material seen in scorbutic animals.

Cytoplasmic Invaginations in Trophoblasts and Epithelial Cells of Rat

1971 ◽  
Vol 29 ◽  
pp. 524-525
Author(s):  
Iracema M. Baccarini
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Nuclear Inclusions ◽  
Mucous Cells ◽  
Electron Microscopic ◽  
Cervical Epithelium ◽  
Intact Membrane ◽  
Microscopic Studies ◽  
Abnormal Cells ◽  
Nuclear Features

Some morphological nuclear features (invaginations) in normal and abnormal cells have been described in several electron microscopic studies. They have been referred to by others as blebs, loops, pockets, sheets, bodies, nuclear inclusions and cytoplasmic invaginations. Identical appearing structures were found in cells of the uterine cervical epithelium, in trophoblasts of blastocysts and in trophoblasts of rat placenta.Methods. Uterine cervix (normal rats), rat placenta (9-10 days gestation) and blastocyst were placed in 3% glutarahdehyde for 3 hours. The tissue was washed in phosphate buffer for 24 hours, postfixed in 1%. buffered osmium tetroxide for 1-2 hours and embedded in epon araldite. Sections were double stained with uranyl acetate and lead citrate and viewed in E. M. Siemens 200.Observations. Nuclear invaginations were found in basal, parabasal and mucous cells of the cervix epithelium, in trophoblasts of blastocyst and in trophoblasts of placenta. An oval, round or elongated invagination contained heterogenously cytoplasm surrounded by a double intact membrane; usually several invaginations were found in the same nucleus.

Effects of Mg2+ on Chromatic Structure in Isolated Chicken Liver Nuclei

1990 ◽  
Vol 48 (3) ◽  
pp. 130-131
Author(s):  
Soichiro Arai ◽  
Yuh H. Nakanishi
Keyword(s):  
Chromatin Structure ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Divalent Cations ◽  
Chromatin Condensation ◽  
Chicken Liver ◽  
Electron Microscopic ◽  
Razor Blade ◽  
Microscopic Studies ◽  
Liver Nuclei

Although many electron microscopic studies on extracted chromatin have provided considerable information on chromatin condensation induced by divalent cations, there is only a little literature available on the effects of divalent cations on chromatin structure in intact nuclei. In the present study, the effects of Mg2+ on chromatin structure in isolated chicken liver nuclei were examined over a wide concentration range of Mg2+ by scanning electron microscopy.Nuclei were prepared from chicken liver by the method of Chauveau et al. with some modifications. The nuclei were suspended in 25 mM triethanolamine chloride buffer (pH7.4) with 1 mM EDTA or in the buffer with concentrations of MgCl2 varying from 1 to 50 mM. After incubation for 1 min at 0°C, glutaraldehyde was added to 1.8% and the nuclei were fixed for 1 h at 4°C. The fixed nuclei were mixed with 15% gelatin solution warmed at about 40°C, and kept at room temperature until the mixture set. The gelatin containing the nuclei was fixed with 2% glutaraldehyde for 2-4 h, and cut into small blocks. The gelatin blocks were conductive-stained with 2% tannic acid and 2% osmium tetroxide, dehydrated in a graded series of ethanol, and freeze-cracked with a razor blade in liquid nitrogen.

scholarly journals ELECTRON MICROSCOPIC STUDIES OF MITOSIS IN AMEBAE

1960 ◽  
Vol 8 (1) ◽  
pp. 207-220 ◽  
Author(s):  
L. E. Roth ◽  
S. W. Obetz ◽  
E. W. Daniels
Keyword(s):  
Electron Microscope ◽  
Nuclear Envelope ◽  
Osmium Tetroxide ◽  
Thin Sheet ◽  
Amoeba Proteus ◽  
Electron Microscopic ◽  
Interphase Nuclei ◽  
Nucleolar Material ◽  
Microscopic Studies ◽  
Early Reconstruction

Individual organisms of Amoeba proteus have been fixed in buffered osmium tetroxide in either 0.9 per cent NaCl or 0.01 per cent CaCl2, sectioned, and studied in the electron microscope in interphase and in several stages of mitosis. The helices typical of interphase nuclei do not coexist with condensed chromatin and thus either represent a DNA configuration unique to interphase or are not DNA at all. The membranes of the complex nuclear envelope are present in all stages observed but are discontinuous in metaphase. The inner, thick, honeycomb layer of the nuclear envelope disappears during prophase, reappearing after telophase when nuclear reconstruction is in progress. Nucleoli decrease in size and number during prophase and re-form during telophase in association with the chromatin network. In the early reconstruction nucleus, the nucleolar material forms into thin, sheet-like configurations which are closely associated with small amounts of chromatin and are closely applied to the inner, partially formed layer of the nuclear envelope. It is proposed that nucleolar material is implicated in the formation of the inner layer of the envelope and that there is a configuration of nucleolar material peculiar to this time. The plasmalemma is partially denuded of its fringe-like material during division.

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.

scholarly journals ELECTRON MICROSCOPIC STUDIES ON THE INDIRECT FLIGHT MUSCLES OFDROSOPHILAMELANOGASTER

1963 ◽  
Vol 17 (2) ◽  
pp. 363-0373 ◽  
Author(s):  
S. Ahmad Shafiq
Keyword(s):  
Cell Membranes ◽  
Plasma Membranes ◽  
Electron Microscopic ◽  
Cytoplasmic Inclusions ◽  
Fibrillar Material ◽  
Microscopic Studies ◽  
Flight Muscles ◽  
The Individual

The differentiation of the indirect flight muscles was studied in the various pupal stages of Drosophila. Fibrillar material originates in the young basophilic myoblasts in the form of short myofilamants distributed irregularly near the cell membranes. The filaments later become grouped into bundles (fibrils). Certain "Z bodies" appear to be important during this process. The "Z bodies" may possibly be centriolar derivatives and are the precursors of the Z bands. The first formed fibrils (having about 30 thick myofilaments) are already divided into sarcomeres by Z bands. These sarcomeres, however, seem to be shorter than those of the adult fibrils.The H band differentiates in fibrils having about 40 thick myofilaments; the fibrils constrict in the middle of each sarcomere during this process. The individual myofibrils increase from about 0.3 µ to 1.5 µ in diameter during development, apparently by addition of new filaments on the periphery of the fibrils. The ribosomes seem to be the only cytoplasmic inclusions which are closely associated with these growing myofibrils. Disintegration of the plasma membranes limiting individual myoblasts was commonly seen during development of flight muscles, supporting the view that the multinuclear condition of the fibers of these muscles is due to fusion of myoblasts.

Transmission and Scanning Electron Microscopy of the Follicle in the Human Ovary

1974 ◽  
Vol 32 ◽  
pp. 142-143
Author(s):  
I. M. Baccarini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Granulosa Cells ◽  
Osmium Tetroxide ◽  
Human Ovary ◽  
Scanning Microscope ◽  
Electron Microscopic ◽  
Ultrastructural Studies ◽  
Microscopic Studies ◽  
Scanning Electron

Several ultrastructural studies demonstrated that the granulosa cells changed the structure since their differentiation, maturation and degeneration. However, little is known about the organization of the granulosa cells in the follicle for instance, the connection between the cells and cellular interchanges.Fragments of ovary obtained from the surgery room were fixed in 3% buffered glutaraldehyde for scanning microscope and post-fixed in 1% buffered osmium tetroxide for electron microscopic studies.

Morphology of Leukocytes from Cats Affected with α-Mannosidosis and Mucopolysaccharidosis VI (MPS VI)

1989 ◽  
Vol 26 (4) ◽  
pp. 294-302 ◽  
Author(s):  
J. Alroy ◽  
G. O. Freden ◽  
V. Goyal ◽  
S. S. Raghavan ◽  
K. L. Schunk
Keyword(s):  
White Blood Cells ◽  
Membrane Structures ◽  
Electron Microscopic ◽  
Ultrastructural Studies ◽  
Fibrillar Material ◽  
Mps Vi ◽  
Arylsulfatase B ◽  
Microscopic Studies ◽  
Mucopolysaccharidosis Vi ◽  
Metachromatic Granules

The morphology and ultrastructure of circulating white blood cells from six Persian and from five Russian Blue/Siamese cats deficient in lysosomal activity of α-mannosidase and arylsulfatase B, respectively, were studied and compared to cells from corresponding normal and carrier cats. In cats with mannosidosis, light microscopic examination revealed vacuoles in lymphocytes and monocytes, whereas electron microscopic studies demonstrated additional vacuoles in neutrophils, eosinophils, and basophils. In cats with mucopolysaccharidosis VI (MPS VI), vacuoles containing metachromatic granules were observed in lymphocytes, neutrophils, eosinophils, and monocytes. Ultrastructural studies of these cells identified the accumulation of fibrillar material, which often was associated with lamellated membrane structures.

scholarly journals ELECTRON MICROSCOPIC STUDIES OF MITOSIS IN AMEBAE

1962 ◽  
Vol 12 (1) ◽  
pp. 57-78 ◽  
Author(s):  
L. E. Roth ◽  
E. W. Daniels
Keyword(s):  
Calcium Ions ◽  
Osmium Tetroxide ◽  
Interphase Nucleus ◽  
Divalent Cations ◽  
Divalent Ions ◽  
Electron Microscopic ◽  
Oriented Molecules ◽  
Protein Molecules ◽  
Microscopic Studies ◽  
Calcium Magnesium

Dividing nuclei from the giant ameba Pelomyxa carolinensis were fixed in osmium tetroxide solutions buffered with veronal acetate to pH 8.0. If divalent cations (0.002 M calcium, magnesium, or strontium as chlorides) were added to the fixation solution, fibrils that are 14 mµ in diameter and have a dense cortex are observed in the spindle. If the divalent ions were omitted, oriented particles of smaller size are present and fibrils are not obvious. The stages of mitosis were observed and spindle components compared. Fibrils fixed in the presence of calcium ions are not so well defined in early metaphase as later, but otherwise have the same diameter in the late metaphase, anaphase, and early telophase. Fibrils are surrounded by clouds of fine material except in early telophase, when they are formed into tight bundles lying in the cytoplasm unattached to nuclei. Metaphase and anaphase fibrils fixed without calcium ions are less well defined and are not observably different from each other. The observations are consistent with the concept that spindle fibrils are composed of polymerized, oriented protein molecules that are in equilibrium with and bathed in non-oriented molecules of the same protein. Partially formed spindle fibrils and ribosome-like particles were observed in the mixoplasm when the nuclear envelope had only small discontinuities. Remnants of the envelope are visible throughout division and are probably incorporated into the new envelope in the telophase. Ribosome-like particles are numerous in the metaphase and anaphase spindle but are not seen in the telophase nucleus, once the envelope is reestablished, or in the interphase nucleus.

Ultrastructure of Developing Granulosa and Theca Cells

1970 ◽  
Vol 28 ◽  
pp. 92-93
Author(s):  
Iracema M. Baccarini
Keyword(s):  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Ether Anesthesia ◽  
Rat Fetuses ◽  
Theca Cells ◽  
The Past ◽  
Microscopic Studies

The embryology of granulosa and theca cells is not understood thoroughly. Electron microscopic studies in the past have been concerned mainly with mature granulosa cells and less with their development.Material and Methods. Rat fetuses were removed surgically under ether anesthesia at 16-17, 17-18 and 18-19 days of gestation. Their abdominal cavities were opened, and the fetuses were placed immediately into 3% glutaraldehyde (pH 7.2) for 3 hours. During this time, the fetal ovaries were dissected under a microscope. The tissue was washed in phosphatebuffer for 24 hours, post-fixed in 1% phosphate buffered osmium tetroxide for 1-2 hours at 4°C, and embedded in Durcupan ACM (Fluka). Sections were double stained with uranyl acetate and lead citrate, and viewed in an RCA-EMU-3D electron microscope.

Electron Microscopic Studies of Labeled Nucleic Acids

1976 ◽  
Vol 34 ◽  
pp. 328-329
Author(s):  
M. D. Cole ◽  
S. D. Rose ◽  
J. W. Wiggins ◽  
M. Beer
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Nucleic Acids ◽  
Osmium Tetroxide ◽  
Signal To Noise Ratio ◽  
Scattered Intensity ◽  
Signal To Noise ◽  
Electron Microscopic ◽  
Modified Nucleic Acids ◽  
Microscopic Studies

Quantitative conversion of cytosine nucleotides to N4-furfuryloxy derivatives followed by reaction with osmium tetroxide plus bipyridine yields an electrondense stain suitable for visualization in the electron microscope. Chemical analysis shows that two osmium atoms become attached to each furan-modified cytosine nucleotide. Osmium tetroxide also reacts with thymine and uracil nucleotides, resulting in the attachment of one osmium atom each. Therefore the treatment of cytosine-modified nucleic acids with osmium tetroxide should allow recognition of cytosine and thymine nucleotides.Nucleic acids labeled with osmium by the above reactions have been viewed in a high resolution STEM. The signal used to form the image is the ratio of the elastically scattered intensity to the unscattered and ineiastically scattered intensity. The dosage that yields a signal to noise ratio sufficient for focussing is >104 electrons/ Å2.

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