High-voltage electron microscopic studies of the interrelationship between microglial cells and amyloid fibrils in scrapie-infected mouse brains

1991 ◽  
Vol 49 ◽  
pp. 86-87
Author(s):  
A. S. Lossinsky ◽  
M. J. Song ◽  
H. M. Wisniewski
Keyword(s):  
High Voltage ◽  
Cell Attachment ◽  
Microglial Cells ◽  
Stereo Pair ◽  
Amyloid Formation ◽  
Electron Microscopic ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Amyloid Deposits

We have previously demonstrated the usefulness of high-voltage electron microscopy (HVEM) in the study of microvessels and inflammatory cell attachment in the central nervous system (CNS). In the present study, we used HVEM to further explore the interrelationship between microglial cells (MCs) and amyloid deposits in scrapie-infected mice. Scrapie infection in the mouse has been employed as an animal model to study the pathogenesis of amyloid fibril formation. The central question was whether three-dimensional (3-D) stereo-pair reconstruction would offer further insight into amyloid formation by MCs, which is currently the view of our group. Brains or cervical spinal cords from IM mice previously inoculated with 87V scrapie agent were used. One-half-micrometer thick plastic sections were stained with uranyl acetate and lead citrate. Light-microscopy views enabled us to target primary inoculation channels associated with amyloid deposits. Cells located at the periphery of the amyloid were identified as MCs (Fig. 1).

High-voltage electron microscopic studies of inflammatory cell attachment during blood-brain barrier inflammation

1990 ◽  
Vol 48 (3) ◽  
pp. 276-277
Author(s):  
A.S. Lossinsky ◽  
M.J. Song
Keyword(s):  
High Voltage ◽  
Inflammatory Cell ◽  
Cell Attachment ◽  
Electron Microscopic ◽  
Vascular Perfusion ◽  
Tissue Samples ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron

Previous studies have suggested the usefulness of high-voltage electron microscopy (HVEM) for investigating blood-bram barrier (BBB) injury and the mechanism of inflammatory-cell (IC) attachment. These studies indicated that, in evaluating standard conventional thin sections, one might miss cellular attachment sites of ICs in their process of attaching to the luminal endothelial cell (EC) surface of cerebral blood vessels. Our current studies in animals subjected to autoimmune disease suggest that HVEM may be useful in localizing precise receptor sites involved in early IC attachment.Experimental autoimmune encephalomyelitis (EAE) was induced in mice and rats according to standard procedures. Tissue samples from cerebellum, thalamus or spinal cords were embedded in plastic following vascular perfusion with buffered aldehyde. Thick (0.5-0.7 μm) sections were cut on glass knives and collected on Formvar-coated slot grids stained with uranylacetate and lead citrate and examined with the AEI EM7 1.2 MV HVEM in Albany, NY at 1000 kV.

Three-Dimensional Analysis of Tranverse Tubules in Normal and Failing Heart: A Combined Confocal and High Voltage Electron Microscope Study

1997 ◽  
Vol 3 (S2) ◽  
pp. 231-232
Author(s):  
M. E. Martone ◽  
V. M. Edelman ◽  
A. Thor ◽  
S. J. Young ◽  
S. P. Lamont ◽  
...  
Keyword(s):  
High Voltage ◽  
Three Dimensional ◽  
Cardiac Cells ◽  
Electron Microscopic ◽  
High Voltage Electron Microscopy ◽  
Spontaneously Hypertensive ◽  
3 Dimensional ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
T Tubules

Early electron microscopic studies documented that significant changes in the membrane systems of cardiac cells occur in both ischemic and non-ischemic heart failure. These studies relied on analysis of two-dimensional sections and although quantitative changes were observed, the overall organization of the tranverse tubules (T-tubules) and the sarcoplasmic reticulum could not be assessed. In a 3-dimensional study using high voltage electron microscopy (EM) of the T-tubules in spontaneously hypertensive rats, Nakamura and Hama (1991) observed that concomitant with an increase in surface area, the T-tubule system becomes progressively more disorganized and exhibits structural irregularities such as increased numbers of longitudinal tubules, numerous short dead end branches and complex tubular aggregates. These authors suggested that this disorganization may interfere with synchronous contraction over the entire cell.In the present study, we examined the 3-dimensional organization of T-tubules in the left ventricle of explanted human hearts using confocal microscopy and EM tomography.

Histo-grade diamond knives may be an appropriate tool for high-voltage electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 296-297
Author(s):  
M.E. Rock ◽  
J.A. Anderson ◽  
P.S. Binder
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Stereo Pair ◽  
Specimen Thickness ◽  
Serial Sections ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Diamond Knife

High voltage electron microscopy (HVEM) has been employed in various ways (whole mounts of cells stereo pair imaging, axial tomography, and serial sections for reconstruction) to elucidate three dimensional (3-D) ultrastructural data. The increased specimen thickness allows further data analysis unobtainable from ultra-thin sections. HVEM can reduce the number of sections needed in 3-D reconstructiortby approximately ten times over conventional transmission electron microscopy (CTEM). But increasing section thickness also increases wear on the diamond knife used to section. We have compared the serial sections obtained from a histo-grade diamond knife with those from an E.M. grade ultra-knife. Both sets of sections were cut 0.5 μm thick from the same block, and evaluated under the one million volt beam of the HVEM.

Correlative confocal light microscopy and high-voltage electron microscopy of neurons

1992 ◽  
Vol 50 (1) ◽  
pp. 564-565
Author(s):  
J.N. Turner ◽  
D.H. Szarowski ◽  
D. Decker ◽  
K.L. Smith ◽  
M. Fejtl ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
Light Microscope ◽  
Brain Slices ◽  
Ultrastructural Level ◽  
Three Dimensions ◽  
Electron Microscopic ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron

Neurons are cells with extensive dendritic and axonal arborizations extending from the cell body hundreds of micrometers or more in all three-dimensions. These structures have specializations, such as dendritic spines, that are at or just below the level of resolution of the light microscope (LM), and others, such as synapses, that can be resolved only in the electron microscope. Thus, it can be essential to correlate light and electron microscopic images from the same specimen. Due to its discrimination along the z-dimension (optic axis), the confocal light microscope is ideal for investigating neurons and correlating their structure and function. At the ultrastructural level, we use the high-voltage electron microscope (HVEM) to collect three-dimensional data, because it images thick objects. We are studying neurons in culture, and in thick acute and long term cultured brain slices. LM observations are made either after fixation or live by LM, and these images are correlated with HVEM ultrastructural observations.

High Voltage Electron Microscopy of Ion-Milled Dental Enamel

1974 ◽  
Vol 32 ◽  
pp. 60-61
Author(s):  
L. D. Ackerman ◽  
S. H. Y. Wei
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Third Molar ◽  
Polarized Light ◽  
Dental Enamel ◽  
Longitudinal Section ◽  
Ion Milling ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron

Mature human dental enamel has presented investigators with several difficulties in ultramicrotomy of specimens for electron microscopy due to its high degree of mineralization. This study explores the possibility of combining ion-milling and high voltage electron microscopy as a means of circumventing the problems of ultramicrotomy.A longitudinal section of an extracted human third molar was ground to a thickness of about 30 um and polarized light micrographs were taken. The specimen was attached to a single hole grid and thinned by argon-ion bombardment at 15° incidence while rotating at 15 rpm. The beam current in each of two guns was 50 μA with an accelerating voltage of 4 kV. A 20 nm carbon coating was evaporated onto the specimen to prevent an electron charge from building up during electron microscopy.

Three-Dimensional Visualization of the T-System of Frog Muscle Using High Voltage Electron Microscopy and a Lanthanum Stain

1977 ◽  
Vol 35 ◽  
pp. 570-571 ◽  
Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Three Dimensional ◽  
Biological Tissues ◽  
High Voltage Electron Microscopy ◽  
Transverse Tubular System ◽  
Peroxidase Reaction ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
T System

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.

Radiation-Induced Precipitation at Thin Foil Surfaces in Ni-Be Alloys

1982 ◽  
Vol 40 ◽  
pp. 598-599
Author(s):  
T. Mukai ◽  
T. E. Mitchell
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Electron Irradiation ◽  
High Vacuum ◽  
Thin Foil ◽  
Homogeneous Precipitation ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Radiation Induced

Radiation-induced homogeneous precipitation in Ni-Be alloys was recently observed by high voltage electron microscopy. A coupling of interstitial flux with solute Be atoms is responsible for the precipitation. The present investigation further shows that precipitation is also induced at thin foil surfaces by electron irradiation under a high vacuum.

Some Biological Applications of High Voltage Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 298-299
Author(s):  
Hans Ris
Keyword(s):  
High Voltage ◽  
Chromosome Structure ◽  
Nerve Fibers ◽  
Good Resolution ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
High Voltage Electron ◽  
One Year ◽  
The University

The High Voltage Electron Microscope Laboratory at the University of Wisconsin has been in operation a little over one year. I would like to give a progress report about our experience with this new technique. The achievement of good resolution with thick specimens has been mainly exploited so far. A cold stage which will allow us to look at frozen specimens and a hydration stage are now being installed in our microscope. This will soon make it possible to study undehydrated specimens, a particularly exciting application of the high voltage microscope.Some of the problems studied at the Madison facility are: Structure of kinetoplast and flagella in trypanosomes (J. Paulin, U. of Georgia); growth cones of nerve fibers (R. Hannah, U. of Georgia Medical School); spiny dendrites in cerebellum of mouse (Scott and Guillery, Anatomy, U. of Wis.); spindle of baker's yeast (Joan Peterson, Madison) spindle of Haemanthus (A. Bajer, U. of Oregon, Eugene) chromosome structure (Hans Ris, U. of Wisconsin, Madison). Dr. Paulin and Dr. Hanna are reporting their work separately at this meeting and I shall therefore not discuss it here.

High-voltage electron microscopy of maxillary gland of spirochete-infected brine shrimp: lesion of efferent tubule

1988 ◽  
Vol 46 ◽  
pp. 362-363
Author(s):  
G. E. Tyson ◽  
M. J. Song
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Brine Shrimp ◽  
Natural Populations ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Infected Adult

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.

On the High Voltage Electron Microscopy (1 MeV) of Biological Thick Sections

1972 ◽  
Vol 30 ◽  
pp. 464-465
Author(s):  
William H. Massover
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Present Report ◽  
Biological Tissues ◽  
Specimen Preparation ◽  
Technical Problems ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron

Stereoscopic examination of thick sections of fixed and embedded biological tissues by high voltage electron microscopy has been shown to allow direct visualization of three-dimensional fine structure. The present report will consider the occurrence of some new technical problems in specimen preparation and Image interpretation that are not common during lower voltage studies of thin sections.Thick Sectioning and Tissue Coloration - Epon sections of 0.5 μm or more that are cut with glass knives do not have a uniform thickness as Judged by their interference colors; these colors change with time during their flotation on the knife bath, and again when drying onto the specimen support. Quoted thicknesses thus must be considered only as rough estimates unless measured in specific regions by other methods. Chloroform vapors do not always result in good spreading of thick sections; however, they will spread spontaneously to large degrees after resting on the flotation bath for several minutes. Ribbons of thick sections have been almost impossible to obtain.

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