Digital Commons Network^™

High Resolution Electron Microscopy Of The Junction Between Enamel And Dental Calculus, Yoshihiko Hayashi

Scanning Microscopy

Newly formed dental calculus grows on the enamel surface after the tooth crown is exposed to the oral environment. In order to demonstrate the crystal coherence, the junction between enamel and dental calculus was examined in the high resolution electron microscope. Ultrathin sections were also used for selected area electron diffraction to reveal any newly formed mineral phase.

High resolution electron microscopy (HREM) revealed that lattice fringes of dental calculus crystals directly coincided with those of enamel crystals. Two types of coherence were identified at the junction: in one type, a dental calculus crystal contacted the side of an enamel …

The Influence Of Trichinella Spiralis Infection On Heat Shock Protein 72 Production In Mrl++ Mouse Intestinal Cells, Lisa Ann Kilejian

Dissertations and Theses

The production of Heat Shock Protein 72, the inducible form of the highly conserved 70 kilodalton heat shock protein family, was investigated in MRL++ mouse intestine during the two weeks of a Trichinella spiralis infection. Within hours of an oral infection using the encysted Trichinella spiralis found in the diaphragm of an infected mouse, the larvae are released from the cyst in the stomach. They travel to the intestine and burrow into the epithelial layer of the intestine. The jejunum is the primary site of the intestinal phase of trichinosis. This stage of infection in the jejunum was the focus …

White-Tailed Deer Habitat Use On Surface-Mined Areas In Eastern Kentucky, Devetta A. Hill

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Devetta A. Hill on July 2, 1993.

Management Proposals For 1993/94 And 1994/95 Western Rock Lobster Season., Rock Lobster Industry Advisory Committee

Fisheries Management Papers

The Rock Lobster Industry Advisory Committee (RLIAC) in reviewing management arrangements for the rock lobster fishery, were concerned with two principle objectives: 1. That the management measures adopted would arrest the ongoing decline in breeding stock and seek to re-establish the number of breeding female rock lobster to levels consistent with known historic safe levels in the fishery. 2. That the management arrangements adopted would properly take into account market requirements in order to maximise returns to fishermen from an appropriate level of catch.

Scanning Tunneling Microscopy: A Chemical Perspective, C. Julian Chen

Scanning Microscopy

In this review article, scanning tunneling microscopy (STM) is presented in a chemical perspective. The typical distance from the nucleus of the apex atom of the tip to the top-layer nuclei of the sample is 4-6 Å, where a strong attractive atomic force, i.e., a partial covalent bond, arises between the tip and the sample. The origin of the covalent bond is the back-and-forth transfer of electrons between two atoms, which Pauling has called resonance. While a bias voltage is applied between them, a net electron current in a specific direction arises. This tunneling current is a result of …

Immunological Pathogenesis Of Endolymphatic Hydrops And Its Relation To Meniere's Disease, S. Tomiyama, T. Yagi, M. Sakagami, K. Fukazawa

Scanning Microscopy

This study was designed to investigate an immunologically induced endolymphatic hydrops (ELH) and to focus on the issue of its pathogenesis in relation to Meniere's disease. The time course of ELH was evaluated by light microscopy in a 2-hour to 7-month period following direct antigen challenge to the endolymphatic sac (ELS) in systemically pre-sensitized guinea pigs. ELH began to appear in the vestibule and the basal turn 5-7 hours after inner ear challenge and developed gradually. During the interval from the second day to the first week, ELH rapidly developed in all the cochlear turns and reached a maximum size. …

An Energy Dependent Model For Type I Magnetic Contrast In The Scanning Electron Microscope, W. K. Chim, D. S. H. Chan, J. C. H. Phang, T. S. Low, S. Thirumalai

Scanning Microscopy

The modelling of the magnetic contrast phenomenon in the scanning electron microscope (SEM) is important in understanding the physics of the contrast mechanism and the associated signal detection. In this paper, we report an improved analytical model for Type I magnetic contrast calculations using an approximate form of the Chung and Everhart secondary electron (SE) energy distribution. Previous studies have neglected this factor by assuming a mono-energetic model in order to simplify the calculations. This new model can be used to study different material specimens by appropriate choice of the work function and field-distance integral. The effect of energy filtering …

Evaluation Of Erbium:Yag Laser Radiation Of Hard Dental Tissues: Analysis Of Temperature Changes, Depth Of Cuts And Structural Effects, A. F. Paghdiwala, T. K. Vaidyanathan, M. F. Paghdiwala

Scanning Microscopy

Temperature elevations, depths of cuts and structural changes produced by 2.94 micron pulsed Erbium:YAG laser radiation of hard dental tissues, at different power levels and exposure times of the laser, were studied. The depth of cut produced was found to vary significantly as a function of power level and exposure time on dry teeth. The mean temperature rise with laser radiation was also influenced both by power level and time of exposure. The effect of water flow on the teeth during laser exposure was evaluated; the results indicate that the ablation efficiency was better, temperature elevations lower and structural changes …

Scanning Electron Microscopy Of Age-Related Changes In The C57bl/6j Mouse Cochlea, Kunihiro Mizuta, Osamu Nozawa, Hirofumi Morita, Tomoyuki Hoshino

Scanning Microscopy

Hair cells and nerve fibers inside the organ of Corti of the C57BL/6J mouse, which is known as the precocious presbycusis model, were studied using the scanning electron microscope. For this study, we used thick serial sections cut from celloidin blocks.

In the 5-week-old mice, hair cell loss was not seen. The upper tunnel radial fibers crossed the upper part of the tunnel of Corti and entered the Nuel's space between the outer pillar cells. The fibers varied in diameter and showed many varicosities. The basilar fibers emerged into the tunnel of Corti beneath the upper tunnel radial fibers …

Sample Preparation Techniques For Conventional And High Resolution Scanning Electron Microscopy Of The Central Nervous System. The Cerebellum As A Model, Orlando J. Castejon

Scanning Microscopy

In the present paper some basic sample preparation techniques for scanning electron microscopy of nervous tissue are described. These basic preparative methods include conventional scanning electron microscopy or slicing technique, ethanol-cryofracturing technique, freeze-fracture method using either liquid nitrogen (slow freezing) or Freon 22 cooled by liquid nitrogen (fast freezing), improved freeze-fracture method with delicate specimen preparation and chromium coating, ultrasonic microdissection, and "creative tearing" technique. Some basic principles, advantages and limitations are critically considered. In addition, some specific applications in neurobiological research are reported. Emphasis is placed upon understanding the sources and nature of artifacts that are likely to be …

A Review Of New Concepts In Renal Stone Research, L. C. Cao, E. R. Boevé, W. C. De Bruijn, W. G. Robertson, F. H. Schröder

Scanning Microscopy

Clinical and basic research in the field of urolithiasis has developed rapidly in recent years. Progress in extracorporeal shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PNL) has brought about a revolution in the surgical treatment of urolithiasis and research at the cellular and molecular level is now expanding. In spite of these advances, however, clinical treatment of urolithiasis remains far from satisfactory. Stone recurrence in many patients cannot be predicted and is beyond control of urologists mainly because the mechanisms of stone formation are still not fully understood. It is necessary to study the process of stone formation more intensely …

Analysis Of Synthetic Dnas And Dna-Protamine Complexes With The Scanning Tunneling Microscope, Michael J. Allen, Robert J. Tench, Joe A. Mazrimas, Mehdi Balooch, Wigbert J. Siekhaus, Rod Balhorn

Scanning Microscopy

Three duplex DNAs 22, 47, and 100 base-pairs in length have been imaged with the scanning tunneling microscope (STM) after deposition on highly oriented pyrolytic graphite (HOPG). Images of the 47 base-pair (bp) molecules are resolved sufficiently to identify the two phosphodiester strands, the direction of helical coiling (this molecule contains three turns of left-handed helix), and single-stranded ends. Length measurements indicate that all three DNA sequences have adopted an "A-like" conformation. DNA-protamine complexes were also prepared and imaged under similar conditions. Length measurements of the complexes demonstrate that the binding of bull protamine 1 to the 47-mer stabilizes the …

Specimen Preparation And Chamber For Confocal Microscopy Of The Ex Vivo Eye, Barry R. Masters

Scanning Microscopy

A chamber is described for maintaining the mechanical and physiological stability of the ex vivo eye during observation with confocal microscopy. The mechanical stability is provided by a plastic ring situated on the limbal region of the eye. The ring and supporting chamber are designed to reduce mechanical motion of the specimen. The ring and chamber size vary with the species and size of the eye under examination. The physiological stability over a period of approximately one hour is provided by immersing the eye in a bicarbonate Ringer's solution that is exchanged every five minutes. This fluid exchange is made …

Scanning Electron Microscopy Of 2,8-Dihydroxyadenine Crystals And Stones, P. Winter, A. Hesse, K. Klocke, R. M. Schaefer

Scanning Microscopy

The lack of purine salvage enzyme, adenine phosphoribosyltransferase (APRT), leads to 2,8-dihydroxyadenine stone formation and/or crystalluria because it is insoluble in urine. Urolithiasis composed of 2,8-dihydroxyadenine is not only formed in a complete defect of APRT, but also in a partial deficiency of this enzyme. The defect is inherited as an autosomal recessive trait, the homozygous state is associated with high urinary levels of 2,8-dihydroxyadenine and with crystalluria, calculus formation, and potential nephrotoxicity. Determination of the APRT activity will facilitate quantification of the enzyme deficiency and elucidation of the hereditary history. 2,8-dihydroxyadenine excretion in the 24-hour urine and its circadian …

Avian Hatching Asynchrony: Brood Classification Based On Discriminant Function Analysis Of Nestling Masses, Given Harper, Steven Juliano, Charles Thompson

Scholarship

Studies of hatching asynchrony in altricial birds have used several methods to determine if a brood hatches synchronously or asynchronously. The most commonly used methods include making frequent nest visits during the time of hatching and using nestling mass or other measures of size on a given day to estimate nestling age or to describe the extent of the size hierarchy within broods. We made daily nest visits to determine if House Wren (Troglodytes aedon) broods hatched synchronously or asynchronously, and then compared classification of these broods based on discriminant function analysis with that based on mass differences of nestlings. …

Modelling Avian Distributions Of The Navarrese Region In Northern Spain With A Geographic Information System, Samuel Soret-Garcia

Loma Linda University Electronic Theses, Dissertations & Projects

GIS (Geographic information Systems) technology was used for identifying relations between environmental characteristics and the breeding distributions of nine avian species of the Navarrese region in northern Spain. Data overlays of multiple GIS layers derived the explanatory variables for modelling the breeding distributions from logistic regressions. A spatial autocorrelation analysis was conducted to characterize the distribution patterns and to incorporate spatial factors (neighborhood effects) into their analysis.

All nine patterns analyzed exhibited a high level of spatial autocorrelation. Accordingly, the basic hypothesis of spatial randomness was rejected in favor of spatial clustering for the sample data. The breeding distributions strongly …

Factors Affecting Behavioral Variation Of Individual Glaucous-Winged Gulls (Larus Glaucescens) While On Territory, Michael Murdoch

Loma Linda University Electronic Theses, Dissertations & Projects

Factors affecting the patterns of behavior of individual Glaucous-winged Gulls (Larus glaucescens) on Protection Island, Jefferson County, Washington were examined. Males were found to be present on territory often than females. Proportions of behavior varied by time of season. Gulls tended to be more alert (used upright and intermediate-upright displays) during the "chick" stage than earlier in the season. Attendance rates were very similar between individuals of the same gender, and a significant correlation was found between the attendance rates of members of a pair. However, sequences of territorial behavior varied significantly between genders.

Inconsistent Divergence Of Mitochondrial-Dna In The Spontaneously Hypertensive Rat, Mark L. Johnson, Steve W. Perry, Daniel Ely, Monte E. Turner

Biology Faculty Research

We have recently shown that the spontaneously hypertensive rat (SHR) and the Wistar-Kyoto (WKY) rat differ at a frequency of 1 per 62 bases in their nuclear DNA (Hypertension 1992;19:425-427). Given the origin of these strains this level of divergence was unexpected. To investigate the origin of this nuclear divergence we have examined mitochondrial DNA. Mitochondrial DNA was isolated from SHR and WKY rats, digested with several restriction enzymes, electrophoresed in 1.0% agarose gels, and the fragments visualized with ethidium bromide staining. This approach allowed us to analyze 220 base pairs of mitochondrial DNA. No differences were detected between SHR …

Effect Of Hindlimb Unweighting On Single Soleus Fiber Maximal Shortening Velocity And Atpase Activity, Kerry S. Mcdonald, Robert H. Fitts

Biological Sciences Faculty Research and Publications

This study characterizes the time course of change in single soleus muscle fiber size and function elicited by hindlimb unweighting (HU) and analyzes the extent to which varying durations of HU altered maximal velocity of shortening (V_o), myofibrillar adenosinetriphosphatase (ATPase), and relative content of slow and fast myosin in individual soleus fibers. After 1, 2, or 3 wk of HU, soleus muscle bundles were prepared and stored in skinning solution at -20 degrees C. Single fibers were isolated and mounted between a motor arm and a transducer, and fiber force, V_o, and ATPase activity were …

Nucleotide Sequence And Comparison Of The 5s Ribosomal Rna Genes Of Rochalimaea Henselae, R-Quintana And Brucella Abortus, Michael F. Minnick, Gary L. Stiegler

Biological Sciences Faculty Publications

No abstract provided.

Protein Inhibitors Of Calcium Salt Crystal Growth In Saliva, Bile And Pancreatic Juice, J. M. Verdier, B. Dussol, Y. Berland, J. C. Dagorn

Scanning Microscopy

The control of the formation of crystals in biological fluids is one of the most exciting field of research involving both organic and biochemical areas. Many organisms have evolved mechanisms which minimize or avoid the effects of nucleation and crystal growth formation. One of the most important mechanism is the interaction of specific proteins, called inhibitors, with crystals which alters their habits and leads to their elimination. This article, focused on saliva, pancreatic juice and bile, reviews our present knowledge on the structure-function relationships existing between these proteins and their ability to inhibit the growth of different calcium salt crystals.

Energy-Filtering Transmission Electron Microscopy Of Biological Specimens, W. C. De Bruijn, C. W. J. Sorber, E. S. Gelsema, A. L. D. Beckers, J. F. Jongkind

Scanning Microscopy

By energy-filtering transmission electron microscopy (EFTEM) electrons can be separated by their energy losses. An electron-energy filter, added to the microscope column allows the measurement of the energy distribution of transmitted electrons that have lost energy (< 2,000 eV, with an energy resolution of ~ 1 eV). These filtered electrons, recorded either as a spectrum or as an image, are composed of two parts superimposed on top of each other: (a) the unspecific energy-loss population (= the continuum) and (b) the specific element-related energy-loss population (= the edges). At the edges, electron data in spectra and images are mathematically processed, to obtain the desired element-related net-intensity values or images. These data are related to the total transmitted electron intensity, from the zero-and low-loss spectral region giving the relative spectral-or image intensity ratios (^SR*_x, ^IR*_x), which can be related to the element concentration. The acquisition of the zero-loss and low-loss data is hampered by the restricted dynamic range of the TV camera. By improvements through the introduction of calibrated attenuation filters in the optical path to the TV-camera, more reliable values for ^SR*_x and ^IR*_x can …

A Cationic Protein From A Urate-Calcium Oxalate Stone: Isolation And Purification Of A Shared Protein, J. P. Binette, M. B. Binette

Scanning Microscopy

A protein extracted from a urate - calcium oxalate stone by electrodialysis is also excreted in the urine which served as the source material for its purification by FPLC after separation on an ACA44 column. It has an amino acid composition appropriate for a cationic protein. One peptide obtained by cyanogen bromide cleavage has significant (approximately 60%) homology with CD59 protein (protectin). Both proteins have wide distribution, the unknown having been found in bile, cholesterol gallstones, and the wall of the aorta. However, the two proteins appear to be immunologically different.

Bcg Cell Imaging Using Scanning Probe Microscopy, Antonio A. Garcia, William C. Pettigrew, John Graham

Scanning Microscopy

Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) were used to obtain images of the surface of whole, intact BCG (bacille Calmette Guerin, a mycobacterium) cells in air and under solution by immobilizing the cells onto glass slides (AFM only) or highly oriented pyrolytic graphite. The technique used for AFM imaging involved depositing a submonolayer of cells under a centrifugal force followed by fixation/dehydration using polar organic solvents. AFM images agree well with images from light and electron microscopy and showed large numbers of BCG cells in their distinctive cord arrangement. The AFM also proved useful for identifying extracellular …

Absence Of A Transcellular Oxalate Transport Mechanism In Llc-Pk1 And Mdck Cells Cultured On Porous Supports, C. F. Verkoelen, J. C. Romijn, W. C. De Bruijn, E. R. Boevé, L. C. Cao, F. H. Schröder

Scanning Microscopy

Transepithelial oxalate transport across polarized monolayers of LLC-PK₁ cells, grown on collagen-coated microporous membranes in Transwell culture chambers, was studied in double-label experiments using [¹⁴C]-oxalate together with [³H]-D-mannitol as an extracellular marker. The [¹⁴C]-labeled glucose analog α-methyl-glucoside (α-MG) was used as functional marker for active proximal tubular sugar transport. Cellular uptake of oxalate and α-MG at both the apical and basolateral plasma membrane was determined. When added to the upper compartment, α-MG was actively taken up at the apical membrane, directed through the cells to the basolateral membrane and transported to the lower …

Comparative Aspects Of Splenic Microcirculatory Pathways In Mammals: The Region Bordering The White Pulp, E. E. Schmidt, I. C. Macdonald, A. C. Groom

Scanning Microscopy

Splenic microcorrosion casts prepared using minimal volumes of material show that most of the flow passes through the region bordering the white pulp. However, the nature of these microcirculatory pathways has received little attention. We have studied these in dog, cat, rat, mouse, and normal versus diseased human spleens. In all 5 species, a marginal sinus (MS) of anastomosing vascular spaces 5-10 μm thick lies between the white pulp and marginal zone (MZ). The morphology differs between species and the MS is absent in immune thrombocytopenia. The MS fills by circumferential flow before blood passes outward to the MZ. Many …

Studies On Structure Of Calcium Oxalate Monohydrate Renal Papillary Calculi. Mechanism Of Formation, F. Grases, A. Costa-Bauzá, A. Conte

Scanning Microscopy

A scanning electron microscopy study of the ultrastructure of 18 calcium oxalate monohydrate papillary calculi was performed with the purpose of establishing the main steps in calculus formation. It is concluded that these calculi originate in a "core" located near the central part of the calculus. Significant quantities of organic matter as well as calcium phosphates can be found in the "core" and at the surface of adhesion to the papilla and, in some cases, fibers and calcified tubules can also be found in the contact zone. In no case did this material affect the crystalline structure of the calculi, …

The Systematic Relationship Of Hipposideros Commersoni Matungensis To Other Species Of Rhinolophidae (Chiroptera), Maureen E. Koneval '93

Honors Projects

The hyoid morphology of Hipposideros commersoni matungensis was dissected and compared to the morphology of other bats in the family Rhinolophidae. Several significant differences in morphology were found: a modified stylohyal, fused to the auditory bulla; loss of the stylohyoid; addition of a new muscle, possibly from the stylopharyngeus; a modified mylohyoid profundus; and insertion of the ceratohyoid onto only the stylohyal. Cladistic analysis suggests that of all bats examined, H. commersoni is most closely related to H. armiger, and Triaenops persicus is most closely related to Rhinonycteris aurantius. This result is unexpected because the ranges of the species are …

Casting With Mercox-Methylmethacrylic Acid Mixtures Causes Plastic Sheets On Elastic Arteries. A Scanning And Transmission Electron Microscopic Study, Seyedhossein Aharinejad, Peter Böck

Scanning Microscopy

Lungs and systemic vessels of rats were cast with Mercox, both undiluted and diluted with monomeric methylmethycrylate (MMA; v:v/4:1), and studied by scanning electron microscopy (SEM). A sheet, less than 5 μm thick, surrounded the surface of cast pulmonary arteries and the aorta, when using diluted Mercox. This envelope was absent when casts were prepared with undiluted Mercox. Transmission electron microscopy (TEM) of unmacerated cast arteries showed all constituents of the vascular wall. Sections of thoroughly macerated vascular casts, however, still showed elastic lamellae in the vascular wall region, whereas muscular components and endothelial lining were completely digested. It is …

The Effect Of Temperature On The Growth Of The Zebra Mussel, Dreissena Polymorpha (Pallas), Tamara K. Ross '93

Honors Projects

Dreissena polymorpha (Pallas), zebra mussels, are recent invaders of North American freshwater systems. They have a high reproductive rate and settle in high densities which can clog water intake valves and pipes. Many studies investigating the use of heat as a control measure have examined the effects of high temperatures on zebra mussel mortality. Much less is known about the effect of temperature on the actual growth rate and development of zebra mussels. This study examined the growth rates of zebra mussels at 10°C, 20°C, and 25°C over two four-week periods in the laboratory. Mussels were placed in culture dishes …