Digital Commons Network^™

Generation Of Oxygen-Derived Free Radicals Stimulated By The Fumigant Insecticide Phosphine: In Vivo And In Vitro Studies, Caroline Jane Bolter

Digitized Theses

Previous studies have shown that phosphine (PH{dollar}\sb3{dollar}) inhibits cytochrome oxidase and that a direct relationship exists between oxygen concentration during fumigation and insect mortality. This study was undertaken to test the hypothesis that mortality is due to cumulative damage of cellular components by free radicals derived from superoxide (O{dollar}\sb2\sp\div){dollar} generated by the inhibited respiratory chain.;Hydrogen peroxide {dollar}\rm(H\sb2O\sb2),{dollar} a product a O{dollar}\sb2\sp\div{dollar} dismutation, was measured spectrophotometrically using yeast cyctochrome c peroxidase as an indicator. The respiratory inhibitors; PH{dollar}\sb3{dollar}, antimycin and myxothiazol stimulated the release of {dollar}\rm H\sb2O\sb2{dollar} from mitochondria isolated from granary weevils (Sitophilus granarius). Peroxide release increased with the addition …

The Microcirculation In A Glioma Model, Catherine Lynn Farrell

Digitized Theses

Microcirculatory functions in glial tumors are abnormal. High permeability leads to the formation of cerebral edema. Low blood flow may compromise the delivery of chemotherapeutic agents into tumor tissue. The purpose of this thesis was to examine the microcirculation in a glioma model in order to obtain a quantitative picture of how abnormal function relates to microvascular network structure.;A model of human malignant glioma was developed by implantation of multicellular spheroids into the brains of rats. The vessels in the tumor were permeable to exogenous tracers. Grossly, tracer leakage was correlated with tumor growth but microscopically, it appeared that in …

The Effect Of Streptozotocin-Induced Diabetes And Thyroid Hormone Alterations On Skeletal Muscle Contractile, Histochemical And Biochemical Properties, Carol Dawn Rodgers

Digitized Theses

The purpose of this study was to examine the role of diabetes-associated hypothyroidism in changes in plantaris muscle contractile, histochemical and biochemical properties. Three experiments were designed to examine this relationship. Experiment I evaluated the time course of diabetes-associated hypothyroidism and examined the effect of daily triiodothyronine (T3) supplementation on serum T3 and thyroxine (T4) levels in the diabetic rat. The effects of diabetes and diabetes in conjunction with T3 supplementation on plantaris muscle contractile, histochemical and biochemical properties were examined in Experiments II and III respectively.;The results of Experiment I indicated that T3 levels exhibited a transient change after …

Comparative Study Of The Isozymes Of The Cationic And The Anionic Peanut Peroxidases, Chunfang Hu

Digitized Theses

Peroxidase isozymes are distributed throughout the plant kingdom. In order to understand the functions of the isoperoxidases, the nature and degree of the heterogeneity between them need to be clarified. The cationic (C.PRX) and the anionic peanut peroxidases (A.PRX) are used for such a study.;The physico-chemical properties of the two peroxidases are reported. They are similar in MW, carbohydrate content and pH optimum for catalysis, but differ in Ca{dollar}\sp{lcub}2+{rcub}{dollar} contents and isoelectric point. The basis for the difference in pI is found in the different relative content of the acidic and basic amino acids, with more acidic residues present in …

Structural And Chemical Characterization Of The S-Layer Of Lampropedia Hyalina, John William Austin

Digitized Theses

The S-layer of Lampropedia hyalina is made of two separate layers. The inner, perforate layer, is composed of a 32kD polypeptide arranged in p6 symmetry with a lattice spacing of 14.6nm. The outer, punctate layer, is composed of tubular units connected by fine linking arms centred on p3 symmetry axes, to created a layer with p6 symmetry and a lattice constant of 25.6nm. Incubation of cell envelopes with 3M urea dissolved the punctuate layer and released three polypeptides of 60kD, 66kD and 240kD. These polypeptides reassembled to form the native punctate layer when dialysed against buffer containing 10mM CaCl{dollar}\sb2{dollar} or …

Regulation Of Mitogen-Regulated Protein/Proliferin Gene Expression In Cultured Mouse Cells, Alison Margaret Connor

Digitized Theses

Mitogen-regulated protein/proliferin (MRP/PLF), a member of the prolactin-growth hormone family that occurs in the mouse, is expressed in a number of immortal cell lines including 3T3 and BNL. Neither MRP/PLF protein nor mRNA is detected in the mouse embryo fibroblasts (MEFs) from which the 3T3s are derived. One aim of this work was to identify the level at which this regulation of MRP/PLF expression is occurring. Differences were not observed in the MRP/PLF gene copy number, DNase I hypersensitive sites or methylation patterns of immortal cell lines compared to MEFs. RNA transcriptional mapping did not detect MRP/PLF hybridizing transcripts in …

Analysis Of Secreted Phosphoprotein (2ar; Osteopontin) Gene Expression And Association With Carcinogenesis, Ann Marie Craig

Digitized Theses

The murine cDNA encoding secreted phosphoprotein 1 (SPP) was cloned in this lab on the basis of induction of the mRNA (originally designated 2ar) by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate in JB6 epidermal cells. The polypeptide predicted from the cDNA sequence is 84% identical to rat osteopontin (44 kDa bone phosphoprotein; sialoprotein I). Many primary structural features are conserved, including an ArgGlyAsp (RGD) cell adhesion site and an unusual series of 9-10 consecutive aspartate residues. SPP mRNA is most abundant in vivo in bone and kidney, and was localized to the medulla region of adult mouse kidney by in situ hybridization. …

Contributions To The Analysis Of Familial Data, Michael Eliasziw

Digitized Theses

A unified noniterative approach to point and interval estimation of interclass and intraclass correlations is presented in the context of family studies where there may be more than one individual in each of two classes. The procedure involves a generalization of the Pearson product-moment correlation coefficient, where one permits different weights for the pairs of scores. Unlike the maximum likelihood approach, these estimators are not derived under the assumption of a particular parametric form nor do they require an iterative solution.;The asymptotic distributions of the generalized product-moment estimator and of the maximum likelihood estimator are derived under the assumption of …

Variation Within The Life History Strategy Of White Cockle (Silene Latifolia Poiret), Brenda Lee Frick

Digitized Theses

Silene latifolia occurs as an annual, biennial or short-lived perennial. Common garden and greenhouse experiments were used to examine the nature of this variation in life history among populations from Manitoba and Ontario. In a common garden, a majority of individuals lived for two years, and were reproductive in both. Populations differed in mean length of the pre-reproductive period, number of reproductive seasons, life span, reproductive output, and in sex ratio. Manitoba populations were less likely to reproduce in their first year than were Ontario populations. Elgin County populations were more likely to be iteroparous than were London city populations. …

Enzyme Electromorph Variation In Species Of The Lichen Family Umbilicariaceae, Cecilia Mary Hageman

Digitized Theses

Although biochemical features such as secondary phenolics have been used extensively as genotypic indicators in lichen systematics, marcomolecular characteristics such as enzyme electromorphs have thus far been applied to few problems in this field. In this thesis, techniques of isoelectricfocusing and specific enzyme staining were used to produce enzyme electromorph profiles and these were applied to systematic problems in the lichen family Umbilicariaceae. Thalli representing six umbilicate lichen species, Lasallia papulosa (Ach.) Llano, Umbilicaria deusta (L.) Baumg., U. hirsuta (Sw.) Hoffm., U. mammulata (Ach.) Tuck., U. muhlenbergii (Ach.) Tuck. and U. vellea (L.) Ach. were analyzed using these methods.;Reproducible banding …

Translational Control Of Protein Synthesis In Heat-Shocked Maize Seedlings, Nora Catherine Hogan

Digitized Theses

Translational control of protein synthesis in the plumules of heat-shocked maize seedlings was investigated. Maize plumules respond to heat shock by synthesizing nuclear-encoded hsp's with M{dollar}\sb{lcub}\rm r{rcub}{dollar}'s of 108, 89, 84, 76, 73, and 17-29kDa. Synthesis of some, but not all, 25{dollar}\sp\circ{dollar}C (control) proteins is repressed in vivo. RNA blot and in vitro translation analyses of non-polyribosomal and polyribosomal RNP RNA suggest that repression ensues from either a decrease in mRNA levels or from the inefficient translation of control messages in heat-shocked cells (relative to heat shock mRNAs) due to changes in the rates of both initiation and elongation.;Hsp70 and …

Intratesticular Factors Which Mediate The Effects Of Germ Cell Disruption On Leydig Cell Function In The Rat, Gwenderlyn Frances Jansz

Digitized Theses

Treatment in utero with busulfan or irradiation, resulted in adult rats with decreased serum androgen and increase serum lutenizing hormone (LH). Leydig cells (LC) from lesioned rats had increased in vitro androgen production (AP) and increased hCG binding per LC. Serum androgen was decreased, yet AP per LC was increased. Possibly, spermatogenic disruption resulted in gonads with decreased number of LC which had increased LH responsiveness.;To distinguish whether the effects of spermatogenic disruption on LC were due to local or systemic modulation, disruption of spermatogenesis by efferent duct ligation or cryptorchidism was done as unilateral or bilateral treatments. LH stimulated …

Structural And Chemical Organization Of The Rat Interpeduncular Nucleus, Michael David Kawaja

Digitized Theses

The structural and chemical organization of the rat interpeduncular nucleus (IPN) was examined employing wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) and immunohistochemistry at the light and electron microscope level. The topographical and ultrastructural arrangements of habenular efferents innervating the IPN were studied using stereotaxic placements of WGA-HRP. The medial habenula provided a prominent afferent input to the many IPN subnuclei, with the lateral and rostral subnuclei receiving a predominantly ipsilateral input, and the intermediate, central and dorsomedial subnuclei receiving a symmetrical projection. Habenular terminals formed distinct axodendritic synapses in the rostral, lateral, intermediate and central subnuclei.;Projections of the …

Subcapsular Splenic Microcirculation Quantitatively Analyzed By In Vivo Microscopy, Douglas Michael Ragan

Digitized Theses

The objective of this work was to improve in vivo microscopy of the splenic microcirculation to obtain quantitative data such as velocity of RBCs, diameters and volumes of vessels, and to study possible mechanisms controlling redistribution of blood flow.;Illumination limitations necessitated using small spleens. Young rats (27-89 g) were the predominant species studied, although mice were occasionally used. Inverted microscopy and oblique illumination were key elements in obtaining high quality video images for quantitative analysis. Still photographs were obtained from video images by exposing film to several successive fields.;The splenic volume occupied by capillaries, reticular meshwork and sinuses is 0.16%, …

Composition, Structure And Development Of The Crystalline Cone Of The Superposition Compound Eye, Cassandra Lee Schlamp

Digitized Theses

The crystalline cone of beetles and moths is a transparent, solid structure consisting of a small number of concentrated, hydrophobic proteins. Among these polypeptides is a 67kD protein family which are found in the cones of all 9 species examined. In addition, beetle lenses contain a 125kD polypeptide that is immunologically related to a moth 100kD lens polypeptide. The high molecular weight polypeptides may also be related to the 67kD family because (i) antibodies raised against the beetle 67kD polypeptide cross-react with the moth 67kD and 100kD polypeptides, and with the beetle 125kD polypeptide, (ii) enzyme digests of 67kD and …

The Effect Of Vasoactive Intestinal Peptide On Pulsatile Lutenizing Hormone Release In The Ovariectomized Rat, Katherine Margaret Stobie

Digitized Theses

Vasoactive intestinal peptide (VIP) affects the secretion of several pituitary hormones including LH.;The initial objective was to study in greater detail the action of VIP on pulsatile LH secretion.;Ovariectomized rats were used in this study and peptide solutions were infused into the third cerebral ventricle. Venous blood was sampled every 5 min and assayed for LH.;VIP (3.5 nmole/h) lowered the mean LH levels and the pulse frequency but had no effect on pulse amplitude.;To determine whether VIP acts within the brain or at the pituitary GnRH was injected intravenously after infusion of either VIP or saline. The amplitude of the …

Control Of Saccadic Eye Movements In Three-Dimensions, Douglas Blair Tweed

Digitized Theses

This study develops and tests a mathematical model for the neural circuits controlling saccades, the rapid eye movements that shift the direction of gaze. These movements are three-dimensional eye rotations, but current models for their control are based on the mathematical properties of one-dimensional rotations. Surprisingly, the properties of three-dimensional rotations are very different, and so one-dimensional concepts often do not apply to real eye movements. Thus, a key hypothesis of current models--that the brain computes eye position by integrating eye velocity signals--is incorrect because in three dimensions the integral of velocity is not position. This thesis describes a simple …

Regulation Of Sodium,Potassium-Atpase Expression During Mouse Embryogenesis, Andrew John Watson

Digitized Theses

This study determined the time of appearance and cellular distribution of Na/K-ATPase during preimplantation development, the direct involvement of this enzyme in the process of cavitation (blastocoel formation) and the pattern of expression of the Na/K-ATPase alpha (catalytic) subunit mRNA during preimplantation development. Na/K-ATPase was first detected by immunofluorescence in late morulae (84 hr post-hCG). During cavitation, the enzyme changed in its distribution to become restricted to the basolateral membrane domain of the mural trophectoderm and trophectodermal projections. Wheat germ agglutinin treatment of 2-, 4- and 8-cell embryos confirmed the timing of appearance of the enzyme and also showed that …

In Vivo And In Vitro Regulation Of Pituitary Follicle-Stimulating Hormone (Fsh) Secretion By 3alpha-Hydroxy-4-Pregnen-20-One (3hp): A Highly Sensitive And Specific Inhibitor, Patricia Helen Wood

Digitized Theses

The effect of the gonadal steroid, 3{dollar}\alpha{dollar}-hydroxy-4-pregnen-20-one (3HP), is intact and castrate rats and in primary cultures of rat anterior pituitary cells and the possible interaction of 3HP with the signal transduction pathways of luteinizing hormone-releasing hormone (LHRH) was examined.;Intact or gonadectomized, male or female, prepubertal or adult rats treated with 3HP (0-200 {dollar}\mu{dollar}g/100 g BW; 1-4 days) showed a selective reduction in serum FSH levels (25%-60%) without any apparent effect on serum LH levels. The FSH-suppressing effect of 3HP was found to be dose-related, suggesting that 3HP action may be physiological. 3HP was effective in young male rats (10 …

Identification Of The Functional Regions Of The Yeast Activator Adr1, Lynne Taylor Bemis

Doctoral Dissertations

ADR1, a transcriptional activator from the yeast Saccharomyces cerevisiae, is required for activation of the glucose-repressible alcohol dehydrogenase, ADH II (encoded by the ADH2 gene). The ADR1 gene encodes a protein which binds to an upstream activation sequence in the ADH2 promoter. Several methods were used to locate functional regions of the ADR1 protein.

The adr1-1 mutation was identified as a C to G transversion resulting in a nonsense codon at the eleventh codon of ADR1. tRNA-suppressors which substituted an amino acid at the eleventh codon of adr1-1 resulted in a functional adr1-1 protein, indicating that the translational start of …

Regulation Of Magnetosome Biogenesis By Oxygen And Nitrogen, Yuri Alan Gorby

Doctoral Dissertations

Magnetosomes were purified from broken cells of Aquaspirillum magnetotacticum by a magnetic separation technique. Electron microscopic and chemical analyses revealed they consisted of crystalline magnetite (Fe$\sb3$O$\sb4$) cores enclosed by a lipid bilayer membrane containing numerous proteins. Two membrane proteins were absent from the nonmagnetic (membrane or soluble) cell fractions and were absent from cells of non-magnetic mutant strains. Knowledge of their partial sequence is expected to lead to construction of hybridization probes to identify magnetosome-specific DNA sequences.

Cells of this organism in laboratory culture typically achieved low cell yields and were variably magnetic or non-magnetic. Therefore better understanding of physiological …

The Dynamics Of A Nudibranch-Hydroid Predator-Prey Association: Cuthona Nana And Hydractinia Echinata, Nadine C. Folino

Doctoral Dissertations

The purpose of this study was to document the biological interactions in a predator-prey relationship involving a nudibranch and hydroid, respectively. The predator is a hermaphroditic opisthobranch mollusc with direct development, Cuthona nana. Cuthona nana feeds specifically on the colonial hydroid Hydractinia echinata.

Population patterns of predator and prey were documented by collecting hermit crabs with hydroid-covered shells. Results indicate a subannual life cycle for C. nana with juveniles and egg masses present throughout the year. Hydractinia echinata colonies reproduce in the spring and are more abundant in late summer and early fall.

Field and laboratory observations indicate that adult …

Genetic Variation In The Genus Leptographium With Special Reference To Leptographium Wageneri, Paul Jay Zambino

Doctoral Dissertations

The objectives of this research were to determine genetic variation in Leptographium and how it corresponds to the taxonomy of the genus.

The similarity of 88 strains of 27 species of Leptographium was studied using enzyme electrophoresis. UGPMA cluster analysis of similarity matrices (Nei genetic identity, I) generated from data of 267 electrophoretic forms (electromorphs) of 15 enzymes showed a close correspondence between morphology and electrophoretic similarity. Strains of a species clustered at I $\geq$ 0.60, but in two cases, taxa clustered at I $>$ 0.60, suggesting conspecificity.

Additional isozyme studies were made of 76 isolates of Leptographium wageneri …

Pathogenesis, Pathology And Chemotherapy Of Experimental Legionella Pneumophila Infection, Arthur O. Tzianabos

Doctoral Dissertations

Legionella pneumophila is the causative agent of a severe, often fatal pneumonic illness known as Legionnaires' disease. The mechanisms by which L. pneumophila attaches to U937 (transformed human-like fibroblasts) were investigated. Experimental parameters for adherence assays were established prior to blocking studies designed to identify microbial adhesins and/or eukaryotic receptors that mediate bacterial attachment to target cells. Results from these studies indicated that a lectin-like component(s) associated with L. pneumophila may be responsible, at least in part, for microbial adherence to these eukaryotic host cells. Erythromycin is the drug of choice for the treatment of clinical legionellosis; however, difficulties with …

Isozyme And Quantitative Trait Variation Within And Among Natural Populations Of The Wild Soybean, Glycine Soja (Sieb & Zucc), Carol Jean Bult

Doctoral Dissertations

Isozymes and quantitative traits were used to explore the organization of genetic variation within and among seven natural populations of the wild soybean, Glycine soja, from Mishima, Japan. Seed enzymes were separated by horizontal starch and polyacrylamide gel electrophoresis. One-hundred and eleven individuals were scored for their genotypes at 48 gene loci resolved from 20 enzyme systems and one seed protein. Fifteen of the isozyme gene loci were polymorphic. The values for average polymorphism per locus (using the 99% criterion), average number of alleles per locus, and the proportion of heterozygotes observed were 0.140, 1.14 and 0.002, respectively. The average …

Nitrogen Fixation In Beggiatoa, Vitreoscilla, And Thiothrix., James Kevin Polman

LSU Historical Dissertations and Theses

Many strains of Beggiatoa, Vitreoscilla, and Thiothrix were found to be capable of nitrogen fixation and to harbor plasmid DNA of various sizes, including large plasmids, and several plasmids in the 12 to 15 Mdal size range. Nitrogenase induction and activity in Beggiatoa alba were studied with respect to the effects of oxygen, pH, temperature, and nitrogenous compounds. Induction required microaerobic conditions. Nitrate and nitrite repressed induction, but glutamine did not. A pH optimum of 6.5 to 8.0 and a temperature optimum of 29$\sp\circ$C were observed. Nitrogenase activity was immediately and incompletely inhibited by ammonium, but was not inhibited by …

Age And Growth Of King Mackerel, Scomberomorus Cavalla, From The Atlantic Coast Of The United States, Mark R. Collins, David J. Schmidt, C. Wayne Waltz, James L. Pinckney

Faculty Publications

Whole sagittae from 683 and sectioned sagittae from 773 "adult" (age> 0 ; 437-1.310 mm FL), and lapilli from 29 larval (2-7 mm SL) and 69 young-of-the-year (79-320 mm FL) king mackerel, were examined. All fish were from waters off the Atlantic coast of the southeastern United States (Cape Canaveral, Florida to Cape Fear. North Carolina). Back-calculated lengths at ages and von Bertalanffy growth equations were calculated from both whole and sectioned sagittae. Ages determined from sectioned sagittae were significantly greater than ages determined from whole sagittae, and the magnitude of the difference increased with age (from sections). Rings on …

Lipopolysaccharide Serotyping Of Vibrio Vulnificus., Stephen Jeffrey Martin

LSU Historical Dissertations and Theses

Current schemes used to serotype Vibrio vulnificus are based on direct bacterial agglutination using polyclonal rabbit antisera. During the course of serotyping Louisiana V. vulnificus isolates we failed to observe a reproducible agglutination profile for these isolates. The major obstacle in producing serovar specific sera has been the failure to produce high titered anti-LPS sera in rabbits. Anti-LPS serum from rabbits immunized with formalin-killed, heat-killed, or acetone dried whole cell vaccines and LPS-carrier conjugates uniformly produced titers $\leq 320$. Separation of anti-LPS activity from whole sera by affinity chromatography also yielded low titered antisera. A typing system predicated on the …

The Pattern And Process Of Land Loss In Coastal Louisiana: A Landscape Ecological Analysis., Scott G. Leibowitz

LSU Historical Dissertations and Theses

The goals of this research were: to develop a methodology for the study of landscape process and pattern; to determine the spatial pattern of land loss in coastal Louisiana and relate it to causal processes; and to assess the relative importance of natural versus human-induced processes in causing land loss. Land loss was analyzed for a 22 year period at three sites, using a Geographic Information System composed of digital habitat maps. The most significant finding of this research was that land loss is not a simple, spatially homogeneous phenomenon, that occurs uniformly. Instead, large clumps of high loss, or …

Mastitis In Unbred And Primigravid Dairy Heifers., Pedro Trinidad

LSU Historical Dissertations and Theses

Prevalence of mastitis and efficacy of intramammary treatment were determined in unbred and primigravid heifers (n = 116) from 4 dairy herds. Of 97 heifers from which secretion samples were obtained, intramammary infections were detected in 96.9% of animals and 74.6% of quarters. Clinical symptoms were observed in 29% of heifers. Staphylococcus aureus infections were detected in 37.1% of animals. Teat canal colonizations were confirmed in 93.1% of heifers and 70.7% of quarters. The most common isolates from mammary glands were Staphylococcus chromogenes, Staphylococcus hyicus, and Staphylococcus aureus. Average somatic cell counts in secretion from infected and uninfected quarters were …