scholarly journals THE FINE STRUCTURE OF BOVINE NASAL CARTILAGE

1971 ◽  
Vol 49 (3) ◽  
pp. 650-663 ◽  
Author(s):  
H. Clarke Anderson ◽  
Stanley W. Sajdera
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Banding Pattern ◽  
Collagen Fibrils ◽  
Guanidinium Chloride ◽  
Electron Microscopic ◽  
Nasal Cartilage ◽  
Before And After ◽  
Exhaustive Extraction

Bovine nasal cartilage was studied by electron microscopy before and after extraction with 4 M guanidinium chloride or 1.9 M CaCl2. These solvents removed matrix granules, basophilia, and 85% of the proteoglycan complex, measured as hexuronate. Simultaneously, many collagen fibrils were disaggregated into component microfibrils (approximately 40 A thick). In contrast to the above solvents, exhaustive extraction with 0.5 M guanidinium chloride removed 20% of the proteoglycan complex, and matrix granules were reduced in size but not in number. Extraction with 4 M CaCl2 removed only 10% of the proteoglycan complex, did not remove matrix granules, and caused the normal banding pattern of collagen to disappear. The banding was restored by further treatment with trypsin. Trypsin, before or after 4 M CaCl2, removed matrix granules and 90% of the proteoglycan complex. We conclude that matrix granules are an electron microscopic representation of the proteoglycan complex, and consist of more than one proteoglycan macromolecule. It would appear that 4 M guanidinium chloride and 1.9 M CaCl2, in addition to removing most of the proteoglycan complex, also disaggregate some of the collagen fibrils into their component microfibrils.

scholarly journals Supramolecular structure of polymorphic collagen fibrils.

1976 ◽  
Vol 68 (3) ◽  
pp. 521-538 ◽  
Author(s):  
R R Bruns
Keyword(s):  
Electron Microscopy ◽  
Banding Pattern ◽  
Collagen Fibrils ◽  
Graphic Method ◽  
Interaction Sites ◽  
Symmetrical Pattern ◽  
Native Collagen ◽  
Major Period ◽  
Polymorphic Forms ◽  
Specific Band

Reconstituted cartilage collagen fibrils with an oblique banding pattern or with two types of symmetrical patterns, and reconstituted rattail tendon fibrils with a third type of symmetrical pattern were examined by electron microscopy and found to consist of narrow subfibrils having native-type cross-striations. Analysis of the four types of patterns by a graphic method of specific band matching revealed the orientation and axial relation of individual subfibrils and their component molecules. In fibrils with an oblique pattern, subfibrils have the same orientation and a regular 100A axial displacement. Observations on staining characteristics, folded fibrils, and transverse sections of embedded fibrils suggest that the obliquely banded fibrils are ribbonlike or layered structures. In the three types of fibrils with a symmetrical pattern, adjacent subfibrils are oppositely oriented and aligned within a 119-A segment of the 670-A major period. Considered together, the observations suggest that interaction sites on the surface of subfibrils (and perhaps on the surface of native collagen fibrils) occur in various patterns that are manifested accouding to the nature of the environment during fibril formation, and that such patterns can be mapped on the surface of subfibrils by noting the arrangement of subfibrils in polymorphic forms.

An electron microscopic study of Amoeba proteus

1959 ◽  
Vol 150 (939) ◽  
pp. 216-232 ◽  
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Amoeba Proteus ◽  
Contractile Vacuole ◽  
Electron Microscopic ◽  
Functional Implications ◽  
Food Vacuoles

Methods of fixing, embedding and sectioning of Amoeba proteus for electron microscopy are described. The fine structure of the various organelles: nucleus, mitochondria, food vacuoles; and the contractile vacuole, is discussed in detail. A number of minor unidentified objects has also been found. The functional implications of the structural findings are considered.

Fine Structural Analysis of Sarcoma-180 Tumor Before and After cis-Platinum (II) Diamminodichloride

1971 ◽  
Vol 29 ◽  
pp. 386-387
Author(s):  
S. K. Aggarwal ◽  
A. Sodhi ◽  
L. Van Camp
Keyword(s):  
Fine Structure ◽  
Structural Analysis ◽  
Single Injection ◽  
Sarcoma 180 ◽  
Electron Microscopic ◽  
Irreversible Damage ◽  
Before And After ◽  
Microscopic Studies ◽  
And Control ◽  
Tumor Implant

It has been shown that a single injection of 8.0 mg/kg of the cis (Pt(NH3)2cl2) in normal saline is effective in regressing solid Sarcoma-180 tumors in Swiss White mice, with no apparent irreversible damage to the host. Present investigations were undertaken to study the fine structure of Sarcoma-180 under experimental and control conditions. Platinum injections were made on day 10, (taking the tumor implant as day 0), and the animals were sacrificed at 2 day intervals for 12 days after the injections. The tissue from injected and uninjected animals was processed for electron microscopic studies.

scholarly journals Study of Hard Disk and Slider Surfaces Using X-Ray Photoemission Electron Microscopy and Near Edge X-Ray Absorption Fine Structure Spectroscopy

1998 ◽  
Vol 517 ◽  
Author(s):  
Simone Anders ◽  
Thomas Stammler ◽  
C. Singh Bhatia ◽  
Joachim Stöhr ◽  
Walton Fong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Thermal Desorption ◽  
Wear Test ◽  
X Ray ◽  
Absorption Fine ◽  
Nexafs Spectroscopy ◽  
Before And After ◽  
Carbon Overcoats ◽  
X Ray Absorption

AbstractX-ray Photo Emission Electron Microscopy (X-PEEM) and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy were applied to study the properties of amorphous hard carbon overcoats on disks and sliders, and the properties of the lubricant. The modification of lubricants after performing thermal desorption studies was measured by NEXAFS, and the results are compared to thermal desorption data. The study of lubricant degradation in wear tracks is described. Sliders were investigated before and after wear test, and the modification of the slider coating as well as the transfer of lubricant to the slider was studied. The studies show that the lubricant is altered chemically during the wear. Fluorine is removed and carboxyl groups are formed.

scholarly journals Deep-etch visualization of proteins involved in clathrin assembly.

1988 ◽  
Vol 107 (3) ◽  
pp. 877-886 ◽  
Author(s):  
J E Heuser ◽  
J Keen
Keyword(s):  
Electron Microscopy ◽  
Bovine Brain ◽  
Coated Vesicles ◽  
Direct Visualization ◽  
Vesicle Membrane ◽  
Electron Microscopic ◽  
Central Mass ◽  
Before And After ◽  
Assembly Proteins ◽  
Terminal Domains

Assembly proteins were extracted from bovine brain clathrin-coated vesicles with 0.5 M Tris and purified by clathrin-Sepharose affinity chromatography, then adsorbed to mica and examined by freeze-etch electron microscopy. The fraction possessing maximal ability to promote clathrin polymerization, termed AP-2, was found to be a tripartite structure composed of a relatively large central mass flanked by two smaller mirror-symmetric appendages. Elastase treatment quantitatively removed the appendages and clipped 35 kD from the molecule's major approximately 105-kD polypeptides, indicating that the appendages are made from portions of these polypeptides. The remaining central masses no longer promote clathrin polymerization, suggesting that the appendages are somehow involved in the clathrin assembly reaction. The central masses are themselves relatively compact and brick-shaped, and are sufficiently large to contain two copies of the molecule's other major polypeptides (16- and 50-kD), as well as two copies of the approximately 70-kD protease-resistant portions of the major approximately 105-kD polypeptides. Thus the native molecule seems to be a dimeric, bilaterally symmetrical entity. Direct visualization of AP-2 binding to clathrin was accomplished by preparing mixtures of the two molecules in buffers that marginally inhibit AP-2 aggregation and cage assembly. This revealed numerous examples of AP-2 molecules binding to the so-called terminal domains of clathrin triskelions, consistent with earlier electron microscopic evidence that in fully assembled cages, the AP's attach centrally to inwardly-directed terminal domains of the clathrin molecule. This would place AP-2s between the clathrin coat and the enclosed membrane in whole coated vesicles. AP-2s linked to the membrane were also visualized by enzymatically removing the clathrin from brain coated vesicles, using purified 70 kD, uncoating ATPase plus ATP. This revealed several brick-shaped molecules attached to the vesicle membrane by short stalks. The exact stoichiometry of APs to clathrin in such vesicles, before and after uncoating, remains to be determined.

Fine structure of Aldrovanda vesiculosa L: the peculiar lifestyle of an aquatic carnivorous plant elucidated by electron microscopy using cryo-techniques

Microscopy ◽  
2020 ◽  
Vol 69 (4) ◽  
pp. 214-226 ◽  
Author(s):  
Kimie Atsuzawa ◽  
Daiki Kanaizumi ◽  
Mizuki Ajisaka ◽  
Tasuku Kamada ◽  
Kimie Sakamoto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Culture System ◽  
Digestive Enzymes ◽  
Natural Habitat ◽  
Electron Microscopic Observation ◽  
Carnivorous Plant ◽  
Way Of Life ◽  
Electron Microscopic ◽  
Digestive Glands

Abstract The aquatic carnivorous plant Aldrovanda vesiculosa L. is critically endangered worldwide; its peculiar lifestyle raises many questions and poses problems both intriguing on their own and relevant to conservation. While establishing a culture system for its propagation and restoring its natural habitat in Hozoji pond in Saitama, Japan, we conducted ultrastructural observations to examine the various aspects of Aldrovanda’s way of life. Electron microscopic observation in combination with cryo-techniques produced novel information which could not be obtained by other methods. Some of the results are: phosphorous is stored in petiole cells of turions during winter; mucilaginous guides are provided for pollen tubes in parietal placental ovaries; storage of potassium in the vicinity of the midrib of carnivorous leaves may contribute to the rapid closing of the carnivorous leaves; dynamic sequential changes of the ultrastructure of digestive glands are involved in the synthesis and secretion of digestive enzymes, including protease and acid phosphatase. These results should contribute significantly to our understanding of Aldrovanda and the detailed mechanisms of its life.

scholarly journals ALLERGIC INFLAMMATION

1963 ◽  
Vol 118 (4) ◽  
pp. 557-564 ◽  
Author(s):  
Henry Z. Movat ◽  
Neil V. P. Fernando ◽  
Tsuneo Uriuhara ◽  
William J. Weiser
Keyword(s):  
Fine Structure ◽  
Microscopic Examination ◽  
Allergic Inflammation ◽  
Electron Microscopic Examination ◽  
Collagen Fibrils ◽  
Electron Microscopic ◽  
Ultrastructural Evidence ◽  
Antigen Antibody

The fine structure of collagen fibrils at sites of antigen-antibody interaction is described. Following injection of antigen (BSA or ferritin) into the center of the cornea of hyperimmune rabbits, an acidophilic ring of precipitate forms at the periphery of the cornea, where antigen and antibody interact in optimal proportions. The precipitate is soon removed by infiltrating polymorphs, but persists longer in leukopenic animals. Electron microscopic examination of the cornea showed no alteration of the collagen fibrils in the area of antigen-antibody precipitation or in the remaining cornea. Contrary to many claims there was no swelling, fragmentation, or disintegration of the fibrils and they had a normal periodicity. Polymorphs infiltrated the precipitates and phagocytosed the antigen-antibody complexes. There was some ultrastructural evidence that degradation of the complexes took place in the polymorphs.

Soil sterilization effects on in situ indigenous microbial cells in soil

1975 ◽  
Vol 21 (3) ◽  
pp. 263-269 ◽  
Author(s):  
D. P. Labeda ◽  
D. L. Balkwill ◽  
L. E. Casida Jr.
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Enrichment Culture ◽  
Biological Information ◽  
Thin Sections ◽  
Soil Sterilization ◽  
Dry Heat ◽  
Transmission Electron ◽  
Before And After ◽  
Heat Application

Soil was sterilized by various procedures, and then the resident microorganisms were physically separated and concentrated from the soil for viewing by transmission electron microscopy as thin sections and frozen-etched preparations. Remaining cell viability in the soil was tested by conventional plating before and after enrichment culture. The soil proved to be sterile after treatment with 60Co radiation, prolonged autoclaving, prolonged dry heat application at 200C, or glutaraldehyde (if followed by subsequent mild heating), and could be considered sterile after OsO4 treatment. Treatment with glutaraldehyde alone, or 160C dry heat for 3 h, did not sterilize the soil. Cellular fine structure was altered or destroyed by the heat treatments, but was not affected to any extent by any of the other treatments including glutaraldehyde followed by mild heating. These findings are considered in relation to the residual biological information observable by electron microscopy in soil samples which have been sterilized to eliminate possible pathogens before handling of the soil. These findings are also considered with the objective of obliterating the fine structure of the indigenous microorganisms during soil sterilization so that electron microscopy studies can be made of microorganisms inoculated into and grown in the presterilized soil.

Localization of immunolabels by electron microscopy and image averaging

1983 ◽  
Vol 41 ◽  
pp. 282-283
Author(s):  
J. Frank ◽  
P.-Y. Sizaret ◽  
A. Verschoor ◽  
J. Lamy
Keyword(s):  
Electron Microscopy ◽  
Single Particle ◽  
Attachment Site ◽  
Uranyl Acetate ◽  
Limulus Polyphemus ◽  
Resolution Limit ◽  
Electron Microscopic ◽  
Image Averaging ◽  
Top View ◽  
Better Than

The accuracy with which the attachment site of immunolabels bound to macromolecules may be localized in electron microscopic images can be considerably improved by using single particle averaging. The example studied in this work showed that the accuracy may be better than the resolution limit imposed by negative staining (∽2nm).The structure used for this demonstration was a halfmolecule of Limulus polyphemus (LP) hemocyanin, consisting of 24 subunits grouped into four hexamers. The top view of this structure was previously studied by image averaging and correspondence analysis. It was found to vary according to the flip or flop position of the molecule, and to the stain imbalance between diagonally opposed hexamers (“rocking effect”). These findings have recently been incorporated into a model of the full 8 × 6 molecule.LP hemocyanin contains eight different polypeptides, and antibodies specific for one, LP II, were used. Uranyl acetate was used as stain. A total of 58 molecule images (29 unlabelled, 29 labelled with antl-LPII Fab) showing the top view were digitized in the microdensitometer with a sampling distance of 50μ corresponding to 6.25nm.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

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