Nonspecific structures seen in diagnostic muscle biopsies

Author(s):  
R. C. Caughey ◽  
U. P. Kalyan-Raman

In a period of two years we have analyzed 50 muscle biopsies using the transmission electron microscope. Six nonspecific structures consisting of filamentous bodies, tubular aggregates, paracrystalline mitochondrial inclusions, honeycomb arrays, concentric laminated bodies, and finger print profiles were observed in 47 of 50 cases. In order to know the significance of these structures in muscle biopsies, we correlated their occurrence with their clinical history, histological findings, and histochemistry.The biopsies were initially fixed in 2.5% glutaraldehyde (pH. 7.5, 500 mOsm), then randomly minced and post fixed in 1% osmium tetroxide. All biopsies were processed with and without uranyl acetate en bloc staining in Walpole's buffer before ethanol dehydration. They were embedded in Epon 812 epoxy resin, sectioned, and stained with uranyl acetate and lead citrate before evaluation with a JEOL, JEM 100 C Transmission Electron Microscope. All grid squares of six different blocks were scanned to evaluate the ultra-structural pathology.

Author(s):  
R.C. Caughey ◽  
U.P. Kalyan-Raman

Prolactin producing pituitary adenomas are ultrastructurally characterized by secretory granules varying in size (150-300nm), abundance of endoplasmic reticulum, and misplaced exocytosis. They are also subclassified as sparsely or densely granulated according to the amount of granules present. The hormone levels in men and women vary, being higher in men; so also the symptoms vary between both sexes. In order to understand this variation, we studied 21 prolactin producing pituitary adenomas by transmission electron microscope. This was out of a total of 80 pituitary adenomas. There were 6 men and 15 women in this group of 21 prolactinomas.All of the pituitary adenomas were fixed in 2.5% glutaraldehyde, rinsed in Millonig's phosphate buffer, and post fixed with 1% osmium tetroxide. They were then en bloc stained with 0.5% uranyl acetate, rinsed with Walpole's non-phosphate buffer, dehydrated with graded series of ethanols and embedded with Epon 812 epoxy resin.


Author(s):  
W. P. Wergin ◽  
S. Roy ◽  
E. F. Erbe ◽  
C. A. Murphy ◽  
C. D. Pooley

Larvae of the nematode, Steinernema carpocapsae Weiser strain All, were cryofixed and freezesubstituted for 3 days in acetone containing 2% osmium tetroxide according to established procedures. Following chemical fixation, the nematodes were brought to room temperature, embedded in Spurr's medium and sectioned for observation with a Hitachi S-4100 field emission scanning electron microscope that was equipped with an Oxford CT 1500 Cryotrans System. Thin sections, about 80 nm thick, similar to those generally used in conventional transmission electron microscope (TEM) studies were mounted on copper grids and stained with uranyl acetate for 30 min and lead citrate for 5 min. Sections about 2 μm thick were also mounted and stained in a similar fashion. The grids were mounted on an Oxford grid holder, inserted into the microscope and onto a cryostage that was operated at ambient temperature. Thick and thin sections of the larvae were evaluated and photographed in the SEM at different accelerating voltages. Figs. 4 and 5 have undergone contrast conversion so that the images would resemble transmitted electron micrographs obtained with a TEM.


Author(s):  
K. L. Saving ◽  
R. C. Caughey

This presentation is designed to demonstrate how scanning and transmission electron microscopy techniques can be utilized to confirm or support a variety of unusual pediatric hematologic/oncologic disorders. Patients with the following diagnoses will be presented: (1) hereditary pyropoikilocytosis, (2) familial erythrophagocytic lymphohistiocytosis, (3) acute megakaryoblastic leukemia, and (4) pseudo-von Willebrand’s disease.All transmission and scanning electron microscopy samples were fixed in 2.5% glutaraldehyde, rinsed in Millonig’s phosphate buffer, and post-fixed with 1% osmium tetroxide. The transmission samples were then en bloc stained with 0.5% uranyl acetate, rinsed with Walpole ’ s non-phosphate buffer, dehydrated with graded series of ethanols and embedded with Epon 812 epoxy resin. Ultramicrotomy thin sections were stained with uranyl acetate and lead citrate and scanned using a JEOL-JEM 100C, The scanning samples were dehydrated with graded series of ethanols, critical point dried with CO2, gold-coated, and scanned using a JEOL-JSM 35. The peroxidase samples were fixed in 3% glutaraldehyde, incubated in diaminobenzidine (DAB), dehydrated with ethanol, embedded with Epon 812, and scanned without post-staining using a JEOL-JEM 100C.


Author(s):  
R. D. Specian ◽  
V. F. Allison ◽  
J. E. Ubelaker

Although the scolex is the major area of contact between a cestode and its host, most fine structural studies have concentrated on the rest of the body. Davey and Breckenridge postulated, from histochemical data, that neurosecretory cells were present in the scolex of Hymenolepis diminuta. Such cells have been suggested to function in affecting growth and maturation of the strobila. Since a previous study by Rothman failed to determine such cells, the present study was undertaken.Specimens were collected from previously infected laboratory rats, fixed in paraformaldehyde, post-fixed in osmium tetroxide and embedded in Maraglas. Sections were examined on the Hitachi HU11B-2 transmission electron microscope.


Author(s):  
C. F. J. Bong

The cytoplasmic polyhedrosis virus (CPV, Family Reoviridae) is an entomopathogen with a very wide host range, affecting mainly lepidopterous insects. The virus often causes chronic infections in insects, infecting mainly the midgut epithelium. Detailed studies of the effects of CPV on silkworm, Bombyx mori, have been done by Japanese workers , but there is very little information on the histopathology of CPV on other insects.In this study, 5-day old corn earworm (H. zea) larvae were infected per os with CPV. Control larvae were fed sterile water. The midgut was dissected out at 20, 48 and 72h post-treatment for both SEM and TEM studies. In the SEM study the midgut was fixed in 2.5% glutaraldehyde in phosphate buffer at pH 7.2, postfixed in buffered 2% osmium tetroxide at room temperature, dehydrated in ethanol, cryofractured in liquid nitrogen, critical-point dried, mounted, coated with gold-palladium and examined in a Hitachi HHS-2R scanning electron microscope at 20 kV. In the TEM study, the tissues were fixed in half-strength Karnovsky's fixative, postfixed in buffered cold 2% osmium tetroxide, en bloc stained in aqueous 0.5% uranyl acetate, dehydrated in ethanol and embedded in Spurr resin. Ultrathin sections were cut with glass knives, sequentially stained in aqueous uranyl acetate and lead citrate, and observed in a Zeiss 109 transmission electron microscope at 50 kV or a Siemens 101 at 80 kV.


Author(s):  
Caughey R.C. ◽  
Kalyan-Raman U.P.

Uranyl acetate en bloc staining is known to improve overall contrast and membrane preservation and removes glycogen from tissues. This staining procedure complements diagnostic electron microscopic evaluation by enhancing ultrastructural details. The ultrastructural structures enhanced are basement and plasma membranes, mitochondrial membrane and cristae, sarcoplasmic reticulum and T-tubule system. We wanted to study the usefulness of this technique over the conventional method in the study of muscle biopsy. Ultrastructurally, thirty muscle biopsies submitted to our Electron Microscopic Lab were routinely fixed in 2.5% glutaraldehyde and 1% 0S04, dehydrated in a graded series of ethanols, and embedded in Epon 812. Half of the blocks were processed and evaluated with post uranyl acetate/lead citrate staining. The other half were processed and evaluated by en bloc 0. 5% uranyl acetate/Walpole's buffer after 0S04 and before ethanol dehydration. The en bloc half were also stained with post uranyl acetate/lead citrate.


Author(s):  
L. Faso ◽  
E. Rappa ◽  
G. Vernon ◽  
R. Witkus

Although hemocyanin, an oxygen binding protein, is found freely dissolved in the hemolymph of isopods its site of synthesis is still unknown.Circulating blood cel Is such as granular hemocytes have been implicated in hemocyanin synthesis in a number of arthropods including Astacus astacus and Homarus vulgaris. Circulating blood cells of Armadillidium vulgare were examined using a transmission electron microscope (TEM) for evidence of hemocyanin synthesis.For each experiment hemolymph was collected from twenty adult A. vulgare and fixed for 1 hour in 200 uL of 3.5% glutaraldehyde in 0.1M sodium cacodylate buffer pH 7.4 with 0.05% calcium chloride added. Hemolymph was then centrifuged at 3000 rpm in an IEC-DPR-6000 centrifuge for 15 minutes at 15 degrees centigrade. The supernatant was removed, and the resulting pellet was washed with three changes of sodium cacodylate buffer. Postfixation of the pellet was done in 1% osmium tetroxide for 1 hour.


2002 ◽  
Vol 10 (5) ◽  
pp. 20-23
Author(s):  
Paul Beauregard

Recently, there was a suggestion on the MSA listserver about the use of osmium tetroxide (OsO4 and how to handle it. One suggestion was that ampoules be scored, placed in a glass jar, and the ampoule smashed to release the contents. This seemed like a very unsafe way to use osmium tetroxide or ruthenium tetroxide. The purpose of this article is to suggest a way to generate smaller amounts of these compounds in a safer manner than smashing ampoules and wondering about what to do with the unused portion after staining or storing. Another purpose is to discuss a new reaction indicator for mainly osmium tetroxide. The use of a reaction specific indicator was mandatory for judging the level or degree to which staining had proceeded in thin sections for the transmission electron microscope (TEM).


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