An intraerythrocytic virus and rickettsia of frogs from Algonquin Park, Ontario

1984 ◽  
Vol 62 (8) ◽  
pp. 1521-1524 ◽  
Author(s):  
Sherwin S. Desser ◽  
John R. Barta
Keyword(s):  
Electron Microscope ◽  
Rana Catesbeiana ◽  
Blood Parasites ◽  
Rana Clamitans ◽  
Virus Particles ◽  
Spherical Inclusions ◽  
Sphagnum Bog ◽  
Prokaryotic Microorganisms ◽  
Large Spherical

Two prokaryotic microorganisms were observed in the erythrocytes of frogs in a survey of blood parasites of six species of amphibians from a sphagnum bog adjacent to Lake Sasajewun, Algonquin Park, Ontario. A cytoplasmic virus was observed in 12 of 75 Rana catesbeiana and 1 of 75 Rana septentrionalis. The virus particles were hexagonal in section, measured 300–370 nm in diameter, and occurred in groups that were often surrounded by lamellar arrays of stacked membranes. Large spherical inclusions were seen in the erythrocytes of 2 of 57 Rana clamitans. In the electron microscope these inclusions were found to contain numerous rod-shaped prokaryotes which measured 1–1.7 μm × 200–300 nm. These organisms were ultrastructurally indistinguishable from rickettsiae.

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.

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.

Observation of dislocations in dynamically loaded Cu-SiO2

1986 ◽  
Vol 44 ◽  
pp. 424-425
Author(s):  
D. S. Pritchard
Keyword(s):  
Electron Microscope ◽  
Strain Rate ◽  
Single Crystal ◽  
Transmission Electron Microscope ◽  
Volume Fraction ◽  
Screw Dislocations ◽  
Spherical Inclusions ◽  
Transmission Electron ◽  
Crystal Dispersion ◽  
Strain Rate Loading

The effect of varying the strain rate loading conditions in compression on a copper single crystal dispersion-hardened with SiO2 particles has been examined. These particles appear as small spherical inclusions in the copper lattice and have a volume fraction of 0.6%. The structure of representative crystals was examined prior to any testing on a transmission electron microscope (TEM) to determine the nature of the dislocations initially present in the tested crystals. Only a few scattered edge and screw dislocations were viewed in those specimens.

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 AN ELECTRON MICROSCOPE STUDY OF THE DEVELOPMENT OF A MOUSE HEPATITIS VIRUS IN TISSUE CULTURE CELLS

1965 ◽  
Vol 24 (1) ◽  
pp. 57-78 ◽  
Author(s):  
J. F. David-Ferreira ◽  
R. A. Manaker
Keyword(s):  
Electron Microscope ◽  
Inclusion Bodies ◽  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Dense Material ◽  
Virus Particles ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Tubular Body ◽  
Number Of Particles

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.

An electron-microscope study of the structure of Domiati cheese

1973 ◽  
Vol 40 (1) ◽  
pp. 113-117 ◽  
Author(s):  
M. H. Abd El-Salam ◽  
Safinaz El-Shibiny
Keyword(s):  
Electron Microscope ◽  
Internal Structure ◽  
Microscopic Examination ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Electron Microscopic Examination ◽  
Spherical Particles ◽  
Electron Microscopic ◽  
Ultrathin Sections ◽  
Large Spherical

SummaryA technique is described for preparing ultrathin sections from cheese for electron-microscopic examination. The internal structure of fresh Domiati cheese was found to be composed of a framework of large, spherical casein aggregates held by bridges and enclosing fat.After pickling, the casein aggregates were partly disintegrated into small spherical particles forming a loose structure.

The Coccidia (Apicomplexa: Eimeriidae) of frogs from Algonquin Park, with descriptions of two new species

1989 ◽  
Vol 67 (7) ◽  
pp. 1686-1689 ◽  
Author(s):  
G. J. Chen ◽  
S. S. Desser
Keyword(s):  
New Species ◽  
Young Adult ◽  
Rana Catesbeiana ◽  
Polar Granule ◽  
Rana Sylvatica ◽  
Stieda Body ◽  
Rana Clamitans ◽  
Two New Species ◽  
Coccidian Parasites ◽  
Oocyst Residuum

During June and July of 1988, 264 amphibians from Algonquin Park, Ontario, were examined for eimeriid coccidian parasites; the species examined were Rana catesbeiana Shaw, Rana clamitans Latreille, Rana septentrionalis Baird, and Rana sylvatica LeConte. Two distinct types of oocysts were observed in the feces of the frogs. The highest prevalence of infection was recorded from young adult frogs and two new species of Eimeria are described from these animals. Oocysts of Eimeria algonquini n.sp. are spherical, 15.8 (14.5–16.1) μm in diameter, with a thin single-layered wall; micropyle and polar granule absent; large granular oocyst residuum present. Sporocysts banana-shaped, 19.5 (18.7–20.4) × 4.2 (3.8–4.6) μm with prominent granular residuum; Stieda body absent. Oocysts of Eimeria kermiti n.sp. are ovoid, 25.1 (24.7–26.6) × 19.5 (17.6–20.1) μm with thin single-layered wall; polar granule present; micropyle absent; large granular oocyst residuum present. Sporocysts ovoid, 9.9 (9.3–10.4) × 6.6 (6.0–7.1) μm with Stieda body and prominent granular residuum.

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