scholarly journals Observations With the Electron Microscope of Myxoma Virus on Mosquito Mouthparts

1964 ◽  
Vol 17 (4) ◽  
pp. 903 ◽  
Author(s):  
BK Filshie
Keyword(s):  
Electron Microscope ◽  
Aedes Aegypti ◽  
Myxoma Virus ◽  
Virus Particles ◽  
Number Of Particles

The stylets of Aedes aegypti mosquitoes which have fed on rabbits infected with myxomat,osis have been examinod with the electron microscope. Virus particles were observed adhering to the mouthpa.rts. The means of attachment, the totol number of particles, and the distribution along the stylets are discussed.

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.

Chikungunya virus in salivary glands of Aedes aegypti (L.): an electron microscope study

1970 ◽  
Vol 16 (7) ◽  
pp. 581-586 ◽  
Author(s):  
H. G. Janzen ◽  
A. J. Rhodes ◽  
F. W. Doane
Keyword(s):  
Electron Microscope ◽  
Aedes Aegypti ◽  
Salivary Glands ◽  
Chikungunya Virus ◽  
Intercellular Spaces ◽  
Virus Suspension ◽  
Virus Particles ◽  
Enveloped Virus ◽  
Large Numbers ◽  
Cytoplasmic Vesicles

Aedes aegypti were infected with chikungunya virus by being fed on a blood–virus suspension poured over a sugar cube. The virus infection in the salivary glands was then studied with the electron microscope. In the proximal portion of the lateral lobes, 250–310 Å virus precursor particles were seen in the nucleus, in the cytoplasm, and on the membranes of cytoplasmic vesicles. Enveloped 500–580 Å virus particles with a 250–310 Å core were seen within the vesicles, in intercellular spaces, and in large numbers in the apical cavity and periductal space. In the distal portions of the lateral and median lobes precursor particles were present in the nucleus and cytoplasm, but no cytoplasmic vesicles were seen. Numerous enveloped virus particles were seen in the apical cavity and periductal space, and in the median lobe within the duct lumen as well. No evidence of virus replication was seen in the intermediate portion of the median lobe.In the distal portions, virus particles were frequently associated with a concentration of the secretory material. No other microscopically visible pathological changes were seen in the infected salivary glands.

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.

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.

Synthesis and characterization poly (2- formylpyrrole) (PFPy) by Acids catalysis and study of its particles size

2021 ◽  
Author(s):  
ahmad Al-Hamdan ◽  
Ahmad Al-Falah ◽  
Fawaz Al-Deric ◽  
Ibrahim Al-ghoraibi
Keyword(s):  
Electron Microscope ◽  
Hydrochloric Acid ◽  
Fine Powder ◽  
Polymer Structure ◽  
Spherical Particles ◽  
Morphological Properties ◽  
Synthesis And Characterization ◽  
Ft Ir ◽  
Scanning Electron ◽  
Number Of Particles

Abstract In this paper Poly (2-formyl pyrrole) (PFPy) was synthesized using hydrochloric acid as catalysis in alcohol. PFPy is green dark very fine powder. Then the polymer forms glass substrate in the reaction mixture. The resulting polymer was characterized by (FT/IR, EDX and XPS) to determine the polymer structure. The polymer was scanned by scanning electron microscope (SEM) and its film by AFM for its morphological properties. We found the polymer consisting of spherical particles with a rough surface (average diameters of 430 nm) and they formed clusters. We proposed a method for calculated particles size depending on the crystals size (by Scherrer equation) and percentage of crystallization of polymer from XRD. The average particles size is 336.7 nm. The particles size in this method may be closer to reality because the XRD includes a large number of particles and it not optional as SEM and AFM.

Electron Microscopic Study of the Graffi Virus in Bone Marrow of Leukemic Mice.

1966 ◽  
Vol 52 (1) ◽  
pp. 35-59 ◽  
Author(s):  
Natale Pennelli ◽  
Luciano Fiore-Donati ◽  
Luigi Chieco-Bianchi ◽  
Giuseppe Tridente
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Electron Microscopic ◽  
Virus Particles ◽  
Negative Stain ◽  
Cytoplasmic Vesicles ◽  
C57bl Mice ◽  
Ultrathin Sections ◽  
Number Of Particles ◽  
Marrow Cells

Bone marrow from C57BL mice with myeloid leukemia induced by Graffi virus has been studied with the electron microscope by ultrathin section and negative stain techniques. Virus particles were usually found in different types of bone marrow cells as well as in extracellular spaces. However, the highest number of particles in various stages of maturation was observed in the cytoplasm of megakaryocytes. Two main types of virus particle were found: the immature Al particle and the mature C particle. They were morphologically indistinguishable from other murine leukemogenic viruses. In partially purified preparations studied by negative staining, some of the particles which were not penetrated by PTA, frequently showed a tail-like structure of variable length. In ultrathin sections, particles were found to originate by budding from the cell membranes. Budding of particles was particularly evident in megakaryocytes and especially within the granules and cytoplasmic vesicles or in connection with the platelet demarcating membranes. The findings of a high number of virus particles in all stages of maturation in megakaryocytes together with a certain degree of megakaryocytosis observed in the bone marrow suggest that this type of cell is possibly one of the main source of production of the virus. A few particles resembling morphologically mycoplasma were detected within the cytoplasm of some immature bone marrow cells.

scholarly journals THE STRUCTURE OF ANTIGEN-ANTIBODY COMPLEXES

1963 ◽  
Vol 118 (3) ◽  
pp. 327-340 ◽  
Author(s):  
June Almeida ◽  
Bernhard Cinader ◽  
Allan Howatson
Keyword(s):  
Electron Microscope ◽  
Virus Particle ◽  
Cross Linking ◽  
Short Axis ◽  
Antibody Molecule ◽  
Virus Particles ◽  
Ring Structures ◽  
Antigenic Relation ◽  
Antigen Antibody ◽  
Beaded Appearance

Negatively stained aggregates of antigen (polyoma or verruca vulgaris virus) and antibody (from rabbit or goat) were examined in the electron microscope. The antibody molecules appeared as cylindrical rods (often, but not always, showing a beaded appearance) with a long axis of 250 to 270 A and a short axis of 35 to 40 A. The combining sites were at the opposite short ends of the antibody molecules separated by the length of 250 to 270 A of the antibody molecule. Aggregates of antigen and antibody showed regions of orderly arrangements and frequently ring structures of five or more linked virus particles. Sometimes a virus particle in the center of these ring structures was linked to the peripheral particles. In extreme antibody excess, cross-linking was only rarely observed and virus particles were surrounded by a dense aura of antibody molecules. The specificity of the two combining sites of most antibody molecules is identical. This was utilized to examine the antigenic relation between the normal (icosahedral) and aberrant forms of polyoma virus.

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