Expériences sur la nature de particules trouvées dans des cas d'hépatite virale: type coronavirus, antigène Australia et particules de Dane

1974 ◽  
Vol 20 (2) ◽  
pp. 193-203 ◽  
Author(s):  
H.-W. Ackermann ◽  
G. Cherchel ◽  
J.-P. Valet ◽  
J. Matte ◽  
S. Moorjani ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Nucleic Acid ◽  
Phospholipase C ◽  
Guinea Pigs ◽  
Tween 80 ◽  
Australia Antigen ◽  
Dane Particles ◽  
Antigenic Relationships

Coronavirus-like serum particles, Australia antigen, and Dane particles were treated by various chemicals and enzymes. Results were studied by electron microscopy. Coronavirus-like particles have no nucleocapsid, no detectable nucleic acid, no antigenic relationships with Australia antigen, and seem to be phospholipoproteins. Similar particles have been found in sera of guinea pigs and in human lipoproteins, especially in the HDL and VHDL fractions. Australia antigen which appears devoid of nucleic acid, and the envelope of Dane particles are sensitive to most agents and behave as phospholipoproteins. Phospholipase C produces ring-like structures. Results differ markedly from those obtained by other workers. The capsid of Dane particles is resistant to most agents. It is separated from the envelope by Tween 80, urea, and other agents. Dane particles seem to contain nucleic acid.

scholarly journals Genetic, Morphological and Antigenic Relationships between Mesonivirus Isolates from Australian Mosquitoes and Evidence for Their Horizontal Transmission

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1159
Author(s):  
Natalee D. Newton ◽  
Agathe M. G. Colmant ◽  
Caitlin A. O’Brien ◽  
Emma Ledger ◽  
Devina Paramitha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Monoclonal Antibodies ◽  
Nucleic Acid ◽  
Genetic Relationships ◽  
Mosquito Species ◽  
Horizontal Transmission ◽  
Antigenic Relationship ◽  
High Level ◽  
Antigenic Relationships ◽  
Prototype Virus

The Mesoniviridae are a newly assigned family of viruses in the order Nidovirales. Unlike other nidoviruses, which include the Coronaviridae, mesoniviruses are restricted to mosquito hosts and do not infect vertebrate cells. To date there is little information on the morphological and antigenic characteristics of this new group of viruses and a dearth of mesonivirus-specific research tools. In this study we determined the genetic relationships of recent Australian isolates of Alphamesonivirus 4 (Casuarina virus—CASV) and Alphamesonivirus 1 (Nam Dinh virus—NDiV), obtained from multiple mosquito species. Australian isolates of NDiV showed high-level similarity to the prototype NDiV isolate from Vietnam (99% nucleotide (nt) and amino acid (aa) identity). Isolates of CASV from Central Queensland were genetically very similar to the prototype virus from Darwin (95–96% nt and 91–92% aa identity). Electron microscopy studies demonstrated that virion diameter (≈80 nm) and spike length (≈10 nm) were similar for both viruses. Monoclonal antibodies specific to CASV and NDiV revealed a close antigenic relationship between the two viruses with 13/34 mAbs recognising both viruses. We also detected NDiV RNA on honey-soaked nucleic acid preservation cards fed on by wild mosquitoes supporting a possible mechanism of horizontal transmission between insects in nature.

Nucleic Acid Molecules Prepared by Monolayer Techniques

1972 ◽  
Vol 30 ◽  
pp. 178-179
Author(s):  
Dimitrij Lang
Keyword(s):  
Electron Microscopy ◽  
Standard Deviation ◽  
Nucleic Acid ◽  
Cytochrome C ◽  
Nucleic Acids ◽  
Contour Length ◽  
Sample Standard Deviation ◽  
Molecular Weights ◽  
Length Measurements ◽  
Protein Monolayer

The success of the protein monolayer technique for electron microscopy of individual DNA molecules is based on the prevention of aggregation and orientation of the molecules during drying on specimen grids. DNA adsorbs first to a surface-denatured, insoluble cytochrome c monolayer which is then transferred to grids, without major distortion, by touching. Fig. 1 shows three basic procedures which, modified or not, permit the study of various important properties of nucleic acids, either in concert with other methods or exclusively:1) Molecular weights relative to DNA standards as well as number distributions of molecular weights can be obtained from contour length measurements with a sample standard deviation between 1 and 4%.

Electron microscopy of the replicative events of A25 bacteriophages in group A streptococci

1972 ◽  
Vol 18 (1) ◽  
pp. 93-96 ◽  
Author(s):  
S. E. Read ◽  
R. W. Reed
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Group A Streptococcus ◽  
Group A Streptococci ◽  
Virulent Phage ◽  
Acid Pool ◽  
Group A ◽  
A Cell

The replicative events of a virulent phage (A25) infection of a group A Streptococcus (T253) were studied using the electron microscope. The first intracellular evidence of phage replication in a cell occurred 30 min after infection with arrest of cell division and increase in the nucleic acid pool. Phage heads were evident in the nucleic acid pool of the cells 45 min after infection. Release of phages occurred by splitting of the cell wall along discrete lines. This appeared to be at sites of active wall synthesis, i.e., near the region of septum formation. Many phage components were released but relatively few complete phages indicating a relatively inefficient replicative system.

Carbon Microspheres Prepared by High Internal Phase Emulsion Polymerization

2011 ◽  
Vol 239-242 ◽  
pp. 3105-3108
Author(s):  
Ming Xian Liu ◽  
Li Hua Gan ◽  
Jun Hu ◽  
Hong Lai Liu ◽  
Long Wu Chen
Keyword(s):  
Electron Microscopy ◽  
Specific Surface ◽  
Aqueous Phase ◽  
Apparent Density ◽  
Tween 80 ◽  
Carbon Microspheres ◽  
High Internal Phase Emulsion ◽  
Surface Areas ◽  
Internal Phase ◽  
Specific Surface Areas

In this paper, we present a novel approach for the synthesis of carbon microspheres via the polymerization of a high internal phase emulsion (HIPE). By using Span 80 and Tween 80 as emulsifiers, 1iquid paraffin as oil phase, and the mixture of resorcinol/formaldehyde (R/F) solution as aqueous phase, an O/W emulsion was obtained. This emulsion phase inverted to a W/O HIPE induced by ammonia which served as the polymerization catalyst. Carbon microspheres (CMs) were prepared by polymerization of the HIPE, followed by drying and carbonization. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analyzer were used to characterize as-prepared CMs. The results indicate that, in case of 0.25 wt% ammonia of the HIPE, the diameters of CMs decreased from about 2 to 1 μm when the mass fraction of aqueous R/F decreased from 0.714 to 0.357; the apparent density and the specific surface areas of the CMs, however, did not change obviously, which are about 0.6 g/cm3and 200 m2/g, respectively. The dosage of ammonia has a significant influence on the morphology and properties of CMs. With increasing of the ammonia mass to 1 wt% of the HIPE, the resultant carbon materials comprise not only CMs, but also some carbon sheets; the apparent density of which increased to 0.9 g/cm3and the specific surface areas of which decreased to below 100 m2/g. In addition, the other parameters for CMs preparation were also investigated. It was found that the proper conditions were controlling the temperature of 303-333 K and the oil/aqueous phase mass ratio of 2.5:7.

scholarly journals Use of scanning electron microscopy in the cochlea of guinea pigs

2020 ◽  
Vol 86 (2) ◽  
pp. 222-227
Author(s):  
Luiz César Nakao Iha ◽  
Oswaldo Laércio Mendonça Cruz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Guinea Pigs ◽  
Scanning Electron

scholarly journals Morphological and Chemical Studies of the Spores and Parasporal Bodies of Bacillus laterosporus

1958 ◽  
Vol 4 (5) ◽  
pp. 639-650 ◽  
Author(s):  
Philip C. Fitz-James ◽  
I. Elizabeth Young
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Nucleic Acid ◽  
Total Nitrogen ◽  
Phosphorus Content ◽  
Bacillus Species ◽  
Chemical Studies ◽  
Bacillus Laterosporus ◽  
Total P ◽  
High Phosphorus Content

Spores of Bacillus laterosporus were studied to determine the chemical and morphological nature of their basophilic canoe-shaped parasporal bodies. An unusually high phosphorus content of these spores compared to other Bacillus species appeared to be associated with the parasporal body. Preparations of these "canoes" still attached to the spore coats were indeed high in phosphorus, but also in nitrogen. They were free of lipide-soluble and nucleic acid phosphorus and stained for protein. Some 50 per cent of the total nitrogen, but only 6 to 10 per cent of the total P were liberated by extraction with alkali-thioglycollate (pH 11.5) or alkali alone (pH 12.2–12.5). Proteinaceous material was recovered from these alkaline extracts and electron microscopy indicated that there had been a marked loss of "canoe" substance. Extraction with acid, removed some 80 per cent of the phosphorus associated with the "canoes" as orthophosphate. Chromatographic analyses for amino acids indicated some 14 ninhydrin-positive spots in the canoe-coat preparations whereas the whole spores contained at least 16.

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