Ultrastructural Characteristics of Vaginal Epithelium of Persistent Estrous Rats

Author(s):  
Khosho Francis K. ◽  
Kaufmann Robert C. ◽  
Amankwah Kofi S.

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.

Author(s):  
J.E. Laffoon ◽  
M.J. Kremer ◽  
C.A. Squier ◽  
C.A. Lesch

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).


Author(s):  
T. Shirahama ◽  
A. S. Cohen ◽  
O. G. Rodgers

Forty-micron nonfrozen sections of myocardium from several healthy young adult New Zealand white rabbits, without pretreatment or 10-15 minutes after an intravenous ferritin injection (100 mg ferritin/100 gm. body weight), were double fixed with 2% formaldehyde - 2.5% glutaraldehyde in 0.1M cacodylate buffer and 2% OSO4 in 0.1M cacodylate buffer in the presence of 1000, 100, 50 or 20 ppm ruthenium red (RR), and embedded in Epon. Thin sections of small blood vessels including capillaries, unstained or stained with uranyl acetate and/or lead citrate, were photographed at initial magnifications of 40,000 or 80,000. The results were analysed to delineate the ultrastructural relation of mucopolysaccharides (MPS) in the architecture of pinocytic vesicles and the MPS role in pinocytosis.


1978 ◽  
Vol 24 (2) ◽  
pp. 89-104 ◽  
Author(s):  
T. J. Beveridge

Purified cell walls of Bacillus subtilis were subjected to solutions of 40 independent metals and the metal uptake, the electron-scattering power of thin sections, and the type of staining response evaluated. This was repeated for six typical electron-microscopic stains (uranyl acetate, uranyl magnesium acetate, osmium tetroxide, Os-meth, osmium-dimethylethylenediamine, and ruthenium red) and one new staining reagent (a potassium platinum chloride – dimethylsulfoxide complex) whose specificity is for amine functions. The reaction of select metals can be specific in terms of both uptake and staining response. Of the metals studied most transition elements had a high affinity for the wall fabric and some (i.e., Sc III, most lanthanides, U IV, Zr IV, Hf IV, Fe III, Pd II, Ru III, and In III) may be suitable as contrasting agents for electron microscopy. Furthermore, when the thickness of metal-reacted walls was compared to freeze-each and ultracryotomy data, statistical-dimensional differences were commonly seen, which indicates that wall ultrastructure can be profoundly affected by the type of metal and (or) staining reagent.


Author(s):  
C.N. Sun ◽  
P. Morgan ◽  
W.R. Bowen

The causal agents of Legionnaires’ Disease and related respiratory ailments in humans are gram-negative rod-shaped bacterial species belonging to the newly recognized genus, Legionella. During a comparative study of the ultrastructural organization of the cell boundary in several species, additional information regarding the presence and nature of various appendages of the cell envelope in these bacteria was observed.Cultures of L. pneumophils (including several serogroups) and L. micdadei were grown on charcoal yeast extract agar with increased humidity at 37°C. Samples were removed after 5 days of growth and immediately fixed in either glutaraldehyde/ruthenium red (GA/RR) followed by osmium tetroxide/ruthenium red (OSO4/RR) or glutaraldehyde/tannic acid (GA/TA) followed by osmium tetroxide. Thin sections were stained with uranyl acetate and lead citrate.


Author(s):  
T. Guha ◽  
P.F. Prentis

Type A spermatogonia in tilapia (Oreochromis ni1oticus) have been studied by electron microscopy. These are stem cells from which spermatogenesis beings in this species. In this paper we report presence of two cytoplasmic organelles, annulate lamellae and nucleolus-like bodies (nuages), in type A spermatogonia in O. niloticus.Testes were fixed in 2% gluteraldehyde for 4 hrs. at 4°C and then in 1% osmium tetroxide for 1 hr. at 4°C, both in 0.1M cacodylate buffer (pH 7.4). Fixed tissues were processed in the conventional way for electron microscopy. Thin sections of tissues were stained by uranyl acetate and lead citrate. These were examined in a Carl Zeiss electron microscope operated at 40kV.Nucleolus-like bodies (nuages) have been reported in rat spermatocytes, early postimplantation rat embryos, fish and amphibian oocytes and guppy (fish) spermatogonia. Annulate lamellae have been found in fish spermatogonia and oocytes. Type A spermatogonia (Figs. 1,2,3,4) in O. niloticus show presence of nucleolus-like bodies (nuages) and annulate lamellae in the cytoplasm.


Author(s):  
Amankwah K.S. ◽  
A.D. Weberg ◽  
R.C. Kaufmann

Previous research has revealed that passive (involuntary inhalation) tobacco smoking during gestation can have adverse effects upon the developing fetus. These prior investigations did not concentrate on changes in fetal morphology. This study was undertaken to delineate fetal neural abnormalities at the ultrastructural level in mice pups exposed in utero to passive maternal smoking.Pregnant study animals, housed in a special chamber, were subjected to cigarette smoke daily from conception until delivery. Blood tests for determination of carbon monoxide levels were run at 15-18 days gestation. Sciatic nerve tissue from experimental and control animals were obtained following spontaneous delivery and fixed in 2.5% gluteraldehyde in 0.1M cacodylate buffer pH 7.3. The samples were post-fixed in osmium ferrocyanide (1:1 mixture of 1.5% aqueous OSO4 and 2.5% K4 Fe(CN)6). Following dehydration, the tissues were infiltrated with and embedded in Spurr. Sections were stained with uranyl acetate and lead citrate.


Author(s):  
C. N. Sun ◽  
C. Araoz ◽  
H. J. White

The ultrastructure of a cerebral primitive neuroectodermal tumor has been reported previously. In the present case, we will present some unusual previously unreported membranous structures and alterations in the cytoplasm and nucleus of the tumor cells.Specimens were cut into small pieces about 1 mm3 and immediately fixed in 4% glutaraldehyde in phosphate buffer for two hours, then post-fixed in 1% buffered osmium tetroxide for one hour. After dehydration, tissues were embedded in Epon 812. Thin sections were stained with uranyl acetate and lead citrate.In the cytoplasm of the tumor cells, we found paired cisternae (Fig. 1) and annulate lamellae (Fig. 2) noting that the annulate lamellae were sometimes associated with the outer nuclear envelope (Fig. 3). These membranous structures have been reported in other tumor cells. In our case, mitochondrial to nuclear envelope fusions were often noted (Fig. 4). Although this phenomenon was reported in an oncocytoma, their frequency in the present study is quite striking.


Author(s):  
M. Kessel ◽  
R. MacColl

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.


Author(s):  
Patricia L. Jansma

The presence of the membrane bound vesicles or blebs on the intestinal epithelial cells has been demonstrated in a variety of vertebrates such as chicks, piglets, hamsters, and humans. The only invertebrates shown to have these microvillar blebs are two species of f1ies. While investigating the digestive processes of the freshwater microcrustacean, Daphnia magna, the presence of these microvillar blebs was noticed.Daphnia magna fed in a suspension of axenically grown green alga, Chlamydomonas reinhardii for one hour were narcotized with CO2 saturated water. The intestinal tracts were excised in 2% glutaraldehyde in 0.2 M cacodyl ate buffer and then placed in fresh 2% glutaraldehyde for one hour. After rinsing in 0.1 M cacodylate buffer, the sample was postfixed in 2% OsO4, dehydrated with a graded ethanol series, infiltrated and embedded with Epon-Araldite. Thin sections were stained with uranyl acetate and Reynolds lead citrate before viewing with the Philips EM 200.


Author(s):  
C. N. Sun

Myoepithelial cells have been observed in the prostate, harderian, apocrine, exocrine sweat and mammary glands. Such cells and their numerous branching processes form basket-like structures around the glandular acini. Their shapes are quite different from structures seen either in spindleshaped smooth muscle cells or skeletal muscle cells. These myoepithelial cells lie on the epithelial side of the basement membrane in the glands. This presentation describes the ultrastructure of such myoepithelial cells which have been found also in the parotid gland carcinoma from a 45-year old patient.Specimens were cut into small pieces about 1 mm3 and immediately fixed in 4 percent glutaraldehyde in phosphate buffer for two hours, then post-fixed in 1 percent buffered osmium tetroxide for 1 hour. After dehydration, tissues were embedded in Epon 812. Thin sections were stained with uranyl acetate and lead citrate. Ultrastructurally, the pattern of each individual cell showed wide variations.


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