Electron microscopy of an endoparasitic fungus, Gonimochaete pyriforme, infecting nematodes

1985 ◽  
Vol 63 (12) ◽  
pp. 2326-2331 ◽  
Author(s):  
Masatoshi Saikawa ◽  
Takashi Anazawa
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Density ◽  
Germ Tube ◽  
Adhesive Layer ◽  
Ruthenium Red ◽  
Ruthenium Red Staining ◽  
Dense Vesicles

Gonimochaete pyriforme Barron was studied using the electron microscope. Protoplasm in the pyriform-shaped aplanospore is filled with electron-dense vesicles (0.1–0.3 μm) except at the base where it is vacuolated. The globose knob at the apical end of the spore is covered with a very thin adhesive layer (ca. 0.1 μm) whose electron density is slightly enhanced by ruthenium red staining but which does not show a fibrillose appearance. After attachment to the nematode's cuticle, a narrow germ tube (0.15 μm) arises from the globose knob and penetrates through the adhesive layer and the host's cuticle into the nematode body. The adhesive knob of the aplanospore in G. pyriforme is very similar in ultrastructure to the encysted zoospore of Myzocytium humicola Barron and Percy in the Lagenidiales after the cyst has germinated.

An electron microscope study of initiation of infection by conidia of Harposporium oxycoracum, an endozoic nematophagous Hyphomycete

1983 ◽  
Vol 61 (3) ◽  
pp. 893-898 ◽  
Author(s):  
Masatoshi Saikawa ◽  
Junko Totsuka ◽  
Chiharu Morikawa
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Electron Microscope ◽  
Electron Microscope Study ◽  
Germ Tube ◽  
Ruthenium Red ◽  
Convex Side ◽  
En Bloc ◽  
Dense Mass ◽  
Ultrathin Sections

Infective conidia of an endozoic nematophagous hyphomycete, Harposporium oxycoracum Drechsler, were examined by means of electron microscopy. Each of the conidia is very narrow and has a sharply pointed distal and slightly swollen basal end. The swollen basal end was shown, in ultrathin sections stained with ruthenium red en bloc, to be an electron-dense mass of fibrils (ca. 2–3 μm in diameter). The fibrils, thought to be derived from the conidial cell wall, were densely aggregated and were surrounded by a network of more sparsely aggregated fibrils spreading from the fibrous mass of the conidial base. The spreading fibrils seemed to correspond to the mucous droplet observed under the light microscope. It was also found in the present study that the conidia of the fungus were swallowed by nematodes into their lower gut. On germination in the lower gut, a narrow germ tube 5–6 μm wide developed from the convex side of the conidium and produced a simple pore septum at the site of penetration to delimit the empty conidium.

Application of ruthenium red/osmium tetroxide to bacteria, plant and animal tissue

1986 ◽  
Vol 44 ◽  
pp. 54-55
Author(s):  
R. L. Grayson ◽  
N. A. Rechcigl
Keyword(s):  
Electron Microscopy ◽  
Electron Density ◽  
Osmium Tetroxide ◽  
Biological Materials ◽  
Ruthenium Red ◽  
Animal Tissue

Ruthenium red (RR), an inorganic dye was found to be useful in electron microscopy where it can combine with osmium tetroxide (OsO4) to form a complex with attraction toward anionic substances. Although Martinez-Palomo et al. (1969) were one of the first investigators to use RR together with OsO4, our computor search has shown few applications of this combination in the intervening years. The purpose of this paper is to report the results of our investigations utilizing the RR/OsO4 combination to add electron density to various biological materials. The possible mechanisms by which this may come about has been well reviewed by previous investigators (1,3a,3b,4).

Morphology and ultrastructure of oral strains of Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus

1980 ◽  
Vol 30 (2) ◽  
pp. 588-600
Author(s):  
S C Holt ◽  
A C Tanner ◽  
S S Socransky
Keyword(s):  
Electron Microscopy ◽  
Ruthenium Red ◽  
Actinobacillus Actinomycetemcomitans ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Large Numbers ◽  
Haemophilus Aphrophilus ◽  
Ruthenium Red Staining ◽  
Amorphous Surface ◽  
Scanning Electron

Selected human oral and nonoral strains of the genera Actinobacillus and Haemophilus were examined by transmission and scanning electron microscopy. The strains examined were morphologically identical to recognized Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, and Haemophilus paraphrophilus. By transmission electron microscopy, the cells were typically gram negative in morphology, with several strains possessing some extracellular ruthenium red-staining polymeric material. Numerous vesicular structures, morphologically identical to lipopolysaccharide vesicles, were seen to originate from and be continuous with the surface of the outer membrane. Large numbers of these vesicles were also found in the external environment. Scanning electron microscopic observations revealed that both actinobacilli and haemophili possessed surface projections and an amorphous surface material which connected and covered adjacent cells.

Observation of exopolysaccharides (EPS) from Lactobacillus helveticus SBT2171 using the Tokuyasu method

Microscopy ◽  
2020 ◽  
Vol 69 (5) ◽  
pp. 286-290
Author(s):  
Takamichi Kamigaki ◽  
Akihiro Ogawa
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Colloidal Gold ◽  
Ruthenium Red ◽  
Lactobacillus Helveticus ◽  
Ruthenium Red Staining ◽  
Observation Method ◽  
Β Lactoglobulin

Abstract Some species of lactic acid bacteria used for the production of natural cheese produce exopolysaccharides (EPS). Electron microscopy is useful for analyzing the microstructure of EPS produced by lactic acid bacteria. However, pretreatments used to observe the microstructure of EPS by electron microscopy, such as dehydration and resin embedding, can result in EPS flowing out easily from the cell. Therefore, in this study, the Tokuyasu method was conducted on cryosection to reduce EPS outflow. Two types of observation method, namely, using lectin and ruthenium red, were conducted in an attempt to observe EPS produced by Lactobacillus helveticus SBT2171. Observation using the lectin method confirmed that colloidal gold particles conjugated with a lectin recognizing β-galactoside were present in the capsule. Structures that appeared to be β-galactoside-containing slime polysaccharides that were released from the cell wall were also observed. Observation using ruthenium red showed that capsular polysaccharides (CPS) in the capsule were present as a net-like structure. Colloidal gold conjugation with an anti-β-lactoglobulin antibody, in addition to ruthenium red staining, allowed the identification of slime polysaccharides released from the cell wall in the milk protein network derived from the culture medium. Based on these results, the Tokuyasu method was considered to be a useful pretreatment method to clarify and observe the presence of EPS. In particular, both CPS in the capsule and slime exopolysaccharides released from the cell wall were visualized.

Electron microscopic localization of sulfated glycosaminoglycans and proteoglycans in pleomorphic adenomas

1983 ◽  
Vol 41 ◽  
pp. 774-775
Author(s):  
Ronald Lam
Keyword(s):  
Electron Microscopy ◽  
Myoepithelial Cells ◽  
Mesenchymal Cells ◽  
Ruthenium Red ◽  
Major Salivary Gland ◽  
Electron Microscopic ◽  
Ultrastructural Studies ◽  
Pleomorphic Adenomas ◽  
Cellular Source ◽  
Ruthenium Red Staining

Although “myoepithelial” cells in pleomorphic adenomas have been implicated by several ultrastructural studies as responsible for the production of myxomatous and chondroid stroma, the cellular source of stromal glycosaminoglycans and proteoglycans has yet to be demonstrated histochemically by electron microscopy.Three major salivary gland pleomorphic adenomas were examined by electron microscopy after fixation in 2.5% glutaraldehyde and in 0.2% ruthenium red-glutaraldehyde. Routine ultrastructural preparations revealed a spectrum of cells with epithelial and mesenchymal features. The mesenchymal cells in the myxoid region displayed intracytoplasmic 70-80Å microfilaments, prominent Golgi complex, RER, and secretory vesicles. The fine structural appearance with ruthenium red stained tissue was similar to that of routine preparations. However, with ruthenium red staining, proteoglycans of the myxoid stroma could be visualized as numerous extracellular 250-500Å polygonal matrix granules with fine projecting filaments (Fig. 1A). Similar positive ruthenium red stained intracellular granules were observed within the cytoplasmic vacuoles of the mesenchymal cells, a feature not present in cells with epithelial differentiation (Fig. 1B).

Lophodermium pinastri: certain fine-structural features of ascocarp morphology

1974 ◽  
Vol 52 (8) ◽  
pp. 1993-1995 ◽  
Author(s):  
B. A. Silverberg ◽  
J. F. Morgan-Jones
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Electron Density ◽  
Structural Features ◽  
Acid Mucopolysaccharide ◽  
Scanning Electron ◽  
Mucilaginous Material

As viewed by the electron microscope, the 'carbonaceous' appearance of the ascocarp clypeus in Lophodermium pinastri (Schrad) Chev. is due to a dark substance in the interhyphal spaces; this substance is believed to originate within the hyphae since the latter contain dark inclusions of the same electron density. The mucilaginous material in the ascocarp cavity is primarily in the nature of an acid mucopolysaccharide, together with minimal amounts of carbohydrates and proteins. Examination of the interthecial hyphae by means of scanning electron microscopy (SEM) shows them to be true paraphyses, not pseudoparaphyses as previously supposed.

Improved staining of extracellular polymer surrounding Eucapsis sp. and Anabena cylindrica: a comparative study

1974 ◽  
Vol 20 (5) ◽  
pp. 735-738
Author(s):  
Gerald D. Cagle
Keyword(s):  
Electron Microscope ◽  
Comparative Study ◽  
Green Algae ◽  
Freeze Drying ◽  
Ruthenium Red ◽  
Blue Green Algae ◽  
Modified Method ◽  
Ruthenium Red Staining ◽  
Extracellular Polymer

Extracellular polymer surrounding two blue-green algae, Eucapsis sp. (No. 1519) and Anabena cylindrica Lemm. (No. 629), was examined with the electron microscope. Conventional glutaraldehyde–OsO4 fixation, freeze-drying before fixation, and two ruthenium red staining procedures (Luft's method and the modified method of Cagle et al.) were used. The data obtained indicate that observation of extracellular polymer is successively enhanced over conventional fixation when (i) freeze-drying, (ii) Luft's ruthenium red method, and (iii) the modified method of Cagle et al. are used. Each of the methods was also observed to improve cytological detail, particularly in A. cylindrica.

The formation of microcolonies by rumen bacteria

1980 ◽  
Vol 26 (9) ◽  
pp. 1104-1113 ◽  
Author(s):  
K.-J. Cheng ◽  
J. W. Costerton
Keyword(s):  
Electron Microscopy ◽  
Rumen Fluid ◽  
Ruthenium Red ◽  
Solid Surfaces ◽  
Morphological Data ◽  
Specimen Preparation ◽  
Rumen Bacteria ◽  
Fibrous Matrix ◽  
Ruthenium Red Staining ◽  
Exchange Function

When rumen fluid is fixed for electron microscopy, without centrifugation, a large amount of material sediments spontaneously and ruthenium red staining shows this material to be partially composed of bacterial microcolonies in which morphologically similar sister cells are enclosed in an extensive fibrous exopolysaccharide glycocalyx. The exopolysaccharide matrix condenses, to variable degrees, during the dehydration steps of specimen preparation for electron microscopy but some fibers are stabilized by their attachment to solid surfaces at multiple points and the extent of this matrix can be deduced from morphological data. Even after condensation, the glycocalyces of rumen bacteria occupy more space than the cells themselves and they completely surround most cells with a fibrous matrix, whose chemical composition dictates an ion-exchange function, that must be assumed to be protective against some bacteriophage and antibacterial agents.

scholarly journals Microplicae: characteristic ridge-like folds of the plasmalemma.

1976 ◽  
Vol 68 (3) ◽  
pp. 420-429 ◽  
Author(s):  
P M Andrews
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Alimentary Tract ◽  
Ruthenium Red ◽  
Specific Function ◽  
Free Surfaces ◽  
Transmission Electron ◽  
Dense Zone ◽  
Ruthenium Red Staining ◽  
Scanning Electron

Scanning electron microscopy reveals that the free surfaces of stratified squamous epithelial cells lining the alimentary tract, cornea, and conjunctiva exhibit characteristic ridge-like folds of plasmalemma. These microplicae are approximately 0.1-0.2 micronm in width, of variable height (0.2-0.8 micronm) and length, may followstraight or winding paths, often branch, and exhibit a wide variety of patterns over the surfaces of cells. Transmission electron microscopy reveals that microplicae often have a fine (100-150 A) electron-dense zone subjacent to their plasmalemma and an intracellular matrix characterized by a disorderly arrary of fine filaments (40-60 A in diameter). Microplicae appear to arise from plasmalemmal fold which once provided for intercellular interdigitation and desmosome abhesion between adjacent cells. Ruthenium red staining demonstrates that microplicae and interplical grooves are covered with a polyanionic glycocalyx. Although free surface microplicae may merely represent the renmants of intercellular interdigitations or a modified expression of microvillous-like extensions, it is also possible that they serve another specific function. In this regard it is speculated that microplical and interplical grooves may function to hold a layer of lubricating and cushioning mucin designed to protect the underlying plasmalemma from abrasive abuse.

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