bluuebunny/crossref_metadata_2025 huggingface dataset:
Parallax stereograms obtained by using the Nimslo© process
Authors: Wittry D. B.
Published: June 2020

Although popular interest in stereophotography has waxed and waned several times since the introduction of the Holmes stereoscope in the 1850's, the importance of stereophotography in scientific and technical applications has steadily increased. It has been of great value for contour mapping in geophysics and cartography, for displaying crystal and molecular structures, for locating and viewing internal structures in radioscopy, and for presenting 3-dimensional images obtained by optical microscopy, by x-ray projection microscopy and by electron microscopy.

A persistent problem limiting the wider use of stereophotography has been the problem of viewing the image. Because stereo viewers are awkward to use, other methods of stereo viewing have been developed, including the following: 1) “reading in 3-D” with the use of eye training; 2) the use of a stereo pair with one image printed backwards and viewed with a plane mirror between the images; 3) the hologram method and 4) the parallax stereogram method.
The RS layer of a Pseudomonas species
Authors: Fraser G. H. , Hall M. , Murray R. G. E. , Whippey P. W.
Published: June 2020

A Pseudomonas species, isolated from a feeder culture for Euglena viridis, shows an unusual form of tetragonal array on the external surface of the cell wall in negatively stained preparations. These regular surface [RS] layers have been demonstrated on a variety of gram positive and gram negative bacteria and form the primary interface between the cell wall and its environment. It is thought to function as a protective barrier layer against predators and other deleterious agents such as enzymes.

Ammonium molybdate was the most effective negative stain at relatively high concentrations (4-8% w/v); uranyl acetate did not display the RS layer. The micrographs were investigated with the aid of optical diffraction and digital image enhancement. Areas of micrographs that were free from obvious irregularities such as stacking faults and uneven staining were selected visually, Fig. 1(a).
Spermatogenesis in Aeolidia papillosa (Nudibranchia)
Authors: Berlo Robert
Published: June 2020

Spermatogenesis was studied in Aeolidia papillosa by disection of the ovotestis. Morphologically, developing spermatogonia and accessory cells are similar to those described in Spurilla neopolitana except for spermatid development. Sperm also were examined for the presence of carbohydrates. The reproductive tissue comprises the posterior two thirds of adult nudibranchs in the form of an ovotestis, divided into acini that contain both male and female follicles. The male follicles develop in the proximal half of the acinus. Accessory cells and early spermatocytes are attached to the basal laminal wall demarking each acini (Fig.1).

Germinal spermatogonia give rise to large primary spermatocytes. The nucleus is spherical in shape, with an occasional eccentric nucleolus and scattered condensed chromatin, mostly located peripherally. The cytoplasm contains some mitochondria. The primary spermatocytes give rise to smaller trapezoidal secondary spermatocytes. These cells have nuclei with one or two large irregular nucleoli and scattered clumps of chromatin. The cytoplasm contains several Golgi complexes and mitochondria (Fig.1).
The Interpretation of Irregularities in Lattice Fringe Images
Authors: Cockayne D. J. H.
Published: June 2020

The appearance of lattice fringe images formed from perfect crystals is sensitive to parameters such as lens defocus, beam orientation and foil thickness. For certain values of these parameters the lattice fringe image shows contrast which can be interpreted directly in terms of the projection of the crystal structure. Extensive computations and image simulation have established the conditions under which this direct interpretation is valid, and the method is now recognized as a powerful analytical tool at the limit of resolution of the electron microscope.
The Structure of Macromolecules at 5 Angstroms
Authors: Ottensmeyer F. P. , Whiting R.F. , Korn A.P.
Published: June 2020

Most modern electron microscopes can boast a resolving power of about 3 A. Nevertheless, virtually all images of biological specimens display but a 20-30 A resolution, limited by the coarseness of the virtually obligatory heavy atom stain or shadow required for contrast and visibility. The loss in visibility incurred by the omission of heavy atoms can be overcome by the use of dark field electron microscopy. Moreover, for macromolecules, chromatic aberration, which limits the resolving power of the technique in the case of thick specimens, is not a problem. The sole remaining question then is whether the exquisitely fragile specimen, now unsupported and unprotected by heavy atom stains or shadows, can withstand the increasingly enormous radiation doses required to obtain the higher resolutions.
Phase Transformations in the Zirconium-Aluminum-Hydrogen System
Authors: Faulkner D. , Cameron D. J.
Published: June 2020

Zr-Al alloys based on the intermetallic compound Zr3Al are presently being considered as structural materials for use in nuclear environments. Theoretically, the single-phase Zr3Al alloy should contain 8.97% Al, but in practice single phase material is not produced, and alloys containing approximately 8.0 to 8.5% Al contain a dispersion of α-Zr solid solution in the Zr3Al matrix (fig. 1). At higher Al concentrations Zr2Al may also be present.

In this paper we describe the structures observed in a Zr-8.3% Al alloy containing up to 1300 μg/g hydrogen. Hydrogen was introduced into the alloy in two ways. The first technique involved the exposure of a weighed sample, at 650°C to a known volume of hydrogen at a predetermined pressure. The pressure was monitored during hydriding until it dropped to a value corresponding to the required uptake of hydrogen.
An Electron Microscope Study of Deformation-Strain Cycling Effects in 304 Stainless Steel
Authors: Staudhammer K.P. , Murr L.E.
Published: June 2020

While there have been numerous experiments concerned with the effects of cold rolling and shock deformation on stainless steel residual structure, there have been no systematic attempts to investigate the effect of sequencing of these deformation modes for any material.

In the present experimental program, type 304 stainless steel sheet was cold rolled (CR) 15 and 30% and incorporated (along with annealed, undeformed specimens) in a sandwich assembly for shock loading (SL), utilizing a flyerplate technique as previously described (at shock pressures of 150, 250, and 350 kilobars, and at a constant shock pulse-duration of 2.0 μ sec.
Critical Voltages
Authors: Ploc R.A. , Miller M.A.
Published: June 2020

An earlier report noted that the shape of the Bloch Wave (BW) excitation amplitude, , curves in the region of the critical voltage, Vc, (vs accelerating voltage, Va), for a crystal set at the exact second order diffracting position, was dependent on the number of beams used in the calculation. Since that report vs Va curves have been replotted for amplitudes from -1.0 to 1.0 where the sign of was determined by the relative sign of - see Figure 1. Also reported was a sharp rise in the second order diffracted intensity (I2ḡ) at Vc.
The Development of Recrystallization Texture in Titanium
Authors: Rath B. B. , O'Neal J. E. , Lederlch R. J.
Published: June 2020

When deformed metals and alloys are annealed at sufficiently high temperatures, strain-free nuclei appear at preferential sites and grow predominantly by grain-boundary migration. A majority of these strain-free grains collectively exhibit specific types of crystallographic orientations which significantly differ from those of the deformed matrix. The texture thus formed is frequently related to the deformation texture by simple angular rotations about particular crystallographic axes. In contrast to most metals and alloys for which the recrystallization and deformation textures are distinctly different, Ti exhibits a similar texture in both the cold-rolled and recrystallized conditions; this texture is characterized by two symmetrical texture components such that the (1010) in each remains parallel to the rolling direction and the [0001] is tilted along the transverse direction between 30 and 40 deg from the rolling-plane normal.
In situ Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.
Authors: Louchet F. H. , Kubin L. P.
Published: June 2020

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.

The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].

Our results concern:

- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.
Observations on the Fine Structure of Siliceous Microfossils from the Oamaru Diatomite (Upper Eocene), II. Archaeomonads.
Authors: Jendrzejewski John P.
Published: June 2020

Archaeomonads are a fossil group of marine siliceous cysts and are thought to represent resting stages in the life history of chrysophycean algae. The morphology of the cysts is generally simple with spherical, spheroidal, and elliptical outlines common. The cysts are characterized by the presence of an opening (pore) piercing the wall. A thickened structure (neck) often develops around the pore. The cyst usually is composed of one layer of silica although cysts with double and triple layers are common. The outer layer of the cyst may be smooth, or ornamented with spines, warts, pits, flanges or ridges of silica. Due to their small size (3-25 microns in diameter) and to the presence of minute ornamentation, identication of many forms solely with light microscopy is difficult. The application of scanning electron microscopy (SEM) together with light microscopy (LM) enables one to precisely determine the ornamentation and accurately define a species.
Characterization of RF Sputtered ZnO Piezoelectric Films Using Transmission Electron Microscope
Authors: Yeh Kemining W. , Muller Richard S. , Wu Wei-Kuo , Washburn Jack
Published: June 2020

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.
Conversion of an EM-200 to a Dual-Gun Electron Microscope for TEM and SEM
Authors: Brewer A. W. , Gold C. L. , Ong P. S.
Published: June 2020

A Philips EM-200 electron microscope has been modified to incorporate two electron guns as described by Ong and Gold, for operation in the conventional (TEM) and scanning (SEM) mode.

The second gun, the SEM gun, is mounted below the viewing chamber and uses the imaging system of the microscope as the probe forming electron optic. The electrons follow essentially the same path as the image forming electrons for TEM, only in the opposite direction.

The modifications to the microscope column are designed to provide the space for the scanning coil assembly, the various detectors, and the second gun. A spacer is located above the objective lens to house the transmission electron detector, another spacer, below the objective lens, incorporates the scanning coil and a secondary electron detector.
A SEM Attachment for the Corinth Electron Microscope
Authors: Anderson K. , Brookes K.A. , Watson J.M.
Published: June 2020

A scanning attachment has been designed for the Corinth electron microscope enabling either standard transmission images of thin specimens (TEM) or reflection scanning images of bulk specimens (SEM) to be obtained from the one instrument.

At the heart of the modified instrument is a lens which acts as both the final projector lens for the TEM and also as the objective lens for the SEM with a working distance of 5mm. Thus even when used as a SEM the whole length of the Corinth column is traversed by the beam and this presents the choice of two possible modes of operation, namely, a two lens mode in which only the first condenser and final projector are excited, or a three lens mode in which the TEM objective lens is also excited. The three lens mode provides a range of much higher gaussian demagnifications.
Fixed-Beam-Excitation Auger EM with Simulated Specimens: AEM-1
Authors: Coleman J. W. , Jacobsen E.H.
Published: June 2020

AEM-1 is the first in a series of three prototypes of a fixed-beam-excitation Auger electron microscope. Because Auger electrons have energies dependent only upon the structure of the atoms from which they are emitted, they are atomic signatures. If the Augers can be used for imaging the specimen, the sites of the emitting atoms can also be established. With such an energy-analyzing optical-imaging system, there is no need for heavy metal staining or isomorphic replacement for low-Z atoms, and thus our ultimate goal (with AEM-3) is the direct observation of atomic carbon, oxygen, and nitrogen in micrographs of biological material. AEM-1, however, was built specifically to study the problems of high quality imaging with very wide angle lenses, and it uses an Auger electron source simulated by an microgun of variable (50-700ev) energy.
A 10,000 Lines/Field Scanning Electron Microscope System
Authors: Jones G.A.C. , Ahmed H. , Nixon W.C.
Published: June 2020

A special type of post-lens single deflection coils have been developed for use in various applications of micro electron beam technology. The coil geometry has been chosen to give small values of the uncorrectable aberrations and to correct for field curvature by dynamic focusing. With this system 10,000 lines/field may be used in scanning electron microscopy leading to electrical raster shift only to search a specimen. The same type of system could be used to produce high resolution special purpose displays or for direct electron beam photographic recording.

In Figure 1 the lettered grid is 3 mm in diameter and the scanned circle is 9 mm in diameter.
The Unipotential Foil Lens
Authors: Wittels N. D. , Jacobsen E. H.
Published: June 2020

We are investigating theoretically and experimentally the optical properties of an electrostatic unipotential lens whose center electrode is an aperture and whose outer electrodes are electron-transparent foils. This lens is potentially useful as a spherical aberration corrector for a high-quality magnetic lens.

The electrostatic field inside the lens is calculated analytically from a Bessel-Fourier series expansion of the potential. This method gives results that are accurate in all regions of the lens, including those near the conducting foils, and readily allows the lens boundaries and excitation to be varied. The equations of motion are integrated numerically to determine the lens' optical properties. Since we are specifically interested in the aberrations of this lens, considerable effort has been made to assure the validity of the non-paraxial ray calculations.
Superior 2X2 Slides
Authors: Schaefer Harry , Wetzel Bruce
Published: June 2020

High resolution 24mm X 36mm positive transparencies can be made from original black and white negatives produced by SEM, TEM, and photomicrography with ease, convenience, and little expense. The resulting 2in X 2in slides are superior to 3¼in X 4in lantern slides for storage, transport, and sturdiness, and projection equipment is more readily available. By mating a 35mm camera directly to an enlarger lens board (Fig. 1), one combines many advantages of both. The negative is positioned and illuminated with the enlarger and then focussed and photographed with the camera on a fine grain black and white film.

Specifically, a Durst Laborator 138 S 5in by 7in enlarger with 240/200 condensers and a 500 watt Opale bulb (Ehrenreich Photo-Optical Industries, Inc., New York, NY) is rotated to the horizontal and adjusted for comfortable eye level viewing.
On Distinguishing between Small Vacancy and Interstitial Dislocation Loops Using a Non-Conventional Weak Beam Dark Field Technique
Authors: Wu Wei-Kuo
Published: June 2020

It is well known that both the burgers vector and the habit plane of dislocation loops are needed in order to determine their type, e.g. vacancy or interstitial. The conventional bright field and dark field techniques give a dislocation image width ⋍300Å or an image shift from the core position even larger than the true size of a small dislocation loop. This makes loop type determination very difficult.

In this paper, the newly developed weak beam dark field technique, which decreases the effective extinction distance, ξg, has been used to reduce the dislocation image width (∽1/3 ξg), so that the shape (habit plane) and loop types of small dislocation loops (<500Å) can be determined unambiguously.
Theory of Topographical Image Contrast
Authors: Nakahara S. , Cullis A. G. , Maher D. M.
Published: June 2020

It has been shown recently that image contrast arising from specimen topographical structure may be obtained using the transmission electron microscope (TEM). The contrast was produced with an adaptation of the Foucault technique in which electrons suffering deviations of typically 10-4 to 10-3 rad were selected by the lateral displacement of a standard objective aperture. The mechanism of image formation was discussed in terms of electron refraction within the specimen inner potential, the contrast being amplitude in nature.

In the present paper the imaging process is described by a detailed mathematical formulation.

The theoretical treatment is based upon the concept of information theory for image transfer, in which successive Fourier transforms are utilized to derive the wave function of the image from an appropriate object.
Topographical Imaging in the Transmission Electron Microscope
Authors: Cullis A. G. , Maher D. M. , Nakahara S.
Published: June 2020

A technique which employs an adaptation of the Foucault method for direct topographical imaging in the transmission electron microscope (TEM) was described recently. Image contrast is produced by selection, with a displaced objective aperture, of electrons which have been deflected through small angles within the specimen inner potential. In this manner, the aperture is employed effectively as a half-plane which, to a first approximation, removes half the spectra in the back-focal plane of the objective lens. The purpose of the present article is to illustrate the mechanism of image formation and also to demonstrate applications of the technique.

Crystallites of MgO, formed by the combustion of Mg in air, are useful test objects since they have regular cubic geometry. When these were examined in the J EM 200 TEM under kinematical conditions and using an objective aperture in the half-plane position, they yielded images (after astigmatism correction) which exhibited topographical amplitude contrast.
The Accurate Measurement of the Energy Dependence of Radiation Damage Rates in Organic Materials
Authors: Howitt D. G.
Published: June 2020

In electron microscopy and radiation damage studies in organic materials it is important to be able to make an accurate assessment of the rate at which the damage processes proceed.

Approximate values for these radiation damage rates have been calculated using solid state detectors in order to measure the appropriate beam current densities, however the strong intensity dependence of these devices (Fig. 1) and their susceptibility to radiation damage imposes large errors when any consistency in their efficiency is assumed.

A Faraday cup has been constructed (Fig. 2) which is capable of measuring currents down to 10-15 amperes cm-2 from the final image plane of an electron microscope, with an error of less than 1%. The cup, being positioned beneath the final viewing screen is therefore capable of distinguishing local incident intensities in the object plane.
Stereomicroscopy for Phase Objects by Use of Defocus Contrast
Authors: Nakahara S.
Published: June 2020

The principles for obtaining stereomicrographs by transmission electron microscopy (TEM) with crystalline as well as non-crystalline specimens are well-established and are based on the introduction of parallax between two exposures by tilting a specimen inside a microscope. Previous applications of the technique have only been made to objects which give rise to amplitude contrast (provided by the elimination of electrons scattered outside the objective aperture). Recently, the technique has been further extended to objects, the images of which originate from phase contrast.

The method employs defocus contrast for imaging such phase objects in combination with the conventional tilting operation. This paper describes the principle of the method and discusses a field of potential application.
Fresnel Diffraction and Lattice Plane Images in a Conventional STEM
Authors: Geiss R. H. , Howitt D. G. , Arnal H.
Published: June 2020

According to the theorem of reciprocity, as related to STEM and CTEM images, identical images should be formed under equivalent operating conditions in the two modes of microscopy. Experimental results have shown this to be generally true for diffraction contrast images. The electron optical parameters are such that higher resolution is usually achieved in CTEM, and the advantages of image processing and increased sample penetration are realized in STEM. Electron diffraction patterns can be obtained by both, with better angular resolution in CTEM and very small selected areas (< 25 Å) attainable in STEM. The equivalence of phase contrast images has been demonstrated by means of Fresnel diffraction and lattice plane images. All the STEM results reported have been obtained using high brightness field emission or LaB6 guns. Incident probe coherence and poor signal/noise have effectively excluded the use of conventional tungsten hair-pin sources.
The Detection of Transmitted Energy Loss Electrons for Elemental Analysis
Authors: Johnson D. E. , Isaacson M.
Published: June 2020

Elemental analysis by means of energy loss electrons transmitted through thin specimens has the potential of being a very useful technique for the microanalysis of light elements (e.g. 1-5). The advantages of the energy loss technique over x-ray detection have been discussed in detail in ref. 1. They are basically, the lack of dependence of the detection efficiency on the fluorescent yield (which decreases rapidly with decreasing Z) and the possibility of increased collection efficiency of the energy loss electrons (which are concentrated at relatively small angles with respect to the incident beam direction).
Molecular Degradation in the Electron Microscope: A Tunneling Spectroscopy Study
Authors: Parikh M. , Hansma P. K.
Published: June 2020

Molecular degradation in the electron microscope has been studied by energy loss spectroscopy, mass loss analysis and other techniques; none of these, however, have provided explicit information about the changes in the physical structure of the molecules. Here we present results from the use of inelastic electron tunneling spectroscopy as a probe in the study of degradation of molecular specimens in an electron microscope. The technique involves including the molecules of interest in a metal-insulatormetal junction and then monitoring the junctions current-voltage (I-V) characteristic. Explicitly, the measurement of d2I/dV2 vs. V provides a spectrum of vibrational frequencies (related to IR and Raman active modes) of the molecule; thus information about molecular bonds and physical configuration can be obtained. Upon electron irradiation, changes in the molecular structure are visible as changes in the heights and positions of the peaks in the tunneling spectrum.
Generation and Dislocations at the Interface Between Oxygen Precipitates and Silicon
Authors: Tan T. Y. , Tice W. K.
Published: June 2020

The generation of dislocations at the interface between misfitting particles and a ductile matrix by the stress relief mechanism of prismatic punching was first discussed by Seitz and observed by others in AgCl and Al. In this paper we report the observation of such-phenomena in semiconductor silicon. Oxygen rich (∼2x1018 at./cc) Czochralski grown <001> silicon wafers were annealed at 1050°C for 60 hours and slowly cooled. TEM observations show that the alleged SixOy type precipitates are a few thousand Angstroms in size and are plate-like in morphology. The precipitate forms by the nucleation of a cross-shaped ribbon on a {001} plane with the ribbon branches along the two <100> directions in the appropriate {001} plane. The ribbon branches are widened by dendritic growth until the completion of a square plate on a {001} plane with sides along the two appropriate <110> directions. Thickening of plates in the <001> direction is also common, and sometimes two or more plates having mutually perpendicular {001} hibit planes grow together, Fig. 1.
Boron Precipitates in Ion Implanted Silicon
Authors: Wu Wei-Kuo , Washburn Jack
Published: June 2020

Long rod-like defects are observed in ion implanted silicon when boron is present either as a prior dopant addition or as the implanted species. For many years, these rods have been described variously as precipitates, lines of point defects, dislocation dipoles, or elongated dislocation loops. The diffraction contrast from the defects has been difficult to interpret unambiguously because of their very narrow spacing. Our recent work indicates that they have the characteristics of narrow extrinsic dipoles or elongated dislocation loops and that there are two different types along each of the six <110> directions.

In this paper, an alternative method, annealing kinetics, has been used to identify the nature of these defects formed during post-implantation annealing in boron ion (100 keV) implanted silicon irradiated at room temperature to a dose of 2x1014/cm2.
The Microstructure of Xe Implanted GaAs
Authors: Hills C. R. , Thomas G. J. , Stein H. J.
Published: June 2020

Previous investigators have shown that the surface regions of GaAs samples implanted at room temperature with 40-100 keV Ne ions become amorphous after a dose of the order of 1x1014ions cm-2. Their study also indicated that implantation above room temperature (35°-200°C) results in the retention of crystallinity even with fluences two to three orders of magnitude higher. Investigators using ion backscattering and optical absorption have shown that ion dose rate is also an important variable in ion implantation. In the present investigation, transmission microscopy has been used to further study the temperature and dose rate effects of ion implantation in GaAs. A number of {111} and {l00} single crystal GaAs samples have been implanted with 275 keV Xe ions to doses of 1015 and 1016 ions cm-2 at dose rates ranging from 2.5x1012 to 8.1xl012ions cm-2 sec-1.

Low dose (1015ions cm-2) implantations at room temperature produced amorphous layers at all dose rates.
Electron Microscopy of Frozen, Hydrated Biological Specimens
Authors: Taylor Kenneth A.
Published: June 2020

Recently, a method has been developed in this laboratory for maintaining the hydration of biological materials by using frozen specimens. With this technique specimens are prepared using folding grids on which are mounted composite support films of carbon and SiO. The technique essentially embeds the biological material in a thin aqueous film between the two supporting films. The sandwiched specimens are then frozen directly in liquid nitrogen. While it was thought at first that freezing directly in liquid nitrogen might cause disordering of periodic or crystalline biological specimens, this has been shown not to be the case. High resolution electron diffraction patterns have been obtained from frozen unstained catalase crystals.

The microscopy of frozen specimens depends on their resistance to damage by electron irradiation. The critical exposure for fading of the electron diffraction intensities from frozen unstained catalase crystals has been measured.
Morphological Observations on the Granule Types in Rabbit Extra-Adrenal Chromaffin Cells.
Authors: Mascorro Joe A. , Yates Robert D.
Published: June 2020

Extra-adrenal chromaffin organs (abdominal paraganglia) constitute rich sources of catecholamines. It is believed that these bodies contain norepinephrine exclusively. However, the present workers recently observed epinephrine type granules in para- ganglion cells. This report investigates catecholamine containing granules in rabbit paraganglia at the ultrastructural level.

New Zealand white rabbits (150-170 grams) were anesthetized with 50 mg/kg Nembutal (IP) and perfused with 3% glutaraldehyde buffered with 0.2M sodium phosphate, pH 7.3. The retroperitoneal tissue blocks were removed and placed in perfusion fluid for 4 hours. The abdominal paraganglia were dissected from the blocks, diced, washed in phosphate buffer and fixed in 1% osmic acid buffered with phosphate. In other animals, the glutaraldehyde perfused tissue blocks were immersed for 1 hour in 3% glutaraldehyde/2.5% potassium iodate buffered as before. The paraganglia were then diced, separated into two vials and washed in the buffer. A portion of this tissue received osmic acid fixation.
Immunoferritin Studies on Naturally Occurring Antibodies in Mouse Sera Against the Mouse Mammary Tumor Virus (MMTV)
Authors: Miller M. F. , Dmochowski L. , Bowen J.M. , Scanlon M. , Chesner J. , Kenny R.
Published: June 2020

Few immunoelectron microscopic studies have been carried out in which sera of mice bearing mammary tumors were tested for the presence of naturally occurring antibodies to MMTV. In one study it was reported that sera of mice with spontaneous mammary tumors did not contain antibodies to MMTV tested by the direct immunoferritin method. It was recently reported that sera of mice bearing spontaneous mammary tumors and at least some tumor- free mice possess antibodies to MMTV which can be demonstrated by the indirect immunoperoxidase procedure. The present study was undertaken to determine (i) if naturally occurring serum antibodies to MMTV could be detected using the indirect immunoferritin method, (ii) the distribution of such antibodies in various strains of inbred mice and(iii) the degree to which immunoferritin results correlate with results derived from the same sera tested by fixed immunofluorescence.
Ultrastructure of Epidermal Cells in Prostaglandin-Treated and Wounded Rats
Authors: Lupulescu A. , Habowsky J.E. , Milkintas J. , Birmingham D.
Published: June 2020

Prostaglandins (PGE1, PGE2, and PGF2α) are hormones which exhibit a multifold effects on the fine structure of cells. Recently, there is increasing evidence that prostaglandins exert an important biological role on the structure of epidermal cells. Thus, it has been reported that PGB1, selectively affects the ultrastructure of epidermal mitochondria of embryo chick skin in culture; also accelerates the keratinization and cell differentiation. In order to study the effect of prostaglandins (PGE1, PGE2and PGF2α) on the ultrastructure of epidermal cells, we induced wounds in rats. It is known that experimental wounds are good models for the study of cell growth and kinetics.

Adult male rats (Sprague-Dawley strain) were wounded under ether anesthesia. (Two linear incisions of 2 cm long). They were divided in four groups; each of 10 rats.
Regeneration of Peripheral Nervous System (PNS) in Rats Under Dietary and/or Endogenous Cholesterol Variations
Authors: Rawlins F. A.
Published: June 2020

Both exogenous and endogenous cholesterol are rapidly incorporated into PNS myelin during its formation. We have found that a decrease in endogenous cholesterol induces a retardation in the normal development of the myelin sheath. In order to study the relative importance of these two sources of cholesterol for the myelin formation and maintenance in the present experiments, the regeneration of the sciatic nerve has been used as a model to study myelin formation under conditions of high and low levels of endogenous and exogenous cholesterol. For this, rats (starting a 1 month of age) were subjected to one of the following conditions: a) normal diet; a') normal diet plus treatment with the cholesterol biosynthesis inhibitor AY-9944*; b) 2% cholesterol diet; b') 2% cholesterol diet plus treatment with AY-9944; c) cholesterol free diet; and c') cholesterol free diet plus treatment with AY-9944.
Viruslike Particles in Human Prostate Cancer and Virus Particles in Normal Prostate of Mice
Authors: Ohtsuki Y. , Seraan G. , Bowen J. M. , Dmochowski L.
Published: June 2020

As part of a multidisciplinary approach to study the relationship of viruses to the etiology of human prostate cancer, 42 (34 cases of cancer, and 8 cases of benign hyperplasia) specimens of prostate tumors have been examined by electron microscopy. Preliminary results of this ultrastructural study have been reported.

Intracisternal 150-200 nm viruslike particles (Figs. 1a,b) were found in epithelial cells of five cases of prostatic cancer. The particles were also seen budding from the cisternal walls (Fig. 2a). Some particles show two inner concentric layers (Figs. 2a,b) or an electron dense core (Figs. 1a,b). Dumbbellshaped particles (Fig. 2c) and elongated, probably virus-related structures (Fig. 2d) were also observed.

In parrallel with studies on human tissues, prostatic glands of normal young (6 weeks old) and adult (1 year old) mice from the high mammary cancer strains RIII/Dm, C3H/Dm and A/Dm and from C57/BL/6/Dm low mammary cancer strain have been examined to determine if prostate was a potential source of transmissible oncornaviruses in mice.
Morphologic and Biochemical Characteristics of H-4II-E Rat Hepatoma Clones
Authors: Lovig C. A. , Nordquist R. E. , Muragishi H. , Bottomley R. H.
Published: June 2020

Previous work has demonstrated that differences in enzyme levels in HeLa cells were associated with differences in genetic complement. This study was designed to see if hepatoma cells cloned from the H-4II-E cell line with different genetic complements might differ morphologically as well as biochemically.

A large number of clones were established using the method of Patuleia and Friend and Pluznik and Sachs. Five of the cloned lines were picked on the basis of their modal chromosome number and used for biochemical and morphological studies and for further genetic analysis. A sufficient number of cells were set up in T-75 flasks so that all studies could be done on cells of the same generation passage.

Karyotypic analysis showed that all of the cloned lines picked were differnt cytogenetically.

Biochemical analysis showed that the levels of enzyme activity of alkaline phosphatase varied markedly from one cloned line to another (figure 1) and was higher in four of the clones than in normal liver.
A New Human Breast Tumor Cell Line
Authors: Nordquist R.E. , Wasik R.M. , Riggs P.J. , Munson P.L. , Schafer F.B.
Published: June 2020

An infiltrating ductal cell carcinoma was removed from the breast of a postmenopausal Caucasian female. The excised tissue was divided into three parts; one part for electron microscopy, one part for tissue culture and the remainder frozen for immunological studies.

The tissue for culture was minced finely with sterile razor blades and cultured in Falcon flasks containing Eagel's MEM supplemented with 10% heat denatured fetal calf serum. The tissue for electron microscopy was fixed in 6.25% glutaraldehyde in 0.1 M PO4 buffer plus 5% sucrose and postfixed in 1% OsO4 in the same buffer. The fixed tissue was dehydrated in graded ethanol and embedded in Spurr.

The tissue which was cultured began to grow out after approximately six weeks and became a continuous epithelial cell line which was designated BOT-2 (Breast Original Tumor). Electron microscopic examination revealed that these cells had epithelial characteristics, i.e. the presence of tonofilaments and well formed desmosomes.
Ultrastructural Study of Human Mammary Carcinoma Cells (MCF-7) Grown in Collagen-Coated Sponge
Authors: Russo J. , Bradley R. , Soule H.D.
Published: June 2020

MCF-7 is an established cell line derived from a mammary carcinoma, that reproduces the tumor histological pattern when cultured in collagen-coated cellulose sponge.

Cells grown in monolayer for more than 120 passages are seeded in a collagen-coated cellulose sponge and cultured in Eagle's nutrient medium, supplemented with insulin and 10% calf serum for 7 to 14 days. The sponges were fixed in Hirsch-Fedorko, embedded in Epon, and sectioned for electron microscopy.

The cells are observed growing in clusters of 4 to 50 cells per level of section and also acinar-like structures.

A common ultrastructual pattern can be described for most of the cells. The cell surface presents numerous microvilli, that have a positive ATPase histochemical reaction. The cells are joined by desmosomes, intermediary, and tight junctions with cell interdigitations among them, but no junctions are observed between the cells and the collagen coat (Fig. 3).
Sclerosing Glomerulonephritis
Authors: Mandal A. , Chrysant K. , Nordquist J. , Kraikitpanitch S. , Xoung D. , Lindeman R.
Published: June 2020

A small but undefined percentage of adults with idiopathic proteinuria, microscopic hematuria and hypertension with partial or no response to corticosteroid or immunosuppressive therapy, progress slowly to renal failure. Histological diagnosis of membranous, membranoproliferative or chronic glomerulonephritis were made in these patients. Retrospective reevaluation of renal pathology in such patients has resulted in the emergence of a new clinicopathological entity. We are reporting a retrospective study of renal biopsies using light microscopy (LM) and electron microscopy (EM) from six patients with previous diagnosis of proliferative glomerulonephritis (2 patients), membranous glomerulonephritis (2 patients), nephrosclerosis (1 patient) and end stage kidney (1 patient). These patients were aged between l6 and 51 years, four males and two females. They had initial average 24 hour proteinuria of 1.3 gm (range 0.5-3.4 gm) and blood urea nitrogen of 24 mgm percent (range 12-32 mgm percent).
Mucosal Response to Acetylsalicylic Acid
Authors: Lightfoot F. G. , Cassidy M. M.
Published: June 2020

An ultrastructural study was undertaken to chronicle the morphologic aspects of the response of the alimentary tract to the presence of acetylsalicylic acid in the lumen. A clinical dose (10 mg/kg) of buffered acetylsalicylic acid was administered to male Wistar rats by (a) gastric intubation (feeding tube), and (b) gastrointestinal perfusion. The animals used in this study were sacrificed at various intervals 15, 30, 60 minutes and 4 hours after administration of the dose. Tissues from the fundus of the stomach and the jejunal region of the small intestine were examined.

Tissues were examined by light microscopy as well as transmission and scanning electron microscopy. Significant deviations from the appearance of control tissue samples were observed in all animals. Surface gastric erosions were observed in both intestine and stomach, as well as localized areas of punctate hemorrhage. Conventional light micrographs revealed a separation of the epithelial lining from the basement membrane structure: the intercellular space was greatly distended compared to normal.
Ultrastructural Pathology of Ischemic Myocardium as Revealed by the Freeze Fracture Technique
Authors: Ashraf M. , Mayr W.
Published: June 2020

Myocardial cells undergo extensive ultrastructural changes during ischemia, easily observed after 30 minutes of coronary artery occlusion. Although various membranous organelles remain intact during acute ischemia, biochemical evidence indicates several metabolic alterations in affected cells. Since cell membranes and membranes of intracellular organelles play an important role in the pathogenesis of myocardial cell injury, changes in their interiors could be informative. However, such changes are not easily detectable in conventional thin sections. This study examined ultrastructural alterations in the membranous organelles of ischemic myocardium using the freeze-fracture technique to improve detection of such changes.

After 5 and 24 hours of coronary artery occlusion the hearts from dogs and rats were perfused with buffered glutaraldehyde. Small pieces of the left ventricle were dipped in Freon 22 and immediately frozen in liquid nitrogen before fracturing in a Balzer's freeze-etch apparatus at -100 or -120°C.
Ultrastructural Studies of Bovine Respiratory Disease Complex
Authors: Kim James C.S.
Published: June 2020

Bovine respiratory diseases cause serious economic loses and present diagnostic difficulties due to the variety of etiologic agents, predisposing conditions, parasites, viruses, bacteria and mycoplasma, and may be multiple or complicated. Several agents which have been isolated from the abnormal lungs are still the subject of controversy and uncertainty. These include adenoviruses, rhinoviruses, syncytial viruses, herpesviruses, picornaviruses, mycoplasma, chlamydiae and Haemophilus somnus.

Previously, we have studied four typical cases of bovine pneumonia obtained from the Michigan State University Veterinary Diagnostic Laboratory to elucidate this complex syndrome by electron microscopy. More recently, additional cases examined reveal electron opaque immune deposits which were demonstrable on the alveolar capillary walls, laminae of alveolar capillaries, subenthothelium and interstitium in four out of 10 cases. In other tissue collected, unlike other previous studies, bacterial organisms have been found in association with acute suppurative bronchopneumonia.
A Comparative Study of the Effects of Cyclocytidine and Fluorocyclocytidine on Murine Submaxillary Salivary Glands
Authors: Liss Robert H. , Charest Maria C. , Mead John A.R.
Published: June 2020

The clinical utility of 1-β-D-arabinofuranosylcytosine (araC), NSC 63878, a chemotherapeutic agent active against a number of acute leukemias and lymphomas, is compromised by the deamination of araC to arabinosyluracil, an inactive metabolite. This observation has led to the study of 2,2'-anhydro-l-β-D-arabinofuranosylcytosine (cyclocytidine, cycloC), NSC 145668, a structurally related, potent anti-tumor agent which is less easily deaminated than is araC. The fluorinated derivative of cycloC, 2,2'-anhydro-l-β-arabinofurano-syl-5-fluorocytosine (fluorocyclocytidine, F-cycloC), NSC 166641, also is an active chemotherapeutic in patients with acute leukemias, and may be most useful in subjects who are resistant to araC. The clinical advantages associated with cycloC are limited, however, by severe salivary gland discomfort and hypersalivation in patients receiving this compound. The present study was undertaken to characterize the cytopathologic alterations in murine submaxillary glands following cycloC therapy and to compare these observations with similar data from studies of mice treated with F-cycloC.
An Ultrastructural and Cytochemical Study of Aging in the Thyroid of the Domestic Cat
Authors: Ives Phil J.
Published: June 2020

Thyroid follicular cell lysosomes have been shown to have a definite function in thyroglobulin degradation and thyroid hormone production. Thyroid activity which decreases with age is an important factor affecting cellular energy generation, enzyme activity, and protein synthesis. Autophagy, degradative enzyme release, and interruption of normal functions related to cellular slow down and cell death are involved in the aging process.

The present study was conducted to observe the cytochemical and ultrastructural changes in thyroid follicular cells during this aging process. A total of fourteen domestic cats (Felis domesticus) were studied using two animals from each of the following age groups: 2 and 6 months, 1, 3, 5, 7 and 8 years.

Hormone production in the thyroid follicular cell is characterized by many vesicles of various electron densities. They appear to originate from the Golgi areas, rough endoplasmic reticulum (RER) and apical membrane (Fig. 5, arrow).
The Location of Vitamin A-Storing Cells in Hepatic Fibrosis Induced by Carbon Tetrachloride
Authors: Minick Odell T. , Bahu Raja M. , Lyon Harvey W. , Tiecke Richard W. , Inouye Tohru , Kent Geoffrey
Published: June 2020

Recent reports indicate that chronic hypervitaminosis A in humans may be associated with perisinusoidal fibrosis in the liver. A prominent feature of excess vitamin A administration is the increased number of irregularly shaped, vacuolated cells in the spaces of Disse. These vitamin A-storing cells are known as Ito cells, lipid storing cells or lipocytes. Their precise function is not established, but their appearance and location suggest that they may also play the role of fibroblasts; their massive accumulation in hypervitaminosis A may thus be causally related to perisinusoidal fibrosis. Although we have been unsuccessful in producing perisinusoidal fibrosis experimentally with vitamin A alone, we elected to use the vitamin in conjunction with the fibrosis-inducing agent carbon tetrachloride (CC14) to clarify the relationship of these cells to newly formed collagen.

Rats were divided into groups receiving (1) vitamin A and CC14, (2) vitamin A alone and (3) CC14 alone, for periods up to four months.
Stereoscopic Visualization of Selectively Stained Neuromuscular Junctions Using High Voltage Electron Microscopy
Authors: Westfall Jane A. , Ellisman Mark H. , Porter Keith R.
Published: June 2020

High voltage electron microscopy (HVEM) combined with selective histochemical staining yields information otherwise difficult to obtain. Such selective staining follows the irregular contours, channels or surfaces of the structures being studied and thus is not easily traced in conventional thin section electron microscopy. Often the amount of enzyme activity is insufficient to provide an accurate estimate of quantitative differences in reaction product between experimental and control tissues. By taking stereo pairs of micrographs of serial thick sections at 1 MeV it is possible to obtain precise localization of very electron dense reaction products at high resolution and to view the three-dimensional aspects of enzyme distribution. Using stereoscopic visualization a cholinesterase reaction product is identified in neuromuscular junction regions isolated from the hind limb muscles of a dystrophic strain of mice.
Prostatic Acid Phosphatase (PAP) Differentiated Ultracytochemically from Lysosomal Acid Phosphate in the Rat with a PAP/Specific Substrate, Phosphorylcholine
Authors: Allen Shannon W. , Serrano José A. , Wasserkrug Hannah L. , Serrano Anna A. , Seligman Arnold M.
Published: June 2020

During the design and synthesis of new chemotherapeutic agents for prostatic carcinoma based on phosphorylated agents which might be enzyme-activated to cytotoxicity, phosphorylcholine, [(CH3)3+NCH2CH2OPO3Ca]Cl-, has been indicated to be a very specific substrate for prostatic acid phosphatase (PAP). This phenomenon has led to the development of specific histochemical and ultracytochemical methods for PAP using modifications of the Gomori lead method for acid phosphatase. Comparative histochemical results in prostate and kidney of the rat have been published earlier with phosphorylcholine (PC) and β-glycerophosphate (βGP). We now report the ultracytochemical results.

Minced tissues were fixed in 3% glutaraldehyde-0.1 M phosphate buffered (pH 7.4) for 1.5 hr and rinsed overnight in several changes of 0.05 M phosphate buffer (pH 7.0) containing 7.5% sucrose. Tissues were incubated 30 min to 2 hr in Gomori acid phosphatase medium (2) containing 0.1 M substrate, either PC or βGP.