Light and scanning electron microscopic observations of calcium oxalate crystals produced during growth of Sclerotium rolfsii in culture and in infected tissue

1984 ◽  
Vol 62 (10) ◽  
pp. 2028-2032 ◽  
Author(s):  
Z. K. Punja ◽  
S. F. Jenkins
Keyword(s):  
Oxalic Acid ◽  
Calcium Oxalate ◽  
Sclerotium Rolfsii ◽  
Crystal Formation ◽  
Positive Staining ◽  
Staining Reaction ◽  
Electron Microscopic ◽  
Characteristic Energy ◽  
Electron Microscopes ◽  
Scanning Electron

Crystals produced during growth of Sclerotium rolfsii on cellophane overlaying water agar were identified as calcium oxalate based on their solubility characteristics in certain acids, positive staining reaction with silver nitrate – dithiooxamide, and characteristic energy-dispersive X-ray emission spectrum. Addition of calcium salts to water agar enhanced crystal formation. Similar crystals of calcium oxalate were observed with the light and scanning electron microscopes in sugar beet and carrot leaf tissues infected by Sclerotium rolfsii. They frequently formed along the infecting hyphae or were associated with hyphal aggregates and were observed in abundance within the tissue. Addition of oxalic acid solutions to leaf discs resulted in necrosis of the tissue, and crystals similar in all respects to those produced in infected tissues were formed. These observations indicate that the oxalic acid produced by Sclerotium rolfsii in culture or in diseased tissue may sequester available calcium to form calcium oxalate, and provide evidence for the role of oxalic acid in pathogenesis.

Oxalic acid and calcium oxalate produced by Leucostoma cincta and L. persoonii in culture and in peach bark tissues

1987 ◽  
Vol 65 (9) ◽  
pp. 1952-1956 ◽  
Author(s):  
J. A. Traquair
Keyword(s):  
Oxalic Acid ◽  
Calcium Oxalate ◽  
Crystal Morphology ◽  
Culture Media ◽  
Positive Staining ◽  
Acid Solutions ◽  
Calcium Oxalate Crystals ◽  
Oxalate Crystals ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Oxalic acid and crystals of calcium oxalate were produced during growth of Leucostoma cincta and L. persoonii on potato dextrose agar and in peach bark tissues. The identification of calcium oxalate was based on solubility characteristics, the results of KMnO4 titration, positive staining with silver nitrate – dithiooxamide, and crystal morphology as observed with light and scanning electron microscopes. Oxalic acid was detected by gas chromatography. This is the first report of oxalic acid production by both Leucostoma species causing peach canker. Calcium oxalate crystals observed on or near hyphae in culture were similar to crystals in artificially inoculated peach bark tissues. Addition of oxalic acid solutions alone to inner bark tissues caused maceration and necrosis. These results indicate a role for oxalic acid in the early stages of pathogenesis by Leucostoma spp. Tetragonal (bipyramidal) and prismatic calcium oxalate crystals formed on bark wounds treated with oxalic acid solutions were similar to those observed in infected tissues and in culture media amended with oxalic acid.

The nuclear pore complex: three-dimensional surface structure revealed by field emission, in-lens scanning electron microscopy, with underlying structure uncovered by proteolysis

1993 ◽  
Vol 106 (1) ◽  
pp. 261-274 ◽  
Author(s):  
M.W. Goldberg ◽  
T.D. Allen
Keyword(s):  
Nuclear Pore Complex ◽  
Three Dimensional ◽  
Underlying Structure ◽  
Nuclear Pore ◽  
Electron Microscopic ◽  
Biologically Relevant ◽  
Fine Grained ◽  
Outer Periphery ◽  
Electron Microscopes ◽  
Scanning Electron

The structure of the nuclear pore complex (NPC) has been previously studied by many different electron microscopic techniques. Recently, scanning electron microscopes have been developed that can visualise biologically relevant structural detail at the same level of resolution as transmission electron microscopes and have been used to study NPC structure. We have used such an instrument to visualise directly the structure of both cytoplasmic and nucleoplasmic surfaces of the NPC of manually isolated amphibian oocyte nuclear envelopes that have been spread, fixed, critical point dried and coated with a thin fine-grained film of chromium or tantalum. We present images that directly show features of the NPC that are visible at each surface, including coaxial rings, cytoplasmic particles, plug/spoke complexes and the nucleoplasmic basket or fishtrap. Some cytoplasmic particles are rod-shaped or possibly “T”-shaped, can be quite long structures extending into the cytoplasm and may be joined to the coaxial ring at a position between each subunit. Both coaxial rings, which are proud of the membranes, can be exposed by light proteolytic digestion, revealing eight equal subunits each of which may be bipartite. We have determined that the nucleoplasmic filaments that make up the baskets are attached to the outer periphery of the coaxial ring at a position between each of its subunits. These filaments extend into the nucleoplasm and insert at the distal end to the smaller basket ring. The space left between adjacent basket filaments would exclude particles bigger than about 25 nm, which is consistent with the exclusion limit previously found for NPC-transported molecules.

scholarly journals ULTRASTRUCTURE OF SARCOPLASMIC RETICULUM PREPARATIONS

1969 ◽  
Vol 42 (1) ◽  
pp. 296-307 ◽  
Author(s):  
D. W. Deamer ◽  
R. J. Baskin
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Calcium Oxalate ◽  
Calcium Transport ◽  
Osmium Tetroxide ◽  
Positive Staining ◽  
Rabbit Muscle ◽  
Calcium Oxalate Crystals ◽  
Electron Microscopic ◽  
Staining Techniques ◽  
Microscopic Techniques

Fragmented sarcoplasmic reticulum (FSR) from rabbit muscle was examined by positive staining, negative staining, and freeze-etch electron microscopic techniques in the absence and presence of calcium transport conditions. The existence of 30–40 A particles covering the outer surface of FSR vesicles was confirmed by two different negative stains in unfixed, glutaraldehyde-fixed and osmium tetroxide-fixed material. Freeze-etch microscopy revealed a second type of particle, 80–90 A in diameter, on the fractured surfaces of FSR vesicles. Following calcium oxalate accumulation, negative and positive staining techniques provided evidence for large nodular deposits within FSR vesicles which probably correspond to calcium oxalate crystals and are responsible for increments in turbidity during calcium oxalate accumulation. The most probable configuration of FSR vesicles in solution is spherical. "Tadpole" or tubular configurations were not seen by freeze-etch microscopy, positive staining, or in prefixed negatively stained material.

Scanning Electron Microscopic Studies on the Tegument of Trematodes

1974 ◽  
Vol 32 ◽  
pp. 182-183
Author(s):  
J. E. Ubelaker ◽  
R. D. Specian ◽  
V. F. Allison
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Host Response ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Microscopic Studies ◽  
Physiological Demands ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Among the parasitic flatworms, only members of the trematoda have exploited nearly every conceivable niche. Since physiological demands in each habitat present special problems in eluding the host response as well as obtaining nourishment the surface epithelia of such organisms warrant special attention. To gain an appreciation of tegumental diversity in the trematoda, representative trematodes from numerous habitats in their respective hosts were examined by scanning electron microscopySpecimens were collected from natural infections, fixed in paraformaldehyde and dehydrated in alcohol. Ethanol was exchanged with amyl acetate prior to CO2 drying in a Denton DCP-1 critical point dryer. The dried specimens were mounted on metal holders, outgassed and rotary coated with gold-palladium. These were then examined with the ISI Mini-SEM and AMR 1000 scanning electron microscopes.

scholarly journals Cytology of Fibrous Roots from Citrus Blight-Affected Trees

Plant Disease ◽  
2000 ◽  
Vol 84 (2) ◽  
pp. 164-167 ◽  
Author(s):  
A. G. C. Lindbeck ◽  
R. H. Brlansky
Keyword(s):  
Electron Microscopy ◽  
Positive Staining ◽  
Staining Reaction ◽  
The World ◽  
Decline Disease ◽  
Citrus Blight ◽  
Root Grafting ◽  
Water Transmission ◽  
Fibrous Roots ◽  
Scanning Electron

Citrus blight is an economically important decline disease of citrus in various areas of the world. The cause of citrus blight is unknown, but transmission via root grafting has been demonstrated. Root tissue from fibrous roots of citrus blight-affected and healthy citrus trees were compared. Amorphous plugs of the type previously observed in the trunk xylem and large roots of blighted trees were also found in the fibrous roots. The plugs were yellow to light gold in color, gave a positive staining reaction for the presence of lignin, and were retained when kept overnight in water. With scanning electron microscopy the amorphous plugs appeared to be solid, occluding part or all of the vessel. These plugs have previously been implicated in the reduction of water transmission in blighted trees.

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

Silver Staining of Pancreatic Islets as Revealed by Electron Microscopy

1967 ◽  
Vol 25 ◽  
pp. 44-45
Author(s):  
Kazuaki Misugi ◽  
Nobuko Misugi ◽  
Hiroshi Yamada
Keyword(s):  
Pancreatic Islet ◽  
Silver Staining ◽  
Islet Cells ◽  
Severe Hypoglycemia ◽  
Granular Cell ◽  
Electron Microscopic Level ◽  
Staining Reaction ◽  
Electron Microscopic ◽  
Pancreatic Islet Cell ◽  
D Cell

The authors had described the fine structure of a type of pancreatic islet cell, which appeared different from typical alpha and beta cells, and tentatively considered that this third type of granular cell probably represents the D cell (Figure 1).Since silver staining has been widely used to differentiate different types of pancreatic islet cells by light microscopy, an attempt to examine this staining reaction at the electron microscopic level was made.Material and Method: Surgically removed specimens from three infants who suffered from severe hypoglycemia were used. The specimens were fixed and preserved in 20% neutral formalin. Frozen sections, 30 to 40 micron thick, were prepared and they were stained by Bielschowsky's method as modified by Suzuki (2). The stained sections were examined under a microscope and islet tissues were isolated. They were fixed in 1% osmium tetroxide in phosphate buffer for one hour and embedded in Epon 812 following dehydration through a series of alcohols and propylene oxide.

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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