Electron Microscopic Evaluation of the Effect of Therapeutic Silicone Hydrogel Lenses on the Limbal Area

2006 ◽  
Vol 32 (3) ◽  
pp. 133-137 ◽  
Author(s):  
Canan G??rdal ◽  
Tamer Takmaz ◽  
Mustafa F. Sargon ◽  
Alpaslan Anayol ◽  
Ebru Ylmaz ◽  
...  
Author(s):  
J. W. Horn ◽  
B. J. Dovey-Hartman ◽  
V. P. Meador

Osmium tetroxide (OsO4) is a universally used secondary fixative for routine transmission electron microscopic evaluation of biological specimens. Use of OsO4 results in good ultrastructural preservation and electron density but several factors, such as concentration, length of exposure, and temperature, impact overall results. Potassium ferricyanide, an additive used primarily in combination with OsO4, has mainly been used to enhance the contrast of lipids, glycogen, cell membranes, and membranous organelles. The purpose of this project was to compare the secondary fixative solutions, OsO4 vs. OsO4 with potassium ferricyanide, and secondary fixative temperature for determining which combination gives optimal ultrastructural fixation and enhanced organelle staining/contrast.Fresh rat liver samples were diced to ∼1 mm3 blocks, placed into porous processing capsules/baskets, preserved in buffered 2% formaldehyde/2.5% glutaraldehyde solution, and rinsed with 0.12 M cacodylate buffer (pH 7.2). Tissue processing capsules were separated (3 capsules/secondary fixative.solution) and secondarily fixed (table) for 90 minutes. Tissues were buffer rinsed, dehydrated with ascending concentrations of ethanol solutions, infiltrated, and embedded in epoxy resin.


Author(s):  
W.T. Gunning ◽  
J.N. Turner ◽  
K. Buttle ◽  
E.P. Calomeni ◽  
N.A. Lachant ◽  
...  

There are a variety of conditions which have been associated with prolonged bleeding times. If other etiologies including von Willebrand's disease have been ruled out, a platelet function disorder must be considered. The best, if not only, technique to make this diagnosis is the electron microscopic evaluation of whole air dried platelets. Bull first described the presence of dense granules in whole platelets in 1968 and the technique has been utilized extensively The electron dense or delta granules are easily distinguished from the larger more numerous alpha granules which are electron lucent. The significance of the dense granules is that they are known to be “storage pools” of serotonin, calcium, adenosine di- and triphosphate, and pyrophosphate. Prolonged bleeding times may be directly related to an insufficiency of these substances. The diagnosis of a storage pool deficiency is made when either the storage content of the dense granules is abnormal or their number is diminished. We observe normal platelets to have 4-6 dense granules, which agrees with the literature.


1989 ◽  
Vol 17 (12) ◽  
pp. 1335-1340 ◽  
Author(s):  
JAVIER DIAZ-BLANCO ◽  
ROBERT C. CLAWSON ◽  
SHIRLEY M. ROBERSON ◽  
CAROL B. SANDERS ◽  
ARUN K. PRAMANIK ◽  
...  

1982 ◽  
Vol 30 (5) ◽  
pp. 481-486 ◽  
Author(s):  
R E McClung ◽  
J Wood

Analytical electron microscopy was used to determine the quantitative effects of paraformaldehyde pretreatment on the formation of the biogenic amine-glutaraldehyde-chrome complex. Pretreatment with paraformaldehyde prevented the glutaraldehyde-chrome reaction with norepinephrine in the rat adrenal medulla. In contrast to the effect of paraformaldehyde on norepinephrine, pretreatment did not prevent the chrome reaction in serotonin-containing argentaffin cells of the gut. X-Ray energy spectrographic analysis revealed a significant decrease in chrome content in the paraformaldehyde treated tissue, but sufficient chrome did react to produce an electron-dense product. Thus by treating tissue with paraformaldehyde prior to the glutaraldehyde chrome procedure, serotonergic sites may be differentiated from catecholaminergic areas at the electron microscopic level.


Andrologia ◽  
2009 ◽  
Vol 19 (5) ◽  
pp. 551-553 ◽  
Author(s):  
R. VIJAYAKUMAR ◽  
B. NDUBISI ◽  
S. PRIEN ◽  
F. LEON ◽  
W. HEINE

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