scholarly journals ELECTRON MICROSCOPY OF CULTURED SPHERULES OF COCCIDIOIDES IMMITIS

1961 ◽  
Vol 9 (3) ◽  
pp. 627-637 ◽  
Author(s):  
Abraham M. Breslau ◽  
Thomas J. Hensley ◽  
John O. Erickson
Keyword(s):  
Electron Microscopy ◽  
Cytoplasmic Membrane ◽  
Coccidioides Immitis ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Ca 50 ◽  
Hyphal Wall ◽  
Section Electron Microscopy ◽  
Peripheral Cytoplasm

Spherules of C. immitis have been grown in vitro in modified Roessler's medium under CO2 tension and continuous cultures now maintained for over 18 months. Transformation of hyphae and development of the spherule form have been studied by thin section electron microscopy. Cells of organisms in the hyphal stage have thin (ca. 50 mµ), apparently structureless walls and a cytoplasmic membrane. Many nuclei, elongated mitochrondria with both transverse and longitudinal cristae, and lipid particles are present. The hyphal wall thickens and the cell transforms into spherules. A large central accumulation of electrontransparent polysaccharide appears in the spherule. The peripheral cytoplasm contains nuclei, each enclosed in a double-layered membrane, mitochondria, and small dense particles. Prior to cleavage the polysaccharide droplets are lost, while mitochrondria become small and spherical. Endospores are formed and liberated when the spherule wall breaks. These begin to grow and repeat the cleavage cycle.

The Infection of Cells by Bullet-Shaped Viruses

1969 ◽  
Vol 27 ◽  
pp. 372-373
Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Host Cell ◽  
Thin Section ◽  
Cultured Cells ◽  
Cell Infection ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

Effect of taxol on the interaction of tubulin with myosin filaments

1984 ◽  
Vol 62 (9) ◽  
pp. 878-884 ◽  
Author(s):  
Toshihiro Fujii ◽  
Tatsuo Suzuki ◽  
Akira Hachimori ◽  
Michiyo Fujii ◽  
Yoshiyuki Kondo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Skeletal Muscle ◽  
Atpase Activity ◽  
Cross Section ◽  
Molar Ratio ◽  
Tubulin Polymerization ◽  
Myosin Filaments ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The interaction between polymerized tubulin from porcine brain and myosin from rabbit skeletal muscle was examined. The addition of myosin to the solution of tubulin polymerized by taxol resulted in a remarkable increase in turbidity within a few minutes at 37 °C, and a dense and stable precipitate was formed. The maximal molar ratio of tubulin bound to myosin was calculated to be about 4, while the value was about 2 when 6S tubulin was used. Both podophyllotoxin and colchicine suppressed the taxol-dependent increase of the binding of tubulin to myosin, but only when they were preincubated with tubulin prior to addition of taxol. 6S tubulin inhibited with aetin-activated Mg2+-ATPase activity of myosin, and polymerized tubulin inhibited the Mg-ATPase more than 6S tubulin. Dense precipitates of tubulin and myosin were observed by thin-section electron microscopy. Microtubules were observed to be entangled in myosin filaments and single microtubules were occasionally surrounded by five myosin filaments in a cross section, similar to actin–myosin arrays in muscle. After incubation of tubulin with myosin, taxol was able to induce tubulin polymerization in the same way as it polymerized microtubules in the absence of myosin.

scholarly journals STUDIES OF THE ULTRASTRUCTURE AND RIBOSOMAL ARRANGEMENTS OF THE PLEUROPNEUMONIA-LIKE ORGANISM A5969

1965 ◽  
Vol 25 (1) ◽  
pp. 139-150 ◽  
Author(s):  
Jack Maniloff ◽  
Harold J. Morowitz ◽  
Russell J. Barrnett
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Chemical Analysis ◽  
Thin Section ◽  
Differential Centrifugation ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy ◽  
Cellular Organelles

Thin-section electron microscopy, together with isolation of cellular organelles by differential centrifugation and chemical analysis, has been used to investigate the ultrastructure of the avian pleuropneumonia-like organism A5969. Each cell (approximate diameter 5500 A) was surrounded by a 150 A plasma membrane. In the center of the cell was an unbounded area, granular in appearance and containing the cell's DNA. The periphery of the cell contained granules of several different sizes and densities. The most dense particles (150 A) corresponded to the 78S ribosomes. These particles exhibited two predominant arrangements: (a) sometimes they showed cubic packing; (b) most arrays, however, were consistent with cylindrical arrangements of approximately 50 particles. Bundles of up to 18 arrays were observed. Structured blebs have been found protruding from the surface of log phase cells.

Mycoplasma-like organisms as causal agents of potato purple top wilt in Queensland

1985 ◽  
Vol 36 (3) ◽  
pp. 443 ◽  
Author(s):  
RM Harding ◽  
DS Teakle
Keyword(s):  
Electron Microscopy ◽  
Thin Section ◽  
Strong Evidence ◽  
Tomato Plant ◽  
Tomato Plants ◽  
Potato Plants ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Potato Purple Top ◽  
Section Electron Microscopy

The eggplant little-leaf agent was graft transmitted to tomato causing big-bud symptoms. Transmission from the big-bud tomato to potato by grafting or the leafhopper Orosius argentatus resulted in the development of purple top wilt symptoms. Thin-section electron microscopy revealed mycoplasma-like organisms present in the phloem sieve elements of a big-bud tomato plant and purple top wilt potato plants infected by grafting or leafhoppers. When tubers from graft-infected potato plants were planted, 73% produced spindly shoots and 44% of these later developed purple top wilt symptoms. When scions from either field-infected or experimentally infected potato plants showing purple top wilt symptoms were grafted onto tomato plants, 24% and 62% respectively developed big-bud symptoms. The results provide strong evidence for the mycoplasmal aetiology of some, if not all, potato purple top wilt in Queensland.

scholarly journals Structural characterization of altered nucleoporin Nup153 expression in human cells by thin-section electron microscopy

Nucleus ◽  
2014 ◽  
Vol 5 (6) ◽  
pp. 601-612 ◽  
Author(s):  
Vincent Duheron ◽  
Guillaume Chatel ◽  
Ursula Sauder ◽  
Vesna Oliveri ◽  
Birthe Fahrenkrog
Keyword(s):  
Electron Microscopy ◽  
Thin Section ◽  
Structural Characterization ◽  
Human Cells ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

Thin-Section Electron Microscopy of Mature Myxosoma cerebralis (Myxosporidea) Spores

1975 ◽  
Vol 61 (3) ◽  
pp. 476 ◽  
Author(s):  
Philip D. Lunger ◽  
Betty L. Rhoads ◽  
Ken Wolf ◽  
Maria E. Markiw
Keyword(s):  
Electron Microscopy ◽  
Thin Section ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

scholarly journals Lack of correlation between transepithelial transport capacity and paracellular pathway ultrastructure in Alcian blue-treated rabbit gallbladders.

1979 ◽  
Vol 83 (2) ◽  
pp. 383-393 ◽  
Author(s):  
O Frederiksen ◽  
K Møllgård ◽  
J Rostgaard
Keyword(s):  
Electron Microscopy ◽  
Thin Section ◽  
Alcian Blue ◽  
Fluid Transport ◽  
Paracellular Pathway ◽  
Transepithelial Transport ◽  
Rabbit Gallbladder ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The effects of mucosal application of 1 mg% Alcian blue (a trivalent cationic phthalocyanine dye) on functional and ultrastructural parameters of the isolated rabbit gallbladder have been studied. Apart from minor changes in the shape of the group of central microvilli observed in thin-section electron microscopy and scanning electron microscopy, the major ultrastructural change induced by Alcian blue was an almost complete collapse of intercellular spaces in the region above the tight junctions up to the bases of the marginal microvilli as revealed by thin-section electron microscopy. Freeze-fracture electron microscopy demonstrated a complete disappearance of intramembrane particles of neighboring cell membranes corresponding to the region of interspace collapse. Transepithelial electrical resistance (RT) increased from 44.5 to 58.7 ohm . cm2 upon treatment with Alcian blue. This increase could be well accounted for by the observed structural changes in the paracellular pathway if this pathway determines the low resistance of the rabbit gallbladder epithelium. Despite the increase in RT, net mucosa-to-serosa fluid transport and the spontaneous mucosa-positive potential difference of 3 mV were unaltered by Alcian blue treatment, supporting the hypothesis that the transepithelial transport mechanism per se is electroneutral. A calculation of the maximal paracellular mucosa-to-serosa waterflow in response to a lateral intercellular space hypertonicity of 20 mosM demonstrates that in the Alcian blue-treated gallbladder the resulting figure is about three orders of magnitude too low to keep up with the unaltered spontaneous transepithelial net fluid transport. It is therefore concluded that the tight junction pathway in rabbit gallbladders does not serve as a route for net fluid transport.

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