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Quantitative And Computer Assisted Electron Microscopic And Microprobe Studies In Dermatology, B. Forslind, A. Emilson

Scanning Microscopy

Electron microscopes are not yet routine instruments in modern dermatological pathology even though they have provided detailed data about pathological changes in the skin for more than three decades. At present, dermatopathology is still dominated by light microscopy and especially so since the introduction of immunological techniques such as the use of monoclonal antibodies. These tools applied at electron microscopic resolution, however, may provide the ultimate identification of cells and subcellular components. In addition, electron microscopes have no peers in areas of quantitative investigation at subcellular levels, e.g. morphometry.

The electron microprobe provides a unique tool in elemental analysis and …

Ultrastructural Effects Of Therapeutic Irradiation On Human Epithelial Tumors, P. Kellokumpu-Lehtinen

Scanning Microscopy

Irradiation induces several cellular changes leading to death of cancer cells and normal cells which is followed by repairing processes of normal cells. We have studied the effects of therapeutic irradiation on head and neck cancers. Tissue samples taken before and during the radical irradiation (50-80 Gy) of the squamous cell carcinomas of the head and neck region were examined by light and electron microscopy. Nuclear atypia was most pronounced cellular change during irradiation. The tumor invasion pattern remained unchanged but the number of mitoses decreased. Lymphocytic infiltration increased at the beginning of the therapy (from 10 to 30 Gy) …

Importance Of Mild Hyperoxaluria In The Pathogenesis Of Urolithiasis - New Evidence From Studies In The Arabian Peninsula, W. G. Robertson, H. Hughes

Scanning Microscopy

The hypothesis that mild hyperoxaluria is more important than hypercalciuria in the pathogenesis of urolithiasis is re-examined in the light of new evidence. Small increments in urinary oxalate in the normal to high-normal range are much more critical than similar rises in urinary calcium for increasing the relative supersaturation of urine with respect to calcium oxalate, the oxalate/calcium ratio in urine, the total volume of calcium oxalate crystals excreted, the proportion of abnormally large crystals and aggregates of calcium oxalate and the severity of the disorder as defined by the recurrence rate of stone-formation. Data from the Arabian Peninsula, where …

Calibration Of Atomic Force Microscope Tips Using Biomolecules, T. Thundat, X.-Y. Zheng, S. L. Sharp, D. P. Allison, R. J. Warmack, D. C. Joy, T. L. Ferrell

Scanning Microscopy

Atomic force microscope (AFM) images of surfaces and samples mounted on substrates are subject to artifacts such as broadening of structures and ghost images of tips due to the finite size and shape of the contacting probe. Therefore, knowledge of the radius of the AFM probe tip is essential for the interpretation of images. We have deduced the shape of the AFM tip by imaging cylindrical biological molecules of various diameters such as deoxyribonucleic acid (DNA), tobacco mosaic virus (TMV), tobacco etch virus (TEV) and bacteriophage M-13 (M-13). Using a paraboloidal tip model and numerically solving equations of contact, the …

Atomic Force Microscopy Of Dna On Mica And Chemically Modified Mica, T. Thundat, D. P. Allison, R. J. Warmack, G. M. Brown, K. B. Jacobson, J. J. Schrick, T. L. Ferrell

Scanning Microscopy

Atomic force microscopy (AFM) was used to image circular DNA adsorbed on freshly cleaved mica and mica chemically modified with Mg(II), Co(II), La(III), and Zr(IV). Images obtained on unmodified mica show coiling of DNA due to forces involved during the drying process. The coiling or super twisting appeared to be right handed and the extent of super twisting could be controlled by the drying conditions. Images of DNA observed on chemically modified surfaces show isolated open circular DNA that is free from super twisting, presumably due to strong binding of DNA on chemically modified surfaces.

Effect Of Chronic Treatment With Diuretics On Mouse Liver: A Morphological And Microanalytical Investigation, Ann-Christin Mork, Anne Von Euler, Godfried M. Roomans

Scanning Microscopy

In an attempt to produce an animal model for the disease cystic fibrosis (CF), mice were treated chronically with the diuretics amiloride and furosemide, in order to cause chronic inhibition of transepithelial ion transport. Experiments were carried out on adult mice (2 months treatment); in addition, pregnant mice were treated with diuretics, and tissue from offspring 2 and 7 days post partum was investigated. Since biliary cirrhosis is a common occurrence in CF, hepatocytes in the treated mice were investigated by X-ray microanalysis and by light and electron microscopy.

Treatment with amiloride caused a significant decrease in cellular Na concentration …

Charge Dynamics At The Silicon(001) Surface Studied By Scanning Tunneling Microscopy And Surface Photovoltage, David G. Cahill, R. J. Hamers

Scanning Microscopy

Scanning tunneling microscopy measurements of local surface photovoltage of the Si(001) surface reveal the existence of local charging produced by the tunneling current. Since the tunneling current is confined to a region of near atomic dimensions, charge transport between surface and bulk electronic states is probed with high spatial resolution. The surface charge is enhanced while tunneling at the bonded, type-B atomic step and at specific point defects demonstrating atomic-scale variations in the charge dynamics.

The Spatial Distribution Of Backscattered Electrons Revisited With A New Monte Carlo Simulation, Kenji Murata, Masaaki Yasuda, Hiroaki Kawata

Scanning Microscopy

A Monte Carlo simulation program including the discrete energy loss process has been developed, based on the Mott cross section for elastic scattering and the Vriens cross section for inelastic scattering. A deficiency of the previous model which is based on the screened Rutherford cross section and the Bethe law is made clear, from comparison between the new and old results such as the energy distribution of backscattered electrons for a Cu target. With the new Monte Carlo model, the radial spreading and penetration depth of both all and low-loss backscattered electrons have been studied for the Cu target at …

Dentinogenesis And The Calciotraumatic Response To The Injection Of Lead Or Fluoride Ions, John Appleton

Scanning Microscopy

A number of ions can disturb the formation of dentine resulting in a calciotraumatic response. The calciotraumatic response following the injection of sodium fluoride was investigated using backscattered electron imaging in the scanning electron microscope and compared with the response to lead acetate. With fluoride, there was formation of a hypermineralized band succeeded by a relatively hypomineralized band, but with lead acetate, only a hypomineralized band was produced. However, there were some differences in the response between the labial and lingual dentine with both ions. In the labial dentine following injection of sodium fluoride, the onset of hypermineralization was less …

Scanning Electron Microscope Observations Of Brine Shrimp Larvae From Space Shuttle Experiments, Lynnette Debell, Avelina Paulsen, Brian Spooner

Scanning Microscopy

Brine shrimp are encysted as gastrula stage embryos, and may remain dehydrated and encysted for years without compromising their viability. This aspect of brine shrimp biology is desirable for studying development of animals during space shuttle flight, as cysts placed aboard a spacecraft may be rehydrated at the convenience of an astronaut, guaranteeing that subsequent brine shrimp development occurs only on orbit and not on the pad during launch delays.

Brine shrimp cysts placed in 5 ml syringes were rehydrated with salt water and hatched during a 9 day space shuttle mission. Subsequent larvae developed to the 8th larval stage …

Scanning Electron Microscopy Of Intracellular Organelles In The Young Odontoblasts Of Rats, Yasutomo Iwai-Liao, Yoshikage Higashi, Masakazu Ishikawa, Hideaki Hori

Scanning Microscopy

Intracellular structures of the odontoblasts were studied by scanning electron microscopy (SEM) using a modified AODO (aldehyde prefixed-osmium-DMSO-osmium) method. Well-developed flattened and layered rER (rough endoplasmic reticulum), paved with its associated ribosomes on its outer surface, were clearly observed in the odontoblast. Branched tubular mitochondria with nodules and swollen endings, interposing between and passing through the fenestrated layered rER, were demonstrated in the functional cells. Oblique and cross-sections of both the rER system and tubular mitochondria showed orthodox configurations similar to those usually described in transmission electron microscopy (TEM) studies. Many finger-like projections constructing the cristae directing towards the inner …

On The Origin Of Electron-Beam-Induced-Current Contrast Of Extended Defects In Silicon, M. Kittler, W. Seifert

Scanning Microscopy

The paper reviews the origin of bright and dark Electron-Beam-Induced Current (EBIC) contrast due to extended defects in silicon, inclusively a brief discussion of contrast modelling. Particular emphasis is put on the role of impurities demonstrated to determine contrast in many cases (extrinsic contrast origin). The understanding of the prevalent contrast type -dark contrast due to enhanced recombination at defects -is well supported by existing phenomenological contrast models which can, therefore, be used as a basis for contrast interpretation. In the context of extrinsic vs. intrinsic contrast origin, the influence of defect dimensionality on contrast is addressed, indicating that grain …

The Normal, Cryptorchid And Retractile Prepuberal Human Testis: A Comparative Morphometric Ultrastructural Study Of 101 Cases, Saverio Cinti, Giorgio Barbatelli, Claudia Pierleoni, Manlio Caucci

Scanning Microscopy

Fifty-two surgical biopsies from retractile testes of patients in pediatric age (3-14 years), of which 25 were treated with hormonal therapy (RT) and 27 did not undergo therapy before orchidopexy (RNT), were compared with the biopsies of 19 normal (N) and 30 cryptorchid or ectopic (E) testes. A light and electron microscopic morphologic and morphometric study was performed. For the quantitative investigation 4 parameters were selected: a) the mean tubular diameter (on 20 cross-sections); b) the mean spermatogonial number per tubular section; c) the mean nucleolar area of the Sertoli cells; and d) the mean thickness …

Microvasculature Of Normal And Hydropic Labyrinth, Yoshiaki Nakai, Haruhiko Masutani, Makoto Moriguchi, Kazuhiro Matsunaga, Akihumi Kato, Hitoshi Maeda

Scanning Microscopy

The microvasculature of the inner ear in guinea pigs and humans was observed with a scanning electron microscope using corrosion casting method. Alterations in the inner ear vasculature which occurred in association with experimental endolymphatic hydrops were also investigated. The results thus obtained are summarized as follows:

1. In the cochlea and vestibule, the arteries, coiled arterioles, and the veins are endowed with their respective characteristic morphologic features and play a role in the regulatory mechanisms of circulation.

2. The point in humans which is most different from guinea pigs was that coiled arterioles in the cochlea and the coil-like …

Cochlear And Vestibular Epithelia From A Patient With Meniere's Disease: A Case Study, K. C. Horner

Scanning Microscopy

Scanning electron microscopy observations were carried out on the cochlear and vestibular epithelia of the left temporal bone of a Meniere' s patient. There was almost complete absence of hair cells in the basal turn of the cochlea. The outer hair cells of the second turn presented an abnormal shortening of the shorter stereocilia within a tuft, reminiscent of the specific atrophy of the short and middle stereocilia in the ciliary tufts of outer hair cells in the guinea pig with experimental hydrops. The cilia of the inner hair cells showed fusion and giant cilia formation. Hair cells were observed …

Investigation Of Living Cells In The Nanometer Regime With The Scanning Force Microscope, J. K. H. Hörber, W. Häberle, F. Ohnesorge, G. Binnig, H. G. Liebich, C. P. Czerny, H. Mahnel, A. Mayr

Scanning Microscopy

Membrane structures of different types of cells are imaged in the nanometer regime by scanning force microscopy (SFM). The images are compared to those obtained with a scanning electron microscope (SEM). The SFM imaging can be done on the outer cell membrane under conditions that keep the cells alive in aqueous solutions. This opens up the possibility of observing the kinematics of the structures that determine the interaction of a cell with its environment. Therefore, STM observations, together with information obtained with the electron microscope, open up new ways of studying the development of biological structures. With the currently possible …

Enhanced Bacterioplankton Production And Respiration At Intermediate Salinities In The Mississippi River Plume, Gerardo Chin-Leo, Ronald Benner

Faculty Publications

Bacterial abundance and production (thymidine and leucine incorporation) were measured along a salinity gradient from the Mississippi River (0 %₀) to the open waters of the Gulf of Mexico (36 %₀) during July-August 1990 and February 1991. Bacterial production in surface waters was maximal at intermediate salinities (15 to 30 %₀). Nutrient enrichment experiments suggested that bacterial growth near the outflow of the river was C limited whereas bacteria in plume waters of intermediate salinities were P and N limited. Rates of plankton community oxygen demand measured during winter were also maximal at intermediate …

The Splenic Microvasculature Of The Red-Eared Turtle (Chrysemys Scripta Elegans): A Study Concerning The Question Whether The Circulation Is Anatomically Open Or Closed, R. Blumer, H. Ditrich, H. Splechtna

Scanning Microscopy

The splenic microvasculature of the turtle Chrysemys scripta elegans was studied by means of scanning electron microscopy of vascular corrosion casts and critical point dried tissue. In addition light- and transmission electron microscopic investigations were carried out. Within the organ the arteries are surrounded by periarterial lymphoid sheaths. The majority of the arterial capillaries, which emerge from these central arteries have open endings within the reticular meshwork of the red pulp. Approximately 10% of the capillaries directly connect with the venous origins. Since these venous capillaries of C. scripta elegans resemble those of nonsinusal mammalian spleens we termed them pulp …

Modelling Techniques For The Quantification Of Some Electron Beam Induced Phenomena, Wk Chim, Dsh Chan, Ts Low, Jch Phang, Ks Sim, Kl Pey

Scanning Microscopy

This paper presents simulation models for quantifying the voltage contrast, cathodoluminescence and indirect specimen charging phenomena in the scanning electron microscope (SEM). The voltage contrast model comprises an electric field computation program using the finite-element approach, and a secondary electron trajectory tracking algorithm employing a linear electric field assumption. This trajectory tracking algorithm is more accurate than the conventional electron trajectory tracking algorithms which make use of a constant electric field assumption within each computation step. Using this model, results of qualitative voltage contrast effects on secondary electron trajectories in the specimen chamber of the SEM are shown. This model …

Techniques For Low Voltage Scanning Electron Microscopy Linewidth Measurements, Kenneth S. Maher

Scanning Microscopy

Present scanning electron microscopy (SEM) linewidth measurement systems, although "state of the art", require better defined techniques in deriving operating parameters for precision measurements. Experiments were performed to check techniques used on cleaved and uncleaved specimens, void of conductive coatings to obtain optimum SEM operating parameters, and the variations in results due to changes in system operating conditions. In addition, a method was devised to select and use different calibration standards and evaluate SEM linewidth measurement systems.

Response Of The Esophageal Epithelium To Concomitant Cis-Dichlorodiammineplatinum(Ii) And Radiation Treatment. An Electron Microscopic Study In Rabbits, M. Albertsson, M. Cwikiel, C. H. Håkansson, M. Palmegren

Scanning Microscopy

The rabbit esophageal mucosa was irradiated with daily fractions of 2 Gy up to an accumulated dose of 20 Gy (total dose 2, 6, 10. 16 or 20 Gy). Fifteen to forty-five minutes before the start of each irradiation 0.3 mg Cis-dichlorodiammineplatinum (cis-DDP, cisplatinum) was given by intraperitoneal injection to each rabbit. Examinations were carried out 1-10 days after each fractionation schedule, when specimens were taken for morphological investigations.

Scanning electron microscope (SEM) examination showed a gradual development of damage with cell loss and structural disarrangement of the microridges and whorls on the surface. However, with further treatment the esophageal …

Rate Maintenance Of Cell Division In Escherichia Coli B/R: Analysis Of A Simple Nutritional Shift-Down, Arieh Zaritsky, Charles E. Helmstetter

Biomedical Engineering and Sciences Faculty Publications

A competitive (nonmetabolizable) inhibitor of glucose uptake, α- methylglucoside, was used to limit the growth of Escherichia coli. Cell division during such a nutritional shift-down was studied in batch cultures and with the 'baby-machine' technique. Following a brief delay, the rate of division was maintained for 60 to 70 min in batch cultures and for an extended period in the baby machine. Decreases in cell size were due, in part, to a possible reduction in the mass per chromosome origin at the time of replication initiation and a shorter time interval between initiation and the subsequent division. These unusual findings …

Ecological Evaluation Of Proposed Dredged Material From Richmond Harbor, M. R. Pinza, J. A. Ward, H. L. Mayhew, J. Q. Word, Dev Niyogi, N. P. Kohn

Biological Sciences Faculty Research & Creative Works

During the summer of 1991, Battelle/Marine Sciences Laboratory (MSL) was contracted to conduct sampling and testing of sediments proposed for dredging of Richmond Harbor, California. The MSL collected sediment cores to a depth of [minus]40 ft MLLW ([minus]38 ft + 2 ft over depth) from 28 (12-in. core) and 30 (4-in. core) stations. The sediment cores were allocated to six composite samples referred to as sediment treatments, which were then subjected to physical, chemical, toxicological, and bioaccumulation testing. Physical and chemical parameters included grain size, total organic carbon (TOC), total volatile solids (TVS), oil and grease, total petroleum hydrocarbons (TPH), …

The Cockburn Sound Fishery Management Plan. Summary Of Submission And Final Recommendations For Management., A. Millington

Fisheries Management Papers

Identifiable "unit" fisheries in Cockburn Sound are: Beach bait fishing netting Fish set netting Crab netting Mussel diving Line fishing and pot fishing This report recommends measures for the longer term management of these fisheries In particular, that they be managed as limited entry fisheries under Section 32 of the Fisheries Act 1905. Strict entry criteria are proposed for continued access to these fisheries. Rules are proposed for boat replacement. Licence transferability is considered in detail. No decisions to be made on the policy for licence transfers until the final number of participants in each fishery is determined. Owner operation, …

Avian Forelimb Muscles And Nonsteady Flight: Can Birds Fly Without Using The Muscles In Their Wings?, Kenneth P. Dial

Biological Sciences Faculty Publications

Intensity patterns of electromyographic (EMG) signals from selected muscles of the wing were studied during different modes of flight in trained Rock doves (Columba livia). Shoulder muscles exhibited a stereotypic pattern producing maximal EMG intensity during the deceleration phases of the upstroke and the downstroke, whereas the muscles of the brachium and antebrachium acted primarily as joint stabilizers during level flapping flight. During nonsteady flight (e.g. takeoff, landing, vertical ascending flight), the distal forelimb muscles exhibited maximal EMG intensity; their primary function appears to be associated with changing the camber and planform of the wing during rapid oscillation. During steady …

The Drosophila Period Gene And Dye Coupling In Larval Salivary Glands: A Re-Evaluation, Kathleen King Siwicki, K. K. Flint, J. C. Hall, M. Rosbash, D. C. Spray

Biology Faculty Works

No abstract provided.

Two Mechanisms For Growth Inhibition By Elevated Transport Of Sugar Phosphates In Escherichia Coli, Robert J. Kadner, G. Patrick Murphy, Craig Stephens

Biology

The Escherichia coli uhp T gene encodes an active transport system for sugar phosphates. When the uhp T gene was carried on a multicopy plasmid, amplified levels of transport activity occurred, and growth of these strains was inhibited upon the addition of various sugar phosphates. Two different mechanisms for this growth inhibition were distinguished. Exposure to glucose-6-phosphate, fructose-6-phosphate or mannose-6-phosphate, which enter directly into the glycolytic pathway, resulted in cessation of growth and substantial loss of viability. Cell killing was correlated with the production of the toxic metabolite, methylglyoxal. In contrast, addition of 2-deoxyglucose-6-phosphate, galactose-6-phosphate, glucosamine-6-phosphate or arabinose-5-phosphate, which do …

Retention Of Cellular Viability And Growth Potential In Cryopreserved Bovine Arterial Tissue: Implications For Clinical Use Of Cryopreserved Vascular Allografts, Kip G. Gardner

Biological Sciences Theses & Dissertations

Segments of bovine calf aortas and pulmonary arteries were cryopreserved at -196° C for two weeks to 18 months and subsequently thawed. Cellular morphology, viability, and growth potential in these segments were then compared with the same attributes in segments from fresh (control) arteries. Scanning electron microscopy revealed no disruption of intimal surfaces attributable to cryopreservation. Endothelial cells were successfully cultured from all cryopreserved arterial segments. Endothelial monolayers grown from cryopreserved arteries had a cobblestone appearance and expressed Factor VIII antigen but not smooth muscle alpha-actin. Plating efficiency in primary cultures of endothelial cells was lower for cryopreserved arteries than …

Scanning Electron Microscopy Observation Of The Interaction Between The Surface Acoustic Waves And Regular Domain Structures In The Linbo3 Crystals, D. V. Roshchupkin, Th. Fournier, M. Brunel, O. A. Plotitsyna, N. G. Sorokin

Scanning Microscopy

This paper reports a scanning electron microscope study of the interaction between the surface acoustic waves and regular domain structures in LiNbO3 crystals. The regular domain structures in LiNbO3 crystals were formed by the method of the thermo-electric treatment after growth. We investigated two modes of interaction: the surface-acoustic-waves propagate along and across the regular domain structures. It is shown that the regular domain structures in the first case can be used as an acoustical wave-guide, because the power-flow vector of the surface acoustic waves has the direction along the domain structure. Also we observed that the surface acoustic wave …

The Effect Of Varying Environmental Conditions On Phytolith Morphometries In Two Species Of Grass (Bouteloua Curtipendula And Panicum Virgatum), T. B. Ball, J. D. Brotherson

Scanning Microscopy

Solid deposits of SiO₂ (phytoliths) accumulate in many plants in specific intracellular and extracellular locations. Phytoliths have morphological characteristics unique to some taxa and therefore have taxonomic significance. Phytoliths persist and maintain their morphological integrity long after a plant has died, thus becoming a microfossil of the plant that produced them. Development of phytolith sytematics for microfossil phytoliths has traditionally followed a typological approach based on simple verbal descriptions of shape. A new method for use in phytolith sytematics is the morphometric approach which employs computer-based Image Analysis Systems to make quantified measurements of morphological parameters (size, shape, texture, …