Midgut infection of Heliothis Zea (Lepidoptera: Noctuidae) by cytoplasmic polyhedrosis virus

1989 ◽  
Vol 47 ◽  
pp. 860-861
Author(s):  
C. F. J. Bong
Keyword(s):  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Heliothis Zea ◽  
Uranyl Acetate ◽  
Corn Earworm ◽  
Chronic Infections ◽  
En Bloc ◽  
Cytoplasmic Polyhedrosis Virus ◽  
Half Strength ◽  
Polyhedrosis Virus

The cytoplasmic polyhedrosis virus (CPV, Family Reoviridae) is an entomopathogen with a very wide host range, affecting mainly lepidopterous insects. The virus often causes chronic infections in insects, infecting mainly the midgut epithelium. Detailed studies of the effects of CPV on silkworm, Bombyx mori, have been done by Japanese workers , but there is very little information on the histopathology of CPV on other insects.In this study, 5-day old corn earworm (H. zea) larvae were infected per os with CPV. Control larvae were fed sterile water. The midgut was dissected out at 20, 48 and 72h post-treatment for both SEM and TEM studies. In the SEM study the midgut was fixed in 2.5% glutaraldehyde in phosphate buffer at pH 7.2, postfixed in buffered 2% osmium tetroxide at room temperature, dehydrated in ethanol, cryofractured in liquid nitrogen, critical-point dried, mounted, coated with gold-palladium and examined in a Hitachi HHS-2R scanning electron microscope at 20 kV. In the TEM study, the tissues were fixed in half-strength Karnovsky's fixative, postfixed in buffered cold 2% osmium tetroxide, en bloc stained in aqueous 0.5% uranyl acetate, dehydrated in ethanol and embedded in Spurr resin. Ultrathin sections were cut with glass knives, sequentially stained in aqueous uranyl acetate and lead citrate, and observed in a Zeiss 109 transmission electron microscope at 50 kV or a Siemens 101 at 80 kV.

Ultrastructural comparison of prolactin adenomas of pituitary in men and women

1988 ◽  
Vol 46 ◽  
pp. 346-347
Author(s):  
R.C. Caughey ◽  
U.P. Kalyan-Raman
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Phosphate Buffer ◽  
Pituitary Adenomas ◽  
Osmium Tetroxide ◽  
Secretory Granules ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Men And Women ◽  
Transmission Electron

Prolactin producing pituitary adenomas are ultrastructurally characterized by secretory granules varying in size (150-300nm), abundance of endoplasmic reticulum, and misplaced exocytosis. They are also subclassified as sparsely or densely granulated according to the amount of granules present. The hormone levels in men and women vary, being higher in men; so also the symptoms vary between both sexes. In order to understand this variation, we studied 21 prolactin producing pituitary adenomas by transmission electron microscope. This was out of a total of 80 pituitary adenomas. There were 6 men and 15 women in this group of 21 prolactinomas.All of the pituitary adenomas were fixed in 2.5% glutaraldehyde, rinsed in Millonig's phosphate buffer, and post fixed with 1% osmium tetroxide. They were then en bloc stained with 0.5% uranyl acetate, rinsed with Walpole's non-phosphate buffer, dehydrated with graded series of ethanols and embedded with Epon 812 epoxy resin.

Nonspecific structures seen in diagnostic muscle biopsies

1987 ◽  
Vol 45 ◽  
pp. 846-847
Author(s):  
R. C. Caughey ◽  
U. P. Kalyan-Raman
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Osmium Tetroxide ◽  
Clinical History ◽  
Uranyl Acetate ◽  
Ethanol Dehydration ◽  
Tubular Aggregates ◽  
En Bloc ◽  
Transmission Electron ◽  
Muscle Biopsies

In a period of two years we have analyzed 50 muscle biopsies using the transmission electron microscope. Six nonspecific structures consisting of filamentous bodies, tubular aggregates, paracrystalline mitochondrial inclusions, honeycomb arrays, concentric laminated bodies, and finger print profiles were observed in 47 of 50 cases. In order to know the significance of these structures in muscle biopsies, we correlated their occurrence with their clinical history, histological findings, and histochemistry.The biopsies were initially fixed in 2.5% glutaraldehyde (pH. 7.5, 500 mOsm), then randomly minced and post fixed in 1% osmium tetroxide. All biopsies were processed with and without uranyl acetate en bloc staining in Walpole's buffer before ethanol dehydration. They were embedded in Epon 812 epoxy resin, sectioned, and stained with uranyl acetate and lead citrate before evaluation with a JEOL, JEM 100 C Transmission Electron Microscope. All grid squares of six different blocks were scanned to evaluate the ultra-structural pathology.

Histopathology of cytoplasmic polyhedrosis virus (Reoviridae) infection in corn earworm, Helicoverpa zea (Boddie), larvae (Insecta: Lepidoptera: Noctuidae)

1991 ◽  
Vol 69 (8) ◽  
pp. 2121-2127 ◽  
Author(s):  
C. F. J. Bong ◽  
P. P. Sikorowski
Keyword(s):  
Helicoverpa Zea ◽  
Heliothis Zea ◽  
Goblet Cells ◽  
Corn Earworm ◽  
Cell Organelles ◽  
Cytoplasmic Polyhedrosis Virus ◽  
Polyhedrosis Virus ◽  
Columnar Cells ◽  
Lepidoptera Noctuidae ◽  
Virogenic Stroma

Histopathology of cytoplasmic polyhedrosis virus (CPV) infection in the larval midgut of the corn earworm, Helicoverpa (=Heliothis) zea (Boddie) is described. Small polyhedral inclusion bodies (PIB) are observed in columnar cells of the midgut 1 or 2 days after treatment with CPV. Virions are partially or completely occluded in a polyhedral matrix to form PIB at the periphery of the virogenic stroma. PIB are dodecahedral in shape with a hexagonal outline and measure from less than 1 to 4 μm in size. Virions measure about 50 nm in diameter. Microvilli of infected columnar cells are not affected until immediately prior to rupture of the cell. Some infected columnar cells ruptured to release PIB into the gut lumen 2 or 3 days after infection. PIB are also released into the lumen by extrusion of heavily infected columnar cells. Mitochondria and rough endoplasmic reticulum deteriorate as infection progresses, and in many cells with advanced infection, the nucleus is obscured. PIB are found in goblet cells 5 days after infection. Infected goblet cells degenerate to such an extent that only a few of the original microvillus-like cytoplasmic projections and cell organelles are left. The implications of CPV infection in integrated pest management of the corn earworm are discussed.

Cellular Contacts Within the Interhemal Membrane of the Rat Placenta at Term

1974 ◽  
Vol 32 ◽  
pp. 146-147
Author(s):  
William P. Jollie
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Capillary Endothelium ◽  
En Bloc ◽  
Aldehyde Fixation ◽  
Chorioallantoic Placenta

By routine EM preparative techniques, the tissues which, collectively, separate maternal and fetal bloods in the fully formed chorioallantoic placenta of the rat have been shown to consist of three chorionic layers, or trophoblast, and a layer of allantoic capillary endothelium [Fig. 1]. Relationships between these layers are best demonstrated by special techniques, viz., cacodylate-buffered aldehyde fixation, collidine-buffered osmium tetroxide postfixation, and en bloc staining with uranyl acetate. By using this method on placentas at term, the cells of the outermost chorionic layer (Trophoblast 1) appear to be attached to each other by means of maculae adherentes which sometimes occur in clusters [Fig. 2].

Electron Microscopic Examination of a Transplantable Rat Mammary Carcinoma

1968 ◽  
Vol 26 ◽  
pp. 20-21
Author(s):  
S. Shirahama ◽  
G. C. Engle ◽  
R. M. Dutcher
Keyword(s):  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Electron Microscopic Examination ◽  
Undifferentiated Carcinoma ◽  
Uranyl Acetate ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
North West ◽  
X Irradiation ◽  
Tissue Specimens

A transplantable carcinoma was established in North West Sprague Dawley (NWSD) rats by use of X-irradiation by Engle and Spencer. The tumor was passaged through 63 generations over a period of 32 months. The original tumor, an adenocarcinoma, changed into an undifferentiated carcinoma following the 19th transplant. The tumor grew well in NWSD rats of either sex at various ages. It was invariably fatal, causing death of the host within 15 to 35 days following transplantation.Tumor, thymus, spleen, and plasma from 7 rats receiving transplants of tumor at 3 to 9 weeks of age were examined with an electron microscope at intervals of 8, 15, 22 and 30 days after transplantation. Four normal control rats of the same age were also examined. The tissues were fixed in glutaraldehyde, postfixed in osmium tetroxide and embedded in Epon. The plasma was separated from heparanized blood and processed as previously described for the tissue specimens. Sections were stained with uranyl acetate followed by lead citrate and examined with an RCA EMU-3G electron microscope.

Observations of thick and thin sections in a field-emission SEM

1994 ◽  
Vol 52 ◽  
pp. 1018-1019
Author(s):  
W. P. Wergin ◽  
S. Roy ◽  
E. F. Erbe ◽  
C. A. Murphy ◽  
C. D. Pooley
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Chemical Fixation ◽  
Thin Sections ◽  
Transmission Electron ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

Larvae of the nematode, Steinernema carpocapsae Weiser strain All, were cryofixed and freezesubstituted for 3 days in acetone containing 2% osmium tetroxide according to established procedures. Following chemical fixation, the nematodes were brought to room temperature, embedded in Spurr's medium and sectioned for observation with a Hitachi S-4100 field emission scanning electron microscope that was equipped with an Oxford CT 1500 Cryotrans System. Thin sections, about 80 nm thick, similar to those generally used in conventional transmission electron microscope (TEM) studies were mounted on copper grids and stained with uranyl acetate for 30 min and lead citrate for 5 min. Sections about 2 μm thick were also mounted and stained in a similar fashion. The grids were mounted on an Oxford grid holder, inserted into the microscope and onto a cryostage that was operated at ambient temperature. Thick and thin sections of the larvae were evaluated and photographed in the SEM at different accelerating voltages. Figs. 4 and 5 have undergone contrast conversion so that the images would resemble transmitted electron micrographs obtained with a TEM.

scholarly journals Potassium permanganate is an excellent alternative to osmium tetroxide in freeze-substitution

2022 ◽  
Author(s):  
Martin Schauflinger ◽  
Tim Bergner ◽  
Gregor Neusser ◽  
Christine Kranz ◽  
Clarissa Read
Keyword(s):  
High Pressure ◽  
Potassium Permanganate ◽  
Lipid Membranes ◽  
Osmium Tetroxide ◽  
Freeze Substitution ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Block Face ◽  
Critical Aspects

AbstractHigh-pressure freezing followed by freeze-substitution is a valuable method for ultrastructural analyses of resin-embedded biological samples. The visualization of lipid membranes is one of the most critical aspects of any ultrastructural study and can be especially challenging in high-pressure frozen specimens. Historically, osmium tetroxide has been the preferred fixative and staining agent for lipid-containing structures in freeze-substitution solutions. However, osmium tetroxide is not only a rare and expensive material, but also volatile and toxic. Here, we introduce the use of a combination of potassium permanganate, uranyl acetate, and water in acetone as complementing reagents during the freeze-substitution process. This mix imparts an intense en bloc stain to cellular ultrastructure and membranes, which makes poststaining superfluous and is well suited for block-face imaging. Thus, potassium permanganate can effectively replace osmium tetroxide in the freeze-substitution solution without sacrificing the quality of ultrastructural preservation.

A CYTOPLASMIC POLYHEDROSIS OF HYALOPHORA CECROPIA (LINNAEUS)

1965 ◽  
Vol 11 (4) ◽  
pp. 703-707 ◽  
Author(s):  
W. A. Smirnoff
Keyword(s):  
Electron Microscope ◽  
Viral Infection ◽  
Cytoplasmic Polyhedrosis Virus ◽  
Virus Particles ◽  
Protein Mass ◽  
Viral Particles ◽  
Polyhedrosis Virus ◽  
Hyalophora Cecropia

Hyalophora cecropia (Linnaeus) is susceptible to infection by a cytoplasmic polyhedrosis virus. Electron microscope studies showed spherical viral particles known as "cores" which remain in groups of 12 to 17 subunits. The virus particles were embedded in a protein mass located in craters of the polyhedra. Larvae of the first, second, and third instars were more susceptible to viral infection than later instars. However, up to 50% of the larvae of later instars sometimes survived. The larvae of subsequent instars and the pupa were very resistant and periodic injections of strong dosages of virus material produced no ill effect. In general, larvae infected by this cytoplasmic virus shrank to less than half normal size before death.

Ultrastructural Morphology of the Anagen Stage Hair Follicle of Male Beagle Dogs

1977 ◽  
Vol 35 ◽  
pp. 652-653
Author(s):  
F. A. Al-Bagdadi ◽  
C. W. Titkemeyer ◽  
J. E. Lovell
Keyword(s):  
Electron Microscope ◽  
Basement Membrane ◽  
Skin Biopsy ◽  
Osmium Tetroxide ◽  
Dermal Papilla ◽  
Uranyl Acetate ◽  
Ground Substance ◽  
Lead Citrate ◽  
Beagle Dogs ◽  
Cytoplasmic Processes

Skin biopsy samples were collected monthly from the lateral sides of 9 male Beagle dogs over a period of 1 year. The samples were fixed in 3% gluteral- dehyde and post fixed in 1% osmium tetroxide using phosphate or S-Collidine as buffers. They were dehydrated, embedded in Epon 812, sectioned with an LKB Ultrotome III, and stained with Reynolds' lead citrate and 1% uranyl acetate. They were examined and photographed by use of an RCA-3H electron microscope.The dermal papilla during anagen consisted of fibroblast-like cells some of which had cytoplasmic processes. The cytoplasm contained many mitochondria. (Fig. 1) The cells of the dermal papilla were either peripherally arranged spindle-shaped cells or polygonal cells. The basement membrane was either related to the fibroblast cytoplasmic processes or was free of the cytoplasmic processes but with a thick zone composed of fibers, granular ground substance and spaces.

Electron Microscopy as an aid to diagnosis in pediatric hematology/oncology

1989 ◽  
Vol 47 ◽  
pp. 1062-1063
Author(s):  
K. L. Saving ◽  
R. C. Caughey
Keyword(s):  
Electron Microscopy ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Thin Sections ◽  
Megakaryoblastic Leukemia ◽  
Pediatric Hematology ◽  
Transmission Electron ◽  
Microscopy Techniques

This presentation is designed to demonstrate how scanning and transmission electron microscopy techniques can be utilized to confirm or support a variety of unusual pediatric hematologic/oncologic disorders. Patients with the following diagnoses will be presented: (1) hereditary pyropoikilocytosis, (2) familial erythrophagocytic lymphohistiocytosis, (3) acute megakaryoblastic leukemia, and (4) pseudo-von Willebrand’s disease.All transmission and scanning electron microscopy samples were fixed in 2.5% glutaraldehyde, rinsed in Millonig’s phosphate buffer, and post-fixed with 1% osmium tetroxide. The transmission samples were then en bloc stained with 0.5% uranyl acetate, rinsed with Walpole ’ s non-phosphate buffer, dehydrated with graded series of ethanols and embedded with Epon 812 epoxy resin. Ultramicrotomy thin sections were stained with uranyl acetate and lead citrate and scanned using a JEOL-JEM 100C, The scanning samples were dehydrated with graded series of ethanols, critical point dried with CO2, gold-coated, and scanned using a JEOL-JSM 35. The peroxidase samples were fixed in 3% glutaraldehyde, incubated in diaminobenzidine (DAB), dehydrated with ethanol, embedded with Epon 812, and scanned without post-staining using a JEOL-JEM 100C.

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