Life Sciences Commons^™

Structural And Calcification Patterns Of The Neonatal Line In The Enamel Of Human Deciduous Teeth, Tetsuo Kodaka, Tsuneyoshi Sano, Shohei Higashi

Scanning Microscopy

The neonatal line of the enamel in human deciduous teeth was observed by scanning electron microscopy using secondary and backscattered electron signals. The neonatal line containing irregular structures of enamel prisms with disordered crystal arrangements was basically formed by the abrupt bending of the prisms towards the root. Usually, the prisms gradually bent back again to regain their previous orientation, but the prisms in the inner and the surface layer sometimes ran straight ahead after bending. The prism sheath regions showing hypocalcification contained a relatively large amount of organic material as shown by treatment with chromium sulfate. When etched with …

A Novel Method For Viewing Heavy Metal Stained And Embedded Biological Tissue By Field Emission Scanning Electron Microscopy, R. Geoffrey Richards, Iolo Ap Gwynn

Scanning Microscopy

Backscattered electron (BSE) imaging was used to display heavy metal stained biological structures of various embedded specimens. Samples were fixed, stained and embedded in resin blocks as with preparation for the transmission electron microscope (TEM). Blocks were trimmed to center the specimens in a trapezoidal face of up to 5 mm² and their sides painted with conductive silver paint leaving the face uncovered. Blocks were sputter coated with 6-8 nm of silver, chromium or aluminum, with aluminum providing the best specimen contrast in BSE mode. Samples were examined in a field emission scanning electron microscope operated at a high …

Consistency In Calibrated Backscattered Electron Images Of Calcified Tissues And Minerals Analyzed In Multiple Imaging Sessions, E. G. Vajda, J. G. Skedros, R. D. Bloebaum

Scanning Microscopy

Pure metal standards have been used to calibrate the operating environment in quantitative backscattered electron (BSE) imaging of mineralized tissue, allowing comparisons to be made between various mineralization states of bone at the microscopic level. It has not previously been documented that calibration procedures produce consistent, reliable results over multiple imaging sessions. In this study, BSE images were obtained from bones, pure metals, and a naturally occurring mineral in multiple imaging sessions over a six day period. The graylevel histogram profile (GHP) from each specimen was analyzed for changes in the shape and relative placement on the graylevel spectrum. Computer …

Backscattered Electron Imaging And Energy-Dispersive X-Ray Microanalysis Studies Of Evidence For Calcium Salt Heterogeneity In Fifteen Gallstones From An Elderly Human, Tetsuo Kodaka, Ryoichi Mori, Kazuhiro Debari, Reiji Takiguchi, Shohei Higashi

Scanning Microscopy

We examined 15 variably-sized gallstones, taken from an elderly male, by backscattered electron imaging and energy-dispersive X-ray microanalysis to learn the structural and distribution patterns of gallstone calcium (Ca-) salts. Of the 13 cholesterol-rich stones, nine stones had peripheral concentric layers of Ca-carbonate, whereas 2 stones had peripheral layers of Ca-phosphate. No Ca-salts were detected from 2 cholesterol-rich stones. The 2 stones containing Ca-phosphate had no Ca-salt cores, whereas the stones containing Ca-carbonate were separated into 3 different types: two stones with a Ca-carbonate core, four stones with several Ca-bilirubinate cores of glass-like structure, and 3 stones lacking Ca-salt cores. …

A New Scanning Electron Microscopy Approach To The Quantification Of Bone Mineral Distribution: Backscattered Electron Image Grey-Levels Correlated To Calcium Kα-Line Intensities, P. Roschger, H. Plenk Jr., K. Klaushofer, J. Eschberger

Scanning Microscopy

The introduction of backscattered electron (BSE) imaging in scanning electron microscopy (SEM) has led to new possibilities for the evaluation of mineral distributions in bone on a microscopic level. The different grey-levels seen in the BSE-images can be used as a measure for the local mineral content of bone. In order to calibrate these BSE-grey-levels (BSE-GL) and correlate them to mineral contents, various attempts, using reference samples with known weighted mean atomic number and/or using simulated bone tissues with known hydroxyapatite concentrations, have been made. In contrast, a new approach is presented here based on measurements of the X-ray intensities …

Cell Surface Changes Of Hemopoietic Cells During Normal And Leukemic Differentiation: An Immuno-Scanning Electron Microscopy Study, D. Soligo, E. P. De Harven, N. Quirici, L. Caneva, G. Lambertenghi Deliliers

Scanning Microscopy

Hemopoietic cells display a wide range of cell surface antigens which are either lineage specific or acquired during differentiation. Monoclonal antibodies can be used, in conjunction with colloidal gold markers, to identify under the scanning electron microscopy (SEM) at the single cell level, specific lineage or maturation stages in the hemopoietic bone marrow. Normal bone marrow cells, either gradient separated or purified by immuno-magnetic methods and leukemic cell samples, which can be considered as "frozen" stages of hemopoietic differentiation, have been studied with this method. Typical cell surface morphologies, which characterize immature progenitor cells and cells committed or differentiated towards …

Scanning Electron Microscopy And Energy-Dispersive X-Ray Microanalysis Studies Of Several Human Calculi Containing Calcium Phosphate Crystals, Tetsuo Kodaka, Kazuhiro Debari, Tsuneyoshi Sano, Masayuki Yamada

Scanning Microscopy

Human calcium phosphate calculi: two sialoliths, a urolith, a rhinolith, and a tonsillolith were investigated by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The sialoliths and urolith had appositional shells with thick cortices, respectively, around several nuclei composed of calcospherulites and a rubber-film fragment. The rhinolith had a thin cortex with appositional laminations around a glomerulus-like mass of calcified cotton-like strings. The tonsillolith had a rough cortex with appositional laminations. Its porous interior was composed of numerous calcified conglomerates with microorganisms and calcified masses with fine appositional laminations around the conglomerates. The major crystals were identified as biological …

Direct Visualization And Silver Enhancement Of Ultra-Small Antibody-Bound Gold Particles On Immunolabeled Ultrathin Resin Sections, York-Dieter Stierhof, Bruno M. Humbel, Rene Hermann, Max T. Otten, Heinz Schwarz

Scanning Microscopy

Ultra-small gold colloids bound to immunolabeled ultrathin resin sections were visualized using transmission, scanning, and scanning transmission electron microscopy (TEM, SEM, STEM). The best marker contrast is obtained in a field emission STEM (200 kV) equipped with a high-angle annular dark-field (HAADF) detector. HAADF STEM renders possible the simultaneous visualization of ultra-small gold and ultrastructural details in unstained resin sections, and an overall presentation of a labeled E. coli cell.

For routine work, an enhancement step is a prerequisite for easy detection of bound marker molecules. Five different silver enhancing solutions were tested for their suitability for ultra-small gold intensification. …

An Approach To Solid Phase Identification In A Ca-S-O System By Quantitative Energy Dispersive X-Ray Microanalysis, K. Wieczorek-Ciurowa, S. J. Sivonen, P. Kokkonen

Scanning Microscopy

Solid phases formed in the limestone sulphation reaction were identified by scanning electron microscopy with backscattered electron (BSE) imaging and by quantitative energy dispersive X-ray (EDX) microanalysis of calcium and sulphur. Since calcium and sulphur can form several compounds in the Ca-S-O system, two quantities, the sum of oxides (CaO+SO₃) and the molar ratio (CaO/SO₃), were used to calculate empirical formulae for the compounds actually present.

A method for analysing the experimental results is proposed, the mathematical expressions employed are presented and the numerical coefficients tabulated. It is shown with some examples that the method used …

A Cytochemical Scanning Electron Microscopy Study Of Non-Specific Acid Esterase And Acid Phosphatase Activities In Human Peripheral Blood Lymphocytes, A. Campos, E. Fernández-Segura, J. M. García-López

Scanning Microscopy

We analyzed the distribution patterns of nonspecific acid esterase and acid phosphatase activities with cytochemistry-scanning electron microscopy in backscattered and secondary electron imaging modes in isolated normal human peripheral blood lymphocytes . The analysis of non-specific acid esterase activity in the backscattered electron imaging mode showed, in some cells, focal distribution with a well-defined, homogenous deposit. Two patterns of acid phosphatase activity were evident with the backscattered electron imaging mode, i.e., focal and granular. Peripheral blood lymphocytes showing focal activity of both enzymes presented a smooth surface with few scattered microvilli as seen with the secondary electron imaging mode ; …

The Use Of Backscattered Electron Imaging, X-Ray Microanalysis And X-Ray Microscopy In Demonstrating Physiological Cell Death, I. D. Bowen, N. A. Worrill, C. A. Winters, K. Mullarkey

Scanning Microscopy

The cytochemical localization of enzymatic activity by means of backscattered electron imaging (BEi) is reviewed and the application of BEI to changes in acid phosphatase and ATPase distribution during physiological (programmed) cell death in Heliothis midgut is explored. Programmed cell death entails the release of nascent free acid phosphatase as extracisternal hydrolase. This shift can readily be detected by means of the atomic number contrast imparted by BEI of the lead phosphatase reaction product, thus enabling the distribution of dying cells to be mapped. BEI is particularly useful in this context as it allows the examination of bulk specimens at …

Changes In Quality Of Bone Mineral On Aging And In Disease, M. D. Grynpas, D. Holmyard

Scanning Microscopy

This paper reviews the changes in the quality of bone mineral with age and in disease. After a brief review of morphological changes with aging in mammalian bones, microradiography is compared to backscattered electron imaging and their use in bringing out subtle changes in bone mineralization outlined.

Changes in the quality of bone with disease is described using osteoporosis as an example. Chemical changes in the skeleton are then discussed and related to morphological changes. Finally, some examples of localized and generalized changes in bone mineral are given. This paper emphasizes that understanding the nature of the mineral phase in …

Application Of Backscattered Electron Imaging And Lectin-Gold Cytochemistry To Visualize The Distribution Of Glycoconjugates In A Basal Lamina, Antonio Nanci, Sylvia Zalzal, Charles E. Smith

Scanning Microscopy

Basement membranes generally appear in transmission electron microscopy as thin, cross-sectioned profiles. Face-views are difficult to obtain particularly when their contours are curved or undulated. Such preparations are suited for the study of the distribution of basement membrane constituents through thickness but are limited for examining their spatial distribution. Scanning electron microscopy offers the potential of visualizing surface views. We have applied this approach to examining the three-dimensional distribution of glycoconjugates in a basement membrane. Large, face-views of the basal lamina related to maturation ameloblasts in the region where enamel of the rat incisor is EDTA soluble were exposed. Glycoconjugates …

Advanced Scanning Electron Microscopy Methods And Applications To Integrated Circuit Failure Analysis, E. I. Cole Jr., C. R. Bagnell Jr., B. G. Davies, A. M. Neacsu, W. V. Oxford, R. H. Propst

Scanning Microscopy

Semiconductor device failure analysis using the scanning electron microscope (SEM) has become a standard component of integrated circuit fabrication. Improvements in SEM capabilities and in digital imaging and processing have advanced standard acquisition modes and have promoted new failure analysis methods. The physical basis of various data acquisition modes, both standard and new, and their implementation on a computer controlled SEM image acquisition/processing system are discussed, emphasizing the advantages of each method. Design considerations for an integrated, online failure analysis system are also described. Recent developments in the integration of the information provided by electron beam analysis, conventional integrated circuit …

Immunogold Labeling Of Human Leukocytes For Scanning Electron Microscopy And Light Microscopy: Quantitative Aspects Of The Methodology, E. De Harven, D. Soligo

Scanning Microscopy

When cell surface antigens are labeled with the colloidal gold marker, backscattered electron images (BEI) reveal all the gold particles and, therefore, permit total counts. Secondary electron images (SEI) show only a small percentage of the gold particles and are inadequate for quantitative evaluation.

For determination of the cellular labelinq index, a time-consuming method implies the screening of 100 cells by scanninq electron microscopy, at a magnification of approximately 12,000 to 15,000x, with continuous SE/BE shifts. A much more efficient method is to transfer the SEM sample or its equivalent under the light microscope and to count the total number …

Colloidal Gold - A Powerful Tool In Scanning Electron Microscope Immunocytochemistry: An Overview Of Bioapplications, G. M. Hodges, J. Southgate, E. C. Toulson

Scanning Microscopy

Colloidal gold may be conjugated to a wide variety of macromolecules, provides a versatile system for immunocytochemical studies by various types of microscopy (light and fluorescent microscopy, scanning (SEM) and transmission (TEM) electron microscopy), and is significantly contributing to the development of SEM immunocytochemistry as a routine analytical procedure.

A comprehensive overview has been compiled of the literature on SEM bioapplications of colloidal gold. This is illustrated through a selected series of studies focussing on a) cell surface receptor-ligand interactions; b) expression of cell surface lectin-binding sites; c) surface distribution of extracellular matrix components; and d) visualization of gold-labelled cytoskeletal …