scholarly journals ELECTRON MICROSCOPE OBSERVATIONS ON INTRACELLULAR VIRUS-LIKE PARTICLES ASSOCIATED WITH THE CELLS OF THE LUCKÉ RENAL ADENOCARCINOMA

1956 ◽  
Vol 2 (6) ◽  
pp. 725-742 ◽  
Author(s):  
Don W. Fawcett

The common renal adenocarcinoma of the leopard frog was studied in thin sections with the electron microscope. Approximately a third of the tumors examined were found to contain spheroidal bodies of uniform size and distinctive morphology that are believed to be virus particles. These consist of hollow spheres (90 to 100 mµ) having a thick capsule and a dense inner body (35 to 40 mµ) that is eccentrically placed within the central cavity (70 to 80 mµ). Virus particles of this kind occur principally in the cytoplasm but occasionally they are also found in the nucleus and in the extracellular spaces of the tumor. The intranuclear inclusion bodies that are visible with the light microscope are largely comprised of hollow, spherical vesicles with thin limiting membranes. These are embedded in a finely granular matrix. A few of the thin walled vesicles contain a dense inner body like that of the cytoplasmic virus particles. This suggests that they may be immature virus particles. The inclusion bodies are believed to be formed in the course of virus multiplication but they usually contain very few mature virus particles. Bundles of dense filaments and peculiar vacuolar inclusions also occur in the cytoplasm of the tumor cells. These seem to be related in some way to the presence of virus but their origin and significance remain obscure. These findings are discussed in relation to previous work suggesting that the Lucké adenocarcinoma is caused by an organ-specific filtrable agent. It is concluded that the "virus particles" found in electron micrographs of the tumor cells may be the postulated tumor agent. On the other hand, the possibility remains that the particles described here are not those that are causally related to the tumors.

1953 ◽  
Vol 98 (2) ◽  
pp. 157-172 ◽  
Author(s):  
William H. Gaylord ◽  
Joseph L. Melnick

The intracellular development of three pox viruses has been studied with the electron microscope using thin sections of infected tissue. Cells infected with vaccinia, ectromelia, and molluscum contagiosum viruses all form developmental bodies preliminary to the production of mature virus. Developmental bodies, believed to be virus precursors, are round to oval, slightly larger than mature virus particles, less dense to electrons, and have a more varied morphology. It is suggested as a working hypothesis that the process of maturation of a virus particle takes place as follows. In the earliest form the developmental bodies appear as hollow spheres, imbedded in a very dense cytoplasmic mass constituting an inclusion body, or in a less dense matrix near the nucleus in cells without typical inclusion bodies. The spheres become filled with a homogeneous material of low electron density. A small, dense granule appears in each developmental body and grows in size at the expense of the low density material. Following growth of the granule, particles are found with the dimensions of mature virus and having complex internal structure resembling bars or dumbells. Mature virus is ovoid and very dense to electrons. An "empty" interior may be found within its thick walls.


Author(s):  
R. M. McCombs ◽  
M. Benyesh-Melnick ◽  
J. P. Brunschwig

Measles virus is an agent that is capable of replicating in a number of different culture cells and generally causes the formation of multinucleated giant cells. As a result of infection, virus is released from the cells into the culture fluids and reinfection can be initiated by this cell-free virus. The extracellular virus has been examined by negative staining with phosphotungstic acid and has been shown to be a rather pleomorphic particle with a diameter of about 140 mμ. However, no such virus particles have been detected in thin sections of the infected cells. Rather, the only virus-induced structures present in the giant cells are eosinophilic inclusions (intracytoplasmic or intranuclear). These inclusion bodies have been shown to contain helical structures, resembling the nucleocapsid observed in negatively stained preparations.


1965 ◽  
Vol 24 (1) ◽  
pp. 57-78 ◽  
Author(s):  
J. F. David-Ferreira ◽  
R. A. Manaker

Samples taken at different intervals of time from suspension cultures of the NCTC 1469 line of mouse liver—derived (ML) cells infected with a mouse hepatitis virus have been studied with the electron microscope. The experiments revealed that the viruses are incorporated into the cells by viropexis within 1 hour after being added to the culture. An increasing number of particles are found later inside dense cytoplasmic corpuscles similar to lysosomes. In the cytoplasm of the cells from the samples taken 7 hours after inoculation, two organized structures generally associated and never seen in the controls are observed: one consists of dense material arranged in a reticular disposition (reticular inclusion); the other is formed by small tubules organized in a complex pattern (tubular body). No evidence has been found concerning their origin. Their significance is discussed. With the progression of the infection a system of membrane-bounded tubules and cisternae is differentiated in the cytoplasm of the ML cells. In the lumen of these tubules or cisternae, which are occupied by a dense material, numerous virus particles are observed. The virus particles which originate in association with the limiting membranes of tubules and cisternae are released into their lumen by a "budding" process. The virus particles are 75 mµ in diameter and possess a nucleoid constituted of dense particles or rods limiting an electron transparent core. The virus limiting membrane is sometimes covered by an outer layer of a dense material. In the cells from the samples taken 14 to 20 hours after inoculation, larger zones of the cell cytoplasm are occupied by inclusion bodies formed by channels or cisternae with their lumens containing numerous virus particles. In the samples taken 20 hours or more after the inoculation numerous cells show evident signs of degeneration.


Parasitology ◽  
1953 ◽  
Vol 43 (3-4) ◽  
pp. 191-192 ◽  
Author(s):  
Kenneth M. Smith

An attempt to differentiate by means of the electron microscope between particles of the top and bottom components of the turnip yellow mosaic virus is described. Since the particles of the top component are thought to be hollow spheres, it might be expected that they would collapse after drying and thus throw a smaller shadow than the particles of the bottom component which are thought to have a more solid centre. No difference could be perceived between the two types of particle, so that the apparently hollow particles can withstand the effect of drying without collapsing.Sections were cut of leaves of Chinese cabbage (Brassica chinensis) and particles were observed inside the cells which could conceivably be virus particles.


1956 ◽  
Vol 2 (3) ◽  
pp. 301-306 ◽  
Author(s):  
Kenneth M. Smith

Thin sections have been cut of the virus particles from four types of insect virus diseases: cytoplasmic polyhedroses of lepidopterous larvae, a nuclear polyhedrosis of Tipula paludosa (Diptera), a granulosis from Melanchra persicariae (Lepidoptera), and a new virus disease without polyhedra from T. paludosa. The cytoplasmic polyhedral viruses are thought to have composite particles in some cases. The shape and enveloping membranes of the different virus particles are compared. In the new virus disease of T. paludosa some of the virus particles appear to be empty; inclusion bodies surrounded by complicated membranes are also demonstrated.


1963 ◽  
Vol 19 (3) ◽  
pp. 565-591 ◽  
Author(s):  
Seiichi Matsumoto

The cells of brains of 2- and 3-day old mice infected with street rabies virus were examined in the electron microscope. It was observed that characteristic rod-like or elongated particles were found within a "matrix" in the cytoplasm of nerve cells and of astrocytes. These rod-like particles can be separated into two types, on the basis of slightly different morphological features. One particle is 110 to 120 mµ wide and has double-membraned coats; the other is 120 to 130 mµ wide and is covered by a single limiting membrane. The former is closely associated with the endoplasmic reticulum. The biological relationship between the two types is unknown, but both types of particles are considered to be street rabies viruses because of their structural features. It is believed that segmentation and branching of elongated particles may play a role in virus multiplication. Negri bodies appear as dense round bodies containing various coarse structures but no virus particles.


1963 ◽  
Vol 17 (2) ◽  
pp. 423-441 ◽  
Author(s):  
Nicole Granboulan ◽  
P. Tournier ◽  
R. Wicker ◽  
W. Bernhard

Kidney cells, predominantly from Cercopithecus monkeys but also from baboons, were infected in vitro with the SV40 virus. The infectious cycle was studied with the electron microscope by means of thin sections of cells fixed from 3 hours up to 11 days after infection. The frequency of virus formation and various nuclear and cytoplasmic lesions in relation to the infection are described. The virus particles appear in the nucleus in close contact with the chromatin. In a small number of cells they have been observed as early as 10 to 12 hours after infection, but most often they appear 24 to 48 hours afterward. Their mean diameter is 33 mµ. They have no membrane and are frequently arranged as crystal-like structures. In addition to the appearance of virus, one observes various lesions in the nucleoplasm and particularly in the nucleolus, which shows an early hypertrophy and produces unusual, dense condensations in contact with the nucleolonema. The importance of these nucleolar lesions and the relationship between the SV40 virus and the polyoma, common wart, and Shope papilloma viruses are discussed.


Author(s):  
W. G. Banfield ◽  
G. Kasnic ◽  
J. H. Blackwell

An ultrastructural study of the intestinal epithelium of mice infected with the agent of epizootic diarrhea of infant mice (EDIM virus) was first performed by Adams and Kraft. We have extended their observations and have found developmental forms of the virus and associated structures not reported by them.Three-day-old NLM strain mice were infected with EDIM virus and killed 48 to 168 hours later. Specimens of bowel were fixed in glutaraldehyde, post fixed in osmium tetroxide and embedded in epon. Sections were stained with uranyl magnesium acetate followed by lead citrate and examined in an updated RCA EMU-3F electron microscope.The cells containing virus particles (infected) are at the tips of the villi and occur throughout the intestine from duodenum through colon. All developmental forms of the virus are present from 48 to 168 hours after infection. Figure 1 is of cells without virus particles and figure 2 is of an infected cell. The nucleus and cytoplasm of the infected cells appear clearer than the cells without virus particles.


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.


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