bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute response of lung parenchyma to volcanic ash
Authors: Dodson R.F. , Akematsu T. , Williams M.G. , O'Sullivan M.F. , Hurst G. A. 
Published: June 2020

The eruption of Mt. St. Helens on May 18, 1980, resulted in a concentrated short-term exposure for a large segment of the population of eastern Washington, northern Idaho, and western Montana. Samples were collected from all three regions and the respirable size particles (⋜0.6μ) were separated and analyzed. The predominance of the respirable size fraction was found by X-ray energy dispersive analysis to be alumino silicates. A homogeneous preparation was intratracheally injected into young adult guinea pigs. The dose given the animals consisted of 52.5 mg in saline. This dose provided a short-term heavy exposure setting similar to that of the populus. At the end of the selected post-injection intervals of either 2 or 4 hours or 1 through 7 days, the animals were sacrificed by vascular perfusion through the right ventricle.Embedded tissue samples were reviewed at the light microscopy level and selected fields were thin sectioned for transmission electron microscopy and scanning transmission electron microscopy (correlated with X-ray energy dispersive analysis). The EM was carried out on a JEOL 100CX TEMSCAN.
Presence of antibody in virus-infected brain cells of SSPE ferrets
Authors: Brown Hannah R. , Donato Tammy L. , Thormar Halldor 
Published: June 2020

Measles virus specific immunoglobulin G (IgG) has been found in the brains of patients with subacute sclerosing panencephalitis (SSPE), a slowly progressing disease of the central nervous system (CNS) in children. IgG/albumin ratios indicate that the antibodies are synthesized within the CNS. Using the ferret as an animal model to study the disease, we have been attempting to localize the Ig's in the brains of animals inoculated with a cell associated strain of SSPE. In an earlier report, preliminary results using Protein A conjugated to horseradish peroxidase (PrAPx) (Dynatech Diagnostics Inc., South Windham, ME.) to detect antibodies revealed the presence of immunoglobulin mainly in antibody-producing plasma cells in inflammatory lesions and not in infected brain cells.In the present experiment we studied the brain of an SSPE ferret with neutralizing antibody titers of 1:1024 in serum and 1:512 in CSF at time of sacrifice 7 months after i.c. inoculation with SSPE measles virus-infected cells. The animal was perfused with saline and portions of the brain and spinal cord were immersed in periodate-lysine-paraformaldehyde (P-L-P) fixative. The ferret was not perfused with fixative because parts of the brain were used for virus isolation.
Auger Electron Spectroscopy with the Scanning Electron Microscope
Authors: Hart Raymond K. 
Published: June 2020

Various SEM-AES combinations have been described in the literature during the past six years. All these instruments, with one exception, were dry pumped and capable of operating at pressures below 10-7torr. The equipment described herein, see Fig.1, is a modified ULTRASCAN SEM with an Auger-electron analysis system from Physical Electronics Industries (PHI): it is also dry pumped to the low 10-7torr range.The electron optical column uses two electromagnetic lenses instead of the original three, and with a 200 micron objective aperture it delivers a maximum of 0.6 to 0.8 x 10-8A at the specimen. At the short working distance (1.2 cm) the spatial resolution is between 70 and 80 nm, while at the longer working distance (3.2 cm) the resolution is about 100 nm. The scintillator assembly was transposed to the right side of the specimen chamber so that a PHI small cylindrical-mirror velocity analyzer, with bellows extension could be mounted diametrically opposite the scintillator.
Lattice Imaging of Twin, Lath and α/Martensite Boundaries in Duplex Low Carbon Steels
Authors: Koo J. Y. , Thomas G. 
Published: June 2020

High resolution electron microscopy has been shown to give new information on defects(1) and phase transformations in solids (2,3). In a continuing program of lattice fringe imaging of alloys, we have applied this technique to the martensitic transformation in steels in order to characterize the atomic environments near twin, lath and αmartensite boundaries. This paper describes current progress in this program.Figures A and B show lattice image and conventional bright field image of the same area of a duplex Fe/2Si/0.1C steel described elsewhere(4). The microstructure consists of internally twinned martensite (M) embedded in a ferrite matrix (F). Use of the 2-beam tilted illumination technique incorporating a twin reflection produced {110} fringes across the microtwins.
Analysis Of Multipoints On A Particle Using A Computer Controlled Sem
Authors: Hoover M.R. , Lebiedzikf J. , Strickler D.W. 
Published: June 2020

The computer controlled SEM has been used extensively to study mineral matter in coals and residues from solvent refined coals (SRC). Both dispersed powders and polished sections have been studied. The dispersions have been made on beryllium substrates using the camphor-napthalene (1) and also frozen distilled water sublimination techniques. The polished sections have been prepared by vacuum impregnating the samples with a thermo-setting resin. To achieve some contrast in the electron back-scattered (EBS) signal, a cobalt-rich hardener has been used with the resin. With an inverted EBS signal the coal grains appear brighter than the background.The automated SEM recognizes a grain of coal or other feature of interest by using the fact that a signal (EBS, SEI, etc.) from the feature is brighter than the same signal from the background material. The SEM determines the average diameter of the particle by summing the lengths of eight diameters taken every 22.5° and dividing by eight.
Electron Microscopic Observations on Virus-Like Particles of a Catfish Papilloma
Authors: Edwards M. R. , Samsonoff W. A. 
Published: June 2020

Papillomas in catfishes have been described (1) but the presence of viruses in these tumors has not (2). This report is concerned with the study of a papilloma found on the lower lip of a brown bullhead (letalurus nebulosus) which had been frozen prior to arrival at our laboratory.Tumor tissues were thawed in 2.5% glutaraldehyde and postfixed in 1$ osmium tetroxide. Both fixatives were prepared in Millonig's buffer. Fixation, washing, dehydration, and Epon embedding were accomplished according to conventional electron microscopic techniques.Examination of thin sections revealed virus-like particles in epidermal cells which constituted the major part of the neoplasm (Fig. 1). No particles were found in the connective tissue surrounding the epidermal papillae. The cells containing particles were usually isolated from one another, had a spindle or fusiform shape, and exhibited many cytoplasmic extensions in random directions. Their nuclei were pleomorphic and displayed irregular nuclear envelopes with relatively large lacunae. Vesiculation of the cytoplasm was extensive, apparently caused by dilations of the endoplasmic reticulum.
Comparison of Acrylamide and Agar Gels by Freeze-Etching
Authors: Steere Russell L. , Erbe Eric F. 
Published: June 2020

Thin sheets of acrylamide and agar gels of different concentrations were prepared and washed in distilled water, cut into pieces of appropriate size to fit into complementary freeze-etch specimen holders (1) and rapidly frozen. Freeze-etching was accomplished in a modified Denton DFE-2 freeze-etch unit on a DV-503 vacuum evaporator.* All samples were etched for 10 min. at -98°C then re-cooled to -150°C for deposition of Pt-C shadow- and C replica-films. Acrylamide gels were dissolved in Chlorox (5.251 sodium hypochlorite) containing 101 sodium hydroxide, whereas agar gels dissolved rapidly in the commonly used chromic acid cleaning solutions. Replicas were picked up on grids with thin Foimvar support films and stereo electron micrographs were obtained with a JEM-100 B electron microscope equipped with a 60° goniometer stage.Characteristic differences between gels of different concentrations (Figs. 1 and 2) were sufficiently pronounced to convince us that the structures observed are real and not the result of freezing artifacts.
Visualization of the Structure of the Rat Oocyte by Scanning Electron Microscopy
Authors: Bagavandoss P. 
Published: June 2020

Mammalian oocytes have been well studied with the light and the transmission electron microscopes(1,2). Glutaraldehyde and osmium tetroxide, which offer excellent fixation have certain limitations when used for SEM studies of rat ovaries. These fixatives require very small specimens for penetration, but such small specimens provide only a few intact oocytes for SEM observations. However, for meaningful observation of the changes brought about by various hormone treatments on the oocytes, a maximum number of oocytes must be available frcm a single ovary. Also, aldehyde and OSO4 fixed tissues are not easy to cut into smooth halves. This report cctnmuni- cates preparation techniques that yield useful SEM of the oocyte and associated structures of rat ovaries.Rat ovaries were dissected out and immediately placed in Bouin's fluid for 24 hours at rocm temperature. After fixation each ovary was cut into two halves with a sharp blade and kept in 70% alcohol overnight.
Comparative Scanning Electron Microscopy Study of the Anuran Basilar Papilla
Authors: Lewis E.R. 
Published: June 2020

Frishkopf and his coworkers demonstrated the auditory sensitivity and frequency range of the basilar papilla in the bullfrog; and, more recently, Capranica and his coworkers have demonstrated the auditory sensitivity and frequency range of that organ in other anuran species, spanning four of the five anuran superfamilies. In each case, the receptors of the basilar papilla respond to frequencies well above those that excite the other anuran auditory organ, the amphibian papilla. However, the range of best excitatory frequencies for the basilar papilla varies from species to species. Frishkopf and Flock have examined the bullfrog basilar papilla with TEM and light microscopy, and Lewis and Li have studied receptor surface topography in that organ with SEM; but no previous comparative studies have been reported.To date, we have examined eleven species, spanning five families (three superfamilies) and including four of the species studied by Capranica and his coworkers.
Structural modifications of intercellular junctions.
Authors: Metz J. , Merlo M. , Forssmann W. G. 
Published: June 2020

Structure and function of intercellular junctions were studied under the electronmicroscope using conventional thin sectioning and freeze-etch replicas. Alterations of tight and gap junctions were analyzed 1. of exocrine pancreatic cells under cell isolation conditions and pancreatic duct ligation and 2. of hepatocytes during extrahepatic cholestasis.During the different steps of cell isolation of exocrine pancreatic cells, gradual changes of tight and gap junctions were observed. Tight junctions, which formed belt-like structures around the apex of control acinar cells in situ, subsequently diminished, became interrupted and were concentrated into macular areas (Fig. 1). Aggregations of membrane associated particles, which looked similar to gap junctions, were intermixed within tight junctional areas (Fig. 1). These structures continously disappeared in the last stages of the isolation procedure. The intercellular junctions were finally separated without destroying the integrity of the cell membrane, which was confirmed with porcion yellow, lanthanum chloride and horse radish peroxidase.
Variations of separate junction structure in the invertebrates
Authors: Green Colin R. 
Published: June 2020

Three main variations of the invertebrate septate junction are now generally accepted; the Hydra type, the pleated septate and the smooth septate junctions. A junctional study of many members of a wide range of invertebrate phyla using thin section, lanthanum tracer and freeze-fracture techniques has however revealed at least eight distinct septate junction types, including two anastomosing septate junctions in the higher invertebrate phyla.In the Coelenterata three forms of septate junction occur. The Hydra type found in Hydrozoa (Fig 1), a pegged junction seen in the epidermal cells of Anthozoa and a ladder-like junction seen in the endodermal cells of Anthozoa. The pegged Anthozoa junction consists of septa with distinct short pegs branching at right angles mainly from one side (fig 2). Where two septa run close together, the pegs may form crossbars linking them. The ladder junction has a pegged double septum with crossbars linking the two parts of each septum (fig 3).
Detection of antibodies to rabies virus by immunoelectron microscopy
Authors: Chaudhary R. K. , Charlton K. M. , Monette M. T. , Kelen A. E. 
Published: June 2020

Immunization of humans and domesticated animals at risk of contracting rabies is common practice. The mouse neutralization test (MNT) is still the standard technique used for detecting and measuring antibody to rabies virus in sera of vacinees. However, it suffers from problems of reproducibility associated with tests performed in vivo. It also has the disadvantage of being expensive, time-consuming and hazardous. Hence, there has been a continuous search for a simple, rapid and safe test. In recent years, methods based on haemagglutination, haemadsorption, plaque reduction, immunofluorescence and radioimmunoassay have been developed, but none of them has eliminated the hazard involved in the use of live virus.With emphasis on laboratory safety, attempts were made to use inactivated rabies virus for antibody assay by immunoelectronmicroscopy (IEM), in comparison with the MNT.Inactivated rabies virus grown in human diploid cells was supplied by Connaught Laboratories Limited (CLL). The virus was purified by sucrose density gradient centrifugation and used at a concentration to give 35-50 particles per grid square.
conformational studies of covalently closed circular viroid RNA
Authors: Klotz Günther , Kleinschmidt Albrecht K. , Sänger Heinz L. 
Published: June 2020

Viroids are uncoated infectious RNA molecules pathogenic to certain higher plants. The molecular structure of viroids is characterised by single-strandedness, circularity and partial complementarity within the chain of about 350 nucleotides. In the native state the viroid molecule exists as a highly base-paired rod-like structure. Fig. 1 shows a dark-field micrograph of cucumber pale fruit viroid (CPFV) spread with cytochrome c and positively stained with uranyl salts. Under our conditions rods measure 37. 5 nm ± 2. 5 nm in length. They appear slightly flexible. Specific details are not recognized. Using benzyldimethylalkylammonium chloride (BAC) as the film forming surfactant most of the molecules appear as dumb-bell shaped rods with terminal knots (Fig. 2). Length determination led to the mean value of 33 nm ± 3 nm.The variety of structures previously described was further investigated to assess that they reflect different conformational states of only one species of molecules.
Electron microscopy of nocardial cell division
Authors: Woodward Janet Hearn 
Published: June 2020

Nocardia polychromogenes is an aerobic, gram (+), non-motile, partially acid-fast actinomycete with primary mycelia that fragment into bacillary and coccoid elements.For scanning electron microscopy, N. polychromogenes culture strain Waksman 3409-A was grown on Potato Dextrose Agar at 25 C for 12-72 h. Five mm2 sections of the colonies, including portions of the interior and perimeter were fixed by exposure to osmium fumes for 16-24 h and air dried for 2 h. Specimens, mounted on stubs and sputter coated with gold, were viewed in a Cambridge Stereoscan Mark II scanning electron microscope. For transmission electron microscopy, the organism was grown on Potato Dextrose Agar at 25 C for 12-32 h. Whole colonies, 1-2 mm in diameter, were fixed by exposure to osmium fumes for 24 h. After suspension in noble agar, cells taken from the periphery of the fixed colonies were stained with 0. 5% uranyl acetate made in acetate-veranol buffer.
Behavior of mitochondria during sporulation in yeast
Authors: Stevens Barbara J. 
Published: June 2020

The number and the form of mitochondria in vegetatively growing yeast, Saccharo-myces cerevisiae, have previously been determined by the use of serial thin sections of entire cells. It was found that the number of mitochondria is directly related to the growth phase: logarithmic phase cells contain few mitochondria, less than 10, while stationary phase cells have numerous organelles, from 30 to 50 individual mitochondria. A single mitochondrion was found in 2 log phase, glucose-repressed cells, but all other cells had more than one mitochondrion. In the present study, the behavior of the chondriome during meiosis and sporulation in yeast was followed by the serial section technique and was compared to that in vegetative cells.Diploid strains Z193, Z239-6B6B and s4l were obtained from R. and M. Esposito and S. Klapholz (Univ. of Chicago) and serial sections of strain 112 were kindly provided by D. Zickler (Univ. Paris-Sud). Cells were fixed in glutaraldehyde, treated with glusulase (Endo Lab.) or zymolyase (Kirin Brew. Co.) to remove the cell wall, and post-fixed in Dalton's chrome osmium.
Effects of dextran on ultrastructure and function of renal tubule cells
Authors: Christensen Erik IlsØ , Maunsbach Arvid B. 
Published: June 2020

Dextran, a much used plasma expander, causes pronounced ultrastructural changes in renal proximal tubule cells after intravenous injection. The aim of the present study was to determine the effects of dextran on uptake, transport, and digestion of low molecular weight protein in proximal tubule cells.Rats of a strain tolerant to dextran were infused i. v. with dextran T 40 (10% in saline) at a rate of 7 ml/h to a total dose of 5 g/kg body weight. Control rats were infused with saline only. At the end of the infusion, the rats were injected i. v. with 0. 2 mCi of 125I-1abel1 ed egg white lysozyme. One hour later the kidneys were either fixed by perfusion with 1% glutaraldehyde and prepared for electron microscope autoradiography or slices were taken from the renal cortex and incubated in vitro to determine the lysosomal digestion of lysozyme in the proximal tubule cells.
Gap junction associated filaments in testis interstitial cells of the rat
Authors: David-Ferreira J.F. , David-Ferreira K.L. , Miranda M.H. , Lemos J.C. 
Published: June 2020

The testis interstitial cells of the rat are closely associated forming small aggregates in the vicinity of the vessels. The finality of the present study is to analise the relationship between the interstitial cells and to describe some particularities of their junctions.The observations were made in thin sections from testis of 2 to 3 months old rats fixed by immersion or perfusion with 2 to 3% glutaral- dehyde in s-collidine or cacodylate buffer followed by 2% osmium tetro-xyde in the same buffers. Some specimens have been prepared following the technique of Shea. The thin sections obtained after embedding in Epon were double stained in uranyl acetate and lead citrate. For the cryofracture study the tissues were fixed in 3% glutaraldehyde in cacodylate buffer, impregnated in 28% glycerol, frozen in Freon 22 and stored in liquid nitrogen. Freeze fracture and platinum-carbon shadowing were done in a Balzers 300.
Crystalloids of actin-like filaments in the swine sertoli cell
Authors: Toyama Yoshiro , Obinata Takashi , Holtzer Howard 
Published: June 2020

Crystalloids have been observed by light microscopy in Sertoli cells of both experimentally induced and spontaneous azoospermic testes of the swine and in Sertoli cells of normal human testes. However crystalloids have not been found in normal swine testes with the light microscope. Swine crystalloids are distinguished from human crystalloids in that the diameter of the filaments is 5 nm instead of 10-15 nm. This paper confirms this distinction by showing that the filaments of swine crystalloids bind heavy meromyosin (HMM) but those of human crystalloids do not.Human testes were removed from four patients with prostate cancer, whereas normal and cryptorchid swine testes were acquired from a slaughterhouse. HMM extracted from rabbit skeletal muscle was dissolved in 10 mM Tris buffer (pH 7. 4) containing 0. 1 M KCI and 0. 001 M MgCl2 at a final concentration of 7 mg/ml. Pieces of testicular tissue were exposed to HMM at 4°C for 24 hours after glycerination or saponin treatment.
Exocytosis by multinucleate giant cells
Authors: Papadimitriou J. M. 
Published: June 2020

Multinucleate giant cells which are often found in inflammatory reactions are polykarya formed by the fusion of exuded monocytes. Such syncytia, however, display a reduced phagocytic performance in comparison to mononuclear phagocytes but cell populations containing large numbers of multinucleate giant cells have been shown to selectively secrete lysosomal hydrolases. In this communication the possibility of exocytosis by these polykarya has been investigated by ultrastructural and electron cytochemical techniques.Multinucleate giant cells were produced by the implantation of small sheets of melenex plastic film into the subcutaneous tissues of mice. The macrophage polykarya which formed on the surface of the plastic sheet were then subjected to ultrastructural examination, either untreated or after exposure to cytochalasin B or zymosan or both. In some experiments the cells were exposed to thorotrast or ferritin before the various treatments were performed. Some specimens were stained with tannic acid while in others the electron cytochemical demonstration of acid phosphatase or surface ATPase was performed.
Inclusion body myositis: Electron microscopy study of 9 cases
Authors: Kalyan-Raman U.P. , Kalyan-Raman Krishna , Caughey R.C. 
Published: June 2020

On routine examination of 266 muscle biopsies by histology, histochemistry and transmission electron microscopy, we diagnosed 9 cases of inclusion body myositis (IBM). We analyzed all the ultrastructural features present in these cases as to the pre-dictability of them in diagnosing IBM. All 9 cases shared common transmission electron microscopy features, such as: intranuclear filaments (Fig. 1), filaments within muscle fibers (Fig. 2), membranous whorls (rimmed vacuoles), cytoplasmic bodies (Fig. 3), mitochondrial accumulation and paracrystalline inclusions (Fig. A), honeycomb structures (Fig. 5), and atrophic fibers (Fig 6).266 muscle biopsies were studied. The biopsy was obtained by using the convential muscle clamp in all the cases. After getting the muscle biopsy in each case, about 1/3 of the length was frozen in liquid nitrogen at -170 degrees F to be used for histochemistry. The second 1/3 was fixed in formalin for paraffin section, and the remaining 1/3 was minced in small pieces and fixed in 2.5% glutaraldehyde for electron microscopy study.
Design of an analytical TEM with integrated imaging ω spectrometer
Authors: Bihr J. , Benner G. , Krahl D. , Rilk A. , Weimer E. 
Published: June 2020

Conventional transmission electron microscopy (CTEM) can be used for high resolution imaging of specimens and for the analysis of minute specimen areas. The capabilities of such an instrument are strongly improved by the integration of an imaging electron energy loss spectrometer. All imaging and diffraction techmques are provided in such an energy filtered transmission electron microscope (EFTEM).In addition to the well-known objective lens for Koehler illumination, the new Zeiss EFTEM features a projective lens system which integrates a new imaging ω-spectrometer comprising four individual magnets and one hexapole corrector Fig.l and Fig. 3 show the design of this microscope.