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Microvascular Casting Of The Lung: Vascular Lavage, Dean E. Schraufnagel, Aloisia Schmid

Scanning Microscopy

Corrosion casting is an important tool for the study of microvascular structure, but unlike tissue preparation for light and electron microscopy, few controlled studies of the methods for preparation of microvascular casts for scanning electron microscopy have been reported. Most vascular casting begins with rinsing cells from the lumen of the blood vessels, but the necessity of this has not been shown. Because of a report of successful casting without rinsing and light microscopic evidence of edema with complete rinsing prior to casting, this preparation procedure was examined. Casts of lung vasculature that were thoroughly rinsed were compared to those …

Processing Of Scanning Electron Microscope Images On Basis Of Fast Fourier-Transformation, A. Yu. Sasov, A. A. Shanyavsky

Scanning Microscopy

The solar cell as a combined substrate and detector was used for automated SEM-image analysis. It was noted that an image processing system was created and its operational features are shown in some typical applications. The step size of the fatigue striations was found. The obtained value of the step corresponds to the formula with an accuracy of about 1 per cent. Quantum-mechanical constant of material fracture for aluminum alloys was found to be 𝛥 = 0.22. Two-dimensional periodic analysis was applied to fracture surfaces and a microchannel plate. The integral characteristics of microstructure was determined quantitatively.

Enhanced Floral Analysis By Low Temperature Scanning Electron Microscopy, Brenda Brookes, Ernest Small

Scanning Microscopy

Traditional methods of preparation of botanical specimens for scanning electron microscopy (SEM) have proven to induce artifacts in some specimens which often reduce quality of resulting images, and are highly misleading for taxonomic purposes. The advantages of low temperature SEM are illustrated by an investigation of freshly collected flowers, using a cryo-system interfaced to an SEM. This method overcame the deficiencies of traditional procedures to produce exceptional images of floral surfaces in their natural state. Depending on the nature of the material under investigation, the method my be indispensable (e.g., for accurate details of petal surfaces), preferable (e.g., glandular hairs …

The Effect Of Fatigue On Essential Element Distribution In The Rabbit Masseter, M. B. Engel, J. K. Bressman

Scanning Microscopy

The rabbit masseter is composed of mainly fast fatiguable type IIB fibers which give a positive mATPase reaction at pH 9.3. To study the effect of fatigue on the distribution of some crucial elements, the masseter was stimulated electrically for 45 minutes. The contralateral muscle served as a control. Control and experimental tissues were rapidly excised, and frozen in isopentane cooled to -150°C in liquid nitrogen. Sections were cut in a cryostat and prepared by freeze-drying. Water content of fatigued muscle was significantly higher than controls: 79.3% versus 77.3%. The fatigued state was verified by glycogen depletion viewed in PAS-stained …

The Inorganic Geochemistry Of Coal: A Scanning Electron Microscopy View, Robert B. Finkelman

Scanning Microscopy

The scanning electron microscope (SEM), equipped with an energy dispersive X-ray analyzer (EDX), has been widely used to study the inorganic geochemistry of coal. This system was instrumental in establishing that the bulk of most trace elements in bituminous coals are associated with fine-grained accessory minerals. Textural evidence, as observed in the SEM, indicates that many of these minerals are embedded in relatively large organic particles. As a consequence of this association, these minerals, and the elements they contain, can be rafted up into the lighter specific gravity fractions during sink-float separation of the coal. Textural evidence also indicates the …

Scanning Electron Microscopy And Electron Probe Microanalyses Of The Crystalline Components Of Human And Animal Dental Calculi, R. Z. Legeros, I. Orly, J. P. Legeros, C. Gomez, J. Kazimiroff, T. Tarpley, B. Kerebel

Scanning Microscopy

A review of the use of scanning electron microscopy (SEM) and electron probe microanalyses in the study of dental calculus showed that such studies provided confirmatory and supplementary data on the morphological features of human dental calculi but gave only limited information on the identity of the crystalline or inorganic components.

This study aimed to explore the potential of combined SEM and microanalyses in the identification of the crystalline components of the human and animal dental calculi. Human and animal calculi were analyzed. Identification of the crystalline components were made based on the combined information of the morphology (SEM) and …

The Root Surface: An Illustrated Review Of Some Scanning Electron Microscope Studies, Sheila J. Jones

Scanning Microscopy

This review paper highlights how the advent of a new type of surface microscopy in the late 1960s, scanning electron microscopy (SEM), was responsible for a fresh appraisal of the structure of the root surface. Details of the formation, resorption and repair of cementum, all surface phenomena, and the varied relationships and mineralization patterns of the two sets of fibres within cementum - the hall mark of the tissue - could be seen in a way and at a range of magnifications hitherto impossible. The major interpretational advances were made rapidly using secondary electron imaging of anorganic normal, exposed, carious …

Scanning Electron Microscopy Of The Human Thyroid Gland And Its Disorders, Jahn M. Nesland, Manuel Sobrinho-Simoes, Jan Vincents Johannessen

Scanning Microscopy

The characteristic scanning electron microscopic features of the normal thyroid gland, benign thyroid lesions such as nodular (adenomatous) and colloid goitre, adenomas and thyroiditis, and malignant tumors such as papillary carcinoma, follicular carcinoma, anaplastic carcinoma and medullary carcinoma are described.

One or more cilia are present in the center of the follicular surface of almost every epithelial cell in the normal thyroid gland as well as in most goitres. Their number is reduced in adenomas and differentiated carcinomas. Medullary carcinomas and anaplastic carcinomas usually lack cilia.

Variation in distribution and appearance of microvilli seems to be related to functional differences …

Scanning Electron Microscopy Application In Clinical Research, R. Laschi, G. Pasquinelli, P. Versura

Scanning Microscopy

Our personal experience on the application of scanning electron microscopy in cardiology, gastroenterology and ophthalmology is reviewed.

SEM has not yet significantly contributed to myocardium pathology. However, in the near future, SEM could be a reliable technique to complete the information available from other sources. As to atherosclerosis, SEM allowed us to improve our knowledge of the early stages of the disease; some pathological features, not always detected by conventional morphological examinations, can be documented. An important contribution to gastrointestinal pathology was made by SEM investigations both in the staging of some important diseases (i.e., coeliac disease, peptic ulcer, Crohn's …

The Normal Structure Of Regional Feline Gastric Mucosae: Scanning Electron Microscopic Study, M. Al-Tikriti, F. Al-Bagdadi, R. W. Henry, J. Hoskins, C. Titkemeyer, G. Strain

Scanning Microscopy

Regions of cat's stomach can be identified by looking at the surface epithelial cells by scanning electron microscopy (SEM). The luminal surface of cells of the cardiac region were elongated, of the fundus rounded, of the corpus polygonal shaped, and of the pyloric region diamond shaped. The quantity and distribution of microvilli covering the epithelial cells varies, being abundant and evenly distributed in the cardiac region and gradually decreasing in number toward the gastro-duodenal junction, where they were confined to cell perimeters. The colliculi varied in shape and distribution from few in the fundus and corpus to numerous in the …

Scanning Electron Microscope Solid State Detectors, Zbigniew J. Radzimski

Scanning Microscopy

Solid state detectors (SSD) are the most commonly used backscattered electron (BSE) detectors in scanning electron microscopy (SEM). They have been used for at least 20 years and many types are described in the literature. These detectors can be designed in many shapes and forms but in commercially available SEMs two semiconductor detectors (A and B) are usually placed below the polepiece where they are used for compositional (A+B) and topographic (A-B) contrast enhancement. The range of SSD applications available from BSE is quite extensive. The kind and quality of information depend strongly on the shape and position of the …

Microvascular Corrosion Casting Of The Lung. A State-Of-The-Art Review, Dean E. Schraufnagel

Scanning Microscopy

Corrosion casting and viewing of replicas with the scanning electron microscope is an excellent way to study the microvascular structure of the lung. This method can demonstrate aspects of the three-dimensional relationships, branching patterns, maximum diameters, arterio-venous connections, unusual sized and shaped capillaries, development and growth, neovascular structures and changes in development and disease better than any other means. Comparisons can be made in many experimental conditions and fundamental information obtained to answer physiologic questions. This paper reviews how the lung microvasculature has been studied by corrosion casting and scanning electron microscopy and indicates new areas where investigation might be …

Ultrastructural Analysis Of Enamel Formation During In Vitro Development Using Chemically-Defined Medium, P. Bringas Jr., M. Nakamura, E. Nakamura, J. Evans, H. C. Slavkin

Scanning Microscopy

To test the hypothesis that enamel biomineralization is regulated by sequential expression of an intrinsic genetic program, we designed experiments to determine if a serumless, chemically-defined medium is permissive for position-dependent ameloblast differentiation and subsequent enamel tissue-specific biomineralization in vitro. In the absence of serum or other exogenous growth factors, Swiss Webster strain mouse embryonic (15-and 16-days gestation) mandibular first molar tooth organs (cap stage) developed within 21 days in vitro into well-defined molar tooth organs expressing dentine and enamel biomineralization. Analysis of data obtained from von Kossa histochemistry for calcium salt formation, as well as ultrastructural information obtained …

Fictitious Calculi And Human Calculi With Foreign Nuclei, P.-T. Cheng, K. P. H. Pritzker, J. Richards, D. Holmyard

Scanning Microscopy

The correlative approach employing polarized light microscopy, x-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction and energy dispersive x-ray microanalysis proves to be very useful in identifying fictitious calculi and genuine human calculi with foreign body nuclei. The common artifacts as reported in the literature and observed also by us were minerals, vegetable and plant seeds, cereals, sand grains and sea shell fragments.

Two interesting cases involving foreign body nuclei have been reported: one urinary calculus containing a piece of plastic-coated titanium foil in the center; one nasal calculus with a nut as a nucleus. …

Effects Of Fractionated Irradiation On The Esophageal Mucosa: A Scanning And Transmission Electron Microscopic Study, M. Albertsson, C-H Hakansson, C. Mercke, H. Morner

Scanning Microscopy

The mucosa of rabbit esophagus was irradiated with daily fractions of 2 Gy to an accumulated dose of 20 Gy. Specimens were taken for scanning electron microscopy, transmission electron microscopy and light microscopy investigations. Examination was made 1-10 days after each fractionation schedule. Light microscopy showed dose-dependent edema of the irradiated mucosa which also could be seen and scored from SEM pictures. SEM investigations showed that this was accompanied by loosening of microridges and a slightly increased cell loss. By SEM, a varying amount of bacteria could be seen which did not make intimate contact with the surface cells.

During …

Effects Of Cis-Dichlorodiammineplatinum Alone And In Combination With Ionizing Radiation On The Esophageal Mucosa: A Scanning And Transmission Electron Microscopic Study, M. Albertsson, C-H Hakansson, C. Mercke

Scanning Microscopy

Cis-dichlorodiammineplatinum (cis-DDP) has for more than 20 years been part of the therapeutic arsenal of oncology. Most of the knowledge about its biological action is based on clinical investigations and therefore an examination of the influence of cis-DDP at the cellular and sub-cellular level is necessary. Five mg of cis-DDP was given intraperitoneally (i.p.) to ten rabbits. Ultrastructural examinations were performed on the upper and lower parts of the esophagus each day after the injection on the following ten days. Another 50 rabbits were given 5 mg cis-DDP and were irradiated in an area just beneath the hypopharynx. They were …

Characteristics Of An Electric/Magnetic Quadrupole Detector For Low Voltage Scanning Electron Microscopy, M. Brunner, R. Schmid

Scanning Microscopy

The electric/magnetic quadrupole detector allow's efficient detection of secondary electrons in low voltage scanning electron microscopy without introducing disturbing aberrations. The original detector of this type was built in 1986; it has now been equipped with scintillator-photomultiplier assemblies on both positive electrodes. Their signals, A and B, can be combined to A+B or A-B, thus enhancing or suppressing different types of contrast. The aberration disc produced by the present design of detector was estimated to have a diameter of 10 nm. Experimentally, no deterioration of image resolution was observed. The collection efficiency was predicted to be 26% and can be …

Cell Wall Wrinkling And Solute Leakage In Imbibing Squash And Carrot Seeds, Vandy Cavdek, John N. A. Lott, Patrice Kerr

Scanning Microscopy

Dry seeds placed in an aqueous solution take up water, swell, and leak potassium and a variety of other materials into the solution. It is likely that much of the potassium is from the cell walls. Neutron activation analysis was used to measure the concentration of potassium leaked from both squash embryos and carrot mericarps that had been soaked in solutions of different water content. The cell walls in dry seed tissues are often wrinkled, whereas imbibed tissues have smooth cell walls. Cryogenic preparation for scanning electron microscopy was used to study the degree of cell wall wrinkling in the …

Scanning Electron Microscopy Of Vascular Smooth Muscle Cells From Rat Muscular Arteries, William J. Krizmanich, Robert M. K. W. Lee

Scanning Microscopy

The use of scanning electron microscopy (SEM) for the examination of medial smooth muscle cells (SMC) is limited by the presence of connective tissue mass in the adventitia obscuring the detailed structure of the SMC. This study deals with the description of a method which selectively removes the connective tissue, allowing three dimensional observation of SMC using SEM. A number of methods were tried. One method involving post fixation with 2% Os0₄ used in conjunction with HCl proved most successful in removing the extracellular matrix of large mesenteric arteries from spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto normotensive rats …

Multiplane Sectioning And Scanning Electron Microscopy As A Method For Studying The Three-Dimensional Structure Of Mature Dental Enamel, S. Risnes

Scanning Microscopy

A method is described where teeth are sectioned/ground along at least two planes, etched, and viewed at various angles in the SEM in order to study the three-dimensional structure of enamel. This multiplane sectioning-scanning electron microscopy (MPS-SEM) method has been applied to the study of rat and human enamel. The method demonstrates in a direct way the complex three-dimensional structure of rat incisor enamel; the path of prisms and the distribution of interprismatic substance. The different appearance of alternate prism rows as seen in the longitudinal plane is seen to be due to prisms in alternate rows being inclined to …

The Fine Structure Of The Human Placental Villus As Revealed By Scanning Electron Microscopy, G. J. Burton

Scanning Microscopy

Scanning electron microscopy of the placenta has a history of only twenty years. During that time, however, there have been dramatic advances in instrument technology coupled with the refinement of preparative techniques designed to reduce fixation artifacts to a minimum. As a result many of the early claims must be amended or suitably qualified, and this is one aim of the present review.

Much new data on the internal structure of the placental villus is also presented. By means of the partial digestion technique it is now possible to describe the three dimensional configuration of the various components of the …

A Ring Scintillation Detector For Detection Of Backscattered Electrons In The Scanning Electron Microscope, J. Hejna

Scanning Microscopy

A backscattered electron detector with a cylindrical detecting surface has been constructed and installed in a scanning electron microscope. The detector surrounds the specimen and accepts electrons emitted into a specific range of zenith angles. In the case of untilted specimens it collects electrons emerging from the specimen surface at low exit angles relating to it. This enables us to obtain a good resolution of images of untilted specimens. Moreover, the detect or gives very high level of topographic contrast and good three-dimensional impression of the specimen shape.

Endothelialization Of A New Dacron Graft In An Experimental Model: Light Microscopy, Electron Microscopy And Immunocytochemistry, G. Pasquinelli, P. Preda, T. Curti, M. D'Addato, R. Laschi

Scanning Microscopy

Two types of synthetic vascular grafts, Dacron Triaxial and Dacron Gelseal Triaxial, were implanted into both the common carotids of sheep. The animals were sacrificed 1, 2, 8, and 16 weeks after surgery. Multiple specimens, obtained from grafts and anastomoses, were studied by light microscopy, transmission and scanning electron microscopy. A parallel immunocytochemical analysis was performed on some specimens. Dacron Triaxial grafts failed to develop a complete neointimal coverage. Myofibroblasts and fibroblasts were the dominant cells in such synthetic graft. Moreover, focal areas of stripping, platelet deposition, and thrombosis were observed at 8 and 16 weeks.

In contrast, a stable …

Scanning Electron Microscopic Observations Of The Canine Inner Ear, R. J. Mount, R. V. Harrison

Scanning Microscopy

The sensory epithelia of the inner ear of the dog have been investigated using scanning electron microscopy (SEM). The surface appearance of the cristae ampullares of the semicircular canals and of the macula utriculi are very similar to other mammalian species. The crista ampullaris of the anterior vertical semicircular canal is divided by a non-sensory septum cruciatum, found in cats and rats but not, for example, in man. The vestibular sensory cells possess two distinct types of stereocilia, one is thick and rigid appearing, the other is thin and limp. Neither type of stereocilium is restricted to a particular hair …

Scanning Electron Microscopy Of Ectomycorrhizae Potential And Limitations, H. B. Massicotte, L. H. Melville, R. L. Peterson

Scanning Microscopy

Scanning electron microscopy (SEM) has added considerably to an understanding of the morphology of ectomycorrhizae. Features of the mantle of mature ectomycorrhizae have been studied most frequently. There is considerable variation in arrangement of hyphae and therefore in the appearance of the outer mantle. This variation is due primarily to the fungal symbiont although the host genome may also influence this feature. The Hartig net has been studied from fractured ectomycorrhizal roots and, in the present study, from fractured cryopreserved specimens; general features of the interaction between Hartig net hyphae and contiguous root cells have been described. There are few …

Morphological Variations In Developing Ectomycorrhizae Of Dryas Integrifolia And Five Fungal Species, L. H. Melville, H. B. Massicotte, R. L. Peterson

Scanning Microscopy

A comparative study of ectomycorrhiza formation between the host species Dryas integrifolia and four fungal species belonging to the Basidiomycotina ( Laccaria bicolor, L. laccata, Hebeloma cylindrosporum, Paxillus involutus) and one species in the Ascomycotina (Cenococcum geophilum) showed that patterns in ectomycorrhizal development were distinctive enough to characterize each fungal symbiont. Several aspects of hyphal growth on the plant root during colonization were studied in order to demonstrate the usefulness of SEM in observing the ontogeny of ectomycorrhizae. Each fungal species had a different rate of colonization, and varying root and root hair interactions. As a consequence mantle …

The Use Of Scanning Electron Microscopy In Studying Enamel Caries, R. P. Shellis, A. S. Hallsworth

Scanning Microscopy

SEM studies related to carious change in dental enamel are reviewed, and their contribution to understanding the mechanism of formation of the early enamel lesion and of its repair evaluated. SEM has contributed significantly to understanding the mechanism of enamel dissolution at the level of the single crystal. Etching studies have yielded useful information on the effect of enamel structure on the pattern of acid dissolution at the microscopic level and have highlighted the importance of re- precipitation phenomena in modifying the pattern of mineral loss. High-resolution studies have provided interesting quantitative data on changes in crystal size, and also …

Scanning Electron Microscopy Of Vascular Corrosion Casts In Comparative Studies On Renal Vascular Structure, H. Ditrich, H. Splechtna

Scanning Microscopy

In comparative microcorrosion casting studies on renal vascular systems the following demands should be met: The preparation procedure (anaesthesia, operation, flushing of the blood vascular system, ...) should be in accord with the specific physiological properties of the animal under investigation and the casting procedure (injection, curing, maceration, ...) should be kept constant as far as possible. If these points are considered, comparative data, even of quantitative nature, can be obtained from corrosion casts. Examples of results at the organ, single vessel and intercellular level as well as correlation of the results with physiological data are given.

Scanning Electron Microscopy In Oral Mucosal Research: A Review, A. Kullaa-Mikkonen

Scanning Microscopy

This review paper highlights some aspects of the contribution of SEM in the field of oral mucosa research. These include 1) different preparative techniques, 2) structure of the oral mucosa and its role in normal function, 3) advances in oral microbiology, 4) development of the oral mucosal epithelium, 5) pathological diagnosis and 6) morphometry.

There are four main ways to study the oral mucosa with SEM; biopsy (autopsy) samples, smears, replica technique, and cell culture techniques. The structural studies can be divided as studies of the surface structure of the superficial cells of the oral mucosa and studies of the …

The Use Of Electron Microscopic Methods For The Characterization Of Paints In Forensic Science, R. Goebel, W. Stoecklein

Scanning Microscopy

Apart from the conventional methods for investigating paints in the forensic science laboratory the electron microscope gives many additional types of information. Since the materials for coating objects are produced in large quantities, a merely chemical analysis of paint does not lead to individual identification. Therefore it is necessary to demonstrate morphological peculiarities, such as e.g., features and defects of fabrication. So the material will have to be evaluated by microanalysis and cathodoluminescence, too. Additionally the pigments and extending materials, especially in primers, can be described by transmission electron microscopy. In that way one can obtain information about the distribution …