scholarly journals INTRACELLULAR FORMS OF POX VIRUSES AS SHOWN BY THE ELECTRON MICROSCOPE (VACCINIA, ECTROMELIA, MOLLUSCUM CONTAGIOSUM)

1953 ◽  
Vol 98 (2) ◽  
pp. 157-172 ◽  
Author(s):  
William H. Gaylord ◽  
Joseph L. Melnick
Keyword(s):  
Electron Microscope ◽  
Hollow Spheres ◽  
Molluscum Contagiosum ◽  
Dense Granule ◽  
Homogeneous Material ◽  
Dense Matrix ◽  
Thin Sections ◽  
Virus Particles ◽  
Typical Inclusion ◽  
Mature Virus

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.

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
Keyword(s):  
Electron Microscope ◽  
Tumor Cells ◽  
Inclusion Bodies ◽  
Hollow Spheres ◽  
Virus Multiplication ◽  
Leopard Frog ◽  
Uniform Size ◽  
Thin Sections ◽  
Virus Particles ◽  
Renal Adenocarcinoma

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.

A note on the electron microscopy of the turnip yellow mosaic virus

Parasitology ◽  
1953 ◽  
Vol 43 (3-4) ◽  
pp. 191-192 ◽  
Author(s):  
Kenneth M. Smith
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Mosaic Virus ◽  
Chinese Cabbage ◽  
Hollow Spheres ◽  
Yellow Mosaic Virus ◽  
Turnip Yellow Mosaic Virus ◽  
Hollow Particles ◽  
Brassica Chinensis ◽  
Virus Particles

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.

scholarly journals AN ELECTRON MICROSCOPE STUDY OF THE DEVELOPMENT OF SV40 VIRUS

1963 ◽  
Vol 17 (2) ◽  
pp. 423-441 ◽  
Author(s):  
Nicole Granboulan ◽  
P. Tournier ◽  
R. Wicker ◽  
W. Bernhard
Keyword(s):  
Electron Microscope ◽  
Close Contact ◽  
Kidney Cells ◽  
Thin Sections ◽  
Sv40 Virus ◽  
Virus Particles ◽  
The Relationship ◽  
Infectious Cycle ◽  
Number Of Cells

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.

Further Observations on the Virus of Epizootic Diarrhea of Infant Mice. An Electron Microscopic Study

1967 ◽  
Vol 25 ◽  
pp. 110-111
Author(s):  
W. G. Banfield ◽  
G. Kasnic ◽  
J. H. Blackwell
Keyword(s):  
Electron Microscope ◽  
Infected Cell ◽  
Microscopic Study ◽  
Intestinal Epithelium ◽  
Ultrastructural Study ◽  
Osmium Tetroxide ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Virus Particles ◽  
Infected Cells

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.

Unusual Intranuclear Structures in Chick Sympathetic Neurons

1967 ◽  
Vol 25 ◽  
pp. 188-189
Author(s):  
E. B. Masurovsky ◽  
H. H. Benitez ◽  
M. R. Murray
Keyword(s):  
Electron Microscope ◽  
Sympathetic Neurons ◽  
Uranyl Acetate ◽  
Sympathetic Ganglia ◽  
Lead Citrate ◽  
Thin Sections ◽  
Cns Neurons ◽  
Mammalian Cns

Recent light- and electron microscope studies concerned with the effects of D2O on the development of chick sympathetic ganglia in long-term, organized culture revealed the presence of rod-like fibrillar formations, and associated granulofibrillar bodies, in the nuclei of control and deuterated neurons. Similar fibrillar formations have been reported in the nuclei of certain mammalian CNS neurons; however, related granulofibrillar bodies have not been previously described. Both kinds of intranuclear structures are observed in cultures fixed either in veronal acetate-buffered 2%OsO4 (pH 7. 4), or in 3.5% glutaraldehyde followed by post-osmication. Thin sections from such Epon-embedded cultures were stained with ethanolic uranyl acetate and basic lead citrate for viewing in the electron microscope.

Fine Structure of Interdental Cells in the Mouse Cochlea

1970 ◽  
Vol 28 ◽  
pp. 140-141
Author(s):  
Roberta M. Bruck
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Young Adult ◽  
Uranyl Acetate ◽  
Ground Substance ◽  
Tectorial Membrane ◽  
Lead Citrate ◽  
Unusual Structure ◽  
Thin Sections ◽  
Collagenous Fibers

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.

SEM Examination of a Used Diamond Knife

1971 ◽  
Vol 29 ◽  
pp. 452-453
Author(s):  
J. Temple Black
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
High Magnification ◽  
Metallic Materials ◽  
Wide Spread ◽  
Thin Sections ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron ◽  
Diamond Knife

Since its introduction by Fernandez-Moran, the diamond knife has gained wide spread usage as a common material for cutting of thin sections of biological and metallic materials into thin films for examination in the transmission electron microscope. With the development of high voltage E.M. and scanning transmission E.M., microtomy applications will become increasingly important in the preparation of specimens. For those who can afford it, the diamond knife will thus continue to be an important tool to accomplish this effort until a cheaper but equally strong and sharp tool is found to replace the diamond, glass not withstanding.In Figs. 1 thru 3, a first attempt was made to examine the edge of a used (β=45°) diamond knife by means of the scanning electron microscope. Because diamond is conductive, first examination was tried without any coating of the diamond. However, the contamination at the edge caused severe charging during imaging. Next, a thin layer of carbon was deposited but charging was still extensive at high magnification - high voltage settings. Finally, the knife was given a light coating of gold-palladium which eliminated the charging and allowed high magnification micrographs to be made with reasonable resolution.

Ultrastructure of Testicular Spermatozoon of the Fish Oreochromis Niloticus

1988 ◽  
Vol 46 ◽  
pp. 278-279
Author(s):  
T. Guha ◽  
A. Q. Siddiqui ◽  
P. F. Prentis
Keyword(s):  
Electron Microscope ◽  
Oreochromis Niloticus ◽  
Osmium Tetroxide ◽  
Sperm Cells ◽  
Adult Fish ◽  
Testicular Sperm ◽  
Thin Sections ◽  
Important Fish ◽  
Testicular Spermatozoon ◽  
Diamond Knife

Tilapia, Oreochromis niloticus, is an economically important fish in Saudi Arabia. Elucidation of reproductive biology of this species is necessary for successful breeding program. In this paper we describe fine structure of testicular sperm cells in O, niloticus.Testes from young adult fish were fixed in gluteraldehyde (2%) and osmium tetroxide (1%), both in cacodyl ate buffer. Specimens were processed in the conventional way for electron microscopy and thin sections of tissues (obtained by cutting the blocks with a diamond knife) were stained by ura- nyl acetate and lead citrate. These were examined in a Carl Zeiss electron microscope operated at 40 kV to 60 kV. Sperm cells were obtained from testes by squeezing them in cacodyl ate buffer. They were fixed in gluteraldehyde (2%) in the same buffer, air dried, gold coated and then examined in a Philips scanning electron microscope (SEM) operated at 25kV.The spermatozoon of O. niloticus is consisting of head, midpiece and tail (Fig. 1).

Electron Microscope Study of RNA's of Paramyxoviruses

1972 ◽  
Vol 30 ◽  
pp. 196-197
Author(s):  
Ruchama Baum ◽  
J.T. Seto
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Microscope Study ◽  
Sendai Virus ◽  
Sodium Dodecyl ◽  
Rna Molecules ◽  
Virus Particles ◽  
Molecular Weights ◽  
Length Measurements

The ribonucleic acid (RNA) of paramyxoviruses has been characterized by biochemical and physiochemical methods. However, paramyxovirus RNA molecules have not been studied by electron microscopy. The molecular weights of these single-stranded viral RNA molecules are not known as yet. Since electron microscopy has been found to be useful for the characterization of single-stranded RNA, this investigation was initiated to examine the morphology and length measurements of paramyxovirus RNA's.Sendai virus Z strain and Newcastle disease virus (NDV), Milano strain, were used. For these studies it was necessary to develop a method of extracting RNA molecules from purified virus particles. Highly purified Sendai virus was treated with pronase (300 μg/ml) at 37°C for 30 minutes and the RNA extracted by the sodium dodecyl sulfate (SDS)-phenol procedure.

Studies of a Defective Measles Virus

1968 ◽  
Vol 26 ◽  
pp. 208-209
Author(s):  
R. M. McCombs ◽  
M. Benyesh-Melnick ◽  
J. P. Brunschwig
Keyword(s):  
Inclusion Bodies ◽  
Measles Virus ◽  
Giant Cells ◽  
Helical Structures ◽  
Thin Sections ◽  
Virus Particles ◽  
Extracellular Virus ◽  
Culture Cells ◽  
Infected Cells ◽  
Eosinophilic Inclusions

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.

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