Ultrastructural Changes in Gonadotrophs of the Albino Male Rat after Castration or Treatment With Cyproterone Acetate

1973 ◽  
Vol 31 ◽  
pp. 670-671
Author(s):  
N. H. McArthur
Keyword(s):  
Cyproterone Acetate ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Ultrastructural Changes ◽  
Male Rat ◽  
Benzyl Benzoate ◽  
En Bloc ◽  
Intact Group ◽  
Electron Microscopes ◽  
Group 1

Forty four animals were subdivided into the following groups with three animals per group, except for the intact group which contained five animals: Group 1. Intact; 2. Castrated and injected for 5 weeks with 1.25 mg testosterone beginning on the day of castration; 3-7. Castrated adults killed 1, 2, 3, 4, and 5 weeks postcastration; 8-12. Cyproterone acetate (10 mg daily in benzyl benzoate-castor oil) treated for 1, 2, 3, 4, and 5 weeks duration; 13. Castrated newborns killed as adults, and 14. Castrated new borns killed as adults, after daily injections of 1.25 mg of testosterone for 5 weeks.Following decapitation the adenohypophyses were rapidly removed and fixed in 0.2M phosphate buffered Acrolein-Glutaraldehyde- Paraformaldehyde, postfixed in osmium tetroxide, stained en bloc with 2% uranyl acetate, and embedded in araldite-epon. Lead citrate stained sections were examined in RCA EMU-3c and RCA EMU-4b electron microscopes.

Cellular Contacts Within the Interhemal Membrane of the Rat Placenta at Term

1974 ◽  
Vol 32 ◽  
pp. 146-147
Author(s):  
William P. Jollie
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Capillary Endothelium ◽  
En Bloc ◽  
Aldehyde Fixation ◽  
Chorioallantoic Placenta

By routine EM preparative techniques, the tissues which, collectively, separate maternal and fetal bloods in the fully formed chorioallantoic placenta of the rat have been shown to consist of three chorionic layers, or trophoblast, and a layer of allantoic capillary endothelium [Fig. 1]. Relationships between these layers are best demonstrated by special techniques, viz., cacodylate-buffered aldehyde fixation, collidine-buffered osmium tetroxide postfixation, and en bloc staining with uranyl acetate. By using this method on placentas at term, the cells of the outermost chorionic layer (Trophoblast 1) appear to be attached to each other by means of maculae adherentes which sometimes occur in clusters [Fig. 2].

Ultrastructural comparison of prolactin adenomas of pituitary in men and women

1988 ◽  
Vol 46 ◽  
pp. 346-347
Author(s):  
R.C. Caughey ◽  
U.P. Kalyan-Raman
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Phosphate Buffer ◽  
Pituitary Adenomas ◽  
Osmium Tetroxide ◽  
Secretory Granules ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Men And Women ◽  
Transmission Electron

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.

scholarly journals Potassium permanganate is an excellent alternative to osmium tetroxide in freeze-substitution

2022 ◽  
Author(s):  
Martin Schauflinger ◽  
Tim Bergner ◽  
Gregor Neusser ◽  
Christine Kranz ◽  
Clarissa Read
Keyword(s):  
High Pressure ◽  
Potassium Permanganate ◽  
Lipid Membranes ◽  
Osmium Tetroxide ◽  
Freeze Substitution ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Block Face ◽  
Critical Aspects

AbstractHigh-pressure freezing followed by freeze-substitution is a valuable method for ultrastructural analyses of resin-embedded biological samples. The visualization of lipid membranes is one of the most critical aspects of any ultrastructural study and can be especially challenging in high-pressure frozen specimens. Historically, osmium tetroxide has been the preferred fixative and staining agent for lipid-containing structures in freeze-substitution solutions. However, osmium tetroxide is not only a rare and expensive material, but also volatile and toxic. Here, we introduce the use of a combination of potassium permanganate, uranyl acetate, and water in acetone as complementing reagents during the freeze-substitution process. This mix imparts an intense en bloc stain to cellular ultrastructure and membranes, which makes poststaining superfluous and is well suited for block-face imaging. Thus, potassium permanganate can effectively replace osmium tetroxide in the freeze-substitution solution without sacrificing the quality of ultrastructural preservation.

Nonspecific structures seen in diagnostic muscle biopsies

1987 ◽  
Vol 45 ◽  
pp. 846-847
Author(s):  
R. C. Caughey ◽  
U. P. Kalyan-Raman
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Osmium Tetroxide ◽  
Clinical History ◽  
Uranyl Acetate ◽  
Ethanol Dehydration ◽  
Tubular Aggregates ◽  
En Bloc ◽  
Transmission Electron ◽  
Muscle Biopsies

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.

Electron Microscopy as an aid to diagnosis in pediatric hematology/oncology

1989 ◽  
Vol 47 ◽  
pp. 1062-1063
Author(s):  
K. L. Saving ◽  
R. C. Caughey
Keyword(s):  
Electron Microscopy ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Thin Sections ◽  
Megakaryoblastic Leukemia ◽  
Pediatric Hematology ◽  
Transmission Electron ◽  
Microscopy Techniques

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.

Centromeric heterochromatin in phyllotis darwini

1978 ◽  
Vol 36 (2) ◽  
pp. 216-217
Author(s):  
Couve M. Eduardo
Keyword(s):  
Osmium Tetroxide ◽  
Diploid Number ◽  
Centric Fusion ◽  
Uranyl Acetate ◽  
Centromeric Heterochromatin ◽  
Seminiferous Tubules ◽  
Natural Region ◽  
Chromosomal Change ◽  
Cacodylate Buffer ◽  
Electron Microscopes

Centric fusion plays an important role in karyotype evolution as a mechanism of chromosomal change. Centromeric Heterchromatic regions (CeHR) can be observed in optical and electron microscopes and their location during meiotic stages should be fundamental for the occurrence of centric fusion.This work is concerned with centromeric he terochromatin orientation and cytochemistry of this structure in meiotic male cells of Phyllotis darwini rupestris, obtained from their natural region. This is a Chilean species with diploid number 38, all chromosomes biarmed (meta- and submetacentric). Heterochromatin is always located in the centromere region, except the Y chromosome.Spreads for light microscopy were made from testicular tissues and stained with Arrighi and Hsu (1971) procedure. For electron microscope pieces of seminiferous tubules were fixed in glutaraldehyde 3% in 0.2M cacodylate buffer pH 7.2 and postfixed in osmium tetroxide 1%. Tissue was stained in block with 5% uranyl acetate, dehydrated in ethanol and embedded in Epon 812.

Fine Structure of Oogenesis in the Snail Tarebia Granifera (Melaniidae)

1977 ◽  
Vol 35 ◽  
pp. 610-611
Author(s):  
Michael T. Matthes ◽  
Robert V. Blystone
Keyword(s):  
Osmium Tetroxide ◽  
Ovarian Tissue ◽  
Uranyl Acetate ◽  
Early Prophase ◽  
Sodium Cacodylate ◽  
En Bloc ◽  
Late Prophase ◽  
Ovarian Wall ◽  
Fresh Water Snail ◽  
Tarebia Granifera

The ovary of the fresh-water snail, Tarebia granifera, is found in the caudal upper whorls of the shell. Careful dissection was required to separate the ovary from the digestive gland which shared a common epithelial covering with the ovary. The ovarian tissue was fixed in sodium cacodylate buffered 3% glutaraldehyde, post-fixed in 1% osmium tetroxide, en bloc stained with 0.5% uranyl acetate, dehydrated, and embedded in Epon-Araldite plastic.This study indicated that oocytes of T. granifera were found only in prophase stages of maturation along the length of the ovarian tube. A similar observation has been documented for the closely related snail Melanoides. The T. granifera oocytes were situated in the ovary in such a way that the immature early prophase oocytes were found near the outer ovarian wall and the more mature late prophase oocytes were seen developing toward the center of the ovarian tubular structure.

Uranyl Acetate as a Fixative—from pH 2.0 to 8.0

1971 ◽  
Vol 29 ◽  
pp. 490-491
Author(s):  
V. R. Mumaw ◽  
B. L. Munger
Keyword(s):  
Electron Microscopy ◽  
Oxalic Acid ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Tissue Sections ◽  
Normal Rat ◽  
Lead Hydroxide ◽  
Ultrathin Sections ◽  
Rat Tissue

Numerous applications utilizing uranyl acetate as an electron stain for electron microscopy have been described. Uranyl acetate has become a routine stain used in conjunction with lead hydroxide for staining ultrathin sections. En bloc staining with uranyl acetate following osmium tetroxide post-fixation produces undesirable effects on some cytoplasmic components, especially glycogen. Recent studies using uranyl acetate as a fixative and en bloc stain at pH 7.2 before osmification has shown uranyl acetate to have desirable fixation and staining qualities. Tissues treated with uranyl acetate at a pH of 2.0-8.0 were studied. Normal rat tissue was fixed in Karnovsky's paraformaldehyde-glutaraldehyde fixative. The tissue was post-fixed in 0.5% uranyl acetate in water at pH 2.0 and 0.5% uranyl acetate in 0.1M s-collidine with 0.01M oxalic acid at pH 4, pH 6.0, pH 7.2, and pH 8.0 for 1 hour at 4°C. Following several rinses of 0.1M s-collidine buffer, the tissues were treated with 1.33% osmium tetroxide 1 hour at 4°C followed by rapid dehydration in ethanol and embedded in Durcupan ACM. Tissue sections were stained with lead hydroxide.

Specialized Junctions of the Intercalated Disc of the Active and Hibernating Bat Heart

1972 ◽  
Vol 30 ◽  
pp. 26-27
Author(s):  
Martin Hagopian
Keyword(s):  
Osmium Tetroxide ◽  
Natural Habitat ◽  
Muscle Cells ◽  
Uranyl Acetate ◽  
Myotis Lucifugus ◽  
Intercalated Disc ◽  
En Bloc ◽  
Intercalated Discs ◽  
End To End

Active bats, Myotis lucifugus, were caught in October, and hibernating bats were caught in January from their natural habitat. Left ventricles were fixed in 6.25% cacodylate buffered gluturaldehyde, washed in buffer, and postfixed in 1% osmium tetroxide. Some tissue in each group was stained en bloc with uranyl acetate, dehydrated, and embedded in Araldite or Epon.The muscle cells of the bat heart are approximately cylindrical in shape and are connected with one another end-to-end at the intercalated discs. Occasionally the cardiocytes are connected along the lateral surfaces. In general the intercalated disc is composed of transverse and longitudinal segments.

Ultrastructural Characteristics of Vaginal Epithelium of Persistent Estrous Rats

1985 ◽  
Vol 43 ◽  
pp. 658-659
Author(s):  
Khosho Francis K. ◽  
Kaufmann Robert C. ◽  
Amankwah Kofi S.
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Ruthenium Red ◽  
Female Rats ◽  
Constant Light ◽  
Ultrastructural Changes ◽  
Vaginal Smears ◽  
Thin Sections ◽  
Cacodylate Buffer ◽  
Ultrastructural Characteristics

Adult female rats exposed to constant light will develop anovulatory acyclicity characterized by persistent vaginal cornification (PE) and formation of multiple large cystic follicles on the ovaries. The purpose of the present communication is to describe the ultrastructural changes in vaginal epithelia in PE rats as compared to that in normal estrous rats.Persistent vaginal estrous with PCO was induced in a group of Sprague-Dawely rats by exposure to constant light for 50-150 days. Rats in normal estrous, as determined by vaginal smears, were used as controls. Nembutal- anethesized rats were perfused through the aorta with 2.5% gluteraldehyde in 1M sodium cacodylate buffer (pH 7.3). The mucosa of the vaginal folds just inferior to the cervix were dissected by microsurgery, postfixed, stained with 0.5% ruthenium red in 1% osmium tetroxide, dehydrated, and embedded in polybed. Thick sections (1μ) were stained with toludine blue for light microscopy studies. Thin sections were stained with uranyl acetate and lead citrate.

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