Evaluation of freeze substitution in rabbit skeletal muscle. Comparison of electron microscopy to X-ray diffraction

AbstractThe thick (myosin-containing) filaments of vertebrate skeletal muscle are arranged in a hexagonal lattice, interleaved with an array of thin (actin-containing) filaments with which they interact to produce contraction. X-ray diffraction and electron microscopy have shown that there are two types of thick filament lattice. In the simple lattice, all filaments have the same orientation about their long axis, while in the super lattice, nearest neighbors have rotations differing by 60°. Tetrapods (amphibians, reptiles, birds, mammals) typically have only a super lattice, while the simple lattice is confined to fish. We have carried out X-ray diffraction and electron microscopy of the soleus (SOL) and extensor digitorum longus (EDL) muscles of the rat and found that while the EDL has a super-lattice, as expected, the SOL has a simple lattice. The EDL and SOL of the rat are unusual in being essentially pure fast and slow muscles respectively. The mixed fiber content of most tetrapod muscles and/or lattice disorder may explain why the simple lattice has not been apparent in these vertebrates before. This is supported by only weak simple lattice diffraction in the X-ray pattern of mouse SOL, which has a greater mix of fiber types than rat. We conclude that the simple lattice might be common in tetrapods. The correlation between fiber type and filament lattice arrangement suggests that the lattice arrangement may contribute to the functional properties of a muscle.SummaryThe three-dimensional arrangement of thick filaments in skeletal muscle is studied by X-ray diffraction and electron microscopy. A correlation is found between thick filament lattice type (simple or super lattice) and fiber type (fast/slow). This suggests that lattice organization contributes to muscle functional properties

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Electron Microscopy of Human Gallstones

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065523 ◽

1971 ◽

Vol 29 ◽

pp. 296-297

Author(s):

C. Wolpers ◽

R. Blaschke

Keyword(s):

Electron Microscopy ◽

Room Temperature ◽

Bile Pigment ◽

X Ray Diffraction ◽

Triclinic Crystal System ◽

X Ray ◽

Follow Up Study ◽

Infra Red ◽

Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

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Electron Microscopy of Shock Loaded Polycrystalline Beryllium

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052547 ◽

1974 ◽

Vol 32 ◽

pp. 506-507 ◽

Cited By ~ 1

Author(s):

J. M. Galbraith ◽

L. E. Murr ◽

A. L. Stevens

Keyword(s):

Electron Microscopy ◽

Wave Propagation ◽

Structural Change ◽

Single Crystal ◽

Diffraction Pattern ◽

Shock Loading ◽

Slip Systems ◽

Compression Tests ◽

X Ray Diffraction ◽

X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

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Freeze-Fracture Replication of Frozen Outer Segments of Rat Retinal Rods

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063871 ◽

1969 ◽

Vol 27 ◽

pp. 392-393

Author(s):

Thomas S. Leeson ◽

C. Roland Leeson

Keyword(s):

Electron Microscopy ◽

Cross Section ◽

Outer Segment ◽

Freeze Fracture ◽

X Ray Diffraction ◽

X Ray ◽

Outer Segments ◽

Retinal Rods ◽

Temperature Electron ◽

Freeze Etching

Numerous previous studies of outer segments of retinal receptors have demonstrated a complex internal structure of a series of transversely orientated membranous lamellae, discs, or saccules. In cones, these lamellae probably are invaginations of the covering plasma membrane. In rods, however, they appear to be isolated and separate discs although some authors report interconnections and some continuities with the surface near the base of the outer segment, i.e. toward the inner segment. In some species, variations have been reported, such as longitudinally orientated lamellae and lamellar whorls. In cross section, the discs or saccules show one or more incisures. The saccules probably contain photolabile pigment, with resulting potentials after dipole formation during bleaching of pigment. Continuity between the lamina of rod saccules and extracellular space may be necessary for the detection of dipoles, although such continuity usually is not found by electron microscopy. Particles on the membranes have been found by low angle X-ray diffraction, by low temperature electron microscopy and by freeze-etching techniques.

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A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055904 ◽

1982 ◽

Vol 40 ◽

pp. 722-723 ◽

Cited By ~ 1

Author(s):

R. Gronsky

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Computer Simulations ◽

Structural Characteristics ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

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Identification of calcium oxalate crystals in dried or fixed tobacco leaf

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111550 ◽

1984 ◽

Vol 42 ◽

pp. 288-289

Author(s):

Vicki L. Baliga ◽

Mary Ellen Counts

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Calcium Oxalate ◽

Growth And Development ◽

Polarized Light ◽

Calcium Oxalate Crystals ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

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Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131243 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1322-1323

Author(s):

Howard S. Kaufman ◽

Keith D. Lillemoe ◽

John T. Mastovich ◽

Henry A. Pitt

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Environmental Scanning Electron Microscopy ◽

Environmental Scanning ◽

X Ray Diffraction ◽

Calcium Salts ◽

Cholesterol Gallstones ◽

X Ray ◽

Ca Carbonate ◽

Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

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