bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative and densitometric considerations in bas‐relief electron micrographs
Authors: Hendricks Gregory M. , Sharp William P. 
Published: February 2005

AbstractTwo methods for bas‐relief electron micrographs are described, one to produce transparencies for projection and one to produce prints for publication. The basis of these methods is a controlled misregistration of a positive image and a negative image, both on film, to increase contrast and produce a “bas‐relief” effect. This gives the final image a three‐dimensional appearance. No apparent loss of resolution results and no artificial amendment is required. To produce transparencies, a contact film positive is produced from the negative and the two are sandwiched in a slide mount with the appropriate amount of lateral displacement to give the effect. To produce prints, the film positive and the film negative are used to sequentially expose the same sheet of photographic paper prior to development to realize the effect. The bas‐relief induced by the misregistration of the film plates causes apparent shadows and highlights that produce the apparent height that is seen in the enhanced images.
Clinical sampling device for rapid viral diagnosis by transmission electron microscopy
Authors: Bozzola John J. 
Published: February 2005

AbstractA clinical sampling device useful for rapid viral diagnosis was constructed from a plastic‐shafted throat swab by excision of the cotton or alginate wool tip and heat shaping the end of the plastic shaft to accommodate a Formvar‐ and carbon‐coated grid. The device can be conveniently carried in the coat pocket and can be readily used to obtain specimens at the bedside. Various types of fluids containing virus particles may be examined by transmission electron microscopy to obtain a presumptive diagnosis, often in less than 1 hour.
Backscattered electron imaging of immunogold‐labeled and silver‐enhanced microtubules in cultured mammalian cells
Authors: Goode Dennis , Maugel T. K. 
Published: February 2005

AbstractThis technique permits the visualization of microtubules in situ by employing silver‐enhanced immunogold labeling and backscattered electron imagery. For best results, monolayer cultures of PtK2 cells are lysed with Triton X‐100 in a microtubule stabilizing buffer, fixed with 1% glutaraldehyde, reduced with NaBH4, incubated with monoclonal antitubulin and 5‐nm gold‐labeled anti‐IgG, silver enhanced, freeze dried, lightly coated with aluminum, and examined in an SEM equipped with a backscattered electron detector. A high contrast view of the entire microtubule complex of each cell is obtained. Microtubules in freeze‐dried preparations have relatively smooth surfaces, whereas those in critical point dried preparations are more irregular or beaded. At high magnifications, an unstained inner core of each microtubule can be resolved. Backscattered electron imaging appears to be a promising technique for localizing cytoskeletal proteins and other intracellular antigens that can be labeled with immunogold and enhanced with silver.
Multifunctional mini‐computer program providing quantitative and digital X‐ray microanalysis of cryosectioned biological tissue for the inexperienced analyst
Authors: Heyman R. V. , Saubermann A. J. 
Published: February 2005

AbstractA series of computer programs have been written for use in a multi‐user resource center for biological microanalysis. They are tied together by a “Main Menu” program which acts as a traffic director and guides the investigator into whatever option is desired. These programs have been written with very clear instructions and interaction points. As a result, a complex handbook of options and responses is not required. Consquently, almost no training is required to use these programs as they are essentially self‐explanatory. Extensive error checking has been included so that most errors are identified and corrections are requested without causing a program halt. Options available to the user provide for selected “region” analyses, elementally quantitative image analysis, and sorting of the resulting data files. A complete computer code printout is included in this report.
The conversion of a field‐emission scanning electron microscope to a high‐resolution, high‐performance scanning transmission electron microscope, while maintaining original functions
Authors: Oho Eisaku , Baba Misuzu , Baba Norio , Muranaka Yoshinori , Sasaki Toshihide , Adachi Koichi , Osumi Masako , Kanaya Koichi 
Published: February 2005

AbstractRecently, the reliability of field‐emission electron guns has increased. In addition, the cost of computer systems for on‐line processing has dropped. Hence, we should now consider the use of scanning transmission electron microscopy (STEM) for routine work, especially, in the field of biology where one may expect to utilize digital image processing techniques.An STEM has been constructed, without disturbing the original functions, by converting a commercial scanning electron microscope equipped with a fieldemission gun. The STEM is generally operated at accelerating voltage 30 kV, focal length 7.5 mm, and beam current 1−2 × 10−10 A. Several improvements have been incorporated for removing the effects of vibration, contamination, and stray magnetic fields. Also, an adjustable detector aperture was utilized. The modified instrument was connected to an on‐line digital image processing system for utilizing the information obtained from STEM images. The advantages of the modified system were studied from various viewpoints.
Comparison of surface roughness of sections cut by diamond, sapphire, and glass knives
Authors: Mollenhauer Hilton H. , Bradfute O. E. 
Published: February 2005

AbstractLow‐angle chromium metal shadowing was used to compare the surface roughness of ultrathin sections cut with diamond, sapphire, and glass knives. Surface roughness was less on diamond‐cut and sapphire‐cut sections than on glass‐cut sections, and was greater over tissue than resin, and greatest over red blood cells and mitochondria. Surface roughness contributed to image density variation and thereby lowered contrast and informational content of the sectioned tissue.
Structure of the M Band
Authors: Varriano‐Marston Elizabeth , Franzini‐Armstrong Clara , Haselgrove John C. 
Published: February 2005

AbstractWe have studied the structure of the M band in fish skeletal muscle using thin sectioning and deep‐etching rotary shadowing. A reconstruction of the M band from these images shows it to be formed by obliquely arranged struts, which join the thick filaments to each other. Thickening of the thick filaments' profiles and nodal points where the struts cross each other are responsible for the fine sublines visible in longitudinal sections of the M band region.
Synapses on the mauthner cell of the goldfish: Thin section, freeze‐fracture, and immunocytochemical studies
Authors: Nakajima Yasuko , Tuttle Rebecca , Masuko Sadahiko , Betz Heinrich , Pfeiffer Friedhelm 
Published: February 2005

AbstractLarge myelinated club ending and small‐vesicle bouton synapses on the distal part of the lateral dendrite of the goldfish Mauthner cell were investigated with thin section, freeze‐fracture, and immunocytochemical electron microscopic methods. Large myelinated club endings form mixed synapses, having both gap junctions and chemical synaptic junctions. The correlation of the number of gap junction particles (connexons) and the data from electrophysiological studies of single large myelinated club ending synapses suggest that only a small fraction of gap junction channels are open at any given time during electrical synaptic transmission. The chemical synaptic junctions at the large myelinated club ending synapse have large, round synaptic vesicles, indicating that they are excitatory. This result is in agreement with electrophysiological data demonstrating the excitatory nature of this chemical synapse. Freeze‐fracture of these excitatory chemical synaptic junctions reveals the presence of the intramembrane particle aggregates in the postsynaptic E face.Small‐vesicle boutons form chemical synaptic junctions with small, flat or oval synaptic vesicles. These structural data, in combination with previous electrophysiological studies, suggest that the small‐vesicle bouton synapses are inhibitory. In support of this theory, the cytoplasmic side of the postsynaptic membrane of some of these synapses show positive immunocytochemical reaction to monoclonal antibodies against the rat glycine receptor. Freeze‐fracture data reveal intramembrane particle aggregates in the postsynaptic P face of some small‐vesicle bouton synapses which could possibly represent glycine receptor aggregates.
Three‐dimensional tomographic reconstruction in high voltage electron microscopy
Authors: Frank J. , McEwen B. F. , Radermacher M. , Turner J. N. , Rieder C. L. 
Published: February 2005

AbstractThe methodology is described, as developed at the Albany NIH Biotechnological High Voltage Electron Microscope Resource, for the three‐dimensional reconstruction of objects in thick sections. The reconstructions are obtained from projection sets which are recorded by high voltage electron microscopy. The different steps of the procedure are illustrated in detail, using the cilium reconstruction as an example.
A systematic approach to the discovery of new proteins of ultrastructural interest
Authors: Singer S. J. , Maher Pamela A. , Cox Gerald F. , Tokuyasu K. T. , Dutton Anne H. 
Published: February 2005

AbstractA systematic approach to the discovery of new proteins of ultrastructural interest is discussed. It involves the merging of monoclonal antibody technology with immunocytochemical technology, particularly immunoelectron microscopy. In this approach, monoclonal antibodies are raised to a cellular preparation that can be grossly heterogeneous in its protein composition. The hybridoma culture fluids are screened by immunocytochemistry for the ultrastructural localization of their antibodies. Those monoclonal antibodies that show specific ultrastructural localizations of interest are then selected for further investigation. The antigen to which a given monoclonal antibody is directed is then identified by immunoprecipitation and immunoblotting with that antibody. By this approach, two new striated muscle proteins of ultrastructural interest have been discovered and are named zeugmatin and enactin. The former is a protein of over 500 kD localized by immunoelectron microscopy to the Z‐bands, the latter of 245 kD localized to the N1 line of striated muscle.
Loss of square (orthogonal) arrays from cultured airway epithelial cells
Authors: Friend Daniel S. 
Published: February 2005

AbstractElectron microscopic examination of freeze‐fracture replicas reveals distinctive arrangements and planar distributions of certain membrane constituents. In these replicas, the square (orthogonal) array of 6–7‐nm intramembranous particles is an easily recognizable membrane differentiation commonly observed in transepithelial ion‐transporting epithelia and in several mesenchymal cells, in which they were originally described. Recently, the occurrence, distribution, and number of square arrays have been documented in the lungs of mammals, turtles, and frogs. The current study confirms that there are more than 10 arrays per μm2 basal and lateral portion of the plasma membrane in the alveolar type I and ciliated cells of human, rat, guinea pig, turtle, and frog lung, and in type II pneumocytes of the turtle and frog lung. We have not observed them in mucous cells, brush cells, macrophages, or endothelial cells of any species examined, nor do they appear in the apical portion of the plasma membrane of any airway or alveolar lining cell. Upon elastase or other proteolytic dissociation of the alveolar cells of the mammalian lung, concomitant with breakdown and endocytosis of tight junction strands, the square arrays cluster and are internalized within the membranes of endocytic vesicles that are derived from the lateral and basal portions of the cell. Within 1 day of establishing the cells in tissue culture, tight and gap junctions reappear, but the square arrays do not. Nor do they return to cultures examined on subsequent days. We conclude that the square array is a widespread membrane differentiation throughout the lung and major airways; but extrapolating from results obtained from dog tracheal cells (Widdicombe et al., 1987), the square array configuration of particles is unnecessary for maintaining normal ion transport.
Procedural guide to specimen handling for the ultrastructural pathology service laboratory
Authors: Dvorak Ann M. 
Published: February 2005

AbstractTransmission electron microscopy serves a useful and often diagnostic purpose in the analysis of human disease. The emerging discipline of ultrastructural pathology serves a much wider field than that of kidney pathology and, of necessity, requires two essential elements. These are (1) the interpretive knowledge which covers all cells in all tissues which compose all organs, their normal substructural composition, and the ultrastructural expression of all of the basic mechanisms of the pathobiology of human disease, and (2) technically excellent preparations of these varied specimens.In this review, we emphasize the technical aspects necessary for the preparation of these specimens. These include the handling of varied specimens from the time of interruption of blood flow to the sample until fixation, fixation methodology, and routine processing methods for electron microscopy. Specialized techniques that are readily accomplished in an ultrastructural pathology service laboratory are also described. These include methods for the demonstration of glycogen, peroxidase(s), the glycocalyx. We also describe the preparation of permanent, alkaline Giemsa‐stained 1‐μm plastic sections for light microscopic diagnosis, the use of an agar‐pelleting technique to change cell suspensions into readily handled blocks, and the use of Spurr's (J. Ultrastruct. Res. 26:31, 1969) low viscosity embedding for all skin and heavily collagenized specimens.The diagnostic report for individual samples can routinely be available within 24 hours of specimen arrival in the ultrastructural pathology laboratory with the methods we review here. Examples of these varied samples of human tissues and cells and methods for preparing them are illustrated. We have found such methods useful for diagnostic purposes, e.g., to identify the site of origin of a brain metastasis as the alveolar cell (type II pneumocyte) of the lung, based on the presence of typical lamellar (surfactant) bodies in the metastatic tumor cells (Dvorak and Monahan‐Earley: Norelco Reporter 32:29–36, 1985c), as well as to describe for the first time a new tumor, such as the gut autonomic nerve (GAN) tumor (Walker and Dvorak: Arch. Pathol. Lab. Med. 110:309–316, 1986) or a cell injury process, axonal necrosis, to be characteristic of Crohn's disease (Dvorak et al.: Hum. Pathol. 11:620–634, 1980d; Dvorak and Silen: Ann. Surg. 201:53–63, 1985).
Solutions to difficulties encountered in low‐temperature SEM of some frozen hydrated specimens: Examination of Penicillium nalgiovense cultures
Authors: Allan‐Wojtas Paula , Yang Ann Fook 
Published: February 2005

AbstractPenicillium nalgiovense cultures, which are used in the food industry, were found to be collapsed when prepared by standard procedures for scanning electron microscopy. Neither freeze‐drying nor critical point‐drying preserved the structure of cultures grown on agar media. Cryofixation and preparation of frozen hydrated samples using the Hexland Cryotrans CT 1000 attachment in conjunction with an AMR 1000A scanning electron microscope yielded micrographs of uncollapsed structures which could be used for morphological characterization. Several additional steps had to be used in sample preparation to achieve satisfactory results. Samples were held in a humid chamber prior to freezing; growth substrate was trimmed as thinly as possible (less than 1 mm above the support); the sides of samples were painted with a conductive cement to their upper edge; and frozen samples were coated intermittently with gold sputtered in several 2‐min bursts.
On the Image‐Contrast Characteristics of Strains, Surface Rugosity, and Defects in Small Metallic Particles
Authors: Pérez R. , Avalos‐Borja M. , Pérez‐Ramírez J. G. 
Published: February 2005

AbstractAn analysis of the effects of strain and surface roughness on the contrast of weak beam images of small metallic particles is carried out. in order to study these effects, theoretical calculations of the intensity obtained in wedge‐shaped bent gold crystals were performed. These calculations were based on the standard form (Bethe's approach) of the dynamical theory. The theoretical results were compared with weak beam experimental images of gold particles. It was found that the image contrast obtained in thin crystalline regions is not sensitive to strain. Therefore, intensity variations experimentally obtained in these regions seem more likely to be related to the surface roughness of the crystalline specimen. We also studied (experimentally and theoretically) the image‐contrast characteristics of stacking faults in small particles. The comparison between the experimental micrographs and the theoretical images suggests a possible model of the small particle shape. This model seems to explain most of the experimentally observed image‐contrast characteristics.
Scanning Optical Microscopy via a Scanning Electron Microscope
Authors: Battistella Florent , Berger Steven , Mackintosh Andrew 
Published: February 2005

AbstractWe have described in detail the principles of operation of a commercially available SEM‐based scanning optical microscope. The stage consists of a cathodoluminescent material which converts the scanning electron beam into a scanning optical beam and an optical system to focus the light beam onto the specimen.The resolution attainable with such a stage is discussed as well as the efficiency of electron‐to‐photon conversion. Simplified formulae are given and a set of curves plotted which can be used to determine the appropriate tradeoff between resolution and optical power.Examples of the imaging ability in the optical beam induced current mode from various semiconductor devices are presented.
Visualization of the inner and outer surfaces of the cell membrane and cytoskeleton by polyethylene glycol embedding, subsequent deembedding, and rotary replication with platinum
Authors: Kondo Hisatake 
Published: February 2005

AbstractUsing rotary replication with platinum and carbon to embedment‐free sections of polyethylene glycol (PEG)‐embedded tissue from which PEG had been removed, the membrane specializations on the outer (exoplasmic) and inner (protoplasmic) cell surface as well as the organization of the cytoskeleton was demonstrated. The high quality and excellent preservation were comparable to that obtained by the rapid‐freezing, deep‐etched replica method. The present results indicate that the PEG method is essentially acceptable as a reliable morphological technique. Because either sectioned or replica images from the same tissue cells can be observed simultaneously, the PEG method with rotary replication should provide valuable information on cell ultrastructure.
Electron diffraction structure analysis of phospholipids
Authors: Dorset Douglas L. 
Published: February 2005

AbstractThe use of lamellar electron diffraction data from epitaxially oriented phospholipid crystals for quantitative structure analysis is described in this review of the technique. It is seen that an appropriate correction for crystal texture, which is justified by the analysis of low‐dose lattice images, enables these intensity data to be used much as they would be used in X‐ray crystallography. Analyses of two classes of phospholipids are reviewed, revealing that the recently determined lamellar structures of ether‐linked phosphatidylethanolamine and phosphatidylcholine are quite similar to the acyl‐chain structures. Preliminary analysis of 1,2‐dihexadecyl‐sn‐glycerophospho‐N‐methyl ethanolamine indicates that the headgroup conformation may be similar to that of the ether‐linked lecithin.
Montaging electron micrographs
Authors: Crang Richard E. 
Published: February 2005

AbstractThe preparation of overlapping electron micrographs (particularly from transmission electron microscopy) requires special forethought in planning, exceptional skills in microscopy and photographic techniques, as well as in display preparations which are unique in their handling and execution. In this report, step‐by‐step instructions are given on specimen preparation, micrography, darkroom printing, and mounting for montage display purposes.
The fine structure and morphogenesis of the envelope and nucleocapsid of goat poxvirus and infectious bovine rhinotracheitis virus: A freeze‐fracture study
Authors: Wang Xiao , Ding Mingxiao , Fu Honglan , Wang Mei , Zhai Zhonghe 
Published: February 2005

AbstractWe studied the morphology and morphogenesis of viral envelopes and nucleocapsids of goat poxvirus (GPV) and infectious bovine rhinotracheitis virus (IBRV) by means of the freeze‐fracture technique. The GPV at an early development stage was fractured in its middle, and the envelope was shown to be a bilayer of particles. The mature GPV was fractured between two monolayers of the envelope. These facts suggest that there is little lipid and mainly protein particles in the envelope at the early‐development stage, then the lipid inserts into the envelope during viral development. We found that there were still many intramembranous protein particles in protoplasmic fracture face (PF) and extracellular fracture face (EF) of the envelope of mature GPV in the cytoplasm, and fewer particles in the envelope of released GPV. In the envelope of mature IBRV, however, there were many more intramembrane protein particles in the PF face than that in the EF face. Spike‐like structures could be seen at the outer edge of the IBRV envelope at times. Protein particles were regularly arranged in the plasmic membranes contacting IBRV. This phenomenon seems to be related to IBRV release. The naked cores, empty capsids, and nucleocapsids of IBRV were assembled in the nucleus of infected cells at the same time. The assembled nucleocapsids could be divided into five types according to their different fracturing positions, whose morphology was observed after deep etching. The morphology of the samples prepared with different methods was compared as well.
Electron microscopic study of the morphology and morphogenesis of virus of hemorrhagic fever with renal syndrome
Authors: Chen Dehui , Yang Huibin , Wang Guohua , Zhang Hequi , Ni Dashi , He Hao 
Published: February 2005

AbstractThe morphology and morphogenesis of the virus of hemorrhagic fever with renal syndrome (HFRS) and the associated ultrastructural changes in neurons of the infected mouse brain were examined by electron microscopy. The primary location of the infection in large neurons was in the Golgi apparatus, which had highly proliferated laminar and vesicular profiles. A small number of matured virus particles were found later individually or in small groups within the distended Golgi cisternae and vesicles. Most of the virus particles were round, oval, or elongated and measured about 70–110 nm in diameter. A lipid bilayered viral envelope with an external fringe of surface projections could be resolved at high magnification. The maturation (budding) of the virus occurred exclusively at smooth membrane vesicles, and predominantly at membranes in, or adjacent to, Golgi cisternae. Viral inclusion bodies containing fine filamentous material were seen frequently in close proximity to sites of virus maturation. The known morphological and morphogenetic characteristics of the virus particles observed in infected mouse brain gave further evidence for taxonomic identification of HFRS virus as a member of the family of Bunyaviridae.