bluuebunny/crossref_metadata_2025_split huggingface dataset:
Virus Particles Infected the Erythrocytes of Cultured Eel in Taiwan
Authors: Liu Kuo-chun 
Published: June 2020

The erythrocytes infected by viral particles and the pathological conditions by the presence of those viral particles were reported in cod, herring and few other species of fish in the western waters. This report will present the evidence that the erythrocytes of some of the cultured eel in Taiwan were infected by virus particles.In the summer of 1980, in one of the field trips to the fish farms in Lotung county, northeastern of Taiwan, the author was informed that dead eels from unknown cause were picked up from eel ponds every morning. Samples were collected the following morning. There was no observable external symptom.The internal organs showed a red coloration (Fig. 1,2). Tissues from the livers and gills were processed for electron microscopic observation. Virus particles were found in some of the erythrocytes in both organs (Fig.3).The viral particles aggregated together as an inclusion body in the cytoplasm only. No intranuclear viral particle was found. In a single viral aggregate 1 to 40 particles were observed. A electron lucent ring separated the viral aggregate from the hemoglobin cytoplasm.
Synthesis of Enamel Matrix Glycoproteins as Demonstrated by Radioautography
Authors: Weinstock A. 
Published: June 2020

Enamel matrix, an organic material produced by ameloblasts, contains glycoproteins which are 88-95% carbohydrate (Glimcher & Levine, 1966). Although these glycoproteins have not been well characterized, their carbohydrate moieties are known to consist of monosaccharide units which include glucose, galactose, mannose and fucose. It was decided to investigate the formation of these glycoproteins in ameloblasts using radioautography in order to locate the site of glycoprotein synthesis, and to follow the route of migration of the labeled secretory material out of the cell.Rats weighing 30 gm were injected intravenously or intraperitoneally with 3H-galactose or 3H-glucose. In another experiment, rats were injected with puromycin prior to 3H-galactose administration. At various time intervals ranging from 5 min. to 1 hour after injection, the animals were anaesthetized with ether, and perfused via the left ventricle with phosphate-buffered glutaraldehyde (2.5%). After decalcification, sections of teeth were processed for light and electron microscope radioautography.
Wilson's Disease: Liver Cirrhosis and Virus-like Particles
Authors: Hairstone M. A. , Modjtabai A. , Azerbeygui J. , Shamsa T. 
Published: June 2020

Hepatolenticular degeneration (Wilson's disease) manifests itself in many ways the most obvious of which is a disorder of copper metabolism. Normally copper beyond a certain threshhold is transferred to ceruplasmin which may circulate in the plasma. In patients with Wilson's disease this transfer apparently does not take place. There follows an accumulation of the metal in body tissues most notably the lenticular nucleus and the liver.Needle biopsies taken of the liver of an 11 year old male with Wilson's disease was prepared for light and electron microscopy by conventional methods. Thin sections were examined with Elmiskop 1A.Histologically the liver alteration was that of cirrhosis in which the cells showed fatty and glycogenic degeneration, cytoplasmic coagulation, fibrosis, and pigment deposition. Electron microscopy confirmed and extended light microscopy.
Electron Microscopy of the Nucleic Acid of Mouse Mammary Tumor Virus
Authors: Sarkar N. H. , Moore Dan H. 
Published: June 2020

Mouse mammary tumor virus (MTV) is believed to contain about 0.8% single stranded ribonucleic acid (RNA). This value of RNA content was estimated on a dry weight basis. The subject of this report is an attempt to visualize the RNA molecules of MTV particles.MTV particles were isolated from RIII mouse (tumor incidence approximately 80%) milk according to the method described by Lyons and Moore. Purified virions from 5 ml of milk were finally suspended in 0.2 ml of PBS, pH 7.4 and was mixed with an equal volume of pronase (5 mg/ml). This mixture was incubated at 37°C for an hour. RNA was extracted three times using freshly prepared cold phenol. It was then treated three times with cold ethyl ether to remove any trace of phenol. The RNA thus extracted was divided into two parts. One part was diluted four fold with 8M urea to avoid aggregation of the molecules. The other part was left untreated. Both samples were then mixed with an equal volume of 1M ammonium acetate, adjusted to pH 8.0 with NH3 containing chymotrypsin at a concentration of 0.01%.
Congo Red and Iodine-Stained Amyloid Fibrils Studied by Negative Contrast Electron Microscopy and X-Ray Diffraction
Authors: Gueft Boris 
Published: June 2020

The compound formed by addition of Congo red to suspensions of amyloid fibrils is known to be specific for amyloid and fairly stable. It is analogous to the addition or inclusion compounds of Congo red with cellulose. At one time it was suggested that the Congo red molecule with dimensions of 21 x 8.5 x 3.8 X is sequestered within the fibril. Ashkenazi and his colleagues have demonstrated that the Congo red amyloid complex forms only when the amyloid fibril has its normal sugar content, and, that the complex resists alkalai that would ordinarily remove the sugar content. The conclusion was that Congo red stains the carbohydrate moiety of amyloid.1% aqueous Congo red was added slowly to relatively pure human liver amyloid fibril suspensions prepared from successive aqueous centri-fugations at 4,000 G of upper precipitate layers. Addition was stopped when the supernatant after centrifugation was reddish. The red precipitate was washed for 9 minutes twice in distilled water, and studied by electron microscopy before and after the addition of equal parts of 2% pH 6 potassium phosphotungstate. Amyloid controls free of Congo red were also studied. (RCA EMU 2A; carbon-coated “Formvar” grids).
Electron Microscope Studies of Anti-Antibodies
Authors: Robinson J. P. , Robinson R. D. 
Published: June 2020

The presence of anti-antibodies in sera was first proposed by Najjar and Fisher in 1955. There have subsequently been numerous demonstrations of anti-antibodies and the subject was recently reviewed.According to Najjar's proposal there should be at least two distinguishable types of antibodies involved in the formation of immune complexes. The first antibody is specific for the antigen while the second, anti-antibody, is directed against the antibody portion of the immune complex.This report involves visualizing the anti-antibody portion of complexes by positive staining. It also demonstrates their removal from equivalence complex in acid media.Thin sections of equivalence complex were prepared before and after partial dissociation by exposure to pH 2. 8. The sections were stained by floating on uranyl acetate solutions. Fig. 1 illustrates a preparation of equivalence complex while Fig. 2 shows the remainder of a complex partially dissociated at low pH. Equivalence complex contains large areas of interacting anti-antibodies which are detected by the absence of ferritin molecules. Such areas are greatly reduced or removed from the complex in Fig. 2. Normal γ-globulin mixed with ferritin forms no precipitate.
The Spring-Tactoid-Superspring Concept of Fibrous Proteins
Authors: Borasky Rubin 
Published: June 2020

In the course of studies on the mechanics of protein synthesis it was observed that the subfibrillar elements of collagen fibrils are interwoven. Current concepts of collagen structure do not allow for this interweaving. To explain this phenomenon, therefore, I developed the “spring-tactoid-superspring” concept for the formation and structure of collagen fibrils. The purpose of this report is to summarize the essential features of this concept as it pertains to collagen and other fibrous proteins.Fibrous proteins are copolymers. As such they are constituted of a variety of types of copolymer subunits, many of which have complementary properties. Complementarity of subunits plus favorable environmental factors in intra- and intercellular space promote coalescence of the subunits to form tactoids. These having similar characteristics as the subunits, and being affected by the same environmental factors, coalesce and because of limited intra- or intercellular space are compacted into fibrils. The fibrils, therefore, may be considered to be highly ordered complexes of compacted tactoids, the subunits of which have a lattice structure which may be defined by characteristic x-ray diffraction patterns and electronoscopic appearance. Evidence supporting this concept follows.
Electron Probe Morphological and Chemical Analyses of The Rat Epiphyseal Plate
Authors: Hagerty Jon C. , Tousimis A. J. 
Published: June 2020

The electron probe affords a means not possible with previous techniques for simultaneous morphological and chemical analyses in situ on biological systems. This method of analysis has been applied to the study of the soluble and insoluble components of the epiphyseal plates of the tibias of young growing rats Sections of both frozen dried and chemically treated, i.e. fixed and embedded, epiphyseal plates have been studied through the use of the scanning electron microscope and X-ray microanalytical capabilities of a modified electron probe. The elements Ca, P, S, K, Na, Cl, and Mg have been of specific interest in these studies on the chemical environment of the zones of the epiphyseal plate from resting to mineralization.
Fine Structure of Venus's-Flytrap Plastids
Authors: Schwab D. , Scala J. , Simmons E. 
Published: June 2020

Venus's-flytrap (Dionaea muscipula) is a flowering insectivorous plant. Its leaf consists of two parts, a broad petiole and a two-lobed blade hinged down the middle. The two-lobed blade is especially suited for trapping insects and can enclose an ant in less than one second after it has stimulated two of the three sensitive trigger hairs which are located on the surface of each lobe. During a recent electron microscopic study of Venus's-flytrap it was noted that each of the four main organs (i.e. leaf, lobe, trigger hair, and digestive gland) has a characteristic plastid.Figure 1 shows a typical chloroplast observed in the photosynthetic tissue of the flytrap leaf. The most striking feature of the chloroplasts is their lack of grana or of structures resembling the grana of other higher plants. Although some thylakoids appear on occasion to form a loose association, no evidence of even rudimentary grana has ever been observed. The thylakoids are poorly organized, but predominantly parallel and appear to go around the numerous osmiophilic globules.
A Device for Accurate Sampling of Tissue After Perfusion-Fixation
Authors: Estable R.F.de , Estable-Puig J.F. , Weibel J. 
Published: June 2020

The main technical problems involved in the routine fine structural study of normal and pathological tissue have already been solved. In recent years, considerable attention has been focused on the diverse techniques of fixation by perfusion. Osmium tetroxide perfusion as well as aldehydic perfusion have been shown to preserve remarkably well the different elements of the nervous system. Conventional light and histochemical studies can be carried out in perfused tissue. A fairly good fixation of deeply located structures is now possible without the artifacts involved in the procedure of fixation by immersion. These studies have been extended to other tissues.Nevertheless the conventional sampling of tissue with razor blades usually lacks anatomical precision. Indeed, the study of pathological or neuroanatomical material involve very serious problems in relation to an accurate sampling of a precisely located cell group or tract or that of a minute lesion. Furthermore, the area to be studied may not necessarily be located on the surface of the organ studied and then their excision involves a considerable disruption of the surrounding tissue. The samples are in general very irregular in shape and this makes their orientation very cumbersome.
Particle Counting and Detection
Authors: Ball Frances L. , Harris W. W. 
Published: June 2020

The limit of detection of viral particles with UV absorption is 1010 particles per milliliter and that of the routinely employed electron microscopy technique is 107 to 108 particles per milliliter so that low titre virus preparations such as hepatitis serum must be concentrated severalfold if these physical methods are to be used.The sensitivity of the electron microscope can be increased if all the particles in a given volume of sample can be sedimented onto one microscope grid and a study of this has been made using polio virus which titred 4 X 1012 by light scattering and 6 X 1011 by sedimentation. The number of micrographs and the necessary magnification to detect 105 particles per milliliter were calculated.
On the Location of Stain in Mitochondria
Authors: Haydon G. B. , Smith S. O. 
Published: June 2020

The degree of matrical staining in isolated and tissue mitochondria has been shown to be a function of their state of oxidative-phosphorylation at the time of fixation (J. Histochem. Cytochem. 15:752, 1967). High resolution EM in conjunction with these studies revealed amplitude contrast images 10 AU and larger in diameter which are independent of the focal plane. These amplitude densities have been interpreted as individual aggregates of heavy metal stain (J. Cell Biol. 35:55A, 1967). Two approaches have been used in an effort to locate such stain aggregates.(1) Four micron epoxy sections of skeletal muscle, cardiac muscle, and liver were stained with uranyl acetate, lead citrate, or both, following the methods used to stain 500 AU sections for EM. After staining, the thick epon sections were re-embedded and thin sections cut perpendicular to the stained surface. Either or both of these metal stains penetrate 500 to 1000 AU into the thick section and give the tissue increased contrast similar to that due to staining after thin sectioning. The mitochondrial matrices are lightly stained indicating that they are not in a state of active oxidative-phosphorylation. Figure 1 shows such mitochondria at low magnification before (Figure 1a) and after (Figure lb) restaining with uranyl acetate and lead citrate. After restaining it is no longer possible to identify the original stained surface.
Nuclear Morphogenesis During Spermiogenesis in the Pulmonate Snail Lymnaea Stagnalis
Authors: Ihle James , Humphreys Walter J. 
Published: June 2020

A study by Rebhun on nuclear changes during spermiogenesis in the pulmonate snail Otala lactea has presented evidence that nuclear elongation is accompanied by orientation of nuclear material into 60 A° sheets. The exact nature of the formation of these sheets, however, was not ascertained. In current work on gametogenesis in the pulmonate snail Lymnaea stagnalis observations were made of nuclear morphogenesis which describes this process.The nucleus of a Lymnaea spermatid is spheriod or somewhat ellipsoidal in the early stages of differentiation. The karoplasm consists of a nonhomogeneous matrix of granules. Thereafter, the shape of the nucleus changes to that of an oblate spheriod. The granular nuclear material becomes fibrous in nature and is either clumped together or randomly dispersed in the karoplasm. The nuclear membrane becomes thickened at the prospective anterior and posterior regions of the sperm nucleus.
Fertilization Membrane Structure as Revealed by Freeze Etching
Authors: Humphreys Walter J. , Kreutziger G. Oscar 
Published: June 2020

Many evenly spaced papillae on the surface of the unfertilized egg of Strongylocentrotus purpuratus are revealed with great clarity by freeze etching. They measure about 0.25 μ in diameter and 0.5 μ in length. When flat fracture planes through the cortical granules are obtained, differential etching causes the internal components to appear similar to the structures seen in sectioned eggs. The folded laminar component stands out with a distinctive texture. At fertilization, basic structural subunits 40-45 A° in diameter, originating from ruptured cortical granules, become organized on the inner surface of the vitelline membrane to form an array of closely packed, parallel, 197 A° wide strands diagonally striated by regularly repeating units 108 A° apart at an angle of about 72° to the long axes of the strands.Figure 1 is a surface replica of the fertilization membrane as it appears 90 seconds after fertilization. As in the replicas of isolated and dried fertilization membranes made by Inoue et al. the strands extend into the somewhat regularly spaced shallow protrusions on the membrane surface.
Some Secretory Products of the Invasive Stage of a Digenetic Trematode
Authors: Krupa Paul L. , Bal Arya K. , Cousineau Gilles H. 
Published: June 2020

The fine structure of various gland cells and their secretory products was studied in the invasive stage (cercaria) of the platyhelminth parasite, Cryptocotyle lingua. Secretory granules or droplets occur in several different specialized cell types, but those that we call attention to here are found in the (1) surface cytoplasmic tegument or “cuticle”, (2) ducts of cephalic (penetration) glands, and (3) epithelial lining of the “excretory bladder”.The tegumental granules appear as numerous, membrane-bounded circular or oval profiles of uniform density (Fig. 1). They are scattered more or less randomly among mitochondria and other inclusion bodies of the tegument. Some of the longer granules, with a length to width ratio of about 7 to 1, have their long axes oriented perpendicularly to the surface plasma membrane of the parasite. In cercariae tested for acid hydrolases with sodium β-glycerophosphate in Barka and Anderson's modification of Gomori's medium, clumps of reaction product appear in the vicinity of the granules and elsewhere within the tegument, but not within the granules themselves. As granules that stain with periodic acid-Schiff, they are seen in certain subsurface gland cells as well as in the tegument under the light microscope.
Electron Microscopy of Caprine Cloisonne Renal Proximal Tubular Basement Membranes
Authors: Altman Norman H. , Grossman I. William , Jernigan Norman B. 
Published: June 2020

The pigmented thickening of renal proximal convoluted tubular basement membranes in the goat (Capra hircus), resembling metal wires separating colored areas of enamelwork, has been termed Cloisonne kidney by Light. An associated hemosiderosis of the proximal tubule is occasionally present and the thickened basement membranes yield variable histochemical reactions for iron. The electron microscopy of the thickened basement membranes was studied and correlated with clinicopathological observations in an attempt to determine the pathogenesis of the Cloisonne lesion.Percutaneous renal biopsies were performed on 300 goats, and 5 of these goats were found to have the Cloisonne lesion by light microscopy. Two of the involved kidneys were examined by electron microscopy and were found to have thickened proximal convoluted tubular basement membranes of uniform electron-density approximately 3 times wider than those of a normal goat (figs. 1 and 2). One of the involved kidneys displayed electron-dense deposits measuring approximately 160 A in diameter which were aggregated into larger clumps of varying size on the outer portion of the basement membrane (fig. 2). The 160 A deposits had subunits of approximately 40 A diameter and were consistent with the electron microscopic appearance of ferritin. This particular kidney did not have an associated hemosiderosis of the proximal convoluted tubule. There was no clinicopathological evidence of hemolytic, erythrocytic or urinary abnormalities in the goats with the Cloisonne lesion when compared with a group of control goats with normal renal biopsies.
Langerhans’ Granules in Cells of an Eosinophilic Histiocytoma
Authors: Watson John H. L. , Swedo John L. , Morales A. R. 
Published: June 2020

Recent papers describe Langerhans’ granules in cells of normal skin, in Letterer-Siwe disease, and associated with osseous and pulmonary lesions of histiocytosis X. The present report concerns the structure and occurrence of these granules in a solitary tumor of the human posterior anal wall, diagnosed as an eosinophilic histiocytoma, confirmed by the electron microscopy. The investigation supports the hypothesis that the epidermal Langerhans’ cell is a macrophage. Samples of the recurrent tumor were fixed in cacodylate-buffered 6.4% glutaraldehyde, washed in cacodylate-buffered 0.2M sucrose, and postfixed in OSO4 for electron microscopy. Embedment was in Araldite, and sections were contrasted with uranyl acetate and lead hydroxide.The surface of the tumor cells was very irregular, with numerous microvillus-like projections, and was without both desmosomes and basement membrane. The nuclei were lobulated, and possessed both finely dispersed and coagulated chromatin, with multiple nucleoli. The system of parallel tubules and sacs which composed the Golgi was prominent in most cells. Numerous linear profiles of RER occurred. The RNA particles were also abundant throughout the cytoplasm in groups unrelated to the RER. Centrioles were seen frequently paranuclearly. The mitochondria, with well developed cristae, were frequently altered, being locally swollen, vacuolated or containing myelin figures, Fig. A. The most striking organelles were (i) the Langerhans’ granules (L), observed in abundance throughout the cytoplasm of most of the tumor cells, but predominantly in those cells which contained (ii) the fusiform or ovoid, membrane-bound, electron-dense bodies (B). Many of these rounded, dense bodies contained concentric, double-membranous structures, Figs. C and D.
The Development and Structure of Measles Virus
Authors: Nakai T. , Shand F. L. , Howatson A. F. 
Published: June 2020

Measles virus and the closely related distemper and rinderpest viruses are members of the paramyxovirus group. A feature that distinguishes these viruses from other members of the group is the occurrence in infected cells of intranuclear inclusions. These are present in addition to the cytoplasmic inclusions which are a common feature of infection by all paramyxoviruses.In electron microscopic studies on thin sections of measles-infected primary monkey kidney cells and BSC-1 cells (a continuous line of monkey kidney cells) it was found that the intranuclear inclusions consisted of masses of tubular structures associated with a filamentous matrix. The tubules were 140 Å in diameter and had well-marked cross striations with a spacing of 50 Å. The latter were interpreted as rings of a helix forming the wall of the tubule. Aggregates of identical tubules and associated matrix material were observed in the cytoplasm of infected cells. In any one cell, tubules were usually present either in the nucleus or in the cytoplasm and there was no indication that tubules migrated from one site to another.
Techniques for Transmission Electron Microscopy of the Microstructure and Dislocation Morphology Associated with Fatigue Crack Nucleation
Authors: Shaw G.G. 
Published: June 2020

Fatigue crack nucleation studies By transmission electron microscopy have been limited by the lack of a general technique for sample preparation, and while the work described herein was done with 2024-T4 aluminum alloy, the method may be adapted to a host of metals and alloys.A fatigue sample having the geometry shown in Figure 1 was prepared. The shallow dimple shown was machined to a depth of 12 mils after which it was polished with 600 grit powder to remove burrs. The sample was then carefully heat treated to the T4 condition. The sample was painted with microstop to lines A and B and the central area including the dimple was electropolished removing about 2 mils of metal. Then the sample was mounted in a Sontag fatigue machine and cycled, at an appropriate load, until a starting crack was observed by optical microscopy. Due to the sample geometry cracks usually started at the bottom of the dimple. Some samples were stopped before crack nucleation to observe by transmission electron microscopy precrack microstructure and dislocation morphology.