Life Sciences Commons^™

Mitochondrial Dna Variation Within The Western-Clark's Grebe Complex (Podicipedidae: Aechmophorus), Bruce Alan Eichhorst

Theses and Dissertations

The Western Grebe (Aechmophorus occidentalis) and Clark's Grebe (A. clarkii) are considered to be closely related .. Until recently, they were regarded as color phases of one species--the Western Grebe. I assessed mitochondrial DNA (mtDNA) variation within and between the Aechmophorus color phases. I also evaluated the plausibility of two vicariance models that have been. proposed to explain the evolution of the color phases. Grebes were collected from seven breeding sites, representing three geographic regions of the United States-Canada breeding range. Restriction-enzyme analysis of a total sample of 109 grebes was conducted. Estimates of nucleotide divergence ( dxy, da), nucleotide …

Regulatory Analysis Of Vimentin Expression In Metastatic Versus Nonmetastatic Breast Cancer Cell Lines, Danielle N. Bird

Theses and Dissertations

The intermediate filament gene family, composed of six classes, shows both tissue and development-specific expression. Vimentin is a unique member of the intermediate filament protein family: although it is expressed in cells of mesenchymal origin, vimentin may also be expressed with other intermediate filament proteins during early stages of development. In some cases, as differentiation continues, vimentin is normally down-regulated whereas other intermediate filament proteins, like desmin, glial fibrillary acidic protein, or neurofilaments are turned on in muscle, glial cells, or neurons, respectively. In some metastatic cancers, including breast and prostate cancers, vimentin is aberrantly expressed, despite the embryonic origin …

Expression, Purification And Characterization Of Hepatitis C Virus Core Protein From E.Coli Using A Chemically Synthesized Gene (1), And Cloning, Expression, Purification And Characterization Of The Major Core Protein (P26) From Equine Infectious Anaemia Virus, Ashley James Birkett

Theses and Dissertations

The hepatitis c virus (HCV) core gene has been chemically synthesized and used to direct the expression of core protein in Escherichia coli (E.coli). When cloned downstream of the inducible T7 promotor the core gene directed the expression of a soluble protein with a molecular weight of 22 kDa. Under native conditions the protein behaved in a manner consistent with the formation of a multimeric structure, which may represent assembled core particles. Further, when examined by electron microscopy a heterogeneous mixture of nucleocapsid-like particles were visible. Core protein was specifically recognized by antibodies present in HCV infected serum, suggesting that …

Characterization Of Fibroblasts With A Unique Defect In Processing Antigens With Disulfide Bonds, Brian J. Merkel

Theses and Dissertations

A Chinese hamster ovary (CHO) fibroblast, transfected with murine major histocompatibility complex (MHC) class II genes, inefficiently simulated CD4+ Th cells specific for ovalbumin (OVA), hen egg lysozyme (HEL), and pork insulin which contains disulfide bonds. However, the fibroblasts elicited a T cell response to λ-repressor, which lacks disulfide bonds, and efficiently presented synthetic peptides. A somatic cell hybrid WALC, generated by fusing the hamster fibroblast with a murine L cell fibroblast, very efficiently processed OVA and HEL, suggesting that impaired processing was genetically complemented, suggesting that the processing defect is a recessive trait. Three distinct processing phenotypes were observed …

Cloning, Expression, Purification And Characterization Of Domain B Of Wheat Germ Agglutinin, Ann C. Rice

Theses and Dissertations

Wheat germ agglutinin (WGA) belongs to a family of dimeric chitin binding lectins specific for N-acetyl-D-glucosamine (GlcNAc) and N-acetyl-D-neuraminic acid (NeuNAc). The polypeptide chain consists of a tandem repeat of four conserved 4.3 kDa domains (A, B, C, D) stabilized by four disulfide bonds. Saccharide binding occurs in the dimer interface where domains of different subunits are in contact (A with D, B with C). An aromatic amino acid rich pocket on one domain (sufficient for saccharide binding) and a polar region on the contacting domain constitute a complete binding site. Saccharide binding affinities may differ among the four unique …

A Refinement Of Risk Analysis Procedures For Trichloroethylene Through The Use Of Monte Carlo Method In Conjunction With Physiologically Based Pharmacokinetic Modeling, William J. Cronin Iv, Eric J. Oswald

Theses and Dissertations

This study refines risk analysis procedures for trichloroethylene (TCE) using a physiologically based pharmacokinetic (PBPK) model in conjunction with the Monte Carlo method. The Monte Carlo method is used to generate random sets of model parameters, based on the mean, variance, and distribution types. The procedure generates a range of exposure values for human excess lifetime cancer risk of lxl0 (exp-6), based on the upper and lower bounds and the mean of a 95% confidence interval. Risk ranges were produced for both ingestion and inhalation exposures. Results are presented in a graphical format to reduce reliance on qualitative discussions of …

A Comparative Test And Evaluation Of Lead-Based-Paint Test Kits, Lynn S. Hill

Theses and Dissertations

This research compares the performance of five chemical spot-test kits on lead-based paints. The kits are designed to give a qualitative assessment of lead in paint. The intent of the research effort was to develop a standard evaluation procedure for follow-on studies and assess the baseline performance of the kits. The test kits in this study use either sodium sulfide or sodium rhodizonate to react with the lead. The presence of lead is indicated by a color change. The kits were used to test prepared sample paint films at seven known lead concentrations ranging from 0.04 to 1.3% by weight. …

Physiologically Based Pharmacokinetic Modelling Of Percutaneously Absorbed Dibromomethane Utilizing Multiple Dermal Sub-Compartments, Christopher R. Mcdaniel

Theses and Dissertations

The goal of this study was to develop a physiologically based pharmacokinetic (PBPK) model that predicts mammalian blood concentrations of dibromomethane following exposure by dermal absorption more accurately than a previously developed Homogeneous Dermal Model. The Homogeneous Dermal Model contains a dermal compartment with no dermal sub-compartments. The 1:1 Dermal Model developed in this research contains a dermal compartment with a stratum corneum and a composite dermal sub-compartment of equal volume. This model yields predictions which are 21.4 percent more accurate than the original homogeneous model. In order to represent skin anatomy more accurately, the 1:10 Dermal Model variation was …

A Risk Assessment Of The Health Liabilities From Exposure To Toxic Metals Found In The Composted Material Of Air Force Municipal Solid Waste, Timothy L. Merrymon

Theses and Dissertations

This thesis assesses the risk of the health liabilities from exposure to toxic metals found in the composted material of Air Force municipal solid waste (MSW). The goal is to determine the probability that the composted MSW could be a health hazard if it were used as a soil amendment. The research limited the assessment of the exposure risk to heavy metals found in raw MSW and its resulting compost. The thesis uses reviews of present literature to examine the food and soil ingestion exposure pathways. These pathways are assessed using the heavy metal concentrations found in MSW compost and …

Report Of Developed Services In The El Pinalito Village Of The Chiquimula Municipality, Department Of Chiquimula, Fredy Samuel Coronado López

Theses and Dissertations

This paper reports on efforts to improve socioeconomic conditions and natural resource use in the El Pina lito community, department of Chiquimula, Guatemala. Students participating in supervised practical training at Centro Universitario de Oriente/Universidad de San Carlos de Guatemala (CUNORI) developed projects to address these issues. A general diagnostic instrument was created for this community to assist in the development of specific work projects. Students prepared community first-aid kits, agricultural activities with school children, and instructional sessions with farmers on how to prepare a family garden and efficiently manage domestic animals. Other activities included ornamental tree preparation for female participants …

Characterization Of A Promoter Rearrangement And A Second Promoter In The Human C-Myb Proto-Oncogene, Sarah Margaret Jacobs

Theses and Dissertations

The human cellular proto-oncogene c-myb has been implicated as important in the regulation of hematopoietic cell growth and differentiation. Aberrant expression of this gene and chromosomal aberrations near the c-myb locus have been associated with a number of carcinogenic processes. An alternatively spliced CDNA clone of c-myb, pMbm-2, contains unique 5’ sequences which replace exon 1. The existence of this 5’ divergent CDNA clone led us into a study of the promoter activity of the c-myb gene.

Intron 1 of c-myb is highly conserved between human and mouse throughout the intron, while only those sequences directly adjacent to exons …

Mechanisms Of Complement Resistance By Pathogenic Naegleria Fowleri Amoebae, Denise Marie Toney

Theses and Dissertations

The genus Naegleria is composed of a distinct group of free-living amoeboflagellates that include both pathogenic and nonpathogenic species. N. fowleri, the only pathogenic species of Naegleria to be isolated from humans, is the etiological agent of primary amoebic meningoencephalitis, a rare but rapidly fatal disease of the central nervous system in humans and in laboratory animals. The mechanisms of pathogenicity and the determinants of virulence of N. fowleri are unknown. Both pathogenic and nonpathogenic Naegleria activate the alternative complement pathway, however pathogenic N. fowleri are complement-resistant and nonpathogenic N. gruberi are complement-sensitive. The ability to resist complement-mediated lysis …

Sjögren-Larsson Syndrome: Genetic Studies And Biochemical Characterization Of Human Fatty Aldehyde Dehydrogenase, Todd L. Kelson

Theses and Dissertations

Sjögren-Larsson syndrome (SLS) is an autosomal recessive disorder due to deficiency of the fatty aldehyde dehydrogenase (FALDH) component of fatty alcohol:NAD⁺ oxidoreductase (FAO). We investigated the enzymatic defect in SLS in order to elucidate the role of FALDH in fatty aldehyde and fatty alcohol metabolism.

Genetic studies were performed to investigate carrier detection for SLS. Cultured skin fibroblasts from normal controls, SLS obligate heterozygotes, and SLS homozygotes were assayed for FAO and FALDH activities using 18-carbon substrates. In SLS homozygotes, mean FAO and FALDH activities were 8% of normal, and there was no overlap between the homozygote and heterozygote …

Identification Of Regulatory Mechanisms Of Genes Encoding Citrate Synthase In The Yeast Saccharomyces Cerevisiae, Christine Smith Kell

Theses and Dissertations

The major aim of this research was to investigate the molecular mechanisms of regulation of transcription of CIT1 and CIT2, the genes encoding citrate synthase in yeast. Specifically addressed are the questions of (1) localization of cis-acting sites required for expression or regulation, (2) the roles of HAP1 and HAP2,3,4 in expression of both genes, (3) identification of other trans-acting factors involved in expression of either gene, (4) localization of cis-acting sites involved in up regulation of CIT2 in response to disruption of CIT1 or rho° status (Liao et al., 1991; Liao and Butow, 1993).

I show here that mutations …

Immunomodulatory Effects Of Transforming Growth Factor-Β On T Lymphocytes, Thomas Harris Inge

Theses and Dissertations

Transforming growth factor-β1 (TGFβ) is a peptide cytokine implicated in control of growth, adhesion, and differentiation of cells in numerous tissues. TGFβ has potent inhibitory effects on many lymphocyte responses; we also found that TGFβ could inhibit in vitro generation of tumor-specific CTL. Suppression was largely reversed with exogenous IL-2. Proliferation of memory-stage CTL clones was also inhibited by TGFβ, while the upregulation of cytotoxicity was not inhibited by TGFβ. These studies suggested that TGFβ limited anti-tumor CTL responses via both an indirect effect on IL-2 production, and by a direct effect on proliferation of memory CTL.

In CTLL-2 cells, …

Distribution And Occurrence Of Eriogonum Visheri A. Nels. On The Medora And Mckenzie Districts, Little Missouri National Grasslands, In North Dakota, Staria S. Vanderpool

Theses and Dissertations

Eriogonum visheri A. Nels. (Polygonaceae) is a plant species whose distribution in North Dakota is incompletely known. The plant species is listed by North Dakota Heritage Program personnel as a G5/S2S3 [G5 = demonstrably secure globally, although it may be rare; S2 = imperiled in the state (6-20 occurrences) or vulnerable to extirpation; S3 = rare in the state (20+ occurrences)]. The species is Federally listed as C2 [current information indicates that listing as endangered or threatened may be warranted, but information about the species is presently inadequate to support immediate ruling] (Northern region, USDA Forest Service, 1991). The limited …

Pharmacological Manipulation Of Protein Kinase C Modulates The Growth And Lineage Commitment Of Enriched Human Myeloid Progenitor Cells Induced By Hematopoietic Growth Factors, Fei Li

Theses and Dissertations

The activity of protein kinase C (PK-C) has been implicated in regulating the growth and differentiation of both normal and neoplastic hematopoietic cells. We have examined the effects of the PK-C activators, phorbol 12,13- dibutyrate, mezerein, and bryostatin 1, on the proliferation and lineage commitment of enriched CD34+ human myeloid progenitor cells stimulated by lL-3, GM-CSF, stem cell factor and the lL-3/GM-CSF hybrid cytokine plXY321. Coadministration of these PK-C activators with plateau concentrations of rlL-3 or rGM-CSF induced 100-150% increase in the number of day 14 CFU-GM.with a selective stimulation on neutrophil and macrophage lineages while inhibiting eosinophilic growth. plXY321 …

Stem Cell Factor In Mast Cell And Schwann Cell Proliferation And Hyperplasia, John Joseph Ryan

Theses and Dissertations

Stem cell factor (SCF) is a recently characterized hematopoietic growth factor capable of stimulating the proliferation and differentiation of many hematopoietic cells, including the mast cell. We have cloned the gene encoding SCF from a cDNA library prepared from NIH 3T3 fibroblasts, and have characterized the ability of recombinant SCF to induce the development of mast cell-committed progenitors (MCCP), found in the mesenteric lymph nodes of mice infected with Nippostrongylus brasiliensis (Nb-MLN), but not naive mice. We have also examined Schwann cells, mast cells, and reproductive tissues for their ability to produce SCF.

We have found that recombinant …

Evidence That Nicotine Can Acutely Desensitize Central Nicotinic Cholinergic Receptors In Vivo, John Randolph James

Theses and Dissertations

Current concepts concerning nicotine's central nervous system (CNS) mechanism(s) of action suggest that this drug is producing its effects via an interaction at nicotiniccholinergic receptors (nAChRs) which open a membrane cation channel. Following initial opening of the channel, nicotine appears to induce a rapid desensitization of the nAChRs, closing the channel and resulting in a cessation of nicotine's effects. Research presented here will provide evidence of this secondary desensitization process in vivo by demonstrating nicotine's ability to induce acute tolerance in the discriminative stimulus (DS) paradigm. The ability of nicotine to elicit DS control of behavior was significantly reduced via …

Small Mammal Demographics In North Dakota Conservation Reserve Program Plantings, Larry A. Lysne

Theses and Dissertations

During the summers of 1989 and 1990, capture-recapture methods were used to de~ermine small mammal demographics and population dynamics in Conservation Reserve Program (CRP) plantings in north central North Dakota. Four age classes (1-4 years) of CRP plantings were sampled. Small mammal species diversity was low (H'=0.057-0.374). Eight species of small mammals were captured on CRP tracts, with deer mice (Peromyscus maniculatus) comprising 92% of all small mammals recorded. Largest deer mouse populations (64/ha .and 51/ha) occurred in late August and early September, 1990. Peak densities in 1990 were over twice as high as those of 1989. Home range sizes …

Effects Of 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) On The In Vitro Antibody Response: Differential Effects On The B Lymphocyte Depending On The State Of In Vivo Activation And The Modulation By Serum-Derived Growth Factors, Dale L. Morris

Theses and Dissertations

Previous reports have indicated a dichotomy in the actions of TCDD on humoral immunity, both in vitro and in vitro, in which enhancements and suppression have been identified. The latter effect has been correlated with induction of liver P4501A1 enzyme activity, a response which is regulated by the Ah-gene locus. Additionally, the primary alteration in suppression of antibody responses is in the differentiation of the B cell. Therefore, the current investigation was undertaken to determine the relationship between these dual actions of TCDD on humoral immunity as related to its direct actions on B lymphocyte function. Specific emphasis was placed …

Spatial And Temporal Mechanisms Of Spinal Nociceptive Coding, Robert C. Coghill

Theses and Dissertations

In order to better characterize spatial and temporal mechanisms of nociceptive processing in the central nervous system (CNS), the responses of rat spinal cord neuron populations to prolonged painful stimuli were examined. Metabolic mapping studies revealed that prolonged nociceptive thermal stimuli produced extensive activation in the deep dorsal horn, but minimal activation in the superficial dorsal horn. Electrophysiological investigations of neurons within these regions revealed that the responses of wide dynamic range (WDR) neurons, the predominate nociceptive neuron in the deep dorsal horn, did not habituate substantially to prolonged nociceptive stimuli. In contrast, the responses of nociceptive specific neurons, the …

The Effects Of Carboxyl-Group Specific Modification And Triiodo-L-Thyronine On Cardiac Sodium Channels, Samuel C. Dudley

Theses and Dissertations

The patch clamp method was used to evaluate the effects of 3,5,3'-triiodo-L-thyronine (T₃) and carboxyl modification on adult rabbit ventricular Na⁺ channels. In contrast to TTX-sensitive Na⁺ channels, Ca²⁺ block of cardiac Na⁺ channels was not prevented by selective carboxyl modification by trimethyloxonium (TMO) or water soluble carbodiimide (WSC). In 2 mM Ca²⁺, TMO-treated patches exhibited 3 discrete conductance (γ_Na) levels. An abbreviation of mean open time (MOT) accompanied each decrease in γ_Na. The effects on channel gating of elevating external Ca²⁺ differed from those of TMO …

The Level And Determinants Of Burnout Of Mormon Mothers In A Utah Suburban Town, Christina Mordock

Theses and Dissertations

The purpose of this study was to examine burnout in Mormon mothers in a suburban Utah town. Specifically the amount and some determinants of burnout among these Mormon women was studied. A random sample of 266 Mormon mothers completed a questionnaire and a modified version of the Maslach Burnout Inventory (MBI) which consisted of three subscales, (Emotional Exhaustion, Depersonalization, and Personal Accomplishment), and two categories in each subscale (Frequency and Intensity). The subjects scored in the moderately burned out category in each subscale. Significant relationships were found between the amount of burnout and the following: the age of the mother, …

Role Of Newly Synthesized Steroid Hormone Antagonists In Adrenocortico-Steroid Hormone-Induced Hypertension, Justicia Opoku-Edusei

Theses and Dissertations

Excess adrenocorticosteroid hormones such as glucocorticoids and mineralocorticoids is well known to induce hypertension in several animal species as well as in humans. Therefore, the development of potent and specific glucocorticoid and mineralocorticoid antagonists with antihypertensive effects is clinically necessary. steroid hormone antagonists being used therapeutically present serious endocrinology side effects such as the widely used antimineralocorticoid, spironolactone. The antiglucocorticoids available so far have been active only in vitro or only weakly in viva. Recently, three new exciting adrenocorticosteroid hormone antagonists have been synthesized. RU 486 is a potent antiglucocorticoid (and antiprogesterone with potential as an abortifacient), RU 26752 and …

Molecular And Cytogenetic Characterization Of De Novo Acrocentric Rearrangements In Humans, Lisa Gail Shaffer

Theses and Dissertations

I have studied 26 children who have a de novo rearrangement of the acrocentric chromosomes in order to understand the formation of these aberrations. The families include '25 probands ascertained for Robertsonian-type translocations, 13 between nonhomologous chromosomes and 12 between homologs, and one rea(21;21)(q22;q22). The parental origins of the de novo rearrangements were determined in 26/26 families using QFQ and NOR variants and/or RFLP analyses. While there was no overall difference in the sex distribution of the parents of origin, there were more maternally derived nonhomologous ("true" Robertsonian) translocations (8 mat: 5 pat) and more paternally derived homologous rearrangements (4 …

Immunodominant Antigens Of Actinobacillus Actinomycetemcomitans In Antibody Positive Subjects, Joseph V. Califano

Theses and Dissertations

This study was initiated to look for characteristics of the immunodominant antigen(s) of Actinobacillus actinomycetemcomitans (Aa) that might help explain the high antibody titers reactive with this organism in periodontitis patients. Radioimmunoassays (RIA) and limiting dilution analysis on western blots were used to identify and characterize the immunodominant antigens of Aa in high responder patients (i.e. patients with high antibody titers). Additional experiments focused on specific responding subjects with a range of antibody titers to serotype b (AaY4). This group included both white and black subjects. Similar studies then examined the immunodominant antigens of Aa serotypes a and c. The …

The Development And Failure Of Historic Agricultural Communities Of Utah: A Case Study Of Johns Valley, Utah, Wayne R. Shelley

Theses and Dissertations

Many agricultural communities have developed in Utah since the first settlement, but many no longer exist today. Some of these early communities experienced a "boom and bust," while others struggled for several years and were eventually abandoned. Johns Valley is a good example of these historic communities, as it experienced rapid growth and times of success and prosperity, yet it struggled and was eventually abandoned.
The situation in Johns Valley, from its early settlement to its demise, demonstrates the hope of the people who settled there and their efforts to make Johns Valley a productive and successful area. History also …

Biochemical Characterization Of The Axolemmal Mitogen For Cultured Schwann Cells, Mark A. Decoster

Theses and Dissertations

The molecule(s) involved at the axon plasma membrane (axolemma) which causes Schwann cells to proliferate has been investigated by three biochemical techniques: 1) Alkaline extraction of axolemma resulted in recovery of 95% of the mitogenic activity and 50% of the protein in the membrane-bound portion of the axolemma. 2) The axonal mitogen for Schwann cells may be associated with heparan sulfate proteoglycans at the axonal surface. Treatment of axolemma with heparitinase, which cleaves the glycosidic bonds of sulfated glycosaminoglycans, allowed mitogenic activity to be solubilized. 3) Treatment of axolemma with heparin, a highly sulfated glycosaminoglycan analogous to heparan sulfate, resulted …

Evaluation Of The Antagonism Of Nicotine By Mecamylamine And Pempidine In The Brain, Thomas Jeffrey Martin

Theses and Dissertations

Antagonists have been crucial in the characterization of nicotine's pharmacology. Initial evidence for the existence of central nicotinic receptors was based on the fact that nicotine produced a number of behavioral effects that were antagonized by ganglionic blockers that crossed the blood-brain barrier, such as mecamylamine and pempidine. Although the mechanism of action of these compounds has been studied extensively in the periphery, little is known about their mechanisms of action in the brain. These compounds are thought to be noncompetitive antagonists due to the fact that they do not compete for agonist binding to brain homogenate in vitro. However, …