The fine structure of ascus development in Lasiobolus monascus (Pezizales)

1978 ◽  
Vol 56 (7) ◽  
pp. 862-872 ◽  
Author(s):  
James W. Kimbrough ◽  
Gerald L. Benny

Ultrastructural and cytochemical studies on the ascus of Lasiobolus monascus are presented. Apothecia in various stages of development were obtained in culture and prepared for both light and electron microscopic observations. Ultrathin sections for electron microscopic inspection were often treated with silver methenamine to enhance wall characteristics. Ascus development was followed from fertilization to maturity.In this species, the ascogonium enlarges after fertilization to become the ascus mother cell. Two pores are present in the young ascus, one connecting it to the antheridium and another between the ascus and stalk cell. The ultrastructural features of these pores in the young and maturing ascus are described. During ascus enlargement, as many as four wall layers are found when poststained with silver methenamine. Only two layers are clearly distinguishable when poststained with uranyl acetate and lead citrate. The apical zone of dehiscence is characterized by a distinct annular swelling which appears during early ascosporogenesis. By spore maturation, this swelling is not evident either at the light or electron microscopic level. Instead, there appear to be both physical and chemical changes in the area of dehiscence. The wall is distinctly thinner and much more electron transparent in the area of dehiscence when treated with silver methanamine.

1980 ◽  
Vol 28 (10) ◽  
pp. 1041-1049 ◽  
Author(s):  
H Takamiya ◽  
S Batsford ◽  
A Vogt

A method is described for performing postembedding staining of protein (immunoglobulin) antigen embedded in styrene-methacrylate resin. Fixation of specimens in a combination of 4% paraformaldehyde and 0.2% picric acid and washing in buffer containing 7% sucrose, followed by abrupt dehydration with absolute acetone in the cold preserved the antigenicity, although in a masked form. The masked antigenicity could be reexposed by treatment with nonspecific protease. Staining with fluorescent-, peroxidase-, or ferritin-labeled antibodies on semi- and ultrathin sections resulted in specific localization of the antigen. We applied this technique to the localization of rabbit immunoglobulin in specimens of renal tissue obtained from rats with anti-glomerular basement membrane nephritis; we also localized human IgG in a renal biopsy specimen. The prerequisites for recovery of antigenicity are such that preservation of tissue structure at the light microscopic level is good, but relatively poor at the electron microscopic level.


Author(s):  
P. W. Cole ◽  
R. M. Jamison

A spontaneously occurring, non-invasive mammary tumor was observed in a 7-month-old, non-lactating, random-bred Sprague-Dawley female rat. The tumor was located subcutaneously in the distal mammary line as a firmly encapsulated, lobated growth. The tumor was surgically removed and immersed in Clark's buffer containing 4% glutaraldehyde. (Later conventional histochemical studies revealed this tumor to be a relatively non-differentiated fibro-adenoma.) Exterior and interior portions of the tumor were excised and fixed separately. The tissues were cut into 1 mm cubes and fixed for 4 hours in 4% glutaraldehyde. The specimens were then washed 4 times in buffer and left overnight at 4°C in the buffer. The cubes were postfixed in 2% OsO4 for 2 hours, after which they were dehydrated in a graded series of ethanol. The specimens were then washed with 2 changes of propylene oxide and perfused with a 1:1 mixture of propylene oxide-Epon 812 for 1 hour. Next, the tissue cubes were embedded in a mixture of Epon 812, DDSA, NMA, and DMP 30. Polymerization was allowed to proceed sequentially at 37°C overnight, 45°C for 8 hours, and 60°C for 24 hours. Ultrathin sections were cut with the Porter-Blum MT-2B ultramicrotome equipped with a glass knife. Sections were picked up on copper grids and stained with saturated uranyl acetate and 0.2% lead citrate. Specimens were examined in the Philips 300 electron microscope at instrumental magnifications ranging from 3,000-20,000 times.


1991 ◽  
Vol 39 (4) ◽  
pp. 529-535 ◽  
Author(s):  
O Fukushima ◽  
C V Gay

Guanylyl imidodiphosphate (GMP-PNP) hydrolyzing enzyme activity as a means of detecting plasma membrane guanylate cyclase was demonstrated in osteoblasts of chicken tibial metaphysis using a lead citrate histochemical method at the electron microscopic level. Activity was not discerned in osteoclasts or osteocytes. The reaction product development was completely abolished when the sections were incubated with substrate-free or MnCl2-free medium. Guanylate-(beta, gamma-methylene) diphosphate (GMP-PCP) was a less effective substrate than GMP-PNP, and Mn++ was a stronger stimulator than Mg++. No reaction product was observed on the plasma membrane of osteoblasts when beta-glycerophosphate or p-nitrophenylphosphate was used as substrate instead of GMP-PNP. The results implicate guanylate cyclase as a significant effector of osteoblast regulation at the site of the plasma membrane.


Author(s):  
Kazuhito Yamaguchi ◽  
Kazuhiko Awaya

The lining cells in the cavernous body, which is a branch of the afferent branchial artery, of lamprey gills were studied with transmission (TEM) and scanning electron microscope (SEM).Adult and larval lampreys, Lampertra planeri, were used in this study. Lamprey gills removed after perfusion were fixed in 2 % glutaraldehyde/formaldehyde (pH 7. 4) for 1 hour and postfixed in 1 % osmic acid. For TEM, the gills were dehydrated in ethanol and embedded in epon 812. Ultrathin sections were doubly stained with uranyl acetate and lead citrate. For SEM, most of the gills were dehydrated in ethanol and isoamylacetate and cracked in liquid nitrogen. Some of the gills dehydrated were embedded in stylene monomer. Stylene embedded blocks were cracked with a hummer and dissolved in propylene oxide. All the specimens were dried in a critical point dryer and coated 100 Å thickness with gold-paladium.The cavernous body is composed of trabeculae, between which are blood spaces, the lacunae.


Author(s):  
A. L. Granett

Venturia inaequalis (Cke.) Wint. is the causal agent of scab,a worldwide disease of apples. There have been few electron microscopic investigations on any phase of this fungus. The studies reported herein were initiated to clarify some ultrastructural characteristics of ascospores and conidia.In the spring ascospores develop within perithecia on decaying apple leaves from the previous year. Either whole perithecia were teased from leaves, or ascospores were isolated from leaves in an air tunnel device. Conidia develop on living leaves, blossoms, and fruits. Infected leaves were sprayed with distilled water and these spores were collected and concentrated into a pellet by low speed centrifugation. Perithecia, ascospores, and conidia were fixed in glutaraldehyde and osmium tetroxide; ultrathin sections were stained with uranyl acetate and lead citrate.


Author(s):  
Zeng Xiang-Yuan ◽  
Chong Hang ◽  
Lian Wei ◽  
Zhang Ke-juing

Electron microscopic observation on ultrastructural characteristics of the capillary ofgiant panda was presented. The samples were taken from mesentery and another samples were taken from mucosa of intestine. They were fixed in 2.5% phosphatebuffered glutaraldehyde and 1% osmic acid, and dehydrated by graded series of acetone. Then they were embedded with Epon 812. For orientation under phasecontrast microscope, 0.5--1.0 u thick sections were prepared from the epoxyembedded material. After that, ultrathin sections (30-50) were taken with ultramicrotome LKB-V type and stained by uranyl acetate and lead citrate and examined under DXB2-12 Electron Microscope.Electron microscopic observation showed the capillary diameter in the mesentery microcirculation is larger and capillary wall is thin. The nucleus in endothelium was large and wasn't regular in the shape. Chromatin was loose in the nucleus. There was little plasma inthe endothelium and it looked loose. Organelles in the cytoplasm were little and vacuoles were more in endothelium. The distribution of plasma in the endothelium was different with endothelium of human body.


Author(s):  
E. N. Albert

Silver tetraphenylporphine sulfonate (Ag-TPPS) was synthesized in this laboratory and used as an electron dense stain for elastic tissue (Fig 1). The procedures for the synthesis of tetraphenylporphine sulfonate and the staining method for mature elastic tissue have been described previously.The fine structure of developing elastic tissue was observed in fetal and new born rat aorta using tetraphenylporphine sulfonate, phosphotungstic acid, uranyl acetate and lead citrate. The newly forming elastica consisted of two morphologically distinct components. These were a central amorphous and a peripheral fibrous. The ratio of the central amorphous and the peripheral fibrillar portion changed in favor of the former with increasing age.It was also observed that the staining properties of the two components were entirely different. The peripheral fibrous component stained with uranyl acetate and/or lead citrate while the central amorphous portion demonstrated no affinity for these stains. On the other hand, the central amorphous portion of developing elastic fibers stained vigorously with silver tetraphenylporphine sulfonate, while the fibrillar part did not (compare figs 2, 3, 4). Based upon the above observations it is proposed that developing elastica consists of two components that are morphologically and chemically different.


Author(s):  
K. Yoshida ◽  
F. Murata ◽  
S. Ohno ◽  
T. Nagata

IntroductionSeveral methods of mounting emulsion for radioautography at the electron microscopic level have been reported. From the viewpoint of quantitative radioautography, however, there are many critical problems in the procedure to produce radioautographs. For example, it is necessary to apply and develop emulsions in several experimental groups under an identical condition. Moreover, it is necessary to treat a lot of grids at the same time in the dark room for statistical analysis. Since the complicated process and technical difficulties in these procedures are inadequate to conduct a quantitative analysis of many radioautographs at once, many factors may bring about unexpected results. In order to improve these complicated procedures, a simplified dropping method for mass production of radioautographs under an identical condition was previously reported. However, this procedure was not completely satisfactory from the viewpoint of emulsion homogeneity. This paper reports another improved procedure employing wire loops.


Author(s):  
Kosuke Ueda ◽  
Hiroto Washida ◽  
Nakazo Watari

IntroductionHemoglobin crystals in the red blood cells were electronmicroscopically reported by Fawcett in the cat myocardium. In the human, Lessin revealed crystal-containing cells in the periphral blood of hemoglobin C disease patients. We found the hemoglobin crystals and its agglutination in the erythrocytes in the renal cortex of the human renal lithiasis, and these patients had no hematological abnormalities or other diseases out of the renal lithiasis. Hemoglobin crystals in the human erythrocytes were confirmed to be the first case in the kidney.Material and MethodsTen cases of the human renal biopsies were performed on the operations of the seven pyelolithotomies and three ureterolithotomies. The each specimens were primarily fixed in cacodylate buffered 3. 0% glutaraldehyde and post fixed in osmic acid, dehydrated in graded concentrations of ethanol, and then embedded in Epon 812. Ultrathin sections, cut on LKB microtome, were doubly stained with uranyl acetate and lead citrate.


Author(s):  
Roberta M. Bruck

An unusual structure in the cochlea is the spiral limbus; this periosteal tissue consists of stellate fibroblasts and collagenous fibers embedded in a translucent ground substance. The collagenous fibers are arranged in vertical columns (the auditory teeth of Haschke). Between the auditory teeth are interdental furrows in which the interdental cells are situated. These epithelial cells supposedly secrete the tectorial membrane.The fine structure of interdental cells in the rat was reported by Iurato (1962). Since the mouse appears to be different, a description of the fine structure of mouse interdental cells' is presented. Young adult C57BL/6J mice were perfused intervascularly with 1% paraformaldehyde/ 1.25% glutaraldehyde in .1M phosphate buffer (pH7.2-7.4). Intact cochlea were decalcified in .1M EDTA by the method of Baird (1967), postosmicated, dehydrated, and embedded in Araldite. Thin sections stained with uranyl acetate and lead citrate were examined in a Phillips EM-200 electron microscope.


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