Biology Commons^™

Ranking Corrosion Efficiency: A Latin Square Study On Rat Lung Microvascular Corrosion Casts, Dean E. Schraufnagel

Scanning Microscopy

Scanning electron microscopy of corrosion casts is an important tool for the study of microvascular structure but few systematic studies on methods of specimen preparation have been reported. This study sought to determine the relative importance of factors involved in corrosion. It compared potassium hydroxide, sodium hydroxide and water as major corrosive agents. It tested the size of the tissue sample, and the use of prealkali autolysis, detergent, and proteolytic enzymes in a Latin square designed study. The main findings were that sodium and potassium hydroxide were better than water (P < 0.0001) and the longer the corrosion time the better corroded the samples were (P < 0.0001 ). Although not a controlled factor, higher room temperature was also associated with better corrosion. The use of proteolytic enzymes, detergent, and warm tap water alone before the alkali treatment did not significantly improve the corrosion in this study, although this does not preclude an effect with another experimental design.

Scanning Electron Microscopy In The Study Of Campylobacter Pylori Associated Gastritis, F. Bonvicini, P. Versura, S. Pretolani, G. Gasbarrini, R. Laschi

Scanning Microscopy

The close association between Campylobacter pylori (CP), gastritis and peptic ulcer is now well established. Moreover increasing evidence has been collected of a major etiological role of CP in type B chronic gastritis. For this reason, searching for CP is essential in all patients with upper gastrointestinal symptoms.

Scanning electron microscopy (SEM) is a most reliable technique for studying the distribution of microorganisms and their relationship to the gastric mucosal surface.

The aim of this paper is to compare SEM to other routine methods of detection for CP, such as Giemsa staining on histological sections and Urease Microtiter Test (MT) …

Architecture Of The Medial Smooth Muscle Of The Arterial Vessels In The Normal Human Brain: A Scanning Electron-Microscopic Study, Toshitaka Shiraishi, Saburo Sakaki, Yasuo Uehara

Scanning Microscopy

The architecture of the medial smooth muscle of arterial vessels in normal human brains was investigated using scanning electron microscopy. We could divide the arterial vessels into four subdivisions according to the number of the circular muscle cells. The arteries ( > 100 μm in diameter) had 4-20 layers of circular smooth muscle cells; individual circular muscle cells were spindle-shaped and occasionally had branches at their ends. Multidirectional muscle cells were observed in the medio-adventitial border only at the branching sites in large arteries (>300 μm), but at both branching and non-branching sites in the small arteries (100-300 μm). The …

Analyses Of Dental Pulp In Restored Teeth, D. L. Lentz, J. T. Buchanan, D. R. Basinger

Scanning Microscopy

Restored teeth were extracted from test animals at four time intervals (1 hour, 1 day, 1 week, and 3 months) following amalgam insertion. Extracted teeth were frozen in liquid nitrogen, cryo-fractured so as to expose the pulps and then freeze-dried. Pulps were analyzed for mercury content by energy dispersive spectrometry (EDS) and atomic absorption spectrophotometry (AAS). Mercury levels appeared below the detection limits of EDS but could be detected by AAS which showed the highest readings seven days after amalgam insertion.

Scanning Electron Microscope And X-Ray Diffraction Investigations Of Mudrock Fabrics, Textures And Mineralogy, J. M. Huggett

Scanning Microscopy

Mudstones from a broad range of depositional environments have been investigated to determine whether fabric, texture or mineralogy may (1) be used to identify the environment of deposition and (2) be correlated with poroperm. The diversity of fabrics and textures reflects features of the detrital mudstone composition, compaction and diagenesis, rather than environment of deposition. Preferred orientation has been disturbed by bioturbation and growth of post-compactional authigenic minerals; these factors have reduced to nil any correlation which may have existed between fabric, measured as the illite orientation ratio (O/R) and environment of deposition.

It is mineralogy rather than fabric or …

Preparation Of Dipteran Larvae For Scanning Electron Microscopy With Special Reference To Myiasigen Dipteran Species, I. Ruiz-Martinez, M. D. Soler-Cruz, R. Benitez-Rodriguez, M. Diaz Lopez, J. M. Perez-Jimenez

Scanning Microscopy

Although controversy exists concerning the role of chemical fixatives in scanning electron microscopy (SEM) studies of Dipteran larvae, we have observed that filtered 10% formaldehyde solution gives excellent results as a preservative. After immersing in vivo in formaldehyde, the larvae material is preserved for prolonged periods (up to 8 months), before examination with SEM. As a fixative, formaldehyde preserves the structure of the larval cuticle and produces no visible artifacts. Moreover, postfixation is not necessary.

Due to pecularities of the way of life of Wohlfahrtia magnifica (principally the accumulations of necrotic tissue, purulent particles, and other types of substances that …

The Vascular System Of Xenotransplanted Tumors -Scanning Electron And Light Microscopic Studies-, M. A. Konerding, F. Steinberg, V. Budach

Scanning Microscopy

A widely used model for investigating basic tumor characteristics and different treatment modalities preclinically is the immune-deficient, athymic nude mouse. This model offers many morphological parallelisms to the clinical situation.

The aim of this study is to demonstrate the vascularization pattern of xenotransplanted human melanomas and sarcomas using different methods. Xenotransplanted tumors of 62 congenital thymusaplastic nude mice were examined ultrastructurally and topographically after corrosion cast and tissue preparation. Quantitative measurements of tumors injected with India ink were carried out to obtain comparable information on the vascular densities in the tumors.

Quantitative measurements showed that there is no zonal, topographic …

Vascular "Sphincter" And Microangioarchitecture In The Central Nervous System: Constriction Of Intraparenchymal Blood Vessels Following A Treatment Of Vasoconstrictive Neurotransmitter, K. Nakai, Y. Naka, H. Yokote, T. Ikatura, H. Imai, N. Komai, T. Maeda

Scanning Microscopy

The site of action of neuropeptide Y (NPY), a potent vasoconstrictive neurotransmitter, on the intraparenchymal blood vessels in the rat parietal cortex was demonstrated using a corrosion cast technique with scanning electron microscopy. Our observations were confined to the cortical area where the regional cerebral blood flow (rCBF) had been reduced significantly by in situ application of NPY. A striking finding in that area was the diffuse narrowing of the perforating arteries in the upper cortical layers. Ring-like compressions on the corrosion casts, presumably formed by active vascular sphincters along the arteries, capillaries and venules within the brain parenchyma, seemed …

Measurement Of Fungicide Smoke Application By Electron Beam Analysis, C. R. Krause, C. C. Powell

Scanning Microscopy

Low volume fungicide smoke particle deposits were studied with scanning electron microscopy and energy dispersive X-ray analysis. Under greenhouse conditions, particles deposited on Rhododendron leaf surfaces and onto inert, carbon planchets adjacent to Rhododendron leaves were characterized by electron beam analysis. Angular particles containing chlorine, identified as vinclozolin deposition, were quantified on a per unit area basis. Leaf samples collected from plants immediately adjacent to the smoke applicator had more particles than leaf samples collected elsewhere. More deposition was measured on leaf surfaces than on inert planchet surfaces. This study increased our knowledge about the effectiveness of using less fungicide …

Fine Structure And Organ Culture Of Chick Embryo Dorsal Aorta, C. Ward Kischer, Michael Jaqua

Scanning Microscopy

Embryonic blood vessels have not been grown in organ culture, in a way which might easily submit them to studies of vascular organogenesis. The chick embryo dorsal aorta is easily accessible and relatively simple to explant to culture. Its organ culture may provide a model for wounding and repair of the intima and/or media and provide a model for studies of growth (or maintenance) and differentiation. Fresh dorsal aorta and its organ culture from the chick embryo was characterized morphologically by light microscopy scanning (SEM) and transmission electron microscopy (TEM) from days 4 to 18. Explants were incubated up to …

Crystal Associated Diseases: Role Of Scanning Electron Microscopy In Diagnosis, K. P. H. Pritzker, P. -T. Cheng, M. D. Grynpas, D. P. Holmyard

Scanning Microscopy

As crystals are important etiologic agents for disease, their accurate identification in tissues and body fluids is of utmost importance. This paper surveys the roles of crystals in disease process and outlines current analytical techniques for crystal detection and identification in bone tissues. The value of multiple correlated techniques is demonstrated including scanning electron microscopy, x-ray energy spectroscopy and powder diffraction analysis. The current feasibility of utilizing intermediate voltage scanning transmission analytical electron microscopy to integrate these analytical techniques on the same tissue sample is emphasized.

Signal Of Backscattered Electrons From Multiple Marks In Dependence On Mark Profile, D. Kaczmarek, Z. Czyżewski

Scanning Microscopy

The backscattered electron signal can be detected using a solid state detector system. Because this signal is affected by the surface topography it is necessary to determine the optimal detection condition for a registration mark detection in the electron-beam lithography and for an automatic topographical surface reconstruction.

The BSE signal from surface marks has been measured using semiconductor detectors with a small collection angle. Calculations of the BSE signal have been carried out by means of a simplified model of electron backscattering. The signal shape depends on some parameters of the mark profile, such as length, height and inclination angle …

Mounting Materials For Automated Image Analysis Of Coals Using Backscattered Electron Imaging, W. E. Straszheim, K. A. Younkin, R. T. Greer, R. Markuszewski

Scanning Microscopy

In order to apply SEM-based automated image analysis (AIA) to the characterization of not only minerals in coal but to the coal itself, sample preparation methods need to be developed beyond common practice. A significant consideration is the degree of contrast achievable between the mount media chosen and the coal. Four low-atomic number materials (epoxy, polyethylene, polystyrene and carnauba wax) were compared for their potential as suitable mounting media for coal samples. Epoxy is satisfactory only for characterization of mineral particles since the contrast between epoxy and coal particles is negligible. Polyethylene or polystyrene have marginal application for use as …

Scanning Electron Microscopic Autoradiography Of Lung, K. E. Lauhala, C. L. Sanders, K. E. Mcdonald

Scanning Microscopy

Scanning electron microscopic (SEM) autoradiography of the lung is being used to determine the distribution of inhaled, alpha particle-emitting, plutonium dioxide particles. SEM autoradiography provides high visual impact views of alpha activity. Particles irradiating the bronchiolar epithelium were detected both on the bronchiolar surface and in peribronchiolar alveoli. The technique is being used to obtain quantitative data on the clearance rates of plutonium particles from bronchi and bronchioles.

The Role Of Scanning Electron Microscopy In Ophthalmic Science, P. Versura, M. C. Maltarello

Scanning Microscopy

The eyeglobe is one of the classical domains of Scanning Electron Microscopy (SEM) in biology as it exposes several inner and outer surfaces. Both corneal and conjunctival epithelia towards the tear film as well as the corneal endothelial cells facing the anterior chamber may be accurately evaluated. The architecture of the angle and particularly the morphology of the Schlemm's canal inner wall are clarified by SEM more than by TEM serial reconstruction. The surfaces of the iris and ciliary body, the zonula and the choroidal vessel arrangement are described in great detail. Three distinct types of membrane anchoring devices are …

Preparation Of Cytoskeletons Of Cells In Culture For High Resolution Scanning And Scanning Transmission Electron Microscopy, Paul B. Bell Jr., Margaretha Lindroth, Bengt-Arne Fredriksson

Scanning Microscopy

In this tutorial we describe our methods for preparing detergent-extracted cytoskeletons for observation by high resolution scanning (SEM) and scanning transmission (STEM) electron microscopy. We both discuss the theoretical background and provide practical procedures for each of the following steps: cell culture on Formvar-coated gold grids; prefixation with aldehydes or protein crosslinking reagents (homobifunctional N-hydroxy-succinimide esters); extraction with Triton X-100 or Brij 58 detergent in microtubule stabilizing buffer; postfixation in formaldehyde and glutaraldehyde; dehydration; critical point and freeze drying; sputter coating with 1-2 nm of platinum or tungsten; and examination by SEM and both normal and inverted contrast STEM. These …

Zinc Deficiency: Specific Scalp Hair Defects Seen By Scanning Electron Microscopy May Provide A Valuable New Test, D. W. Gregory, L. Stankler

Scanning Microscopy

Zinc deficiency in man results in multisystem disease. It may be acquired or hereditary; the latter can be fatal if left untreated. Premature babies are particularly susceptible to zinc deficiency. Unfortunately no simple, reliable test for zinc status exists at present.

Short, newly-emerging scalp hair samples from 3 classical cases of zinc deficiency all showed the same characteristic abnormalities when examined by scanning electron microscopy, i.e. straight, blunt tips bearing scales, unusually thick cuticular scales with jagged free-edges, and very fine longitudinal corrugations in individual scales. These abnormal features occurring together appear to be specific for zinc deficiency; they also …

Sem Of Canine Chromosomes: Normal Structure And The Effects Of Whole-Body Irradiation, G. K. Niiro, T. M. Seed

Scanning Microscopy

Canine chromosomes are not only numerous (38 autosomal pairs), but they are small (compared to human chromosomes) and morphologically similar as well. Analysis of the canine karyotype by light microscopy (LM) of banded chromosomes is, thus, difficult, and the literature on the canine karyotype is scanty. In this study, we describe examination of chromosomes from normal and chronically irradiated dogs with the scanning elect ran microscope (SEM). Metaphase chromosomes from bone marrow aspirates were Giemsa-banded with either 0.025% trypsin alone or 0.1% trypsin preceded by 10% H2O2 and prepared for SEM. Examination of chromosomes from normal dogs revealed cylindrical chromosome …

Enamel Structure In Primates: A Review Of Scanning Electron Microscope Studies, L. B. Martin, A. Boyde, F. E. Grine

Scanning Microscopy

Comparative studies of dental enamel microstructure have involved three main areas of enquiry, with structural features having been investigated in relation to developmental mechanisms, function and/or phylogeny. The phylogenetic, or taxonomic aspect has been emphasized in the majority of studies involving the Order Primates, where efforts have focused upon attempts to recognise structural differences among various hierarchical groups.

Studies of primate enamel microstructure by SEM are reviewed here, with emphasis on what has been learned concerning the most suitable preparative techniques that can be employed, and with particular emphasis to the relevance of enamel microstructure in taxonomic analyses of living …

Microscopic Effects Of Predator Digestion On The Surfaces Of Bones And Teeth, John M. Rensberger, Hartmut B. Krentz

Scanning Microscopy

Concentrations of small fossil mammals are frequently encountered in Cenozoic deposits, but the causes for such accumulations have seldom been determined. In many cases the tooth, jaw, and limb fragments appear to be well-preserved under light microscopy, and it is difficult to differentiate damage due to predator digestion from breakage and abrasion due to physical agents. In order to find more specific evidence of predator digestion, we used a scanning electron microscope (SEM) to examine the surface microstructure of bones and teeth consumed by Bubo virginianus (great horned owl) and Canis latrans (coyote), which prey upon similar species. Effects …

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 …

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 …

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. …