Cytopathology and ultrastructure of mild and severe strains of maize chlorotic dwarf virus in maize and johnsongrass

1993 ◽  
Vol 71 (5) ◽  
pp. 718-724 ◽  
Author(s):  
E. D. Ammar ◽  
R. E. Gingery ◽  
L. R. Nault
Keyword(s):  
Electron Microscopy ◽  
Uranyl Acetate ◽  
Dwarf Virus ◽  
Mesophyll Cells ◽  
White Stripe ◽  
Cytoplasmic Inclusions ◽  
Maize Leaves ◽  
Maize Chlorotic Dwarf Virus ◽  
In Cells

In maize leaves experimentally infected with various isolates or strains of maize chlorotic dwarf virus, including a newly characterized strain (M1), and in naturally infected johnsongrass, only two types of cytoplasmic inclusions were consistently observed: (i) quasi-spherical electron-dense granular inclusions, and (ii) curved or straight bundles of fibrous inclusions. Both types were detected by light and (or) electron microscopy in vascular parenchyma and phloem cells, and less frequently in bundle-sheath and adjacent mesophyll cells. The dense granular inclusions usually contained numerous isometric virus-like particles, some of which may have been released into the surrounding cytoplasm. However, a high proportion of these inclusions in cells infected with the mild type strain and a type-like isolate (M8) were either devoid of or contained very few viruslike particles. In maize leaves infected with the white stripe (WS) isolate, the chloroplasts were markedly deformed; in leaves of stunted plants doubly infected with M8 and the serologically distinct M1 strain, some phloem cells appeared degenerated. Electron microscopy of preparations of purified M1 stained with uranyl acetate revealed both stain-impenetrable full particles and stain-penetrable empty or partially empty particles. Both full and apparently empty particles were also found in cells of maize leaves infected with M1, whereas with other strains and isolates, mainly full particles were found both in situ and in vitro. Key words: maize chlorotic dwarf virus, cytopathology, ultrastructure, maize, johnsongrass.

Electron Microscopy of Fibroblasts from Myotonic Muscular Dystrophy Patients

1981 ◽  
Vol 39 ◽  
pp. 498-499
Author(s):  
S. E. Miller ◽  
G. B. Hartwig ◽  
R. A. Nielsen ◽  
A. P. Frost ◽  
A. D. Roses
Keyword(s):  
Electron Microscopy ◽  
Muscular Dystrophy ◽  
Genetic Diseases ◽  
Skin Fibroblasts ◽  
Inborn Errors ◽  
Cytoplasmic Inclusions ◽  
Cultured Skin ◽  
Myotonic Muscular Dystrophy ◽  
Glycosaminoglycan Metabolism

Many genetic diseases can be demonstrated in skin cells cultured in vitro from patients with inborn errors of metabolism. Since myotonic muscular dystrophy (MMD) affects many organs other than muscle, it seems likely that this defect also might be expressed in fibroblasts. Detection of an alteration in cultured skin fibroblasts from patients would provide a valuable tool in the study of the disease as it would present a readily accessible and controllable system for examination. Furthermore, fibroblast expression would allow diagnosis of fetal and presumptomatic cases. An unusual staining pattern of MMD cultured skin fibroblasts as seen by light microscopy, namely, an increase in alcianophilia and metachromasia, has been reported; both these techniques suggest an altered glycosaminoglycan metabolism An altered growth pattern has also been described. One reference on cultured skin fibroblasts from a different dystrophy (Duchenne Muscular Dystrophy) reports increased cytoplasmic inclusions seen by electron microscopy. Also, ultrastructural alterations have been reported in muscle and thalamus biopsies from MMD patients, but no electron microscopical data is available on MMD cultured skin fibroblasts.

Filaments of surfactant protein A specifically interact with corrugated surfaces of phospholipid membranes

1999 ◽  
Vol 276 (4) ◽  
pp. L631-L641 ◽  
Author(s):  
Nades Palaniyar ◽  
Ross A. Ridsdale ◽  
Stephen A. Hearn ◽  
Yew Meng Heng ◽  
F. Peter Ottensmeyer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Protein A ◽  
Lipid Vesicles ◽  
Surfactant Protein ◽  
Uranyl Acetate ◽  
Lipid Vesicle ◽  
Transmission Electron

Pulmonary surfactant, a mixture of lipids and surfactant proteins (SPs), plays an important role in respiration and gas exchange. SP-A, the major SP, exists as an octadecamer that can self-associate to form elongated protein filaments in vitro. We have studied here the association of purified bovine SP-A with lipid vesicle bilayers in vitro with negative staining with uranyl acetate and transmission electron microscopy. Native bovine surfactant was also examined by transmission electron microscopy of thinly sectioned embedded material. Lipid vesicles made from dipalmitoylphosphatidylcholine and egg phosphatidylcholine (1:1 wt/wt) generally showed a smooth surface morphology, but some large vesicles showed a corrugated one. On the smooth-surfaced vesicles, SP-As primarily interacted in the form of separate octadecamers or as multidirectional protein networks. On the surfaces of the striated vesicles, SP-As primarily formed regularly spaced unidirectional filaments. The mean spacing between adjacent striations and between adjacent filaments was 49 nm. The striated surfaces were not essential for the formation of filaments but appeared to stabilize them. In native surfactant preparations, SP-A was detected in the dense layers. This latter arrangement of the lipid bilayer-associated SP-As supported the potential relevance of the in vitro structures to the in vivo situation.

Langerhans’ Granules in Cells of an Eosinophilic Histiocytoma

1968 ◽  
Vol 26 ◽  
pp. 196-197
Author(s):  
John H. L. Watson ◽  
John L. Swedo ◽  
A. R. Morales
Keyword(s):  
Electron Microscopy ◽  
Tumor Cells ◽  
Present Report ◽  
Normal Skin ◽  
Uranyl Acetate ◽  
Dense Bodies ◽  
Lead Hydroxide ◽  
Membrane Bound ◽  
Numerous Microvillus ◽  
In Cells

Recent papers describe Langerhans’ granules in cells of normal skin, in Letterer-Siwe disease, and associated with osseous and pulmonary lesions of histiocytosis X. The present report concerns the structure and occurrence of these granules in a solitary tumor of the human posterior anal wall, diagnosed as an eosinophilic histiocytoma, confirmed by the electron microscopy. The investigation supports the hypothesis that the epidermal Langerhans’ cell is a macrophage. Samples of the recurrent tumor were fixed in cacodylate-buffered 6.4% glutaraldehyde, washed in cacodylate-buffered 0.2M sucrose, and postfixed in OSO4 for electron microscopy. Embedment was in Araldite, and sections were contrasted with uranyl acetate and lead hydroxide.The surface of the tumor cells was very irregular, with numerous microvillus-like projections, and was without both desmosomes and basement membrane. The nuclei were lobulated, and possessed both finely dispersed and coagulated chromatin, with multiple nucleoli. The system of parallel tubules and sacs which composed the Golgi was prominent in most cells. Numerous linear profiles of RER occurred. The RNA particles were also abundant throughout the cytoplasm in groups unrelated to the RER. Centrioles were seen frequently paranuclearly. The mitochondria, with well developed cristae, were frequently altered, being locally swollen, vacuolated or containing myelin figures, Fig. A. The most striking organelles were (i) the Langerhans’ granules (L), observed in abundance throughout the cytoplasm of most of the tumor cells, but predominantly in those cells which contained (ii) the fusiform or ovoid, membrane-bound, electron-dense bodies (B). Many of these rounded, dense bodies contained concentric, double-membranous structures, Figs. C and D.

Changes in the plastid ultrastructure during greening in cultured soybean cells

1989 ◽  
Vol 47 ◽  
pp. 1010-1011
Author(s):  
M.A. Gillott ◽  
G. Erdös ◽  
D. E. Buetow
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gene Regulation ◽  
Uranyl Acetate ◽  
Total Darkness ◽  
Ultrastructural Changes ◽  
Ethanol Dehydration ◽  
Mesophyll Cells ◽  
Plastid Ultrastructure ◽  
Transmission Electron

Mesophyll cells isolated from soybeans (Glycine max, L. Merr. var. Corsoy) can be grown photoautotrophically in suspension culture. The SB-P cell line can be bleached by maintaining them in total darkness in sucrose supplemented media for several weeks, and will regain photosynthetic competency when returned to the light. This system is ideally suited for the study of gene regulation and the biochemical and ultrastructural changes which occur during the greening process.Cells were fixed for electron microscopy after 8 weeks of growth in total darkness and at intervals of 1 h to 12 d after transfer to the light. Chlorophyll measurements were determined for each sample. For transmission electron microscopy, the cells were fixed for 1-2 h in 4% glutaraldehyde in 0.1M Pipes buffer, pH 7.4, washed in the same buffer, then postfixed for 1 h in 1% OsO4 in Pipes, pH 6.8. Following a graded ethanol dehydration series the cells were transferred into propylene oxide and embedded in Epon. Sections were stained with uranyl acetate and observed on a JEOL 100C TEM operated at 80 kV.

Ultrastructural changes in host leaf cells caused by host-selective toxin of Alternaria alternata from rough lemon

1984 ◽  
Vol 62 (12) ◽  
pp. 2485-2492 ◽  
Author(s):  
K. Kohmoto ◽  
Y. Kondoh ◽  
T. Kohguchi ◽  
H. Otani ◽  
S. Nishimura ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Alternaria Alternata ◽  
Bundle Sheath ◽  
Ultrastructural Changes ◽  
Selective Toxicity ◽  
Mesophyll Cells ◽  
Veinal Necrosis ◽  
Rough Lemon ◽  
The Matrix ◽  
In Cells

A pathotype of A. alternata with selective pathogenicity to rough lemon produces two or more substances with selective toxicity to the host. The major toxin was extracted from culture fluids with ethyl acetate and purified by several different chromatographic procedures. Toxin (10 ng/mL, 25 μL) was applied to leaves; within 24 h, water congestion and veinal necrosis were evident. The first toxin-induced change detected by electron microscopy was in the mitochondria; toxin at 1 μg/mL caused swelling, reduction in numbers and vesiculation of cristae, and decreases in electron density of the matrix. At 1 h after toxin treatment, the percentages of affected mitochondria in cells of several tissues were 18 in bundle sheaths, 9 in mesophyll cells adjacent to bundle sheath, and 9% in mesophyll cells remote from sheath. The number of affected mitochondria increased with time, until nearly 100% were affected at 6 h. No effects on other organelles were evident at 6 h. No ultrastructural changes were evident in cells of resistant leaves. The same changes in mitochondria were observed in pathogen-inoculated susceptible but not in resistant leaves by 24 h after incubation. The data indicate that the initial site of toxin action may be in the mitochondria.

Leaf anatomy and histochemistry of Lippia citriodora (Verbenaceae)

2010 ◽  
Vol 58 (5) ◽  
pp. 398 ◽  
Author(s):  
Catherine Argyropoulou ◽  
Anastasia Akoumianaki-Ioannidou ◽  
Nikolaos S. Christodoulakis ◽  
Costas Fasseas
Keyword(s):  
Electron Microscopy ◽  
Histochemical Study ◽  
Glandular Trichomes ◽  
Aromatic Plant ◽  
Mesophyll Cells ◽  
Cytoplasmic Inclusions ◽  
Lippia Citriodora ◽  
Histochemical Tests ◽  
First Time ◽  
Scanning Electron

Lippia citriodora H.B.K. is an aromatic plant indigenous to South America. It is cultivated and commercialised as an ornamental for its lemon-like scent emitted from its leaves and flowers. The present morphoanatomical and histochemical study revealed that leaves of L. citriodora possess one type of setae (non-glandular) and at least five types of glandular trichomes, with the latter differing anatomically and in the composition of their secondary metabolites. Scanning electron microscopy revealed that the same types of trichomes exist also on the calyces. Histochemical tests indicate that the glandular trichomes contain a combination of terpenoids, flavonoids, carbohydrates, phenolics and alkaloids. However, within the vacuoles of the mesophyll cells, terpenoids, phenolics, flavonoids and tannins are stored. The presence of lamellar cytoplasmic inclusions in the mesophyll cells, possibly precursors of tannins stored in the vacuoles, is reported for the first time.

Hexamethyldisilazane: A modified procedure

1989 ◽  
Vol 47 ◽  
pp. 1006-1007
Author(s):  
Verdon Laliberté ◽  
L.L. Hayes ◽  
B.M. Stanulis-Praeger
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Uranyl Acetate ◽  
Cell Contact ◽  
Critical Importance ◽  
Drying Procedures ◽  
Critical Point Drying ◽  
Scanning Electron ◽  
Better Than

Scanning electron microscopy is a powerful tool in the study of cell contact in vitro, and has shown, specifically, that fibroblasts under conditions of growth restriction increase cell contact by filopodia. Accurate quantitation of surface features like filopodia, however, depends particularly upon artifact-free drying procedures. Critical point drying (CPD) of fibroblast monolayers all too often causes cell flattening, shrinkage, loss of surface detail and cracking (Fig. 1). Newer methods utilizing hexamethyldisilazane (HMDS) and uranyl acetate (UA) preserve fibroblast contour and surface architecture better than CPD, but solvent choice in the preparation of UA is of critical importance. UA in 70% ethanol results in the formation of precipitate (Fig. 2) whether the specimens are in the cold (4°C) or at room temperature, overnight or for periods less than 1 hour regardless of filtering. It occurs when incubation is carried out in the dark and when it is followed by copious rinses in 70% ethanol.

Platinum Compounds as Stains for Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 230-231
Author(s):  
S. K. Aggarwal ◽  
P. McAllister ◽  
R. W. Wagner ◽  
B. Rosenberg
Keyword(s):  
Electron Microscopy ◽  
Hela Cells ◽  
Uranyl Acetate ◽  
Sarcoma 180 ◽  
Platinum Compounds ◽  
Kb Cells ◽  
En Bloc ◽  
Human Lymphoma ◽  
Ultrathin Sections ◽  
Blue Coloration

Uranyl acetate has been used as an electron stain for en bloc staining as well as for staining ultrathin sections in conjunction with various lead stains (Fig. 1). Present studies reveal that various platinum compounds also show promise as electron stains. Certain platinum compounds have been shown to be effective anti-tumor agents. Of particular interest are the compounds with either uracil or thymine as one of the ligands (cis-Pt(II)-uracil; cis-Pt(II)-thymine). These compounds are amorphous, highly soluble in water and often exhibit an intense blue coloration. These compounds show enough electron density to be used as stains for electron microscopy. Most of the studies are based on various cell lines (human AV, cells, human lymphoma cells, KB cells, Sarcoma-180 ascites cells, chick fibroblasts and HeLa cells) while studies on tissue blocks are in progress.

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