Postmortem changes of the gill lamellae of fish

Author(s):  
K. C. Liu

The fine structure of the gill lamellae of fish has been reported for several species. All of them consisted the same types of cells and showed the same characteristics. The structural change of the gill lamellae under natural condition, after death was not reported. This report is to present a study on that event.Gill filaments from cultured Anguilla japonica, Tilapia sp. and Chanos chanos, of marketing size, both fresh and dead for different length of time were studied. The samples were fixed with 3% glutaraldehyde and 1% osmic acid, dehydrated with ethanol, and embedded with Epon and Araldite mixture. Thin section were stained with uranyl acetate and lead citrate. Observations were made with a JEOL 100 CX electron microscpe at 60 KV.The gill lamella of all three species studied showed similar fine stuctural characteristics . They consisted a central raw of pillar cells which formed the blood lumen. A layer of epithelium covered the outer surface . There was a prominent layer of basal limina between those two types of cells (Fig. 1). The epithelium showed degeneration first. It disintegrated and ditached from the basal lamina, and formed debris.

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):  
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.


Author(s):  
Fadhil Al-Lami ◽  
R.G. Murray

Although the fine structure of the carotid body has been described in several recent reports, uncertainties remain, and the morphological effects of anoxia on the carotid body cells of the cat have never been reported. We have, therefore, studied the fine structure of the carotid body both in normal and severely anoxic cats, and to test the specificity of the effects, have compared them with the effects on adrenal medulla, kidney, and liver of the same animals. Carotid bodies of 50 normal and 15 severely anoxic cats (9% oxygen in nitrogen) were studied. Glutaraldehyde followed by OsO4 fixations, Epon 812 embedding, and uranyl acetate and lead citrate staining, were the technics employed.We have called the two types of glomus cells enclosed and enclosing cells. They correspond to those previously designated as chemoreceptor and sustentacular cells respectively (1). The enclosed cells forming the vast majority, are irregular in shape with many processes and occasional peripheral densities (Fig. 1).


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.


Author(s):  
Betty I. Roots

In teleosts the optic tectum is the major integrative centre in the brain. The cyto- and fibre architecture of the optic tectum have been studied extensively and a well-defined laminar pattern has been described. Here some aspects of the fine structure of the optic tectum of the goldfish, Carassius auratus, will be described and discussed. Goldfish which had been kept at a temperature of 15°C were fixed by perfusion with 2. 5% glutaraldehyde in a phosphate buffer. After fixation pieces of the optic tectum from both dorsal and ventral regions, cut so that their original orientation in the tectum could be determined by their shape, were removed. They were post-fixed in 1% osmium tetroxide in the same buffer for 1 1/2 h, dehydrated, stained in 2% uranyl acetate and embedded in epon. Sections were stained with lead citrate.Lining the ventrical is the ependyma consisting of epithelial-like cells which are 5. 4 μm in diameter, are ciliated, and joined by both desmosomes and tight junctions between their somata.


Author(s):  
I. M. Baccarini

The cytological ultrastructure of the oocyte in different vertebrates and in insects has been described. Additional information on this subject is the purpose of this report which describes the findings on the oocyte of the rat during the estrous cycle.Vaginal smears were taken daily from 27 inbred Wistar-Furth rats to determine stages of the cycle. The animals were sacrificed with anesthesia in proestrous, estrous and metestrous and the ovaries removed surgically. In each case one ovary was used for electron microscopy and the other for histochemical methods.The ovary for electron microscopy was placed immediately into cold 3% phosphate-buffered glutaraldehyde for 2 hours and then into 1% phosphate-buffered osmic acid for 2-3 hours. The tissue was embedded in Durcupan ACM (FLUKA). The sections were double stained with 50% alcoholic uranyl acetate solution and with lead citrate.


Author(s):  
W.W.K. Cheung ◽  
J.B. Wang

The lantern bug harbours three symbionts, namely a, x and i in its body. These microorganisms are supposed to be transmitted transovarially to the future progeny. The x-symbionts are found in a special pair of organs called the x-organ which bulges to form a rectal organ in adult females. The purpose of this study is to investigate into the fine structure of the x-symbionts. This will serve as a basis for understanding the interactions of this microorganism with its host.The rectum of the lantern bug Pyrops candelaria Linn, was dissected out in buffered insect saline and fixed in 2.5% glutaradehyde in 0.1M sodium cacodylate buffer (pH 7.2) for 1 hr. The rectal organ was subsequently post-fixed in 1% osmium tetroxide (pH 7.2) and dehydrated in alcohol/acetone series. These were blocked in Spurr resin and cut with a Reichert Ultratome. Sections were stained with uranyl acetate and lead citrate and examined with a JEOL JEM-1200EX electron microscope. Thick sections (1 μn) were stained with 1% toluidine blue and examined under a Nikon Optiphot light microscope.


Author(s):  
A. Julio Martinez ◽  
Richard J. Duma ◽  
Doris G. Fultz ◽  
Ruth B. Finley

Ultrastructural components of trophozoites and cysts of Acanthamoeba-Hartmannella (A-H) and Naegleria amebas have been investigated. The present report describes a technique to study the morphological features of such protozoa.The A-H strains selected were cultured for 7 days in axenic amebic media, and the Naegleria strains were cultured for 7 days in axenic media with blood. In situ fixation was accomplished by adding an equal volume of 4% Osmic Acid in Cacodylate buffer at 4¶C for one hour. Following frequent agitation, the tubes were then spun at 2500 RPM for 10 minutes to obtain a pellet. The pellets were dehydrated in graded series of alcohols (from 50% to absolute) and propylene oxide and then embedded in EPON. One micron sections were stained with Paragon (PS 1301) for thirty seconds. Thin sections were cut with a diamond knife, double stained with 5% alcoholic uranyl acetate solution and lead citrate and observed in an Hitachi-HS-8F2 electron microscope.


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):  
K.K. Sekhri ◽  
C.S. Alexander ◽  
H.T. Nagasawa ◽  
R.F. Derr

Several reports have appeared in the literature implicating cobalt in the etiology of the so called "Beer-drinker's cardiomyopathy". Cobalt is also known to induce skeletal and cardiac neoplasms in the rat and "cobalt heart disease" in the rabbit. To elucidate the effects of cobalt on the ultrastructure of liver and heart, six rabbits were injected subcutaneously with 2.5% of cobaltous chloride in doses of 2.5 mg/kg/24 hour for nine days and 25 mg/kg/24 hour for an additional four days. Two rabbits which served as controls received an equivalent dose of 2.2% sodium chloride solution. Tissues were fixed in 2.5% cacodylate buffered glutaraldehyde, post-fixed in 2% osmic acid and embedded in Epon-araldite. Sections were stained with lead citrate and uranyl acetate and examined under an RCA EMU4 microscope.


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