Life Sciences Commons^™

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 …

Matrix Effects In Secondary Ion Mass Spectrometric Analysis Of Biological Tissue, Margaret S. Burns, David M. File, Vaughn Deline, Pierre Galle

Scanning Electron Microscopy

We have made several observations during the course of our studies that show the presence of matrix effects in soft biological tissue and standards. The sputtering rate of gelatin is approximately twice that of epoxy resin, but the ion yield of lithium in gelatin is an order of magnitude less than in epoxy. Osmium impregnation of freeze-dried material significantly alters the localization of calcium, but not potassium and barium. The absolute count rate for calcium in osmicated tissue is increased several-fold above that in freeze-dried tissue. Scanning electron microscopy of sputtered material shows the formation of cones during sputtering, which …

Cryoultramicrotomy And Immunocytochemistry In The Analysis Of Muscle Fine Structure, L. -E. Thornell, G. S. Butler-Browne, E. Carlsson, H. M. Eppenberger, D. O. Fürst, B. K. Grove, B. Holmbom, J. V. Small

Scanning Electron Microscopy

Cryoultramicrotomy, which avoids the use of harsh fixation procedures, deleterious dehydration and plastic embedding can be combined with immunocytochemis try to determine the ultra-structural localization of cellular proteins. Our attempts to use the cryosectioning technique in combination with immunolabelling to bridge the gap between light and electron microscopic analysis of muscle morphology have enabled us to obtain new information on fibre typing at the ultrastructural level. Furthermore, we have obtained a marked improvement in the resolution of myofibrillar structures by using semithin cryosections for fluorescence microscopy. Data are also presented on correlated light and electron microscope immunocytochemistry of myocardial intermediate …

The Enamel Ultrastructure Of Multituberculate Mammals: A Review, D. W. Krause, S. J. Carlson

Scanning Electron Microscopy

The enamel ultrastructure of multituberculate mammals has been sampled extensively and studied intensively and is better known than for any other group of early mammals. The enamel of the earliest multituberculates, those of the Late Triassic-Early Jurassic suborder Haramiyoidea and the Late Jurassic-early Early Cretaceous suborder Plagiaulacoidea, is "preprismatic." With only two exceptions, all Late Cretaceous and early Tertiary genera of multituberculates examined have prismatic enamel. Prisms are either small with circular (complete) boundaries or large with arc-shaped (incomplete) boundaries. There is a remarkably consistent relationship between enamel ultrastructural type and subordinal taxa in that small, circular prisms are usually …

Ninety Degree Tilt Module And Double-Sided Stub For Scanning Electron Microscopy, G. L. C. Mcturk

Scanning Electron Microscopy

A simple inexpensive device to achieve ninety degree tilt in some scanning electron microscopes (SEM) not equipped with this facility. A new method of safely mounting and studying both sides of the same fragile flat specimen, without the hazards of remounting; used in conjunction with this device.

Surveying Battery Cell Sections To Determine The Composition And Spatial Distribution Of Discharge Products Using An Automated Microprobe, B. M. England, M. T. Frost, I. R. Harrowfield, C. M. Macrae, D. A. J. Swinkels, K. E. Turner, C. B. Ward

Scanning Electron Microscopy

Determining the spatial distribution and composition of hydrohetaerolite in polished sections of discharged Leclanché cells requires the measurement of oxygen concentrations on microcrystalline material. This can be done if the composition of the mounting medium is included in the matrix correction of raw intensities. The method of Pouchou and Pichoir (PAP) is used initially to correct raw intensities obtained from surveys of microcrystalline standard material. Mean analyses agree well with the known compositions provided a correction is made for the oxygen content of the mounting medium. The same correction is then applied to the raw data collected when surveying cell …

Characterization Of Clay Fabric Using Critical Point Drying To Preserve Clay Texture And Morphology, B. E. Wawak, W. L. Campbell

Scanning Electron Microscopy

Critical point drying is a sample preparation technique that minimizes damage to some clay fabrics in reservoir rocks. In this technique, the original pore fluids in a sample are replaced successively with acetone, liquid carbon dioxide and air without allowing a high energy meniscus to pass through the sample. Acetone replacement is accomplished in a diffusion dehydration system. SEM micrographs show striking differences between critical point dried clay samples and air dried samples.

Chromatid Behavior In Late Mitosis: A Scanning Electron Microscopy Analysis Of Mammalian Cell Lines With Various Chromosome Numbers, D. A. Welter, D. A. Black, L. D. Hodge

Scanning Electron Microscopy

Chromatid activity during the process of nuclear reformation following metaphase is a period of mitosis where little precise information is available. Nuclear reformation requires that chromosomes, at metaphase and chromatids during anaphase and telophase align, position and associate in a clearly defined sequence to insure the specific design of each nucleus. Four cell lines with chromosome numbers ranging from seven to almost seventy were chosen to determine whether the process of nuclear assembly is the same throughout. Chromosomal alignment at metaphase is found to be radial in all four cell lines. Chromosome positioning is essentially the same in all four, …

Quantitative Microanalysis By Time-Of-Flight Laser Probe Mass Spectrometry, J. F. Eloy

Scanning Electron Microscopy

Quantitative multielement microanalyses of insulators and refractory materials are made with an advanced laser microprobe mass spectrometer (LPMS-2S). A plasma in local thermal equilibrium (LTE) is generated in a field-free region in the ion source by a short laser pulse. A magnetic time-of-flight (TOF) mass analyzer is used to optimize ion transmission and mass separation. And, an Eloy-Unsold wide aperture ion detector provides the low noise and wide dynamic range required for accurate analyses. The characteristics of the LPMS-2S are demonstrated with NBS standard reference glasses and are compared with the characteristics of the commercially available LAMMA and LIMA microprobe …

A New Surface Analytical Technique With Ion And Laser Beams, Christopher H. Becker

Scanning Electron Microscopy

This paper reviews recent results and developments, while presenting some new information, regarding the development of a novel surface analytical technique that uses nonresonant multiphoton ionization (MPI) of neutral atoms and molecules sputtered by an ion beam, or desorbed by an electron or second laser beam or by thermal means. In this method, called surface analysis by laser ionization (SALI), the nonresonant MPI, or "laser ionization," is coupled with state-of-the-art time-of-flight mass spectrometry to provide extremely sensitive, general, and readily quantifiable surface analysis. A discussion also describes the favorable prospects for implementation of SALI with submicron dimension liquid metal ion …

Studies Of Otoconial Development In A “Giant-Crystal” Strain Of Chicks Using Scanning Electron Microscopy, Polarized Light Microscopy, And X-Ray Crystallography, Joanne Ballarino, Howard C. Howland

Scanning Electron Microscopy

Otolith formation was studied in a mutant strain of low-fertility Delaware chicks which exhibit an otolithic defect. In all chicks of this strain, otoliths were present as a fused crystal mass which contained abnormally large (giant) otoconia. Studies of the formation of such otoliths during embryonic development revealed that from the very earliest stages the otoconia were much larger than normal, and in the saccular and utricular otoliths formed a fused mass. These results are interpreted as supporting a hypothesis of the de novo formation of giant otoconia in this giant-crystal strain as opposed to the recrystallization hypothesis proposed for …

Glow Discharge Effects On Polytetrafluoroethylene Polymers Investigated By Secondary Electron Microscopy And X-Ray Photoelectron Spectroscopy, A. Le Moël, J. P. Duraud, C. Le Gressus, H. Okuzumi

Scanning Electron Microscopy

A glow discharge treatment of Polytetrafluoroethylene avoids charging effects and permits observation of the sample in Scanning Electron Spectroscopy; x-ray Photoelectron Spectroscopy has been used to study changes in the surface chemical composition and electronic structure of the polymer produced by this treatment.

Preparation Methods For Light Microscopic And Ultrastructural Studies Of Fetal Rat Bladder, M. Cano, S. L. Johansson, R. B. Wilson, L. B. Ellwein, T. Sakata, S. M. Cohen

Scanning Electron Microscopy

Little is known about in utero urinary bladder embryogenesis and the development of the urothelium of laboratory animals. Previous scanning and transmission electron microscopy studies in rats and mice have indicated that the highly specialized superficial cells of the urothelium complete their differentiation at a very late stage of fetal development or shortly after birth. Limitations in methodology in the past have precluded extensive examination of earlier stages of bladder development. Innovations in preparatory procedures of the bladder of rat fetuses have been developed which make possible detailed scanning and transmission electron microscopic and light microscopic examination of cloaca and …

Scanning Electron Microscopy In Bone Pathology: Review Of Methods, Potential And Applications, A. Boyde, E. Maconnachie, S. A. Reid, G. Delling, G. R. Mundy

Scanning Electron Microscopy

This article reviews the applications of SEM methods to human bone pathologies referring to studies made at UCL. We consider the methods which may be most suitable; these prove to be not "routine" in the context of most bio-medical applications of SEM.

Valuable information can be obtained from a bone sample if its edges are ground flat, before making either (a) a matrix surface preparation by washing away all the cells or (b) a mineralising front preparation, by also dissolving the osteoid -for which hydrogen peroxide is recommended to produce a robust specimen. BSE contrast from a cut block surface …

The Interface Of Cells And Their Matrices In Mineralized Tissues: A Review, S. J. Jones, A. Boyde, N. N. Ali

Scanning Electron Microscopy

The interface between cells and matrices in mineralized tissues formed in vivo has been studied mainly by looking at the matrix surface, which is easily prepared, and not at the cell surface, which presents problems. Vertebrate calcified tissues range from being acellular to highly cellular, but for all the tissues the formative cells lay down and organise a cell-specific matrix, although this may be deposited initially on a different tissue-type. The formation of hard tissues is a group activity of many cells; resorption is the province of one cell, though it may be controlled by others in the vicinity.

Cell-matrix …

Variation In The Sizes Of Resorption Lacunae Made In Vitro, S. J. Jones, A. Boyde, N. N. Ali, E. Maconnachie

Scanning Electron Microscopy

The assessment of in vitro osteoclastic activity has, until recently, been dependent on the analysis of organ culture experiments. We have developed a single cell resorption assay so that the resorptive function of individual osteoclasts could be studied. This paper examines the biological variation in the sizes of resorption lacunae produced by bone cell cultures derived from neonate rats and rabbits, and prehatch or hatchling chicks. Cultures were run for 24h for all species; and in addition for 48h for rat, 9 or 12 hours for rabbit and 3-7 hours for chick. The numbers of the nuclei of osteoclasts seeded …

Hormonal Regulation Of Capillary Fenestrae In The Rat Adrenal Cortex: Quantitative Studies Using Objective Lens Staging Scanning Electron Microscopy, R. P. Apkarian, J. C. Curtis

Scanning Electron Microscopy

High magnification studies of the fenestrated capillary endothelium in the zona fasciculata (ZF) of rat adrenal glands were performed using the objective lens stage of an analytical scanning electron microscope (SEM) equipped with a lanthanum hexaboride emitter (LaB₆). Resolution of surface substructure of the luminal membrane obtained with specimens decorated with gold/palladium (Au/Pd) was compared with that observed in others sputter coated with tantalum (Ta). High magnification (50,000x) of the fenestrated endothelium demonstrates that tantalum coating of the cryofractured adrenals improves the substructural detail compared to that seen in Au/Pd decorated specimens.

The procedures used in specimen preparation, …

Basal Lamina At The Epithelial-Connective Tissue Junction In The Rat Forestomach, Esophagus, Tongue And Palate: Scanning Electron Microscopic Study, Merideth T. Hull, K. A. Warfel

Scanning Electron Microscopy

The squamous epithelium lining the rat foregut was removed by incubating fresh, unfixed specimens in 2N sodium bromide. The surface morphology of the exposed subepithelial basal lamina was examined by scanning electron microscopy. Areas examined included hard and soft palates, oropharynx, tongue, esophagus, and forestomach. The basal lamina was continuous over all surfaces. Basal lamina corrugations were not present at all sites. The saucer-like defects of lymphocyte migration that are present in the basal lamina beneath the squamous epithelium of the skin were not observed in rat foregut. The epithelial-connective tissue interface of the rat esophagus does not have the …

Unique Scanning Electron Microscopic Features Of Hairy Cells In Hairy-Cell Leukemia. A Review And Current Status, Haim Gamliel, Harvey M. Golomb

Scanning Electron Microscopy

Past scanning electron microscopy (SEM) reports demonstrated cell surface undulations, ridges, folds, and ruffles to support the monocytic/histiocytic nature of hairy-cell leukemia (HCL) cells. On the other hand, SEM studies illustrating spikes, villi, and microvilli on the cell surfaces favored the lymphocytic nature of hairy cells (HCs). The evidence for the 'hybrid' nature of the HCs has emerged from the demonstration of concurrent display of monocytic (ruffles) and lymphocytic (microvilli) surface features on each cell. Utilizing improved methods of sampling, fixation, and drying, the current status is that all HCs display microvilli and ruffles simultaneously. However, two distinct morphological types …

Development Of The Otolith In Embryonic Fishes With Special Reference To The Toadfish, Opsanus Tau, Bernd H. A. Sokolowski

Scanning Electron Microscopy

The development of the saccular otolith and the otolithic membrane was studied in the toadfish (Opsanus tau) using scanning and transmission electron microscopy. Development of the saccular otolith and its otolithic membrane in Opsanus begins with the formation of the primordia in embryos of 17-20 somite age. Calcification of the primordia begins shortly afterwards, although increased calcium layering and formation of the otolithic membrane corresponds to the development of a group of cells lying peripheral to the developing sensory epithelium. These cells contain an abundance of rough endoplasmic reticulum.

The Role Of Marrow Architecture And Stromal Cells In The Recovery Process Of Aplastic Marrow Of Lethally Irradiated Rats Parabiosed With Healthy Litter Mates, Keiki Hayashi, Koichi Kagawa, Michiyasu Awai, Shozo Irino

Scanning Electron Microscopy

Bone marrow aplasia was induced in rats by whole body lethal irradiation (1,000 rads by x-ray), and rats died of irradiation injury within 7 days.

Correlative studies at light (LM), transmission (TEM) and scanning electron microscopy (SEM) demonstrated swelling of endothelial and reticular cells and hemorrhage due to detachment of sinus endothelial cells on days 1 and 2. With time, structural recovery occurred without hemopoietic recovery. Reticular cells developed small intracytoplasmic lipid droplets on days 3 and 4. This resulted in fatty a plastic marrow within 7 days. On the other hand, in the marrow of irradiated rats parabiosed with …

Influence Of Ion Implantation And Gas Exposure On The Charge In Silicon Oxide Created By Electronic Excitation, J. P. Vigouroux, F. Jollet, J. P. Duraud, C. Le Gressus

Scanning Electron Microscopy

Low energy electron bombardment of amorphous SiO₂ induces point defects such as oxygen vacancy by electronic excitation. The defects build a macroscopic negative charge by trapping of electrons on the localized levels in the band gap; this phenomenon was previously described as the "mirror" effect. In the present paper, we investigate, by mirror effect, the behavior of the charge after an argon, nitrogen and oxygen implantation at 1 and 4 keV, and after exposure to the same gases at various low pressures. We observe a difference of behavior between Ar (or N₂) and O₂, The …

Freeze-Dried Embedded Specimens For Biological Microanalysis, L. Edelmann

Scanning Electron Microscopy

The main problems associated with freeze-drying of biological material for electron microscopy concern the freeze-drying temperatures and times necessary to minimize artifacts. Due to the many parameters involved these problems have to be resolved experimentally. It can be shown that good morphological preservation of chemically unfixed material is possible when freeze-drying is done exclusively in a temperature range between -80°C and -50°C. OsO₄ vapour fixation of the freeze-dried tissue is not necessary and should be avoided because it may cause ion redistribution artifacts. Embedding at low temperature of properly freeze-dried material does not seem to disturb structure and ion …

Dissection Technique For Cochleas Prepared For Scanning Electron Microscopy, Sven Rydmarker, D. E. Dunn, P. Nilsson, C. Lindqvist

Scanning Electron Microscopy

Scanning electron microscopy (SEM) permits a three-dimensional study of the surface morphology of the organ of Corti that is very useful in evaluating the condition of the apical end of the hair cells and the stereocilia. However, some laboratories have experienced problems with curling of the basilar membrane during critical point drying of cochlear specimens prepared For SEM evaluation using the Murakami or osmium thiocarbohydrazide-procedures. This curling of the basilar membrane can obstruct the view of the reticular lamina and the ciliary ends of the hair cells.

We have used a dissection method, referred to as the anchor technique, to …

Experimental Investigation Of The Genesis Of Struvite Stones In Cats, G. Sanders, A. Hesse, D. B. Leusmann

Scanning Electron Microscopy

Infrared spectroscopy of feline urinary stones revealed that struvite was the main constituent in 77.6 % of all concrements. However, only in 30.8% (16/52) of struvite stone patients were any infections of the urinary tract detected.

Scanning electron microscopical comparison of non-infected feline struvite stones and human struvite concrements which had grown in the presence of infection revealed clear differences. All the feline struvite concrements were of coarse crystalline construction with the crystalline form typical of struvite. Traces of partial solution and stratification were frequently detected on the crystalline surfaces. The human struvite stones whose growth had been accompanied by …

Some Thoughts About The Conservation Of Scanning Electron Microscopic Preparations Of Diatoms In A Museum Repository, J. J. Lee, C. W. Reimer, R. Mahoney

Scanning Electron Microscopy

The Scanning electron microscope (SEM) is now an indispensable tool for the study and the description of diatoms. Many new species have been described from SEM preparations and problems now arise with the preservation of designated types and other comparative material. Moisture contributes to the deterioration of diatom stubs. Special care must be taken to store stubs in vacuum desiccators in order to keep heavy metal coatings from peeling from the siliceous surfaces of diatoms. One alternative is to mount the designated type on a coverglass so that it can be inverted, mounted in Hyrax and preserved indefinitely for light …

Analysis Of Canine Urinary Stones Using Infrared Spectroscopy And Scanning Electron Microscopy, A. Hesse, G. Sanders, D. B. Leusmann

Scanning Electron Microscopy

Infrared spectroscopic analysis of 741 canine urinary calculi revealed that struvite stones, 58% of the total, were the ones most commonly to be found. Cystine stone disease, 21%, is also of great significance for dogs, whereas calcium oxalate, urate and brushite calculi occur only seldom. 3 cases of xanthine stone formation were also noted.

SEM examination revealed structures similar to human stones such as bipyramidal weddelIite, pseudomorphs from whewellite to weddellite, apatite deposits in cystine stones and characteristic mono-ammonium-urate needles. Other, unknown, structures were also discovered such as closely-knit intergrowths of cystine and brushite strata, mono-Na-urate and mono-K-urate intergrowths and …

Visualization Of Cytoskeletal Elements And Associated Retroviral Antigens By Immunogold Transmission Electron Microscopy Of Detergent Extracted Cells, E. J. Basgall, M. M. Soong, W. A. F. Tompkins

Scanning Electron Microscopy

Several investigators have reported an association between the cytoskeleton and viral antigens. In our laboratory, biochemical immunofluorescence and immuno-gold electron microscopy studies were conducted on TX-100 extracted NIH/3T3 cells infected with Moloney-murine leukemia virus. Cytochalasin B treatment causes reversible microfilament disruption and a concomitant decrease in virus production. No effect on microtubules was seen. Immuno-gold electron microscopy reveals an association between cytoskeletal action and the viral antigens gp70 and p15E. The results of these immunocytological and biochemical studies indicate that the cytoskeleton may play an integral role in transport and processing of viral gene-envelope products.

Phorbol Ester (Tpa)-Induced Surface Membrane Alterations In B-Type Hairy Cell And Lymphocytic Leukemia Cells, Aaron Polliack, Dorit Gurfel, Rachel Leizerowitz, Helena Feinstein, Yair Gazitt

Scanning Electron Microscopy

This report documents phorbol ester (TPA)-induced changes in cell morphology, and in vitro growth patterns in 9 patients with hairy cell leukemia (HCL), 21 with B-type CLL and non-Hodgkin's lymphoma in leukemic phase (NHL), and 10 with acute non lymphoblastic leukemia (ANLL). TPA caused cells from HCL to adhere strongly and produce elongated cytoplasmic extensions. Many of these cells had an appearance resembling fibroblasts, while others showed marked surface ruffling and spreading containing increased dense bodies, and phagolysosomal vacuoles as seen by transmission electron microscopy.

This HCL in vitro growth pattern after TPA exposure differed from that seen in B-CLL …