Digital Commons Network^™

The Interaction Of Laser Energy With Ureter Tissues In A Long Term Investigation, U. Stratmann, K. Schaarschmidt, R. R. Lehmann, A. Heinze, G. H. Willital, E. Unsold

Scanning Microscopy

This study investigates tissue responses after laser irradiation of the rabbit ureter, which serves as an experimental model for rectourogenital fistulae of children. Twenty-five rabbit ureters were irradiated intraluminally by a Nd:YAG laser 1320 nm (2 Watt, 20 seconds and 3 Watt, 8 seconds) via an applicator with radialsymmetrical light distribution. Immediately, 2 weeks, 4 weeks, 8 weeks, and 16 weeks after irradiation, the ureters were X-rayed with contrast solution and prepared for light and transmission electron microscopy. For the parameters employed, no apparent morphological differences could be observed. Immediately, the central laser zone showed a transmural therrnonecrosis prevailed by …

Scanning Force Microscopy Of Chromatin, Wolfgang Fritzsche, James Vesenka, Eric Henderson

Scanning Microscopy

Scanning force microscopy (SFM) is a new method to obtain the topography of surfaces with nanometer-resolution. The ability to image under liquids makes the technique attractive for biological applications, especially for the determination of the ultrastructure of biomolecules under native conditions. One growing field of interest is the investigation of chromatin and chromatin-related structures. Different levels of chromatin condensation were the subject of several previous SFM investigations, from the nucleosomal chain, to the 30-nm fiber, ending with the metaphase chromosome. The SFM yielded new information on such fundamental problems as the core spacing of the nucleosomal chain, the internal structure …

The Ampullae Of The Inner Ear In The Lizard Podarcis S. Sicula. Ultrastructural Aspects, G. Balsamo, B. Avallone, D. Calabro, F. Marmo

Scanning Microscopy

The inner ear ampullae of the lizard Podarcis s. sicula were studied to determine better the ultrastructure of ampullar epithelial cells.

Our study confirmed that the ampullae of the membranous labyrinth of this lizard are similar to those of other vertebrates in their ultrastructural aspect.

Moreover, our observations revealed a special type of dark cells, restricted to a small area of the crista. They appeared similar to type II sensory cells and showed a dark, finely granular cytoplasm, containing numerous mitochondria and ribosomes, extensive Golgi apparatus and abundant glycogen.

The morphology of these cells suggests that they may be …

Management Options (Discussion Paper) For The Shark Bay Snapper Limited Entry Fishery, Shark Bay Snapper Limited Entry Fishery Working Group, Doug Bathgate

Fisheries Management Papers

At the Annual Management Meeting of the Shark Bay Snapper Limited Entry Fishery held on 22 July 1994 industry put forward a proposal that supplementary and non-transferable quota that was "lost" to the fishery when a licence holding non-transferable quota was transferred should be retained by the Fisheries Department and leased back to licence holders on an annual basis. As a result of this proposal and the fact that the management arrangements for the fishery are extremely complex and in need of simplification, the Minster for Fisheries approved the establishment of a Working Group to examine the lease-back proposal and …

Management Of The Northern Demersal Scalefish Fishery, Jane Fowler

Fisheries Management Papers

In mid 1994, the Fisheries Department of Western Australia announced that it would prepare a discussion paper setting out options for future management of the demersal scalefish fishery off the Kimberley coast. This paper, which was to be the start of a wider consultative process, was also to include options for possible further development of the trap and line fisheries. This paper is only the first step in a process for developing formal long term management arrangements under the new fisheries legislation, the Fish Resources Management Act 1994. Its aim is to provide some background and to present some management …

Report On Future Management Options For The South West Trawl Limited Entry Fishery, South West Trawl Limited Entry Fishery Working Group

Fisheries Management Papers

As a result of community concern regarding trawling, the current management rules for the South West Trawl Limited Entry Fishery were finalised in February 1989 and the final plan was gazetted in October of that year. However, there was public disquiet about this trawling, and as a result of this disquiet, a research program was initiated by the Fisheries Department with funding received from both the Commonwealth and State Governments. The scientific report, "The impact of trawling for saucer scallops and western king prawns on the benthic communities in coastal waters off south-western Australia" by L J B Laurenson, P …

Static Forces And Moments Generated In The Insect Leg: Comparison Of A Three-Dimensional Musculo-Skeletal Computer Model With Experimental Measurements, Robert J. Full, Anna N. Ahn

All HMC Faculty Publications and Research

As a first step towards the integration of information on neural control, biomechanics and isolated muscle function, we constructed a three-dimensional musculo-skeletal model of the hind leg of the death-head cockroach Blaberus discoidalis. We tested the model by measuring the maximum force generated in vivo by the hind leg of the cockroach, the coxa-femur joint angle and the position of this leg during a behavior, wedging, that was likely to require maximum torque or moment production. The product of the maximum force of the leg and its moment arm yielded a measured coxa-femur joint moment for wedging behavior. The …

Differential Distribution Of D4 And D2 Dopamine Receptors In Rat Brain: An Autoradiographic Study Using [3H]Ym-09151-2 And [3H]Raclopride, Nancy C. Stratman

Masters Theses

Extrapyramidal side effects (EPS) are associated with most antipsychotics for the treatment of schizophrenia since these agents antagonize dopamine D₂ receptors in the nigrostriatal pathway, a brain system that regulates motor functions. Clozapine, an atypical antipsychotic agent in that it does not produce EPS, was found to be more selective for the D₄ than the D₂ receptor. The purpose of this study was to locate the D₄ receptor in rat brain by autoradiographic comparison studies with [³H]YM-09151-2, a D₂ , D₃, and D₄ radioligand, to [³H]raclopride, a D …

Vitamin E Deficiency As A Model Of Precocious Brain Aging: Assessment By X-Ray Microanalysis And Morphometry, Carlo Bertoni-Freddari, Patrizia Fattoretti, Ugo Caselli, Roberta Paoloni, William Meier-Ruge

Scanning Microscopy

Vitamin E (α-tocopherol) is a known biological antioxidant able to quench the lipid peroxidation chain and to protect the cellular structures (e.g., plasma membranes) from the attack of free radicals which are reported to play a primary role in aging. To assess whether the absence of α-tocopherol from the diet of young laboratory animals may be considered a reliable model of precocious brain aging, intracellular ionic content of brain cortex pyramidal cells, ultrastructural features of synaptic contact zones, synaptic mitochondria and perykarial mitochondria positive to the succlillc dehydrogenase (SDH) histochemical reaction with copper ferrocyanide have been investigated by X-ray microanalysis …

The Influence Of 5-Fluorouracil On The Endothelium In Small Arteries. An Electron Microscopic Study In Rabbits, M. Cwikiel, B. Zhang, J. Eskilsson, J. B. Wieslander, M. Albertsson

Scanning Microscopy

5-Fluorouracil (5-FU) is a widely used antineoplastic agent. 5-FU induced cardiotoxicity is a still relatively unknown side-effect of this drug. This phenomenon could be due to a direct cytotoxic effect on the endothelial cells. We tested this hypothesis in an experimental study in rabbits, by scanning or transmission electron microscopic evaluation of endothelium in small arteries (the central artery of the ear) after in vivo treatment with 5-FU. Both local and systemic effects of 5-FU on endothelium were studied 15, 30, 60 and 120 minutes after intra-arterial or intraperitoneal treatment. Perfusion fixation at physiological pressure and temperature was used in …

Effect Of Ototoxic Drugs On The Amphibian Auditory System: Injection Of Gentamicin Sulfate Into Anuran Otic Capsules And Recovery Of Thresholds, Michael Patrick Brown

Dissertations and Theses

Hair cell trauma from aminoglycosides, which may lead to permanent loss of hair cells in mammals, was studied physiologically in frogs by measuring an auditory evoked potential (AEP) in Rana pipiens. The AEP was evaluated in order to measure threshold shift (TS) and recovery from TS after the administration of the aminoglycoside antibiotic, gentamicin. To obtain an AEP, chronic electrodes were implanted into the cranium near the cochlear nucleus. The frogs were then exposed to frequency-specific narrow band "clicks" which included a single period 1 kHz sinewave, and a computer synthesized high frequency and low frequency click. Amphibians have two …

Use Of Microprojectile Bombardment In Transient Expression Assays To Analyze Protochlorophyllide Reductase Gene Expression In Greening Maize Seedling Leaf Cells, Jennifer J. Marden

Senior Scholar Papers

In young cells of leaf meristems the progenitors of chloroplasts are small organelles known as proplastids, which divide and differentiate into chloroplasts. However, in the absence of light, proplastids undergo a different sequence of development and become etioplasts. When light is supplied to etiolated plants during the "greening" process, etioplasts differentiate into chloroplasts containing chlorophyll. An important light dependent step in chlorophyll biosynthesis is the photoreduction of protochlorophyllide to chlorophyllide by the NADPH:protochlorophyllide reductase (PCR) enzyme. This enzyme is present at high activity only in etiolated tissue and during early stages of light-induced chlorophyll synthesis. The enzyme and its corresponding …

3 Genes Of The Map Kinase Cascade, Mek-2, Mpk-1/Sur-1 And Let-60 Ras, Are Required For Meiotic Cell-Cycle Progression In Caenorhabditis-Elegans, Diane L. Church, Kun Liang Guan, Eric J. Lambie

Dartmouth Scholarship

In the germline of Caenorhabditis elegans hermaphrodites, meiotic cell cycle progression occurs in spatially restricted regions. Immediately after leaving the distal mitotic region, germ cells enter meiosis and thereafter remain in the pachytene stage of first meiotic prophase for an extended period. At the dorsoventral gonadal flexure, germ cells exit pachytene and subsequently become arrested in diakinesis. We have found that exit from pachytene is dependent on the function of three members of the MAP kinase signaling cascade. One of these genes, mek-2, is a newly identified C. elegans MEK (MAP kinase kinase). The other two genes, mpk-1/sur-1 (MAP kinase) …

The Effect Of Arf-Excimer Laser Irradiation Of The Human Enamel Surface On The Bond Strength Of Orthodontic Appliances, U. Stratmann, K. Schaarschmidt, M. Schürenberg, U. Ehmer

Scanning Microscopy

This study investigated enamel laser conditioning as an alternative to acid etching in bracket therapy. In preliminary experiments optimal laser parameters for achieving a bond strength of 6-10 N/mm² were defined. Enamel surface morphology was assessed and the ablation depth was measured on serial enamel sections. Thirty human molars were exposed to 193 nm ArF-excimer laser radiation (energy density: 260 mJ/cm²) by single pulse application of 23 nanoseconds. Thirty molars were etched with phosphoric acid (37%) for 60 seconds. The brackets from the treated molars and 30 untreated molars were debonded vertically for tensile bond strength measurement. …

Circadian Rhythm Of Brain Gaba Levels In The Cockroach, Leucophaea Maderae, Juli Martin Mccay, Jeanette Marie Gibson

Mahurin Honors College Capstone Experience/Thesis Projects

Brain levels of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) were determined at three-hour intervals in roaches acclimated to a 12-hour lightl12-hour dark cycle (light onset 0600 h) at 25 ± 2° C using high performance liquid chromatography coupled with fluorometnc detection GABA levels were found to be highest at noon and lowest at 1800 h. A difference between the high and low levels at these two times remained during the second day under constant dark conditions, indicating that GABA levels do indeed vary on a circadian basis. Brain GABA levels were highest at a time of day that corresponded with …

The Bag And Size Limit Review: New Regulations And Summary Of Submissions, F. B. Prokop, J M. Collins

Fisheries Management Papers

Since the new bag and size limits were introduced in December 1991, there have been many suggestions for refinement and improvement of these regulations. This paper includes the summary of submissions to Fisheries Management Paper No 52 - Review of Bag and Size Limit Proposals for Western Australian Recreational Fishers and details new regulations which will come into force on 1 July 1995.

The Best Available Information - Its Implications For Recreational Fisheries Management, F. B. Prokop

Fisheries Management Papers

Workshop at Second National Fisheries Managers Conference, Bribie Island, Queensland, October 18, 1994. Recreational fisheries management is one of the growth areas in Australian fisheries. The Australian Society for Fish Biology Workshop topic for its 1994 Conference was Recreational Fishing - What's the Catch. It was acknowledged at the ASFB conference that there were generally poor levels of information and for the lower value commercial and recreational fisheries there may be no way to gather definitive research data for the foreseeable future. However, in even the high profile fisheries, public perceptions, attitudes, and political will do not allow for the …

Reproduction Of The Rare, Riparian Orchid Spiranthes Diluvialis: Pollination Ecology, Variations In Reproductive Success, And Implications For Conservation, Sedonia D. Sipes

Biology

I examined the reproductive biology and pollination of Ute lady's tresses, Spiranthes diluvialis Sheviak, a rare orchid from Colorado and Utah. S. diluvialis exhibits a mixed-mating system. Outcrossing is promoted by protandrous flowers and by acropetal movement of long-tongued bees (predominantly bumblebees) on inflorescences. However, male and female phases overlap, and flowers are fully self-compatible. No autogamous or agamospermous seed set was observed, indicating a pollinator is required for reproduction. Fruit set and pollinia removal varied greatly within and between flowering seasons. I found evidence for both resource and pollinator limitation of fruit set, and suggest that the limiting factor …

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.

Functional Study Of The Structural Vp6 Protein Of Bluetongue Virus, Emiko Hayama

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was undertaken to investigate the structure-function relationship of VP6 protein of bluetongue virus (BTV) using molecular cloning techniques. VP6 is present in small quantities in BTV and its enzymatic activity and role in the viral replication cycle have not been studied. Since the availability of large amounts of purified VP6 is essential for the analysis of VP6, a BTV-11 S3 gene was cloned into a prokaryotic protein expression system. VP6 protein was expressed in large amounts and purified to near homogeneity. A series of C-terminal and internal deletion mutants of S3 gene was constructed and the truncated VP6 …

In Vitro Evaluation Of Anti-Eimeria Tenella, Gamont-Specific, Monoclonal Antibodies And Partial Characterization Of Their Target Antigens, Eric Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study represents an effort to interrupt the life cycle of Eimeria tenella, the parasite that causes cecal coccidiosis in chickens, with a panel of 12 gamont-specific monoclonal antibodies (Mabs). To facilitate Mab screening, it was first necessary to develop a cell culture-adapted strain of E. tenella (field strain 80) from primary chicken kidney cells (PCKC) to white Leghorn chickens and back to PCKC. This alternation was repeated through 12 such passages. As a result, we have developed a cell culture-adapted strain of E. tenella that produces over 280% more oocysts in vitro than the original parent strain, and …

Cell Death In The Embryonic Developing Limb, J. M. Hurle, M. A. Ros, V. Garcia-Martinez, D. Macias, Y. Ganan

Scanning Microscopy

In amniote vertebrates, the development of form and structure of the limb bud is accompanied by precise patterns of massive mesodermal cell death with morphological features of apoptosis. These areas of cell death appear to eliminate undifferentiated cells which are required only for a limited time period of limb development. Predictable skeletal and morphological anomalies of the limb occur when the pattern of cell death is modified in mutant species or under experimental conditions. Most evidence points to the occurrence of local triggering mechanisms to account for the establishment of the areas of cell death and the subsequent activation of …

The Effects Of Dietary Vitamin E Supplementation On Platelet Aggregation And Plasma Oxidized Low Density Lipoprotein In Hypercholesterolemic Rats, Russell W. Thurman

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 by Russell W. Thurman on April 28, 1995.

Alterations In Mdck And Llc-Pk1 Cells Exposed To Oxalate And Calcium Oxalate Monohydrate Crystals, R. L. Hackett, P. N. Shevock, S. R. Khan

Scanning Microscopy

Structural analysis of human kidney stones reveals the presence of cellular membranes and other cell fragments. Experimentally, calcium oxalate crystallization is facilitated when an exogenous nephrotoxin is given with ethylene glycol, thus providing cellular degradation products to act as heterogenous nuclei. In this report, we tested whether oxalate alone could act as a cell toxin capable of producing damaged cells without the presence of an exogenous agent. Cultured LLC-PK₁ and MDCK cells, when exposed to 1.0 mmol KOx, a concentration at the limit of metastability for calcium oxalate nucleation, were severely damaged as measured by specific lactate dehydrogenase (LDH) …

Radiation Nephropathy: A Review, M. E. C. Robbins, S. M. Bonsib

Scanning Microscopy

The marked radiosensitivity of renal tissue represents a limitation on the total radiotherapeutic dose that safely can be applied to treatment volumes that include the kidneys. Radiation nephropathy is characterized by a progressive reduction in renal hemodynamics associated with a severe anemia. The latter is often normochromic normocytic in character, but can progress to a microangiopathic hemolytic anemia. The pathogenic mechanisms responsible for the development of radiation nephropathy remain ill-defined. Experimental studies which allow serial determinations of functional, morphologic, and cell kinetic radiation-induced changes indicate that primarily glomerular but also tubular alterations occur in the primary stages of radiation nephropathy. …

Gold Coating Of Respiratory Cilia For Scanning Electron Microscopy, E. Toskala, J. Nuutinen, M. Rautiainen, A. Pelttari

Scanning Microscopy

The optimal thickness of gold coating of cilia for scanning electron microscopy was studied using respiratory mucosa obtained from pigs. We tested 8 different coating times, from 10 seconds to 4 minutes, which resulted in gold layer thicknesses varying from 16 ± 1 nm to 100 ± 3 nm. The thickness of the gold layer with a coating time of 60 seconds and voltage of 2.5 kV was 43 ± 5 nm. This thickness of gold layer gave good image quality without causing any electric charging. With thinner gold films, the amount of electric charging increased. When the coating time …

Scanning Electron Microscopic Observation Of Dark Cells After Streptomycin Perfusion Of The Vestibule In Guinea Pigs, Xianxi Ge, John J. Shea Jr.

Scanning Microscopy

Hearing has been stabilized in the majority of patients studied in the treatment of Meniere's disease with streptomycin. This observation suggests that effects of streptomycin may ameliorate endolymphatic hydrops, possibly by attenuating the activity of secretory tissue. The purpose of this study is to observe the dark cells of the utricle in guinea pigs after streptomycin perfusion of the vestibule. Twelve pigmented guinea pigs weighing 250-350 grams were used in this study. The vestibules in five guinea pigs were perfused monolaterally with 150 μg of streptomycin in artificial perilymph and, in seven, the vestibules were perfused only with artificial perilymph …

The Effects Of Diethyldithiocarbamate (Ddc) On The Astrocytic Cytoskeleton, Mary F. Mcmanus, Louis D. Trombetta

Scanning Microscopy

The dithiocarbamates are a group of compounds that are used extensively in industry, agriculture and medicine. Exposure to these compounds has caused deleterious effects to both the central and peripheral nervous systems. Cultured rat hippocampal astroglia treated with 35 μg/ml diethyldithiocarbamate (DDC) in media were studied for alterations to the cytoskeleton. Examination by both immunohistochemistry and scanning electron microscopy revealed disruption of the cytoskeletal elements. This occurred in a progressive time-dependent manner. Electrophoretic patterns demonstrated two cytoskeletal protein alterations. The microtubular protein, β-tubulin, appeared to have an altered mobility while the major intermediate filament protein, glial fibrillary acidic protein (GF …

Gold, Electron Microscopy, And Cancer Therapy, James F. Hainfeld

Scanning Microscopy

Radioactive gold has properties suitable for radiotherapy and can provide lethal irradiation to cells. If the gold is conjugated to a targeting molecule, such as an antibody, it may be possible to specifically deliver the dose to tumor cells. Various gold particles are possible candidates and include gold colloids with adsorption of antibodies or gold clusters with covalent attachment. Different sizes of gold particles are available and some may be preferred for certain situations. Problems with intravenous injection and in vivo delivery are numerous, and a more tractable application is the direct instillation into the urinary bladder of radiogold immunoconjugates …

Semiquantitative Analysis By Scanning Electron Microscopy Of Cochlear Hair Cell Damage By Ototoxic Drugs, Takehisa Saito, Yasuhiro Manabe, Noriyuki Honda, Takechiyo Yamada, Takehito Yamamoto, Hitoshi Saito

Scanning Microscopy

The ototoxicity of cisplatin and carboplatin in the organ of Corti of the guinea pig was evaluated semiquantitatively. Damage of the stereocilia of outer hair cells (OHCs) observed by scanning electron microscopy (SEM) was classified into normal, grade 1 (10-50% loss of stereocilia), grade 2 (less than 50% remaining stereocilia), or grade 3 (missing stereocilia). The OHCs observed by light microscopy (LM) were classified as remaining or missing cells. Fifty OHCs of each row in the middle part of each turn of the cochlea were counted (a total of 150 cells per turn). Guinea pigs were administered 5 mg/kg of …