Biology Commons^™

Cyclic Deposition Of Calcium Salts During Growth Of Cholesterol Gallstones, Peter F. Malet, Norman E. Weston, Bruce W. Trotman, Roger D. Soloway

Scanning Electron Microscopy

Some cholesterol gallstones contain darkly pigmented centers or peripheral concentric pigmented bands. We examined the cross-sectional surface of three cholesterol gallstones which contained both central and peripheral pigmented areas with electron-probe microanalysis (EPM) and energy dispersive x-ray microanalysis (EDXA) to determine the elemental composition of the pigmented regions. Linear EPM across the cross-sectional surface of the stones demonstrated that most of the pigmented regions of all three stones had high Ca and P signals; the nonpigmented intervening areas had markedly lower or no detectable Ca and P signals. In two of the three stones, high O signals coincided with the …

Survival And Growth Of Adult Human Oligodendrocytes In Culture: Scanning Electron Microscopy, Seung U. Kim, Kookmin M. Kim, Giuseppe Moretto, Doo H. Shin

Scanning Electron Microscopy

The oligodendrocytes in culture serve as an important model for the study of demyelination diseases. We have previously originated a method of isolating human oligodendrocytes. In order to establish their three dimensional morphology, scanning electron microscopy of the cultured oligodendrocytes was performed.

The oligodendrocytes bulk isolated from adult human brain were maintained in culture for more than 2 months. At the various periods in culture, the cells were studied by scanning electron microscopy and immunofluorescence staining using marker antibodies for the identification of oligodendrocytes. The three dimensional organization and the surface morphology of the cultured oligodendrocytes were investigated. They displayed …

The Growth Of Fetal Human Sensory Ganglion Neurons In Culture: A Scanning Electron Microscopic Study, Seung U. Kim, Kookmin M. Kim, Giuseppe Moretto, James H. Kim

Scanning Electron Microscopy

Sensory neurons of 8-week human fetal dorsal root ganglia were dissociated into single cells by trypsinization and cultured on coverslips for 4 months, in either serum-containing or serum-free chemically defined media. At different times the cultures were fixed and prepared for scanning electron microscopy. Fetal sensory neurons in culture regenerated axons within 24 hours which were characterized by axonal growth cones at their tips and the neuronal perikarya assumed spherical or a bonnet-like morphology.

Applications Of Scanning Electron Microscopy And X-Ray Microanalysis In Inner Ear Pathology, M. Anniko, D. J. Lim, A. Sobin, R. Wróblewski

Scanning Electron Microscopy

Surface pathology of inner ear structures so far described in detail concern cochlear and vestibular hair cells and the stria vascularis. In man, surgical intervention into the inner ear is very uncommon and when performed is in general with the primary objective of destroying the diseased peripheral end organs. The vast majority of inner ear tissue available for use with scanning electron microscopy (SEM) is therefore obtained from animals.

The present paper reviews the progression of surface pathology caused by aminoglycoside antibiotics, acoustic overstimulation and in a guinea pig strain with genetic inner ear disease. The primary site of onset …

Ultrastructural Studies Of Crystal-Organic Matrix Relations In Renal Stones, P. -T. Cheng, A. D. Reid, K. P. H. Pritzker

Scanning Electron Microscopy

Biochemically the organic matrix of kidney stones contains mucoproteins, mucopolysaccharides, inorganic material and bound water. Morphologically, the organic matrix exists as either amorphous or fibrous forms. We have attempted to critically evaluate results from analytical and morphological studies on stone matrices using light microscopy, histochemistry, x-ray diffraction, scanning electron microscopy, x-ray energy dispersive spectrometry, transmission electron microscopy and selected area electron diffraction.

On the surface of calcium oxalate stones, there are usually large masses of randomly deposited calcium oxalate crystals each coated with organic matrix. Transmission electron microscopy shows these large surface crystals are composed of rows of smaller crystallites …

Detection Of Small (5-15nm) Gold-Labelled Surface Antigens Using Backscattered Electrons, Paul Walther, Martin Müller

Scanning Electron Microscopy

The analysis of surface antigens by scanning electron microscopy represents a practicable alternative to replica techniques. It is generally observed that smaller markers provide for better labelling. In the SEM very small colloidal gold labels however are hardly discerned from contaminants or from surface structures of similar size. They are however unambiguously demonstrated by combining the surface information provided by the secondary electron signal and the material dependent signal provided by the backscattered electrons. A field emission SEM equipped with a highly sensitive single crystal backscattered electron detector allows the routine detection of 5 nm gold particles on biological surfaces. …

Scanning Electron Microscopy In Retinal Research, Bessie Borwein

Scanning Electron Microscopy

The literature on scanning electron microscopy (SEM) pertaining to the retina has been surveyed and described.

The first two papers on SEM and retina appeared in 1969. Most of the earlier studies concentrated on descriptions [by SEM alone, or with light microscopy (LM) and transmission electron microscopy (TEM)] of the appearance of various retinae and retinal cells [fish, newt, primates, rodents and rabbits, bullfrog]; or embryology of the chick retina. Two papers dealt with retinal disease. In all there were 25 papers in SEM/retinal research before and in 1974. Since 1975 there have been 111 papers which have used SEM …

Wave-Length Dispersive Microprobe Analysis Of Coated Samples Of Bulk Tissues, C. Ward Kischer, Thomas M. Teska

Scanning Electron Microscopy

Hypertrophic scars contain highly pleomorphic cells, including many from the erythrocytic series which have been extravasated. The conventional visual mode of SEM cannot distinguish the cell types with certainty except in the case of typical biconcave disc-shaped erythrocytes. Microprobe elemental analysis might be used to differentiate one type from another on the basis of iron and possibly phosphorus (for nucleated cells). Using coated specimens (gold or gold-palladium) precludes simultaneous visual mode SEM with EDX because of energy line interference with phosphorus and other elements. However, wave-length dispersive analysis offers minimal or no interference, and a coated specimen offers the use …

Scanning Electron Microscopy Of The Lateral Ventricle Of The Pigeon Brain, P. Mestres, K. Rascher, J. D. Delius

Scanning Electron Microscopy

Adult pigeons of both sexes were used for this study. Depending upon the distribution of various surface profiles, for example cilia, microvilli and blebs, ependymal areas with differing surface patterns were distinguished in the lateral ventricle. The topographical locations of these areas with respect to the underlying forebrain nuclei were determined in accord with the atlas of Karten and Hodos (1967). The medial surface (A) of the ventricle was much more densely ciliated than the lateral surface (B). There did not appear to be any correlation between a given surface pattern and a specific type of underlying nervous tissue. Comparison …

Ultrasonic Microdissection Of Rat Cerebellum For Scanning Electron Microscopy, C. E. Arnett Iii, F. N. Low

Scanning Electron Microscopy

The cerebelli of rats were initially fixed with aldehydes (modified Karnovsky's fixative; 503 mOsM/L) by cardiac perfusion. Blocks of tissue were razor-cut, usually longitudinal to folia, and immersed in the same fluid for 2-4 hours. Three separate methods of treatment followed: (1) immersion in 1% aqueous boric acid, or (2) in 2% phosphate buffered OsO₄ followed by boric acid or (3) in an 8/2 mixture of boric acid and OsO₄. After 18-48 hours immersion the blocks were dehydrated in ascending grades of acetone. They were then exposed to ultrasound in 100% acetone at frequencies of 80 kHz …

Use Of Scanning Electron Microscopy To Study Structural-Functional Relationships In Normal And Diseased Platelets, J. C. Mattson

Scanning Electron Microscopy

This paper reviews the contribution of scanning electron microscopy (SEM) to our understanding of platelet physiology and pathology. Observations of platelet shape changes which accompany activation and the ability to visualize and analyze platelet aggregation and adhesion in three dimensions make this experimental medium an important tool in the evaluation of healthy and diseased platelets. While SEM adds a valuable third dimension to the study of morphology and ultrastructure, its greatest contribution is realized when studies are correlated directly with light and/or transmission electron microscopic observations and with studies of functional capacity.

Morphological Study Of The Anodic-Oxide And Hydrated-Oxide Films On Pure Aluminium, S. M. El-Mashri

Scanning Electron Microscopy

A high resolution scanning transmission electron microscope (STEM), operated in the SEM mode, has been used to examine the morphology of the oxide anodically formed on a surface of pure aluminium, using different electrolyte solutions (tartaric, oxalic, boric, phosphoric and chromic acids). The microstructural changes of these films following their hydration in hot water showed degradation of the oxide and conversion to an oxy-hydroxide phase (pseudo-boehmite). These observations are in agreement with previous EXAFS measurements of the Al-O bondlength which indicated the formation of crystalline boehmite (AlOOH). Observation of the oxide and oxy-hydroxide derived from anodisation in phosphoric acid electrolyte …

Calcium Oxalate Crystal Production In Two Members Of The Mucorales, M. D. Powell, H. J. Arnott

Scanning Electron Microscopy

Calcium oxalate crystals are found in association with the sporangia of Mucor hiemalis and Rhizopus oryzae. Crystals observed in each species vary in morphology from simple crystals consisting of single spines in M. hiemalis to complex crystals with twin spines, sometimes three-parted, on a common base in R. oryzae. The early development of the crystals is similar in both species with a layer of the cell wall covering in the initial crystals. The spines of M. hiemalis rapidly emerge while the crystals of R. oryzae appear to remain covered with a layer of outer wall material. The crystals …

An Ultrastructural Analysis Of The Physical Organization Of Collagenous (Type I) Matrices: One Determinant Of Urothelium Maintenance In Vitro, G. M. Hodges, C. Rowlatt, A. R. Howlett, L. K. Trejdosiewicz

Scanning Electron Microscopy

Collagenous matrices, used as cell culture substrata, can be prepared from different collagen types in a variety of forms using a range of polymerization procedures. Type I collagen has been most frequently used either as dried collagen films or hydrated collagen gels. Sheets of isolated bladder urothelium, when plated onto such matrices prepared from type I collagen by different polymerization methods (eg. air-drying; NaOH; NaCl; NH₃; or NH₃ followed by glutaraldehyde crosslinking) demonstrate the capability of urothelial cells to attach to a variety of differently prepared matrices irrespective of polymerization procedure. In contrast, both cell proliferation and …

Endometrium Cell Surface Abnormalities In The Syrian Hamster As A Result Of In Utero Exposure To Diethylstilbestrol, J. Gilloteaux, A. W. Steggles

Scanning Electron Microscopy

Scanning electron microscopy (SEM) was used to observe changes in the hamster endometrium cell surface following in utero pre- and/or postnatal exposure to diethylstilbestrol (DES). Some of the changes in cell surfaces are associated with alterations in cell sizes and shapes (from columnar to cuboidal and/or squamous) and in microvilli and mucous secretion. In all cases, DES treated uteri show mucosal cell surface pleomorphism, apocrine secretion and cystic accumulation of secretory material. Microvillous pleomorphism and peculiar linkages attaching one microvillus to others were investigated. Although the function and nature of such linkages is unclear, their presence seems to be more …

The Role Of The Vessels In The Growth Plate: Morphological Examination, K. Draenert, Y. Draenert

Scanning Electron Microscopy

Combined methods of light microscopy to present ossification zones by means of fluorochrome dyes make it possible to explain the contradicting presentations of the vascular system of the growth plate in the literature. The vascular system was casted with methacrylates which can be presented in the scanning electron microscope 3-dimensionally together with the trabeculae as a result of their resistance in the electron beam.

The 3-dimensional presentation in the electron microscope allows a clear distinction between the various vascular sections in the arterial flow system. In the microcorrosion casts the vessels of the epiphyseal side of the growth plate can …

Monte Carlo Electron Trajectory Calculations Of Electron Interactions In Samples With Special Geometries, Dale E. Newbury, Robert L. Myklebust

Scanning Electron Microscopy

Implementing a Monte Carlo simulation for application to electron sample interactions requires use of accurate treatments of elastic and inelastic scattering. In formulating a Monte Carlo simulation, careful testing must be carried out to ensure that the calculation yields sensible and useful results. A suitable testing procedure includes calculation of (1) electron backscatter coefficients as a function of atomic number, including any necessary adjustment of scattering parameters; (2) backscatter coefficients as a function of specimen tilt; (3) backscatter and transmission coefficients for thin foils; (4) backscattered electron energy distributions; (5) electron spatial distributions; and (6) x-rays, including x-ray depth distributions, …