California encephalitis virus development in mosquitoes as revealed by transmission studies, immunoperoxidase staining, and electron microscopy

1975 ◽  
Vol 21 (4) ◽  
pp. 453-462 ◽  
Author(s):  
D. M. McLean ◽  
S. M. Gubash ◽  
P. N. Grass ◽  
M. A. Miller ◽  
M. Petric ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Salivary Glands ◽  
Immunoperoxidase Staining ◽  
Snowshoe Hare ◽  
Immunoperoxidase Technique ◽  
Thin Sections ◽  
Before And After ◽  
Culiseta Inornata ◽  
Transmission Studies ◽  
Marsh Lake

Isolates of the snowshoe hare subtype of California encephalitis (CE) virus from Yukon mosquitoes during 1972 and 1973 were transmitted by bites of Aedes aegypti mosquitoes after 4 to 5 weeks of extrinsic incubation at 55°F after intrathoracic injection, and the 1973 strain was transmitted after mosquitoes were fed virus and held for 3 to 4 weeks at 75°F. Antigen of a 1971 isolate of CE virus (Marsh Lake 23) was detected in salivary glands of infected mosquitoes by the immunoperoxidase technique, using highly purified antiserum before and after conjugation with horseradish peroxidase, plus the use of orthotolidine as a substitute for benzidine. Enveloped virions 45 nm in diameter were observed in thin sections of salivary glands of Culiseta inornata mosquitoes 59 days after intrathoracic injection with the 1971 isolate, after incubation at 55°F.

California encephalitis virus proliferation in Yukon mosquitoes incubated at low temperatures

1976 ◽  
Vol 22 (8) ◽  
pp. 1128-1136 ◽  
Author(s):  
D. M. McLean ◽  
P. N. Grass ◽  
B. D. Judd ◽  
K. S. K. Wong
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Salivary Glands ◽  
Low Temperatures ◽  
Acinar Cells ◽  
Yukon Territory ◽  
Immunoperoxidase Staining ◽  
Snowshoe Hare ◽  
Intrathoracic Inoculation ◽  
Aedes Communis

Replication of a subarctic Bunyavirus, California encephalitis (snowshoe hare subtype), was detected in salivary glands and thoraces of wild-caught Aedes communis mosquitoes from the Yukon Territory, after intrathoracic inoculation with 0.1 to 100 mouse LD50 virus, and incubation for 7 to 21 days throughout their viable temperature range of 0 to 23 °C. Immunoperoxidase staining confirmed that viral replication occurred in the cytoplasm of acinar cells of salivary glands, both by light microscopy and electron microscopy. Replication of another subarctic Bunyavirus. Northway, and a subtropical Flavivirus, Murray Valley encephalitis, was also demonstrated by infectivity titrations and immunoperoxidase reactions in salivary glands of A. communis incubated at 0, 13, and 23 °C for 7 to 21 days.

scholarly journals Combined use of silver staining of the retrograde tracer WGAapoHRP-Au and pre-embedding immunocytochemistry for electron microscopy: demonstration of dopaminergic terminals in synaptic contact with striatal neurons projecting to the substantia nigra in the rat.

1992 ◽  
Vol 40 (6) ◽  
pp. 889-892 ◽  
Author(s):  
R Arai ◽  
Y Kojima ◽  
M Geffard ◽  
K Kitahama ◽  
T Maeda
Keyword(s):  
Electron Microscopy ◽  
Substantia Nigra ◽  
Silver Staining ◽  
Synaptic Contact ◽  
Immunoperoxidase Staining ◽  
Immunoperoxidase Technique ◽  
Striatal Neurons ◽  
Combined Use ◽  
Cryostat Sections ◽  
The Brain

We investigated the applicability of the pre-embedding immunoperoxidase technique to WGAapoHRP-Au retrograde tracing. After injection of the tracer into the substantia nigra of rat, the brain was fixed and cryostat sections were immunostained for dopamine. The sections were osmicated and silver-stained to amplify the colloidal gold particles. Products of both the immunoperoxidase staining and the silver staining could be detected and distinguished by electron microscopy at low magnification. The ultrastructure was so well preserved that synaptic characteristics could be investigated. Dopaminergic terminals were demonstrated to synapse with striatal neurons projecting to the substantia nigra.

scholarly journals "Reticular" and "Areticular" Nissl Bodies in Sympathetic Neurons of a Lizard

1959 ◽  
Vol 6 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Stuart W. Smith
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Sympathetic Neurons ◽  
Sympathetic Ganglia ◽  
Thin Sections ◽  
Phrynosoma Cornutum ◽  
Reticular Structure ◽  
Before And After ◽  
Partial Dispersion ◽  
Nissl Substance

Sympathetic ganglia of the horned lizard, Phrynosoma cornutum, were fixed in OsO4 and imbedded in methacrylate. Thin sections were cut for electron microscopy. Some adjacent thick sections were cut for light microscopy and were stained in acidified, dilute thionine both before and after digestion by RNase. In the light microscope two types of Nissl bodies are found, both removable by RNase: (1) a deep, diffuse, indistinctly bounded, metachromatic variety, and (2) a superficial, dense, sharply delimited, orthochromatic sort. Electron microscopically, the former ("reticular" Nissl bodies) corresponds to the granulated endoplasmic reticular structure of Nissl material previously described by others, whereas the latter ("areticular" Nissl bodies) comprises compact masses of particles of varying internal density and devoid of elements of endoplasmic reticulum. The constituent particles of the areticular Nissl material are 4 to 8 x the diameter of single ribonucleoprotein granules of the reticular Nissl substance and seem, near zones of junction with the reticular type, to arise by clustering of such granules with subsequent partial dispersion of the substance of the granules into an added, less dense material. It is suggested that the observed orthochromasia of the areticular Nissl substance is due to accumulation of a large amount of protein bound to RNA and, further, that these Nissl bodies may represent storage depots of RNA and protein.

scholarly journals Bunyavirus isolations from mosquitoes in the western Canadian Arctic

1977 ◽  
Vol 79 (1) ◽  
pp. 61-71 ◽  
Author(s):  
D. M. McLean ◽  
P. N. Grass ◽  
B. D. Judd ◽  
L. V. Ligate ◽  
K. K. Peter
Keyword(s):  
Salivary Glands ◽  
Northwest Territories ◽  
Viral Antigen ◽  
Canadian Arctic ◽  
Encephalitis Virus ◽  
Snowshoe Hare ◽  
Infection Rates ◽  
Natural Vector ◽  
Culiseta Inornata ◽  
Aedes Communis

SUMMARYStrains of California encephalitis virus (snowshoe hare subtype) were isolated from 8 of 475 pools comprising 23747 unengorged female mosquitoes of five species collected at three of six locations throughout the Mackenzie Valley of the Northwest Territories, Canada, from latitudes 60 to 69° N between 10 and 24 July 1976. Minimum field infection rates included 1:2734 for Aedes communis, 1:256 to 1:3662 for A. hexodontus and 1:911 to 1:1611 for A. punctor. Northway virus was also isolated from 1 of 3662 A. hexodontus mosquitoes collected at Inuvik (69° N, 135° W). Transmission of CE virus by A. communis infected by feeding on virus in defibrinated blood and incubation at 0, 13 and 23 °C for 13–20 days clearly demonstrates the importance of this species as a natural vector, and transmission of CE virus by Culiseta inornata after incubation at 0 and 13 °C following intrathoracic injection strengthens evidence of its role as a natural vector. Immunofiuorescence was less reliable than imunoperoxidase for detection of CE viral antigen in mosquito salivary glands.

Canadian bunyavirus morphogenesis in arctic mosquitoes

1978 ◽  
Vol 36 (2) ◽  
pp. 380-381
Author(s):  
K. K. Wong ◽  
D. M. McLean
Keyword(s):  
Electron Microscope ◽  
Salivary Glands ◽  
Canadian Arctic ◽  
Osmic Acid ◽  
Snowshoe Hare ◽  
Thin Sections ◽  
Aedes Communis

Morphogenesis of two Canadian Bunyavirus isolates, the snowshoe háre subtype of California encephalitis (CE) virus, and Northway (NOR) virus, has been studied in salivary glands of wild-caught Aedes communis mosquitoes from the Western Canadian Arctic. An Australian flavivirus, Murray Valley encephalitis (MVE) virus has also been studied in these mosquitoes. Female mosquitoes were inoculated intrathoracically with 100-1000 mouse LD50 CE or MVE virus or 300 plaque forming units NOR virus. Mosquitoes were incubated at 13°C for extended periods, after which salivary glands were dissected away from mosquitoe thoraces. With the proboscis attached, glands were fixed with glutaraldehyde and postfixed with osmic acid before embedding in Epon 812. Thin sections of salivary glands were examined, using a Philips EM-300 electron microscope. Infectivity titrations of salivary glands or thoraces of the same batch of mosquitoes were performed whenever possible.

Soil sterilization effects on in situ indigenous microbial cells in soil

1975 ◽  
Vol 21 (3) ◽  
pp. 263-269 ◽  
Author(s):  
D. P. Labeda ◽  
D. L. Balkwill ◽  
L. E. Casida Jr.
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Enrichment Culture ◽  
Biological Information ◽  
Thin Sections ◽  
Soil Sterilization ◽  
Dry Heat ◽  
Transmission Electron ◽  
Before And After ◽  
Heat Application

Soil was sterilized by various procedures, and then the resident microorganisms were physically separated and concentrated from the soil for viewing by transmission electron microscopy as thin sections and frozen-etched preparations. Remaining cell viability in the soil was tested by conventional plating before and after enrichment culture. The soil proved to be sterile after treatment with 60Co radiation, prolonged autoclaving, prolonged dry heat application at 200C, or glutaraldehyde (if followed by subsequent mild heating), and could be considered sterile after OsO4 treatment. Treatment with glutaraldehyde alone, or 160C dry heat for 3 h, did not sterilize the soil. Cellular fine structure was altered or destroyed by the heat treatments, but was not affected to any extent by any of the other treatments including glutaraldehyde followed by mild heating. These findings are considered in relation to the residual biological information observable by electron microscopy in soil samples which have been sterilized to eliminate possible pathogens before handling of the soil. These findings are also considered with the objective of obliterating the fine structure of the indigenous microorganisms during soil sterilization so that electron microscopy studies can be made of microorganisms inoculated into and grown in the presterilized soil.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Lead aspartate: a new en bloc stain for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 34-35
Author(s):  
J.R. Walton
Keyword(s):  
Electron Microscopy ◽  
Calcium Ion ◽  
Enzyme Reaction ◽  
Lead Citrate ◽  
Reaction Products ◽  
En Bloc ◽  
Thin Sections ◽  
Lead Salts ◽  
Thin Sectioning ◽  
High Alkalinity

In electron microscopy, lead is the metal most widely used for enhancing specimen contrast. Lead citrate requires a pH of 12 to stain thin sections of epoxy-embedded material rapidly and intensively. However, this high alkalinity tends to leach out enzyme reaction products, making lead citrate unsuitable for many cytochemical studies. Substitution of the chelator aspartate for citrate allows staining to be carried out at pH 6 or 7 without apparent effect on cytochemical products. Moreover, due to the low, controlled level of free lead ions, contamination-free staining can be carried out en bloc, prior to dehydration and embedding. En bloc use of lead aspartate permits the grid-staining step to be bypassed, allowing samples to be examined immediately after thin-sectioning.Procedures. To prevent precipitation of lead salts, double- or glass-distilled H20 used in the stain and rinses should be boiled to drive off carbon dioxide and glassware should be carefully rinsed to remove any persisting traces of calcium ion.

Ectodesmata as Revealed By Freeze-Etch Preparations of Plant Epidermal Cell Walls

1973 ◽  
Vol 31 ◽  
pp. 468-469
Author(s):  
N.C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Electron Microscopy ◽  
Acetic Acid ◽  
Nitric Acid ◽  
Oxalic Acid ◽  
Light Microscopy ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Plant Viruses ◽  
Plant Leaves ◽  
Thin Sections

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

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