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Colloidal Gold Labelling Of Fibrinogen Receptors In Epinephrine – And Adp–Activated Platelet Suspensions, J. A. Oliver, R. M. Albrecht

Scanning Microscopy

It has been generally accepted for over twenty years that epinephrine stimulates platelet aggregation without inducing shape change. However, it has been recently reported that discoid platelets are not recruited into ADP-or epinephrine-stimulated aggregates. Previous work in our laboratory has suggested that platelet shape change is necessary for the binding of fibrinogen to its surface receptor, which is a prerequisite for platelet aggregation. These studies seem to indicate that epinephrine-induced platelet aggregation does involve shape change. To investigate this possibility, the extent of shape change and fibrinogen binding in suspensions of epinephrine-and ADP-activated and control platelets was assessed by scanning …

Light And Electron Microscopic Localization Of Glycoconjugates With Gold-Labeled Reagents, J. Roth

Scanning Microscopy

This paper gives an overview of the use of lectins, glycoproteins, monoclonal anticarbohydrate antibodies, toxins, and glycosyltransferases for the detection and localization of cellular glycoconjugates in sections from embedded tissues by light and electron microscopy. In all these techniques particles of colloidal gold were used as a marker. For light microscopic studies routine conditions of embedding such as paraffin or Epon embedding could be employed. For electron microscopic studies the low temperature embedding technique using Lowicryl K4M was found to be the method of choice for the localization of sugar residues in intracellular compartments, the extracellular matrix and the plasma …

The Scanning Electron Microscopy/Replica Technique And Recent Applications To The Study Of Fossil Bone, Timothy G. Bromage

Scanning Microscopy

The SEM/replica technique employs high resolution replica materials in order to reflect microstructural details of specimens, such as fossil bones, which cannot be observed directly. The described technique is simple, provides excellent resolution, is maximally adaptable to field and laboratory settings, and is applicable to large and topographically complex bone surfaces. The advent of the technique has made it largely possible to address certain issues in anthropology and paleontology. These contributions have principally been concerned with taphonomy as the study of the bone damage process, and bone biology as it relates to bone growth remodeling processes characterizing the facial growth …

Analysis Of Primate Dental Microwear Using Image Processing Techniques, Richard F. Kay

Scanning Microscopy

This paper introduces Fourier transformation as a rapid, replicable means for characterizing and distinguishing patterns of microscopic wear on primate teeth. The two-dimensional power spectra obtained from numerical Fourier transformation are shown to be different between two test patterns, one of which is composed of linear features and the other of randomly-spaced dots. A comparison is made, using Fourier transformation, of dental microwear patterns of small samples of two primate species, Ateles geoffroyi, the spider monkey, and Chiropotes satanas, the bearded saki. Ateles, with a scratch-dominated pattern of microwear, has a Fourier transform resembling that of the …

Morphological Characterization Of Materials Using Low Voltage Scanning Electron Microscopy (Lvsem), Jesse Hefter

Scanning Microscopy

The use of lower energy (0.5 to 10 keV) electron beams in the scanning electron microscope (LVSEM) provides a number of advantages in the imaging of materials, including increased topographic contrast and reduced specimen charging. Application of LVSEM to materials analysis was difficult in the past due to a number of instrumental difficulties, including low gun brightness, the increased effect of chromatic aberration upon lower energy beams, and the increased sensitivity of such electron beams to stray fields. Improvements in design have led to commercial instruments which provide the microscopist with the capability to analyze materials in this low-energy regime. …

Replication Technique For Studying Microstructure In Fossil Enamel, A. D. Beynon

Scanning Microscopy

The present paper describes a two stage impression technique using a silicone elastomer suitable for field replication studies; which requires high dimensional stability, defined resolution, and being capable of reproducing inaccessible details. A test object consisting of etched pearlite possessed fine detail [>1μm to <0.1μm] which was suitable for testing negative/ positive replica combinations. Coltene President light-body impression material was capable of resolving parallel side depressions of widths ≧0.2μm, and it possesses very good dimensional stability with time, allowing the production of positive casts to be deferred for several months. Low viscosity Spurr resin reproduced this detail, and flowed into inaccessible sites.

Although there was evidence of bulk contraction on curing, there was no significant shrinkage on flat [linear] surfaces or in vertical relief dimensions.

Replicas of fractured hominid teeth showed good surface detail, and reproduction of inaccessible three-dimensional features on enamel surfaces. Enamel prism shape was pattern 3.

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 …

Surface Characterization Of Biomaterials By Immunogold Staining - Quantitative Analysis, Kinam Park, Scott R. Simmons, Ralph M. Albrecht

Scanning Microscopy

The labeling of target proteins by immunogold particles has been analyzed based on Einstein's law of Brownian motion. The theory was confirmed from the experiments which employed antifibrinogen gold markers to label fibrinogen molecules adsorbed on the polyethylene surface. The theory predicts that the degree of labeling depends on the concentration of gold markers, temperature, medium viscosity, size of gold markers, and staining time. Of these factors most important is the concentration of immunogold particles. Small change in the marker concentration results in a significant variation in the staining efficiency when other variables are kept constant. The effect of temperature …

The Contribution Of Electron Probe X-Ray Microanalysis (Epxma) To Pollution Studies, A. J. Morgan, C. Winters

Scanning Microscopy

This paper surveys the literature on the use of EPXMA in conjunction with (heavy metal) pollution studies.

Metal-accumulating compartments are usually granules or vacuoles of 6 main types (i) extracellular, soluble and fairly pure calcium carbonate granules; (ii) insoluble, calcium and phosphorus-rich granules, of ten containing several metal contaminants; (iii) multifunctional, calcium and phosphorus granules containing a high proportion of rather complex organic molecules; (iv) copper-(and sulphur) rich granules; (v) iron-(and phosphorus) rich granules; (vi) Cd, Zn, Cu and Hg -containing vacuoles, where the metals are presumably complexed with cysteine-rich metallothionein proteins, or their derivatives. With a few exceptions, types …

In Situ Hybridization At The Electron Microscope Level, Maximilian Binder

Scanning Microscopy

This tutorial paper will review radioactive and non-radioactive in situ hybridization (ISH) techniques at the electron microscope (EM) level; describe our efforts in comparison to those of other groups who recently have published in this field and discuss some potential future applications. Our contribution is the development of a non-radioactive, postembedding technique for the detection of transcripts on thin sections of Lowicryl K4M-embedded cells or tissues. Biotinylated probes were prepared by nick-translation. Signal detection was accomplished with anti-biotin antibody and protein A-gold complexes. Specific labeling was obtained over structures known to be the site of expression. Compared to EM autoradiography …

Replica-Immunogold Technique Applied To Studies On Measles Virus Morphogenesis, W. Bohn, K. Mannweiler, H. Hohenberg, G. Rutter

Scanning Microscopy

The replica technique was applied to studies on the dynamic process of measles virus budding on infected HeLa cells. Virus structures were identified by labeling with anti-measles antibodies and protein A-gold. The combination of these two methods enabled us (1) to characterize the sequence of virus budding at the plasma membrane, (2) to localize virus structures on cytoskeletons of infected cells, and (3) to study the influence of Ca²⁺ ions on virus structures at the plasma membrane. Studies on platinum carbon surface replicas suggest that the process of virus budding is similar to the genesis of cellular microvilli. Replicas …

Low Load Vickers Hardness Measurements Of Nonconducting Materials In A Scanning Electron Microscope, H. Bangert, X. Cai, A. Wagendristel, A. Kaminitschek

Scanning Microscopy

Vickers hardness tests on microscopic small bodies, e.g., fibers, powder particles, thin layers, etc., require imprint dimensions near or even below the resolution limits of light microscopes. Hence, to detect and evaluate these miniature imprints a scanning electron microscope (SEM) has to be used. For such observations in a SEM, nonconducting samples have to be coated with a thin conductive layer. The influence of these films on the imprint size and thus on the hardness value can be rather significant. On the basis of a systematic investigation in the case of a layer much softer than the sample to be …

Nature And Properties Of Cardiovascular Deposits, B. B. Tomazic, E. S. Etz, W. E. Brown

Scanning Microscopy

Mineral deposits from human aortas and bioprosthetic devices implanted in experimental animals show close similarities in chemical composition, solubility and structural characteristics. Chemical analyses show compositions corresponding to a Na, Mg, CO₃ substituted apatitic calcium phosphate. Synergistic XRO, FT-IR and Raman Mi crop robe spectroscopic data provided coherent indication of Type-B CO₃^2- incorporation. Microscopic and electron microprobe microanalyses, however, indicate substantial morphological and spatial heterogeneity in the deposits.

Solubility and kinetic dissolution data of the mineral fraction of deposits can be compared with the corresponding data of octacalcium phosphate (OCP). This may indicate that OCP is a …

Interaction Between X-Irradiated Plateau-Phase Bone Marrow Stromal Cell Lines And Co-Cultivated Factor-Dependent Cell Lines Leading To Leukemogenesis In Vitro, E. Naparstek, P. Ankleasria, T. J. Fitzgerald, M. A. Sakakeeny, J. S. Greenberger

Scanning Microscopy

Plateau-phase mouse clonal bone marrow stromal cell lines D2XRII and C3H c1 II produce decreasing levels of M-CSF (CSF-I), a specific macrophage progenitor cell humoral regulator, following x-irradiation in vitro. The decrease did not go below 40% of control levels, even after irradiation doses of 50,000 rad (500 Gy). In contrast, a distinct humoral regulator stimulating growth of GM-CSF/IL-3 factor-dependent (FD) hematopoietic progenitor cell lines was detected following radiation to doses above 2,000 rad. This humoral factor was not detectable in conditioned medium from irradiated cells, weakly detected using factor-dependent target cell populations in agar overlay, and was prominently detected …

Scanning Electron Microscopy Of Microcorrosion Casts: Applications In Ophthalmologic Research, Peter C. Burger, David B. Chandler, Andrzeji W. Fryczkowski, Gordon K. Klintworth

Scanning Microscopy

In light of the complicated nature of the ocular vasculature, it has been difficult to define the normal ocular anatomy by reference to two-dimensional tissue sections. Since it provides three-dimensional replicas, scanning electron microscopy (SEM) of vascular corrosion casts has therefore been an invaluable addition to the study of ocular vasculature. This technique also often permits identification of a normal vessel's arterial, venous, or capillary nature by its surface features. In addition, this technique is finding increased use in defining anatomical features of human vascular disease and is especially well suited for the study of experimental neovascularization as it relates …

Labeling Of Sweet Taste Binding Sites Using A Colloidal Gold-Labeled Sweet Protein, Thaumatin, Albert I. Farbman, Carolyn K. Ogden-Ogle, Göran Hellekant, Scott R. Simmons, Ralph M. Albrecht, H. Van Der Wel

Scanning Microscopy

Thaumatin, an intensely sweet tasting protein, was bound to colloidal gold and applied to the taste bud-bearing foliate papillae of Rhesus monkeys. Examination of thin sections of taste pores showed that gold particles were bound to merocrine secretions of Type I taste bud cells, to some cell remnants of lysed cells, and, most importantly, to small, membrane bounded blebs of cytoplasm. These blebs are thought to be shed into the pore from the tips of taste bud cell microvilli, particularly those arising from Type II cells. The binding of gold particles to microvillus tips and to the blebs suggest that …

The Ultrastructure Of Membranes In Sympathetic Ganglia, Catarina Andersson Forsman, Lars-Gösta Elfvin

Scanning Microscopy

This review presents some recent observations made on membranes in the mammalian sympathetic ganglia after application of freeze-fracturing and histochemistry. After freeze-fracture clear differences have been found between the neuronal and the satellite cell plasmalemma. The satellite cell plasma membrane exhibits specialized intramembrane particles not found in the neuronal membrane. Freeze-fracture cytochemistry reveals a further difference between the neurons and satellite cells i.e., a higher density of 𝛃-hydroxysterols is present in the satellite cell membrane than in the neuronal membrane.

Histochemical methods to localize 5'-nucleotidase, Ca²⁺-ATPase and Na⁺/K⁺-ATPase in the membranes have been utilized. …

Marsupial And Monotreme Enamel Structure, K. S. Lester, A. Boyde, C. Gilkeson, M. Archer

Scanning Microscopy

We present some recent developments in our understanding of two basic questions: the origin, extent, nature and course of marsupial enamel tubules; and the characterisation of monotreme enamel, more particularly, the prismatic nature of platypus enamel.

Methods used included SEM of methacrylate casts of marsupial enamel tubules, worn and cut surfaces of whole marsupial teeth, developing and erupted platypus teeth, and a well-developed molar of the newly discovered Miocene ornithorhynchid Obdurodon sp., and tandem scanning reflected light microscopy of intact marsupial teeth.

We conclude that there are significant species differences with respect to prism shape, row formation and tubule disposition …

Chiropteran Enamel Structure, K. S. Lester, S. J. Hand

Scanning Microscopy

We have examined sectioned and whole teeth of Hipposideros diadema in order to provide a baseline description of bat enamel at electron microscope level. Intact and worn surfaces of whole teeth from representatives of all superfamilies of the suborder Microchiroptera, representatives of the suborder Megachiroptera, and the Ditjimanka fossil tooth have been surveyed.

Whole chiropteran teeth lend themselves well to non-destructive SEM examination; all except Dobsonia sp. showing evidence of prismatic structure at the outer surface. The majority of prisms in chiropteran enamel are horse-shoe shaped becoming rounded and complete only towards the outer enamel surface. Prism packing is typically …

Materials Characterization Using The Backscattered Electron Signal In Scanning Electron Microscopy, V. N. E. Robinson

Scanning Microscopy

The backscattered electron signal in scanning electron microscopy is sensitive to changes in the atomic number of the specimen. This atomic number information can be measured by calibrating the output of a backscattered electron detector from two known materials. The atomic number of an unknown sample can then be determined by measuring the backscattered electron signal from the unknown sample.

Knowing the atomic number factor of an unknown sample and the heavy elements (Z > 10 as determined from X-ray analysis), the existence of light elements can be detected. From a knowledge of the sample and valence information, the composition of …

Receptor-Mediated Binding, Endocytosis And Cellular Processing Of Macromolecules Conjugated With Colloidal Gold, Dean A. Handley

Scanning Microscopy

Receptor-mediated expression of cellular functions assures biological specificity, regulation, and control of nutritive and metabolic requirements. The study of receptor-ligand interactions is a central theme in many published reports employing colloidal gold labeling. With the ligand directly conjugated with colloidal gold, the investigator is afforded the opportunity to observe all phases of cellular binding, endocytosis, lysosomal delivery and catobolism. Reviewed are published studies employing direct ligand conjugation with colloidal gold, the relative merits and disadvantages of this type of procedure and data from recent studies investigating endothelial receptor binding of proteins in the coagulation and fibrinolysis cascades.

A Comparative Scanning Electron Microscopic View Of The Integument Of Domestic Mammals, W. Meyer, K. Neurand

Scanning Microscopy

Scanning electron microscopy (SEM) demonstrates efficiently species-specific differences of hairy skin (integumentum commune) of domestic mammals (pig, cat, dog, horse, cattle, sheep, goat). This technique is very helpful in characterizing the typical structural features of the epidermal layers, the arrangement of the collagen fibre bundles and the elastic fibre network in the dermis, the external and internal construction of hair follicles and hair shafts, and the functional development of skin glands. It is also possible to observe certain domestication effects, especially where the hair coat is concerned.

SEM supplements the knowledge about the integument as available from conventional transmission electron …

Effects Of High Energy Particle (Hze) Radiation On The Distal Lung, David P. Penney, Delbert E. Philpott, Wayne A. Rosenkrans, Robert A. Cooper Jr.

Scanning Microscopy

Major sources of concern for manned space travel are the effects of high energy particle (HZE) radiation on various biological systems, and the consequences of major solar activity. To date, considerable attention has been directed toward HZE-induced alterations both on non-dividing systems, such as the retina, cornea and brain, and on dividing systems, such as the gut and testis. This paper is focused on the morphologically detectable late-occurring alterations in the distal lung, and toward a comparison of the changes with those induced by x -irradiation. Briefly, the salient alterations involve an increase in 1) the width of the septal …

Vasospastic Phenomena On The Luminal Replica Of Rat Brain Vessels, Enrico D. F. Motti, Hans-Georg Imhof, Jesus Martinez Garza, Gazi M. Yasargil

Scanning Microscopy

Strikingly localized ring-like constrictions (other than sphincters, cushions and offshoot furrows) have appeared on the casted vessels of some of our preparations. Morphology of the phenomena reveals diverse degree of active contraction of the vessel wall, ranging from corrugation of the luminal surface to near severance of the acrylic cast. Distribution of the vasospastic phenomena reveals as particularly affected the arteries in the diameter range between 25 and 75 μm, that belong either to intra-arterial anastomoses between the branches of each of the three major cerebral arteries or to their terminal junctions in the border zones (inter-arterial anastomoses). Among the …

Structure-Function Relationships In Radiation-Induced Cell And Tissue Lesions: Special References To The Contributions Of Scanning Electron Microscopy And Hematopoietic Tissue Responses, T. M. Seed

Scanning Microscopy

Contributions of scanning electron microscopy to the field of radiation biology are briefly reviewed and presented in terms of an overall goal to identify and characterize the structural features of radiation-induced lesions in vital cell and tissue targets. In the context of "lesion" production, the major radiation-elicited response sequences, the types and nature of measured end points, and governing temporal and radiobiological parameters are discussed and illustrated by using results derived from both in vitro cell systems and in vivo studies that measured tissue responses from various organ systems (respiratory, digestive, circulatory, and central nervous systems). Work in our laboratory …

Assessment Of Qualitative And Quantitative Data From Pathological Hairs – A Critical Evaluation Of Scanning Electron Microscope And Proton Induced X-Ray Emission Analyses, B. Forslind, K. Wirén, K. G. Malmqvist

Scanning Microscopy

Analysis of single hair fibres in genetic disorders is a desirable complement to the clinical diagnosis. The scanning electron microscope (SEM) allows detailed study of the surface morphology of hair fibres which may explain some mechanical characteristics of the pathological hair. Quantitative elemental data may indicate biochemical or metabolic abnormalities.

In this preliminary study we assess the feasibility of combining SEM and proton induced X-ray emission (PIXE) analysis on single hair fibres from 12 cases of genetic disease influencing the integument status. We conclude that SEM is a valuable tool in the analysis of hair pathology. The macro-PIXE technique involves …

Fine Structural Observations Of The Apical Organ In The Larva Of Polygordius (Annelida: Polychaeta), Terry Sensenbaugh, Ake Franzén

Scanning Microscopy

The larva of the archiannelid Polygordius was studied using light microscopy (LM), scanning ( SEM) and transmission electron microscopy (TEM). The embryo of Polygordius develops into a large trochophore larva adapted to planktonic swimming and feeding. The young larva is characterized by the presence of an approximately hemispherical episphere including a basal prototroch and a well-developed apical organ which lacks a central ciliary tuft. The conical hyposphere is smaller and contains the metatrochophore segments. The apical organ of the episphere consists of a large, bulbous mass of cells that project deeply into the spacious blastocoel. Two tentacular knobs and two …

Review Of Statoconia Formation In Birds And Original Research In Chicks (Gallus Domesticus), Cesar D. Fermin, Makoto Igarashi

Scanning Electron Microscopy

This paper reviews published materials on statoconia formation in birds, and emphasizes works dealing with the embryonic chick (Gallus domesticus) saccule and utricule. Histological, biochemical and histochemical aspects of forming statoconial membranes and statoconial crystals of mammals are included. Results from our work with chick embryos permitted us to conclude that statoconia probably do not form by seeding of a subunit around central core. Instead, immature statoconia may emerge already formed, from a segmenting mass of organic material that seems to be secreted by the supporting cells of the saccular and utricular maculae. Crystallization of each statoconium may …

Scanning Electron Microscopy Of Eggshells Of Contemporary Reptiles, Mary J. Packard, Karl F. Hirsch

Scanning Electron Microscopy

Eggshells of contemporary turtles and squamate reptiles (lizards, snakes, and the tuatara) are either flexible or rigid, and usually are composed of both a fibrous shell membrane and an overlying calcareous layer. The calcareous layer of turtle eggs is calcium carbonate in the form of aragonite, whereas the crystalline material of squamate eggs generally is calcite. Both rigid and flexible shells of turtle eggs are composed of individual building blocks or shell units. Shell units of rigid shells abut tightly, and few pores penetrate the calcareous layer. In contrast, flexible shells exhibit large numbers of spaces or pores in the …

Early Scanning Electron Microscopic Studies Of Hard Tissue Resorption: Their Relation To Current Concepts Reviewed, A. Boyde, S. J. Jones

Scanning Microscopy

This paper highlights some observations made by the authors in SEM studies of hard tissue resorption and considers their significance in relation to current concepts. All mammalian mineralised tissues may undergo physiological resorption, the resulting surface reflecting the density of mineralisation and the organic matrix chemistry, organisation and orientation. Resorption-repair coupling may follow the resorption of any tissue, but SEM studies first noted this process in the case of the dental tissues. The difference between fetal and adult bone formation and resorption provided evidence against the concept of osteocytic osteolysis. SEM stereophotogrammetric methods for the quantitation of individual resorption lacunae …