bluuebunny/crossref_metadata_2025 huggingface dataset:
The Application of Ferritin-Tagged Antibodies in Viral Diagnosis by Electron Microscopy
Authors: Breese S. S. , Dardiri A. H.
Published: June 2020

In the late summer of 1970, blood and excised skin nodules from an outbreak of disease in cattle in northern Minnesota were received for diagnosis. Clinical signs in a herd of 17 dairy cattle suggested the possibility of lumpy skin disease, a viral infection found primarily in South Africa.

Lesion material and blood samples were passed in primary calf kidney tissue culture. Examination of third passage cultures showed typical herpes virus particles. Bovine herpes virus has been described in England as bovine herpes mammillitis and in South Africa as Allerton virus. These exotic strains of bovine herpes virus and the pox virus (Neethling) presumed to be the causative agent of lumpy skin disease, were also grown in calf kidney tissue culture.

Relationships between these viruses were demonstrated by cross-tagging using specific bovine antisera to each virus and rabbit-anti-bovine serum conjugated with ferritin. Infected tissue cultures in 4-oz. prescription bottles were scraped from the glass and collected in conical tubes in a clinical centrifuge. The cell pellets were gently resuspended first with 0.2 ml of a suitable dilution (1, 1/2, 1/4, 1/8) of each bovine antiserum and allowed to react at room temperature for 30-40 min. They were then washed 3 X with phosphate buffer (PB) and resuspended a second time in a suitable dilution (1, 1/2, 1/4) of rabbit-anti-bovine serum conjugated to ferritin. Antiserum to duck plague (an avian herpes virus) was used as a control.
Multiple Sampling of Attached Bacteria for Electron Microscopy
Authors: Bozzola J. J. , Johnson M. C. , Shechmeister I. L.
Published: June 2020

Sections, replicas, and negative stains of bacteria for TEM and dried, metal-coated preparations for SEM are usually processed separately and at different times. In order to overcome this inconvenience and to standardize the separate manipulations, a method was developed in our laboratory whereby one may perform these operations with the same specimen at the same time. Although this procedure works best with bacteria, such as Streptococcus mutans (and its dextran producing mutants), which firmly attach to surfaces, it is a convenient technic to process samples of other bacteria (E. coli, for instance). In addition, the procedure described below makes it possible to grow uniform layers of bacteria directly on coated grids—a valuable manner for studying not only the surface structure of the cells, but also the attachment of bacteria to inert surfaces and to other cells.
Fine Structure of Nerve Cells in the Brain of the House Fly, Musca Domestica (Diptera)
Authors: Allison Venita F. , Sharma Suraj P. , Sohal R. S.
Published: June 2020

Because of its comparative structural simplicity insect central nervous system has been frequently used for basic neurological studies. However, relatively little is known regarding the cytological organization of the different neuronal types, especially at the fine structural level. The precise localization and identification of particular cell types within the brain would be useful in correlating structural characteristics of neurons with their integrative functional role. The present study reports the fine structure of three different types of nerve cells within the anterior protocerebral region of the brain of the adult male house fly, Musca domestica.

Type I Neuron (Figure 1): Examination of the anterior lateral region of the protocerebrum reveals a small population of uni-polar neurons further characterized by perikarya with a paucity of cytoplasm and proportionately large dense nuclei. The cytoplasm contains poorly developed endoplasmic reticulum, an abundance of ribosomes and a few ovoid to rounded mitochondria with shelf-like cristae. Small Golgi regions and dense inclusion bodies are seen in certain planes of section.
Studies of Comparative Ultrastructure of Snake Cardiac Tissue
Authors: Giaquinta Robert , MacMahon James
Published: June 2020

The ultrastructure of mammalian cardiac muscle has been the subject of numerous investigations attempting to correlate structure with function (Fawcett and McNutt, 1969). As a result there is a wealth of comparative data available for mammalian cardiac muscle. Less information is available concerning the comparative ultrastructure of cardiac tissue in other vertebrate classes. In an attempt to gain more information concerning the structure-function correlations, Sommer and Johnson (1969) compared the cardiac muscle of representative species of various classes of vertebrates and noted differences in structure and concentration of transverse tubules, sarcoplasmic reticulum and muscle fibers. The comparative ultrastructure of reptilian cardiac tissue has received less attention than most other classes of vertebrates and data specifically dealing with snakes are rare. Leak (1967) reported the only detailed ultrastructural study of the cardiac tissue of a snake, the boa constrictor in the family Boidae. His work depicts several distinct features present in snake cardiac muscle which are not found in other vertebrate cardiac tissue.
Retrieval of Frozen Surgical Material for Electron Microscopic Examination
Authors: Hedley-Whyte E. T. , Gilles F. H.
Published: June 2020

During a study of frozen sections of rectal biopsies in neurologic disease of children we wished to examine particular neurons in the electron microscope. We therefore investigated the use of frozen surgical tissue for electron microscopic examination.

Fresh tissue was frozen in liquid isopentane pre-cooled in dry ice and then stored at -80°C. 1-30 days later 16 - 20 μm cryostat sections were picked up on slides or coverslips previously coated with 10% gelatin and immersed in 5% cacodylate buffered glutaraldehyde for 30 mins. to 1 hour at room temperature. The sections were rinsed in Sabatini's washing solution (3 times, 3 minutes each) and post-fixed in Dalton's chrome osmium (30 mins.). Dehydration in graded acetones and propylene oxide and infiltration with Epon-araldite were accomplished at room temperature. In-block staining was carried out in 1% uranyl acetate in 70% acetone for 1 hour. The slides were inverted over flat embedding molds filled with an Epon-araldite mixture and polymerised at 60°C.
Ultrastructural Changes of Canine Kidneys During 24-Hour Perfusion on a LI-400 Preservation System
Authors: Magnusson M. O. , Osborne D. G. , Shimoji T. , Kiser W. S. , Hawk W. A.
Published: June 2020

Short term experimental and clinical preservation of kidneys is presently best accomplished by hypothermic continuous pulsatile perfusion with cryoprecipitated and millipore filtered plasma. This study was undertaken to observe ultrastructural changes occurring during 24-hour preservation using the above mentioned method.

A kidney was removed through a midline incision from healthy mongrel dogs under pentobarbital anesthesia. The kidneys were flushed immediately after removal with chilled electrolyte solution and placed on a LI-400 preservation system and perfused at 8-10°C. Serial kidney biopsies were obtained at 0-½-1-2-4-8-16 and 24 hours of preservation. All biopsies were prepared for electron microscopy. At the end of the preservation period the kidneys were autografted.
Intranuclear Inclusions in the Human Osteogenic Sarcoma Cells
Authors: Yasuzumi G. , Sakamoto H. , Matsuo T.
Published: June 2020

The intranuclear inclusion formation was observed in the human osteogenic sarcoma cells obtained from three patients, which were fixed in glutaraldehyde, postfixed in osmium tetroxide and embedded in epoxy Epon resin. Thin sections were stained doubly with uranyl acetate followed by lead citrate. They were examined with an electron microscope, model JEM-100B, HU-11DS or HU-12.

The sarcoma cell nuclei were differentiated at least into two types according to their chromatin contents: one was abundant in components which were closely associated with a large nucleolus and the nuclear envelope, of found isolated in the nucleoplasm; while the other was relatively electron lucent, showing only a few amounts of chromatin granules dispersed in the nucleoplasm, though the nucleolus is large in size and the nucleolonemata are clearly identified. Such a structure is similar to that observed in the hyperplastic liver nodules in the rat induced by several hepatocarcinogens.
Electron Microscopic Study of a Spontaneous Rat Tumor
Authors: Cole P. W. , Jamison R. M.
Published: June 2020

A spontaneously occurring, non-invasive mammary tumor was observed in a 7-month-old, non-lactating, random-bred Sprague-Dawley female rat. The tumor was located subcutaneously in the distal mammary line as a firmly encapsulated, lobated growth. The tumor was surgically removed and immersed in Clark's buffer containing 4% glutaraldehyde. (Later conventional histochemical studies revealed this tumor to be a relatively non-differentiated fibro-adenoma.) Exterior and interior portions of the tumor were excised and fixed separately. The tissues were cut into 1 mm cubes and fixed for 4 hours in 4% glutaraldehyde. The specimens were then washed 4 times in buffer and left overnight at 4°C in the buffer. The cubes were postfixed in 2% OsO4 for 2 hours, after which they were dehydrated in a graded series of ethanol. The specimens were then washed with 2 changes of propylene oxide and perfused with a 1:1 mixture of propylene oxide-Epon 812 for 1 hour. Next, the tissue cubes were embedded in a mixture of Epon 812, DDSA, NMA, and DMP 30. Polymerization was allowed to proceed sequentially at 37°C overnight, 45°C for 8 hours, and 60°C for 24 hours. Ultrathin sections were cut with the Porter-Blum MT-2B ultramicrotome equipped with a glass knife. Sections were picked up on copper grids and stained with saturated uranyl acetate and 0.2% lead citrate. Specimens were examined in the Philips 300 electron microscope at instrumental magnifications ranging from 3,000-20,000 times.
The Internal Structure of the Oncogenic RNA Viruses
Authors: Sarkar Nurul H. , Nowinski R. C. , Moore D. H.
Published: June 2020

Negative staining technique with potassium phosphotungstate (pH 7.0) was used to study the internal structure of the avian myeloblastosis virus, murine leukemia virus, murine mammary tumor virus and feline leukemia virus. Two essential structural features of the viral interior were observed: 1) single strands (30-50 A° in diameter) randomly oriented to give the appearance of a ball of yarn inside the virion; and 2) paired strands (70-90A° in diameter) that appear to be double helices which upon uncoiling give the single strands. Figs. 1 and 2 show the morphology of type B, and C particles respectively, where helical structures in the interior of the virions can be seen (arrow). The subunit structures observed on the helical regions are morphologically similar to those seen on the surface of the nucleoid that do not show helical symmetry. When helical segments were observed in the virus they were almost always seen at the periphery of the nucleoid. This is in agreement with the hollow spherical nucleoid structure of budding virions seen in thin section and suggests that the nucleocapsid is supercoiled as a hollow sphere.
Immunoelectron Microscopy of Type C Virus Particles Produced in a Cell Line Derived from Pleural Effusion of a Lymphoma Patient
Authors: Shigematsu T. , Priori E. S. , Dmochowski L. , Wilbur J. R.
Published: June 2020

A monolayer culture (ESP-1) was established with cells obtained from pleural effusion of a patient with Burkitt lymphoma (American type). Virus particles, similar to murine type C virus particles, were first observed in cells of the 10th passage of the culture. Mature and immature, including budding, virus particles were frequently found in all subsequent passages of this continuous culture (including 28th).

A human tumor cell line continuously producing type C virus particles provides a valuable new system for immunological studies of such virus particles.
Tracing Permeation Pathways Across Epithelia
Authors: Tormey J. McD. , Wright E. M. , Smulders A. P.
Published: June 2020

The route by which small molecules, such as water, electrolytes and sugars, cross the membranes of epithelial tissues is a central problem in biological transport. Good methods for quantitatively localizing small diffusible molecules within tissues, or for unambiguously demonstrating membrane transport sites, have yet to be developed. In their absence indirect approaches based on anatomical changes have had to be used.

The lateral intercellular spaces of gall bladder epithelium were several years ago found to be widely dilated when salt and water were being actively pumped across the tissue. The spaces were collapsed in the absence of transport. Similar phenomena were subsequently observed in several other tissues. This has been widely interpreted as proof that the spaces are the route of fluid transport.
Formation of Transport Coated Pits and Vesicles Uniquely Stimulated by Exogenous Yolk Proteins in in vitro Oocytes
Authors: Roth Thomas F. , Dodson John , Boss Barbara
Published: June 2020

We have characterized several systems that exhibit selective protein sequestration in order to use them as model systems to elucidate the mechanisms of specific protein endocytosis. One of these, the mosquito ovary, is ideal because it contains synchronous oocytes and is easily cultivated in vitro. To date we have characterized the yolk proteins, established that the oocytes selectively sequester yolk proteins and that the oocytes effectively exclude other proteins. The transport exhibits saturation kinetics typical of active transport and is inhibitable.

To establish the morphological basis of this selection, we incubated ovaries that had been previously active in laying down yolk (24 hr post blood meal) in an in vitro culture with either yolk protein, ferritin, IgG, albumin, or a combination of these proteins. We confirmed earlier observations that significant transport occurs only in the presence of yolk proteins.
Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra
Authors: Westfall Jane A. , Yamataka S. , Enos Paul D.
Published: June 2020

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.

Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).
Delicate Botanical Specimens Preserved for Scanning Electron Microscopy by Critical Point Drying
Authors: Cohen Arthur L. , Garner Gerald E.
Published: June 2020

The surface forms and structures of animal cells have been strikingly preserved for scanning electron microscopy by freeze-drying and by critical point drying both by the method with CO2used as the transitional fluid and the later procedure which uses a fluorocarbon (Freon 13) as a medium for the transition from the liquid to the gaseous environment. Freeze-drying is often prolonged (5-12 hours as compared with an hour or less by the critical point method) and in our experience with mold cultures on agar, the substrate shrivels and cracks and hyphal filaments are distorted.

Despite, and possibly because of a flexible but inelastic cell wall, plant cells often show greater distortion than do animal cells after evaporative drying or replacement dehydration for mixrotechnical work. The animal cell membrane can contract more or less uniformly on drying - as shown by the numerous micrographs of well-preserved erythrocytes, while plant cell walls often crumple. The many scanning electron micrographs of partially collapsed pollen grains bear witness to this fact.
Microscopy of Hydrated Biological Specimens with JEM 200 Stage (Mark II)
Authors: Matricardi V. R. , Hausner G. G. , Parsons D. F.
Published: June 2020

This report presents the results, properties and modifications associated with the dynamically-pumped hydration stage for the JEM 200 first described by Matricardi et al. The new stage (Mark II, see Fig. 1) was built which locates the specimen position above the objective lens polepiece as opposed to the Mark I, which located it in the polepiece gap. The advantages associated with the Mark II are: 1. the long camera length allowing us to take low angle diffraction patterns (400 Å), 2. a manometer and thermocouple measuring the pressure and the temperature at the specimen position, 3. greater long-term thermal stability than that available on the Mark I since the objective lens excitation current has been decreased (120 mA instead of 330 mA required for normal viewing), 4. ease of removal of the stage within 10 minutes, 5. straight-line specimen insertion allowing only a 30 second lapse to occur between insertion and viewing, 6. specimen can be translated in order to examine most of the grid. The resolution is of the order of 40 Å, and the diffraction pattern is sharp but limited to 2 Å.
Microbodies (Peroxisomes) in Sebaceous Glands
Authors: Hruban Z. , Vigil E. L. , Martan J.
Published: June 2020

The cells of the supracaudal gland of guinea pig have abundant cytoplasm, round and ovoid mitochondria, abundant free ribosomes, a few rough cisternae, abundant vesicular reticulum, complex agglomerates of tubular reticulum, a few residual bodies and a few multivesicular bodies. Golgi complex is small. Electron lucid lipid droplets are numerous. Cell membranes interdigitate. Desmosomes and tonofibrils are frequent. Single membrane limited particles 200-300 mμ in diameter show close spatial relations to cisternae and lipid droplets (Fig. 1). Glutaraldehyde fixed tissue reacted for demonstration of catalase identifies these particles as microbodies at light (Fig. 3) and EM (Fig. 5) level. Aminotriazole abolishes reaction.

The uropygial or preen gland of hen is composed of similar cells. Some lipid droplets contain lamellar or reticular material (Fig. 2). Rough reticulum is moderately abundant and lumina contain pale droplets or liposomes. Particles with dense matrix contain pale granules with lamellar substructure. Microbodies (Fig. 2) 200-800 mμ in diameter are numerous. They are associated with ER, lipid or cisternae containing dense fibrils (Fig. 7). DAB reaction is positive at light (Fig. 4) and EM (Fig. 6) level. It is abolished by aminotriazole. Specific activities of catalase in homogenates of both glands are about 50% of those found in livers.
Desmosomes as Transfer Sites in Immunity
Authors: Changus G. W. , Yonan Theodore N. , Changus James E.
Published: June 2020

The induction of the normal immune response by the stimulated histiocyte or macrophage occurs after the antigen has been processed by the macrophage. Exactly how the antigen enters the macrophage or exactly how the “superantigen” enters the immunocompetent lymphocytic cell has not been delineated. We have taken advantage of the lipid-laden, electron-dense eosinophilic granules to serve as labels in eosinophilic histiocytic reactions. The transfer of these granules is preceded by a desmosomal formation between the eosinophil and the macrophage (Fig. 1). The part played by the so-called Langerhans cell granules of the histiocyte in the formation of the desmosome is not known at present but may be of significance in the endocytic process of the macrophage (Fig. 2). They could be infoldings of the plasma membrane which are related to the endocytic sacs. Once the desmosome is formed an active endocytosis by the macrophage and presumably an active exocytosis by larger eosinophilic cellular particles necessitate a “fusion” of the two cellular membranes to establish an opening or continuity.
Ferritin-Conjugated Plant Agglutinins as Specific Stains for Cell Surface Saccharides
Authors: Nicolson G. L. , Singer S. J.
Published: June 2020

Plant agglutinins are proteins which bind to specific sugar ligands. For the ultrastructural localization of specific saccharides, we have now conjugated two different plant agglutinins with ferritin (Fer): concanavalin A (Con A), which binds specifically to sugars sterically related to D-glucose and D-mannose, and ricin (Ric), specific for sugars related to D-galactose and L-rhamnose.

The conjugates Fer-Con A and Fer-Ric are prepared as follows. To a solution containing 8% Fer and 2.5% purified agglutinin in a buffer (SPB) containing 0.5M NaCl, 0.05M Na phosphate, pH 6.8, is added with stirring freshly distilled glutaraldehyde to a final concentration of 0.05%. Alkaline pH must be avoided to prevent aggregation of the agglutinins. After 45 min. at room temperature the mixture is dialyzed against SPB containing 0.1M NH4Cl. The Fer-agglutinins are centrifuged to remove large aggregates and finally chromatographically purified on Agarose A-1.5m (Fer-ConA) or Biogel P300 (Fer-Ric).
Ultrastructural Effects of Sterols on L Cell Mouse Fibroblasts
Authors: Lipetz Jacques , Rothblat George H.
Published: June 2020

Many mammalian tissue culture lines and strains have the capacity to synthesize sterol from a variety of precursors. Recently it has been shown that a mouse L cell line synthesizes desmosterol as its major sterol; however, if these cells are exposed to cholesterol in the medium, they stop synthesizing desmosterol and incorporate cholesterol. No pronounced differences were observed in the growth or gross morphology of these cells when synthesizing desmosterol or incorporating cholesterol from the medium. Ultrastructural comparisons of L cells growing in the presence or absence of cholesterol reveal few differences in their morphology (Figs. 1 and 2).

As part of a larger study of various sterols, the effect of coprostanol, a steric isomer of cholestanol (dihydrocholesterol) was studied. Concentrations as low as 10 μg/ml of this sterol inhibits cell growth after two days. A sizeable proportion of the cells, however, remain adhering to the glass and are thus presumably still alive even after exposures as long as four days to concentrations as high as 40 μg/ml. This was substantiated by the trypan blue exclusion test.
Advances in High Voltage Electron Microscopy
Authors: Thomas L. E. , Lally J. S. , Fisher R. M.
Published: June 2020

Diffraction contrast imaging in a HVEM differs from 100 kv electron microscopy mainly because of the increased importance of many-beam interactions among the systematic reflections from a given set of low index planes. Since the last annual EMSA meeting our understanding of the consequences of these interactions, in particular the marked changes in the diffraction conditions which give optimum transmission and defect contrast, has advanced rapidly. Progress in a number of related areas will be described.

Transmission - Throughout the range 100-1000 kv maximum transmission occurs when the crystal is oriented for systematic diffraction from the lowest index reflecting planes. Relatively poor transmission always results when nonsystematic reflections are simultaneously excited. At 100 kv the Bragg deviation which maximizes transmission in the direct beam is just positive of the 1st order Bragg position, at k ∼ 0.6.
Characterization of Hyper-velocity Particle Impact Craters on Apollo 11 Lunar Soil
Authors: Devaney John R. , Evans Kenneth
Published: June 2020

There exists on the visible surface of the moon, a continuous range of impact craters from the very large to those below the resolution limits of terrestrial telescopes. The RANGER, SURVEYOR and LUNAR ORBITER programs extended the knowledge of existent craters down to those several centimeters in diameter. Prior to the actual examination of lunar material returned by the Apollo 11 mission, a debate was being carried on as to whether craters from hyper-velocity particles existed in the microscopic realm. Soon after the first samples were examined via Scanning Electron Microscopy, the point in question was settled with a definite affirmative.

The initial effort in conjunction with Caltech scientist G. J. Wasserberg had as its goal the solution of two problems:

(1) Can impact craters be differentiated from bubble bursts?

(2) What are the characteristics of impact craters?

To pursue the first problem initial efforts were designed to study samples with low possibility of bubbles or voids. This resulted in the examination of a chip of lunar feldspar with a large pit on its exposed surface.
Ultrastructure of Developing Granulosa and Theca Cells
Authors: Baccarini Iracema M.
Published: June 2020

The embryology of granulosa and theca cells is not understood thoroughly. Electron microscopic studies in the past have been concerned mainly with mature granulosa cells and less with their development.

Material and Methods. Rat fetuses were removed surgically under ether anesthesia at 16-17, 17-18 and 18-19 days of gestation. Their abdominal cavities were opened, and the fetuses were placed immediately into 3% glutaraldehyde (pH 7.2) for 3 hours. During this time, the fetal ovaries were dissected under a microscope. The tissue was washed in phosphatebuffer for 24 hours, post-fixed in 1% phosphate buffered osmium tetroxide for 1-2 hours at 4°C, and embedded in Durcupan ACM (Fluka). Sections were double stained with uranyl acetate and lead citrate, and viewed in an RCA-EMU-3D electron microscope.
Types of Endothelium in Normal and Neoplastic Brain Tissue
Authors: Brightman Milton W. , Reese Thomas S.
Published: June 2020

The junctions between adjacent endothelial cells of the cerebral capillaries in normal vertebrates determine whether or not proteins can leave the capillary lumen to move into the parenchymal interspaces. In rodents (mice and hamsters), these junctions are of the tight variety, such as that shown in Fig.2(TJ), and are typical of endothelium in normal brain tissue. Such tight junctions appear to form circumferential belts of occlusion between contiguous endothelial cells. A protein such as horseradish peroxidase, when injected into the blood, is thereby prevented from leaving the capillary lumen to enter the extracellular clefts of the neuropil. The same tight junctions also stop peroxidase from entering the capillary lumen after this protein has been injected into the cerebral ventricles and has moved throughout the extracellular clefts.
Phase and Electron Microscopy of Olfactory Bulb After Sectioning of its Peduncle
Authors: Estable-Puig Juan F. , de Estable-Puig Rosita F.
Published: June 2020

The unilateral section of the olfactory peduncle was made in adult albino rats in order to produce axonal and terminal degeneration of the whole system of centrifugal projections. This experiment was carried out with a double purpose. First, to tipify the different structural modes of axonal and terminal degeneration in a correlative light and electron microscopy study. Second, to study the distribution of these central projections to the bulb. The animals were sacrificed by fixation-perfusion 4 to 7 days post-operation and samples of olfactory bulbs were processed as routinely for electron microscopy observation. Thick sections stained with paraphenylenediamine (PPDA)(1) were utilized for phase observation.
Effects of Lysozyme CH on Staphylococcus Aureus
Authors: Robinson J. P. , Robinson R. D. , Hash J. H.
Published: June 2020

A number of bacteriolytic agents which are active against Staphylococci have been described in recent years. One such agent, produced by the fungus,Chalaropsis sp., has been isolated, crystallized and physically characterized. The specificity of theChalaropsisenzyme was established as a (&#β-1, 4-N-acetylmuramidase which is identical to that of egg white lysozyme. TheChalaropsisenzyme was also shown to possess (&#β-1, 4-N, 6-O-diacetylmuramidase and was given the trivial name lysozyme Ch.
Osbservations on the Cysts of Entamoeba Histolytica
Authors: Miller J. H. , Deas J. E.
Published: June 2020

Trophozoites of the Laredo, Huff and W B strains of Entamoeba histolytica were grown in Nelson's encystment medium. When numbers of mature cysts were noted, the entire culture was fixed in buffered glutaraldehyde and post osmicated. Embedment was in Araldite and sections were viewed in a Hitachi HU 11-A microscope. With this method trophozoites and cysts in all stages of maturation were obtained.

In the precyst, the first indication of the formation of the cyst wall is the appearance of a fuzzy coat on the plasmalemma of the rounded up trophozoite. Subsequently, exterior to the coat, a thick electron lucid area appears, which may contain debris from the culture medium.
Ultrastructural Synaptology of the Crista Ampullaris of the Frog
Authors: Dunn Robert F. , Honrubia Vicente
Published: June 2020

Electron microscopic observations on the membranous labyrinth of the frog have revealed the presence of multiple synaptic units in the cristae. The afferent and efferent synaptic units are readily distinguishable by their characteristic appearances. Within the afferent synaptic unit, the hair cell contains a dense synaptic sphere with a halo of synaptic vesicles measuring 200-500 Å in diameter; within the neuron are only a few vesicles and a number of mitochondria. Within the efferent synaptic unit, the neuron contains an abundance of synaptic vesicles measuring 300-800 Å in diameter, and a few larger cored vesicles; within the hair cell, a synaptic sphere is absent but a flattened membranous sac is located near the plasma membrane.
Replication of type C Virus Particles in Burkitt Lymphoma Cells in Vitro Treated with Feline or Murine Leukemia Virus
Authors: Maruyama K. , Fujimoto T. , Swearingen G. R. , Dmochowski L.
Published: June 2020

In the course of studies on possible interaction between animal leukemia viruses and a hypothetical human cancer virus(es), a culture line (P3) derived from Burkitt lymphoma and containing herpestype virus was inoculated 10 times with feline or murine leukemia virus. Filtrates (0.45 µ Millipore) of tissue culture fluid from feline lymphoma cell cultures containing type C particles (supplied by Dr. C. G. Rickard) and from human embryo kidney cell cultures infected with Rauscher leukemia virus(supplied by Dr. B. S. Wright) were used as source of virus. Electron micro scopy was carried out on cells from cultures before inoculation, the 4-day-old culture after 10 inoculations, and subcultures at 2nd (30 days), 3rd (40 days), 12th(85 or 95 days) passages after the last inoculation.
Studies on the Acid Mucopolysaccharide Coat on Viral Envelopes and Transformed Cell Surfaces
Authors: Shigematsu T. , Williams W. C. , Lewis M. L. , Hales R. L. , Dmochowski L.
Published: June 2020

It has been reported that cell walls transformed by SV-40 virus (Martinez-palomo,A.,et al.:Cancer Res.,29;925,1969; vorbrodt, A. and Koprowski,H.:J.Nat.Cancer Inst.,43;1241,1969)or Rous sarcoma virus (Morgan,H.R.;J.Virology,2;1133,1968) appear thicker in cross section and more diffuse than normal cell walls following staining with ruthenium red. The Luft method (Luft,J.H.: Proc. 6th Internat.Cong.for Electron Microscopy,2:65,1966), a specific staining technique for acid mucopolysaccharide (AMS) with ruthenium red, has been applied to cultured cells. Cells cultured from NB rat bone tumors induced by Soehner-Dmochowski murine sarcoma virus (SD-MSV) and from RIII strain spontaneous mouse mammary tumors were studied to characterize the nature of virion envelopes. The AMS coat adhering to both type C and type B particles was generally 100 to 200A thick (Fig. 1).
Demonstration of Viruses by Re-embedding H&E Slides
Authors: Blank Harvey , Collins Carol
Published: June 2020

Tissues taken for routine hematoxylin and eosin histopathologic examination by biopsy or autopsy can also be reprocessed for electron microscopy. Although cellular detail is usually badly distorted by formalin fixation, paraffin embedding and staining, the morphology of most viruses remains sufficiently intact for diagnostic purposes. With the following technic for reprocessing old H&E slides for electron microscopy we have demonstrated the viruses of: smallpox, molluscum contagiosum, orf, milker's nodules, warts, adenovirus, cytomegalovirus, herpes simplex, and zoster-varicella. Other viruses undoubtedly can also be found. The technic works with human and animal tissues and has been tried with success on skin, liver, lung, and adrenal. There is no reason to think that it won't work with almost any tissue. The slides used were several days to more than twenty years old.
Electron Microscopic Studies on Streptococci
Authors: M.D. JOHN SWANSON
Published: June 2020

Group A streptococci contain a variety of chemical components in their cell walls. The major components are mucopeptide, group-specific polysaccharide, protein constituents (M,T, and R), and teichoic acid. Investigations have been carried out to determine the location of each of these classes of chemical components. The techniques used include simple, comparative examination of selected strains that lack or possess a particular component, electron histochemical methods, immunoferritin methods, and extraction or removal of a particular component.
Brugia Pahangi Microfilariae: Electron Microscopy and Electron Probe Microanalysis
Authors: Tousimis A.J. , Merrill T.G.
Published: June 2020

Over 200 million persons have elephantiasis in tropical and subtropical climates of the earth. Yet to date no early diagnostic test has been developed for this disease. Studies leading toward such a test and specifically related to the life cycle, epidemiology, morphology and chemical nature of the infectious entity were hampered since the only known host of filarial infection was man himself. Animal adapted strains of B.malayi and in particular B.pahangi can develop in man to the adult stage and produce microfilariae (1,2). The infective larval forms of B.pahangi were studied using the A.quadrimaculatus mosquito as the vector and the cat as the final host (3).
A Comparison of the Ultrastructural Effects of Various Toxic Gases on the Lungs of Laboratory Animals
Authors: Bils R. F. , Evans M. J.
Published: June 2020

Ozone* - Exposure experiments have been conducted using mice ranging from newborn to 24 months of age, and ozone concentrations from 0.4 to 3.5 ppm for 3 hr. to a typical photochemical reaction pattern for 2 or 3 days. The youngest animals were the most sensitive to the gas. The initial effects were swelling (edema) and rupture of the alveolar endothelial cells (Fig. 1). Repeated exposures or the higher concentrations caused severe endothelial damage and rupturing of the RBC membranes. In mature animals fibrin accumulated at some points of alveolar wall breakage. The higher concentrations also caused swelling in the alveolar epithelial cells of older (18 to 22 month) mice. The ozone seemed to stimulate alveolar cell division in the very young mice, but had an inhibitory effect in the older mice.
Transitional Forms of Langerhans Cell Granules in Letterer-siwe Disease
Authors: Shamoto M. , Millhouse E. W.
Published: June 2020

Recently, Langerhans cell granules have been observed not only in the Langerhans cell of normal human epidermis, but also in the histiocytes of Letterer-Siwe disease. The fact that the same Langerhans cell granules have been observed in such unrelated material has aroused interest and led to various speculations regarding their mode of formation.

Biopsy specimens were obtained from the left cervical lymph node (Figs. II, III) of a 17 month old Japanese boy. Autopsy specimens were obtained 19 days later from a left cervical lymph node, spleen (Fig. I), liver (Fig. IV), thymus, and skin.
Preparation of Frozen Thin Sections of Fresh Tissue for Electron Microscopy
Authors: Kent Christensen A.
Published: June 2020

For several years I have been developing a method for cutting frozen thin sections of fresh tissue. Although in this laboratory these sections are being used primarily for autoradiography of diffusible substances (especially steroids), there are also many other uses to which they could be put in cell biology. The essentials of the technique have been published in several abstracts and in a book chapter, and a more complete description is about to be submitted for publication. In this invited talk I will summarize the current routine method, which may be modified to suit particular needs, and will briefly describe the results that are obtained.
Fine Structure of Sea Urchin Sperm Membranes
Authors: Inoue S. , Buday A. , Cousineau G.H.
Published: June 2020

From electron microscope studies of thin sections it is known that the entire surface of a spermatozoon of sea urchin is covered by a plasma membrane, or sperm membrane, of an approximate thickness of 100Å (1). In these experiments the surface replica method was applied for the study of the fine structure of the sperm membrane.

Spermatozoa from Strongylocentrotus purpuratus (sea urchins supplied by the Pacific Biomarine Supply Company, Venice, Calif.) were washed several times by centrifugation in Millipore-filtered sea water. After fixation in a 2.5% glutaraldehyde-paraformaldehyde (sea water mixture at 4°C) for an hour, spermatozoa were washed with sea water and then with distilled water for several times. A few drops of specimen were dried on a glass slide and the surface replica was prepared according to the method previously described (2) with the exception that the spermatozoa were decomposed in 18 N H2SO4 for about 20 hours at room temperature. The replica films were examined with a JEM-7A electron microscope.
Oogenesis in Dirofilaria Immitis
Authors: Lee Chin-Chiu , H. Miller Joseph
Published: June 2020

The ultrastructural aspects of oocyte development in Dirofilaria immitis was studied with reference to the phylogenesis of mitochondria. Segments of ovaries from mature female worms were fixed in glutaraldehyde, postosmicated, dehydrated with ethanol, and embedded with Araldite 502. Thin sections from defined regions of ovaries were stained with uranyl acetate and lead citrate and viewed with a Hitachi HU-11A microscope. The method of Scarpelli, et al.. (1962), utilizing tetranitro-blue tetrazolium, was used for detecting the presence of succinic dehydrogenase and NADH-cytochrome c reductase.

Cells from the germinal zone (within 5 cm. from the tip of ovary) are round and uniform in size. They have pseudppod-like processes (Fig. 1) by which they are interconnected. They possess a simple cytoplasmic organization and contain very few organelles (Fig. 2). The latter include the nucleus, nucleolus, lysosome-like granules, lipid droplets, scanty ribosomes, Golgi complex, and rudimentary mitochondria.
Electron Microscopy of Cells Infected with Adenovirus Type 12
Authors: SUN C. N.
Published: June 2020

The presence of non-viral paracrystalline protein in cells infected with adenovirus type 5 (2) and adenovirus type 2 (4) has been reported.

The present studies revealed adenovirus type 12 produced: (a) paracrystalline bodies in KB cells morphologically similar to that induced by adenovirus type 5 and (b) small crystalline lattices which consisted of tubular subunits.

The sequential developmental studies of adenovirus type 12 were made in KB cells and in cell lines derived from human origin. In the infected KB cells, the intranuclear patches and stipplings were clearly seen beginning at 18th hour of inoculation (Fig. 1).
Radial Access Straining, Tilting and Elevating Sample Holders
Authors: Geiss R. H. , Thompson W. B.
Published: June 2020

With the 500 kV electron microscope at the University of Virginia there are two different methods of introducing samples in the transmission mode. In one of these cartridges are inserted into a stage above the objective lens similar to that in the EMU-4, while in the other the cartridge is inserted radially to an “in-gap” stage between the pole pieces of the objective lens. To expand the research capabilities of the in-gap mode several modifications were made to allow the use of rod type sample holders. These modifications include a newly designed air lock, with pre-pump facilities, a new stage and several sample holders. The use of rod type sample holders has the distinct advantage of possible 360° rotation of the sample about the rod axis for any of the standard operations, e.g., straining, heating, cooling, rotating and tilting, as well as some special operations.
New Techniques in Scanning Electron Microscopy
Authors: Ogilvie Robert E. , Sutfin Lloyd V.
Published: June 2020

The scanning electron microscope is one of the most exciting tools to be applied to the study of materials. However, it has been a logical development to equip the SEM with X-ray spectrometers and in particular solid-state energy dispersion detectors. Other relatively new techniques include Auger electron spectroscopy, Scanning Mirror Microscopy, Coates patterns and a variety of techniques for potential mapping of integrated circuits.

Because of limited time and space we will limit this discussion to the use of the solid-state energy dispersion detector.

Often it is desirable to know the chemical nature of the topographical features of a specimen being studied. Both dispersive and energy dispersion techniques can be used in most cases, however, the energy dispersive technique has many advantages over the dispersive system. The main advantage is the much higher X-ray efficiency and less stringent requirements on specimen geometry.
The Alignment of the Cheistov High Intensity Grip Cap in the Rca Emu-3 And Emu-U Electron Microscopes
Authors: J. Lloyd Bolivar , Christov George
Published: June 2020

The Christov high intensity grid cap (1,2) is being used in RCA EMU-3 and EMU-U electron microscopes with increasing frequency as more investigators are discovering the augmentation of the illumination which permits easy and accurate focus at all magnifications. However, as some operators are not too familiar with the alignment of the new grid cap, it is our purpose to present a simple method of alignment.

Because of the small aperture in the high intensity grid cap, it requires cleaning more often than the standard cap. The filament is aligned in the gun using the filament alignment tool as usual. Then the high intensity cap (held in a lens paper) is carefully threaded onto the gun assembly with the three nylon screws threaded in place so that they do not protrude inside of the cap.
Applications of the Scanning Electron Microscope on Active Semiconductor Devices
Authors: Dobrott Robert D.
Published: June 2020

The scanning electron microscope is rapidly becoming an extremely powerful tool for studying active semiconductor devices. This tool gives an essentially non-destructive means of studying both the bulk and surface electrical characteristics of the device under high magnification. The mapping of electrical potential gradients on the surface of a device under bias is a valuable aid in reliability prediction as well as failure anal-sis of completely non-working or marginally operating devices. Bulk properties (i.e. p-n or isolation junctions) can be studied in the scanning microscope using the specimen conductive mode. This paper will be restricted to the surface potential gradients using the emissive mode(secondary electron signal) for image display.
Annealing Of Radiation Damage in Tungsten
Authors: Rau Robert C. , Moteff John
Published: June 2020

Transmission electron microscopy has been used to study the thermal annealing of radiation induced defect clusters in polycrystalline tungsten. Specimens were taken from cylindrical tensile bars which had been irradiated to a fast (E > 1 MeV) neutron fluence of 4.2 × 1019 n/cm2 at 70°C, annealed for one hour at various temperatures in argon, and tensile tested at 240°C in helium. Foils from both the unstressed button heads and the reduced areas near the fracture were examined.

Figure 1 shows typical microstructures in button head foils. In the unannealed condition, Fig. 1(a), a dispersion of fine dot clusters was present. Annealing at 435°C, Fig. 1(b), produced an apparent slight decrease in cluster concentration, but annealing at 740°C, Fig. 1(C), resulted in a noticeable densification of the clusters. Finally, annealing at 900°C and 1040°C, Figs. 1(d) and (e), caused a definite decrease in cluster concentration and led to the formation of resolvable dislocation loops.
The Characterization of a Grain Boundary by Transmission Electron Microscopy
Authors: Horylev R.J. , Murr L.E.
Published: June 2020

Read has shown that an arbitrary grain boundary has five degrees of freedom associated with it. Three degrees of freedom are necessary to describe the orientation of one grain with respect to the other, while the remaining two degrees of freedom position the boundary plane between the adjacent grains.

Figure 1(a) depicts a general twin boundary-grain boundary intersection. The degrees of freedom for the grain boundary are represented by (HKL)1, (HKL)2, Θ, θGB, ø. Two degrees of freedom are contained in the surface orientations of the grains.
High Resolution Microscopy of Carbon Fibers
Authors: Harling David F.
Published: June 2020

Much interest has been shown over the past few years in carbon fibers, a novel reinforcing material included in the growing field of structural composites. Typical carbon fiber products can easily match the physical properties of steel but with only one-fifth the weight. These unusual properties are attributed to the microstructure of the fibers and the orientation of extremely long graphitic crystallites more or less parallel to the long axis of the fiber. Variations in fiber strengths have been attributed to, among other things, voids between these crystallites.
Structure of Etched {00.1} CdS Surfaces
Authors: Shimaoka G. , Chang S. C.
Published: June 2020

CdS has a wurtzite structure and two types of {00.1} surfaces exist along the {00.1} direction in CdS: one, (00.1), consisting entirely of Cd atoms and the other, (00.1), of S atoms. Many interesting reports have been published on differences in chemical and physical properties between the two faces. Properties of surface states of CdS crystal, particularly their stabilities, have been computed and discussed theoretically. In the present study we have investigated microstructure of etched {00.1} surfaces of CdS crystal by means of electron microscopy and electron diffraction.
Electron Microscope Observations of Mechanical Metamorphism in Iron Meteorites
Authors: Faulkner D. , Lorimer G.W. , Axon H.J.
Published: June 2020

It is now generally accepted that meteorites are fragments produced by the collision of parent bodies of asteroidal dimensions. Optical metallographic evidence suggests that there exists a group of iron meteorites which exhibit structures similar to those observed in explosively shock loaded iron. It seems likely that shock loading of meteorites could be produced by preterrestrial impact of their parent bodies as mentioned above.

We have therefore looked at the defect structure of one of these meteorites (Trenton) and compared the results with those made on

a) an unshocked ‘standard’ meteorite (Canyon Diablo)

b) an artificially shocked ‘standard’ meteorite (Canyon Diablo) and

c) an artificially shocked specimen of pure α-iron.