scholarly journals PEPSIN DIGESTION OF VIRUS PARTICLES IN CANINE HEPATITIS USING EPON-EMBEDDED MATERIAL

1967 ◽  
Vol 15 (11) ◽  
pp. 688-694 ◽  
Author(s):  
KATHLEEN F. GIVAN ◽  
CHARLOTTE TURNBULL ◽  
ANNE-MARIE JÉZÉQUEL

Sixteen-week-old dogs were inoculated with 20,000 tissue culture doses (TCD50) of infectious canine hepatitis virus. Four days after inoculation, liver cells examined in the electron microscope contained both virus particles and nonviral paracrystalline formations. Tissue culture cells also contained virus particles and nonviral paracrystalline formations 48 hr after inoculation with virus. When Epon-embedded sections were treated for 1 hr with 0.5% pepsin in 0.1 N HCl, a selective extraction of the viral coats and of the nonviral paracrystals was observed.

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.


1969 ◽  
Vol 4 (3) ◽  
pp. 371-377 ◽  
Author(s):  
J. Chatterji ◽  
T. S. L. Beswick ◽  
J. A. Chapman

1968 ◽  
Vol 36 (1) ◽  
pp. 231-243 ◽  
Author(s):  
Robert M. McCombs ◽  
Matilda Benyesh-Melnick ◽  
J. Pierre Brunschwig

A technique is described for embedding tissue culture cells that have been adsorbed or grown on Millipore filters. The acetone used during the embedding process rendered the filters transparent so that specific areas or cells could be chosen with the aid of the light microscope. Lymphoblastoid cells processed on the filters possessed well-defined plasma membranes and microvilli which were rarely present in cells from parallel cultures that were prepared by pelleting in the centrifuge. Fibroblast cells grown on filters retained their elongated appearance, in contrast to the rounded cells in pelleted preparations. Millipore filters were also used as a means of embedding virus pellets for sectioning. Preparations containing as few as 4 x 108 virus particles were suitable for study by the filter technique. Crude tissue-culture harvests of vaccinia virus and purified preparations of Rauscher murine leukemia and adeno-satellite viruses were successfully examined.


Author(s):  
A. M. Watrach

During a study of the development of infectious laryngotracheitis (LT) virus in tissue culture cells, unusual tubular formations were found in the cytoplasm of a small proportion of the affected cells. It is the purpose of this report to describe the morphologic characteristics of the tubules and to discuss their possible association with the development of virus.The source and maintenance of the strain of LT virus have been described. Prior to this study, the virus was passed several times in chicken embryo kidney (CEK) tissue culture cells.


Author(s):  
Matias Pardo ◽  
Malcolm Slifkin ◽  
Leonard Merkow ◽  
Marie Sanchez

The simian adenoviruses SV20, SV30 and SA7 have been found to be oncogenic in the Syrian hamster. The growth characteristics and replicative cycle of these viruses in tissue culture therefore appeared appropriate to investigate. Cesium chloride purified simian adenovirus with an infectivity titer of 100 TCID50, was inoculated into monolayers of LLC-MK2 cells. Cells were fixed in osmium tetroxide and embedded for ultrastructural studies at 1, 3, 6, 9, 18, 24, 48, 72, 120 and 192 hours post-infection.At the first hour post-infection, virus particles were adsorbed to the plasmalemma and found within the peripheral cytoplasm of many LLC-MK2 cells (Fig. 1). Although the first detection of infectious virus occurred at 14 hours and infectivity titers did not reach a maximum until 30 hours, intranuclear virus particles were observed by 3 hours in typical adenovirus crystalline array (Fig. 2) by means of electron microscopy. These typical honeycomb arrayed virus particles at 3 hours provided evidence of significant replication in approximately 5 percent of tissue culture cells examined. Simultaneously, a classical nuclear inclusion manifested by peripheral condensation of nuclear chromatin was evident by light microscopy. As early at 6 to 9 hours, unusual intranuclear concentric membranes formed “tubes” which contained linear arranged virus particles (Fig. 3). In transverse or tangential sections, these “tubes” appeared cochlear-like in shape. In longitudinal section, these intranuclear tubular structures contained individual virus particles at various stages of maturation in a linear arranged order. This arrangement resembled “peas in a pod”.


Author(s):  
Heide Schatten ◽  
Neidhard Paweletz ◽  
Ron Balczon

To study the role of sulfhydryl group formation during cell cycle progression, mammalian tissue culture cells (PTK2) were exposed to 100¼M 2-mercaptoethanol for 2 to 6 h during their exponential phase of growth. The effects of 2-mercaptoethanol on centrosomes, chromosomes, microtubules, membranes and intermediate filaments were analyzed by transmission electron microscopy (TEM) and by immunofluorescence microscopy (IFM) methods using a human autoimmune antibody directed against centrosomes (SPJ), and a mouse monoclonal antibody directed against tubulin (E7). Chromosomes were affected most by this treatment: premature chromosome condensation was detected in interphase nuclei, and the structure in mitotic chromosomes was altered compared to control cells. This would support previous findings in dividing sea urchin cells in which chromosomes are arrested at metaphase while the centrosome splitting cycle continues. It might also support findings that certairt-sulfhydryl-blocking agents block cyclin destruction. The organization of the microtubule network was scattered probably due to a looser organization of centrosomal material at the interphase centers and at the mitotic poles.


1982 ◽  
Vol 47 (5) ◽  
pp. 1530-1536 ◽  
Author(s):  
Ladislav Bilisics ◽  
Štefan Karácsonyi ◽  
Marta Kubačková

The presence of UDP-D-glucose 4-epimerase (EC 5.1.3.2) in the culture tissue of white poplar was evidenced. As found, the partially purified enzyme preparation contained UDP-D-glucose glucosyltransferase, UDP-D-galactose galactosyltransferase and non-specific enzymes able to cleave the uridine-diphosphate saccharides into the appropriate hexose monophosphates. The activity change of UDP-D-glucose 4-epimerase in tissue culture cells during the growth was in accord with changes in D-galactose content in cell walls and indicated the possibility to regulate the formation of polysaccharides containing D-galactose at the level of production of UDP-D-galactose in cells.


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