Ultrastructural Changes in Oral Mucosa After Topical Application of Nicotine

1990 ◽  
Vol 48 (3) ◽  
pp. 232-233
Author(s):  
J.E. Laffoon ◽  
M.J. Kremer ◽  
C.A. Squier ◽  
C.A. Lesch
Keyword(s):  
Oral Mucosa ◽  
Osmium Tetroxide ◽  
Ultrastructural Changes ◽  
Epithelial Surface ◽  
Potential Health ◽  
Thin Sections ◽  
Transmission Electron ◽  
Attached Gingiva ◽  
Cacodylate Buffer ◽  
Phosphate Buffered Saline

The potential health risks involved with the use of smokeless tobacco have been well documented. This habit involves the placement of tobacco containing 0.2-8.0% nicotine directly on the oral mucosa. It is possible that such levels of nicotine may have a directly injurious effect; we have examined this using pig oral mucosa, which has a similar oral mucosa to that of man.Biopsies of porcine attached gingiva, buccal (B) and floor of mouth mucosa (FM) were incubated with either 2% or 6% nicotine in phosphate buffered saline (PBS) placed on the epithelial surface at 37°C for 1 or 2 hours. Controls were incubated with PBS at the same pH (7.5%) and osmolarity (450 milliosmoles) as the nicotine solution. The biopsies were prefixed in 2% paraformaldehyde, 2.5% glutaraldehyde, washed with cacodylate buffer, post fixed with 1% solution of osmium tetroxide in cacodylate buffer, dehydrated in graded alcohols, infiltrated, embedded and polymerized in Spurrs epoxy resin. Thin sections were prepared from all specimens and examined in the transmission electron microscope (TEM).

Ultrastructure of lymphatic endothelium

1989 ◽  
Vol 47 ◽  
pp. 924-925
Author(s):  
A. Singh ◽  
D.N. Ezeasor ◽  
N.K. Sidhu
Keyword(s):  
Osmium Tetroxide ◽  
Healthy Adult ◽  
West African ◽  
Lymphatic Endothelium ◽  
Vascular Perfusion ◽  
Thin Sections ◽  
Continuous Layer ◽  
Transmission Electron ◽  
Cacodylate Buffer ◽  
Flocculent Material

Recently, the lymphatics in the caprine hemal nodes have been described. The present study describes some ultrastructural features of the endothelium in the lymphatics of the goat hemal nodes.Hemal nodes located along the aorta, were collected from 15 clinically healthy, adult, West African dwarf goats. The tissues were fixed by either immersion or perfusion methods. For immersion fixation, the nodes were excised, and immersed temporarily in cold 2.5% glutaraldehyde in 0. IM cacodylate buffer, pH 7.3. After 5 min, the nodes were diced into 1-2 mm cubes and further fixed for 2 h in the same fixative. The par-aortic nodes were fixed by vascular perfusion. The two batches of tissues were post-fixed in 2% osmium tetroxide in cacodylate buffer, and further processing was done by conventional methods for transmission electron microscopy. The thin sections were examined and photographed in a Hitachi H-7000 electron microscope.The lymphatic wall comprised a continuous layer of fenestrated endothelial cells. The nuclei were oval and contained heterochromatin. The cytoplasm exhibited fenestrations that were closed by a membrane, and vesicular compartments bound on luminal and/or abluminal aspects by fenestrated membranes(Fig. 1). occasionally lymphocytes(Fig. 2) or erthyrocytes, most probably intransit, occupied these compartments. In material fixed by immersion, most of the vesicles contained flocculent material similar to that contained in the lumen(Fig. 3).

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.

TEM comparison of osmium vs osmium with potassium ferricyanide secondary fixatives and the impact of secondary fixative temperature on tissue preservation/contrast quality

1996 ◽  
Vol 54 ◽  
pp. 910-911
Author(s):  
J. W. Horn ◽  
B. J. Dovey-Hartman ◽  
V. P. Meador
Keyword(s):  
Osmium Tetroxide ◽  
Potassium Ferricyanide ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Microscopic Evaluation ◽  
Cacodylate Buffer ◽  
Transmission Electron Microscopic ◽  
Glutaraldehyde Solution ◽  
Temperature Impact ◽  
The Impact

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.

Observations of thick and thin sections in a field-emission SEM

1994 ◽  
Vol 52 ◽  
pp. 1018-1019
Author(s):  
W. P. Wergin ◽  
S. Roy ◽  
E. F. Erbe ◽  
C. A. Murphy ◽  
C. D. Pooley
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Chemical Fixation ◽  
Thin Sections ◽  
Transmission Electron ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

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.

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.

Hepatic cytoprotection in treatment of canine heartworm

1989 ◽  
Vol 47 ◽  
pp. 918-919
Author(s):  
D.L. Friesen ◽  
A. Singh ◽  
M.E. Hitt
Keyword(s):  
Electron Microscopy ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Light And Electron Microscopy ◽  
Ultrastructural Changes ◽  
Sample Treatment ◽  
Host Animal ◽  
Thin Sections ◽  
Canine Heartworm ◽  
Toxic Metabolites

Thiacetarsamide is an arsenic-containing drug used in the treatment of heartworm in dogs. The effective antihelmintic dose is toxic to the host animal. Acetylcysteine decreases the hepatotoxicity of some compounds by forming a conjugate with toxic metabolites of the compound. The purpose of this study was to evaluate the effectiveness of a cytoprotectant for hepatocytes in dogs treated with therapeutic levels of thiacetarsamide.Eighteen dogs were divided randomly into two groups. All dogs were given four doses of thiacetarsamide over two days. Nine dogs were given 10% acetylcysteine 15 min prior to each dose of thiacetarsamide. Needle biopsies of the liver were taken from each dog prior to the treatment and again one week post-treatment. The biopsies were fixed in 2% gluraraldehyde in phosphate buffer, pH 7.3, post-fixed in 1% osmium tetroxide, and processed for electron microscopy. Semithin and thin sections of the liver were examined by light and electron microscopy, respectively, for histopathologic and ultrastructural changes. The specimens were coded and the sample treatment was not known to the researchers at the time of observation.

The effect of 2,3,4-trimethylpentane on the ultrastructure of proximal tubular cells in primary cell culture

1989 ◽  
Vol 47 ◽  
pp. 1090-1091
Author(s):  
D.R. Mattie ◽  
J.J. Maslanka ◽  
N.J. Del Raso ◽  
M.R. Chase
Keyword(s):  
Proximal Tubule ◽  
Male Rat ◽  
Proximal Tubular Cells ◽  
Thin Sections ◽  
Proximal Tubule Cells ◽  
Tubular Cells ◽  
Transmission Electron ◽  
Cacodylate Buffer ◽  
Proximal Tubular ◽  
Tubule Cells

To aid in the assessment of the risk of Air Force personnel working with hydrocarbon fuels and compounds, an attempt was made to further characterize the nephropathy that results from exposure to hydrocarbons. The purpose of this study was to isolate and establish purified primary cultures of male rat proximal tubular cells suitable for experimental exposure to sublethal concentrations of solubilized 2,3, 4-trimethylpentane (TMP), a model hydrocarbon. Experiments were conducted to evaluate the cytotoxicity and metabolism of solubilized TMP in media containing or lacking the protein albumin.Proximal tubule cells in primary suspension culture were exposed to one of the following levels of TMP: 7.9, 12.0, 15.7, 19.1 or 25.5 mM. After 4 hours of exposure, pelleted cells were fixed for transmission electron microscopy by resuspension in 2% glutaraldehyde and 2.5% paraformaldehyde in 0.1M cacodylate buffer at pH 7.4. After a minimum fixation of at least 24 hours, the cells were post-fixed with 2% osmium tetroxide in 0,1M cacodylate buffer at pH 7.4. Cells were processed into Polybed 812 plastic capsules. Sections one micron thick, were cut in order to verify that cells were intact and suitable for thin sectioning. Thin sections (60- 90 nm) were cut on an ultramicrotome using a diamond knife. Thin sections, stained with uranyl acetate and lead citrate, were examined with a transmission electron microscope at 60 kV. Photographs of representative proximal tubule cells were taken at three levels of magnification.

The detection of P and Ca by X-ray microanalysis in the cyto-chemical reaction product of alkaline phosphatase in the epithelial surface of the rat duodenum

1978 ◽  
Vol 36 (2) ◽  
pp. 128-129
Author(s):  
Takashi Makita
Keyword(s):  
Alkaline Phosphatase ◽  
Lateral Wall ◽  
Transmission Electron Micrograph ◽  
Epithelial Surface ◽  
Fixed Tissue ◽  
Thin Sections ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Rat Duodenum

Alkaline phosphatase activity (ALP-ase) can be localized both over the brush border and on the lateral wall of the duodenal columnar epithelium. (Figs.1,2). Dense precipitate can also be observed on or in the mucus ‘bodies’present on the luminal surface. (Figs.3,4). In order to find out whether it is real phosphatase reaction product(lead phosphate) or not, unstained semi-thin sections (3-500 nm) of glutaraldehyde- fixed tissue, were subjected to X-ray microanalysis, after being incubated in an appropriate substrate medium (Mayahara's lead citrate method), post-fixed in buffered OsO4, and embedded in Spurr resin. A scanning transmission electron micrograph(STEM) was first taken at 25-50 kv(JEOL 50A SEM or 100 C TEM),after which the section was analysed by either a wavelength dispersive detector attached to the SEM or an energy dispersive type enfaced to the TEM at 40-60 kv.

Structure of agarose gels: Mean pore radius

1989 ◽  
Vol 47 ◽  
pp. 884-885
Author(s):  
Gary A. Griess ◽  
Philip Serwer
Keyword(s):  
Osmium Tetroxide ◽  
Pore Radius ◽  
Agarose Gel Electrophoresis ◽  
Gel Structure ◽  
Biophysical Characterization ◽  
Thin Sections ◽  
Agarose Gels ◽  
Transmission Electron ◽  
Self Consistent

To use an agarose gel's sieving for the biophysical characterization of macromolecules and supramolecular complexes, the effective gel's pore radius (PE) is determined as a function of the agarose percentage (A). In previous studies, performed by use of agarose gel electrophoresis, the sieving of spheres of known radius (R) was used, together with two different (unproven) theories of sieving, to obtain PE. The PE values obtained were self-consistent and independent of R. The PE vs. A relationship did not agree with that predicted by a model that represents the gel as straight, randomly-oriented fibers (random fiber model). To test the accuracy of both the empirical PE vs. A relationship and the previously assumed model of gel structure, in the present study thin sections of agarose gels have been examined by use of electron microscopy.Gels of the agarose previously used to quantify sieving (SeaKem LE, Marine Colloids) were cast in the buffer previously used: 0.025 M sodium phosphate, pH 7.4, 0.001M MgCl2. Pieces of gel were fixed with osmium tetroxide, dehydrated and embedded in Epon. Dark gold (120 nm) sections were examined with a JEM-100CX transmission electron microscope. Electron micrographs were captured with a DataTranslation QuickCapture video digitizer and were processed on a Macintosh II computer using the program, Image.4

Scanning and Transmission Electron Microscopy of Isolated Cells of Hydra littoralis

1972 ◽  
Vol 30 ◽  
pp. 160-161 ◽  
Author(s):  
Jane A. Westfall ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Osmium Tetroxide ◽  
Culture Medium ◽  
Sensory Cells ◽  
Isolated Cells ◽  
Sem And Tem ◽  
Transmission Electron ◽  
Cacodylate Buffer ◽  
Calcium And Magnesium Ions

Using scanning and transmission electron microscopy (SEM and TEM), we observed batteries of 20-30 nematocytes, cnidoblasts, sensory cells, and other neurons invaginated within epitheliomuscular cells of Hydra. In an attempt to determine how the cells were structurally interrelated, we isolated cells of Hydra littoralis for further study by SEM and TEM.To isolate cells, 30 Hydra littoralis were placed for 30 minutes in a P19 culture medium modified by omitting calcium and magnesium ions, adding 20% sucrose and stabilizing at pH 7.2 with sodium phosphate, then pipetted gently to free the epithelial cells from the mesoglea. Glutaraldehyde was added to make a 5% solution and the cells were fixed 1 hour at 0-4°C, centrifuged 10 minutes at 1000 X g, resuspended in cacodylate buffer twice, and placed 2 hours in 4% osmium tetroxide at 0-4°C.

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