Ultrastructural study of pulmonary endothelium in mouse model of the IL-2-induced vascuiar leak syndrome

1989 ◽  
Vol 47 ◽  
pp. 1078-1079
Author(s):  
T. M. Valentine ◽  
T. D. Anderson
Keyword(s):  
New York ◽  
Mouse Model ◽  
Pulmonary Edema ◽  
Osmium Tetroxide ◽  
Interleukin 2 ◽  
Left Lung ◽  
Uranyl Acetate ◽  
Ultrastructural Changes ◽  
Pulmonary Endothelium ◽  
Ultrathin Sections

Interleukin-2 is being evaluated in cancer immunotherapy in people. rIL-2 is associated with vascular leak syndrome (VLS) characterized by peripheral edema, ascites and pulmonary edema. The histopathologic changes associated with rIL-2 administration have been described in mouse models, however, the ultrastructural changes in VLS are undefined. In these studies we have utilized a mouse model of VLS to characterize the pulmonary ultrastructural changes which are associated with pulmonary edema.B6D2F1 (BDF) mice, (3M/3F/groups) from Charles River Lab., New York, were treated intraperitoneally for five days with vehicle for rIL-2 or with 30,000 U/gm rIL-2, BID as previously described. At necropsy, lungs were fixed by intratracheally at perfusion pressure of 30cm of H2O with modified Karnovskys fixative diluted with 0.2M sodium caccdylate buffer, ph7.4, for 24 hours. Transverse sections of the left lung (1mm thick) were post-fixed in osmium tetroxide (2hrs) and processed for electron microscopy. Ultrathin sections were stained with uranyl acetate and lead citrate and examined in a Philips 300 electron microscope.

Ultrastructural Changes in the Root Meristem Cells of Rubus Chamaemorus L. (Cloudberry)

1975 ◽  
Vol 33 ◽  
pp. 562-563
Author(s):  
Arya K. Bal
Keyword(s):  
Root Meristem ◽  
Uranyl Acetate ◽  
Particulate Material ◽  
Ultrastructural Changes ◽  
Cell Organelles ◽  
Cytoplasmic Matrix ◽  
Golgi Membranes ◽  
Rubus Chamaemorus ◽  
Dense Substance ◽  
Ultrathin Sections

In the course of studies in the root meristem tissue of Rubus chamaemorus L. some important changes in the ultrastructural morphology were observed during the initiation of senescence at the end of the growing season.Root meristems were collected from naturally growing healthy populations of Cloudberry plants, and fixed in Karnovsky's mixture or in 2.5% glutaraldehyde in phosphate buffer. The samples were osmicated, dehydrated following usual methods and embedded in Epon. Ultrathin sections were stained in uranyl acetate and lead citrate.Figure 1 shows part of a dense cell in the meristem. The electron density of these cells is due to large amounts of a particulate material in the cytoplasmic matrix. The smallest particle seen in electron micrographs is about 40 A, although larger aggregates are also found, which remain randomly distributed in association with various cell organelles. Dense substance has been found associated with golgi membranes, proplastids, vacuoles and microtubules (Fig. 2).

The Identification of Phospholipid Micelles in Glutaraldehyde-Urea Embedded Tissue

1975 ◽  
Vol 33 ◽  
pp. 494-495
Author(s):  
Daniel C. Pease
Keyword(s):  
Electron Micrographs ◽  
Lung Tissue ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Type Ii ◽  
Lead Citrate ◽  
Phospholipid Micelles ◽  
Type Ii Pneumocytes ◽  
Ultrathin Sections ◽  
Polar Water

It is reasonable to think that phospholipid micelles should be visible and identifiable in electron micrographs of ultrathin sections if only they can be preserved throughout the embedding process. The development of highly polar, water-containing, aminoplastic embedments has made this a likely possibility. With this in mind, an investigation of the lecithin-secreting, Type II pneumocytes of the lung is underway.Initially it has been easiest to recognize phospholipid micelles in lung tissue fixed first with glutaraldehyde, and then secondarily exposed to osmium tetroxide. However, the latter is not a necessary concomitant for micellar preservation. Conventional uranyl acetate and lead citrate staining is finally applied. Importantly, though, the micelles have been most easily seen in tissue embedded in 507. glutaraldehyde polymerized with urea, as described in detail by D.C. Pease and R.G. Peterson (J. Ultra- struct. Res., 41, 133, 1972). When oriented appropriately, the micellar units are seen as tiny, bilayer plates.

Myocardial Alterations in Animals Following High Altitude Exposure

1968 ◽  
Vol 26 ◽  
pp. 114-115
Author(s):  
M. B. Bischoff ◽  
W. D. Dean ◽  
T. J. Bucci ◽  
L . A. Frics
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular ◽  
High Altitude ◽  
Sea Level ◽  
Osmium Tetroxide ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Heart Weight ◽  
Morphological Evidence ◽  
Ultrathin Sections

There is a paucity of morphological evidence, particularly at the ultrastructural level, to correlate with tile physiological effects of chronic exposure to high altitude. In this study the myocardium of dogs and rabbits subjected to five months exposure at an altitude of 14,110 feet was compared to that of animals residing at sea level. The animals kept at 14,110 feet were shipped from sea level (160 feet) witnout acclimatization at intermediate altitudes.The physiological parameters including the hematologic changes, pulmonary artery pressures, pulmonary artery oxygen saturations, electrocardiograph changes, right ventricular weight to body weight and right ventricular weight to total heart weight ratios observed in these animals have been reported previously.The animals were necropsied at the end of the five months. The myocardium was quickly removed, cut into small pieces and immersed in 1% osmium tetroxide buffered with veronal acetate. Following fixation the tissues were dehydrated in ascending ethanol concentrations followed by propylene oxide and embedded in Epon 812. Ultrathin sections were doubly stained in uranyl acetate and lead citrate.

Permeability in the Blood-Brain Barrier in Monkeys Following Exposure to High Altitude

1971 ◽  
Vol 29 ◽  
pp. 328-329
Author(s):  
R.S. Demaree ◽  
L.J. Ackerman ◽  
D. L. Anderson
Keyword(s):  
Electron Microscopy ◽  
Cerebral Edema ◽  
Osmium Tetroxide ◽  
Acute Mountain Sickness ◽  
Cebus Apella ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Limited Evidence ◽  
Ultrathin Sections ◽  
Mountain Sickness

People who rapidly ascend to high terrestrial elevations may experience the “acute mountain sickness” syndrome. Speculation and limited evidence suggest that cerebral edema may play an important role in initiating and perpetuating this condition. We have recently demonstrated by electron microscopy that a mild cerebral edema develops in some Cebus apella monkeys rapidly transported to 14,110 feet. In the present study, Cebus apella monkeys were terminated at 1, 3, or 5 days after being shipped from sea level (160 feet) to 14,110 feet without acclimatization at intermediate altitudes.Thorotrast was administered IV 30 minutes prior to termination by perfusion or guillotine. Cerebral cortex was fixed by either perfusion or immersion in glutaraldehyde, and postfixed in osmium tetroxide. Following fixation, the tissues were dehydrated in ascending concentrations of ethanol followed by propylene oxide and embedded in Epon 812. Ultrathin sections were either not stained or doubly stained with uranyl acetate and lead citrate.

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.

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.

Ultrastructure of Angiosarcoma of Mouse Tail

1980 ◽  
Vol 38 ◽  
pp. 740-741
Author(s):  
White Yvonne ◽  
Winslow Sheldon ◽  
James W. Townsend ◽  
Neil A. Littlefield
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Toluidine Blue ◽  
Female Mouse ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Ultrathin Sections ◽  
Resin Mixture

Spontaneous neoplasms rarely occur on the tails of BALB/cStCrlfC3H/Nctr mice, but the neoplasm most frequently observed is a locally invasive non-metastatic angiosarcoma. In this case a female mouse weighing 33.2 g, 706 days of age, presented a soft, red, irregularly-shaped mass, measuring 18 mm in its greatest dimension, in the subcutis of the base of the tail. A portion of the tail tumor was taken for electron microscopy and the remainder was processed for light microscopy. The tissue processed for electron microscopy was fixed in 4% cacodyl ate-buffered glutaraldehyde, post-fixed in 1% osmium tetroxide, dehydrated in a graded series of ethanol solutions, and embedded in Epon-Araldite resin mixture. Sections of 1 μm were stained with toluidine blue for light microscopy and ultrathin sections of 100 nm were stained with uranyl acetate and lead citrate, then examined with a Philips EM201 electron microscope .

scholarly journals HYDROXYPROPYL METHACRYLATE, A NEW WATER-MISCIBLE EMBEDDING MEDIUM FOR ELECTRON MICROSCOPY

1965 ◽  
Vol 26 (1) ◽  
pp. 137-155 ◽  
Author(s):  
Elizabeth H. Leduc ◽  
S. J. Holt
Keyword(s):  
Electron Microscopy ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Rat Tissues ◽  
Enzymatic Extraction ◽  
Hydroxypropyl Methacrylate ◽  
Ultrathin Sections ◽  
Heat Polymerization ◽  
Embedding Medium ◽  
Fasted Rats

Aldehyde-fixed rat tissues were variously dehydrated and impregnated in water-miscible 2-hydroxypropyl methacrylate (HPMA) containing 3 to 20 per cent water and 0.1 per cent α,α-azobisisobutyronitrile as catalyst for subsequent polymerization with ultraviolet light. Heat polymerization was also effective. Blocks of embedded tissue readily gave ultrathin sections, which required staining by uranyl acetate and/or lead stains to give adequate contrast for electron microscopy. The ultrastructure of pancreas, kidney, muscle, and intestine was well preserved by aldehyde fixation alone. Use of postfixation in osmium tetroxide or direct osmium tetroxide fixation was unsatisfactory. The fine structure of aldehyde-fixed liver from fasted rats was well preserved, whereas that from normal rats showed considerable disorganization and collapse, apparently because of extraction of glycogen during the embedding procedure. Enzymatic extraction of proteins by pepsin and of ribonucleic acid by ribonuclease after either formaldehyde or glutaraldehyde fixation was rapidly effected by direct treatment of ultrathin sections with solutions of the enzymes. In contrast, no digestion of chromatin by deoxyribonuclease could be detected. In spite of this present limitation, HPMA appears to have several advantages over earlier water-miscible embedding media for electron microscopy and to be particularly suitable for ultrastructural cytochemistry.

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.

Fine structure of human sperm entry into zona-free hamster oocyte

1978 ◽  
Vol 36 (2) ◽  
pp. 540-541
Author(s):  
C. Barros ◽  
J. González ◽  
E. Herrera ◽  
E. Bustos-Obregón
Keyword(s):  
Osmium Tetroxide ◽  
Human Sperm ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Human Spermatozoa ◽  
Low Viscosity ◽  
Cacodylate Buffer ◽  
Ultrathin Sections ◽  
Hamster Oocyte

Zona-free mammalian oocytes have been observed to fuse, under in vitro conditions, With non-homologous spermatozoa. Taking advantage of this heterologous gamete fusion, we designed a bioassay to test -by means of zona-free hamster oocytes- the fertile ability of human spermatozoa, from semen samples of patients attending an Infertility Clinic. To further validate our bioassay, which Was reported elsewhere, we studied the behavior of gamete membranes during fusion at the ultrastructural level.Zona-free hamster oocytes were mixed in vitro with human spermatozoa. At different times after the start of incubation, oocytes were fixed in 1% glutaraldehyde in 0. 25M cacodylate buffer pH 7. A and post-fixed in 196 osmium tetroxide. After dehydration in acetone, they were embedded in a low viscosity epoxy resin. Ultrathin sections were stained with uranyl acetate and lead citrate and examined with a Phillips 300 electron microscope.

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