Life Sciences Commons^™

Effect Of Metal Ions And Temperature On Stability Of Thiamine Determined By Hplc, Jhong Huei Huang

All Theses

Thiamine degradation occurs during storage and transportation for short and long periods due to the exposure to several factors, such as heat, oxidation-reduction reactions, and alkali. In this study, the effects of four metal ions (i.e., Cu⁺, Cu²⁺, Fe²⁺, and Fe³⁺) on thiamine stability in aqueous solutions at three temperatures (i.e., 25, 40, and 55°C) for the storage time of 7 days were discussed. Thiamine degradation was found to follow the first-order kinetic reaction, and the degradation rate could also be estimated. The factors in influencing thiamine stability included pH values, temperatures, …

Retro-Structural Analysis Of The Four Helix Bundle Motif In Binuclear Proteins, Walker Pedigo, Maggie Smith

Honors Theses

Protein structure is directly related to protein function. There are four levels of protein structure: primary, secondary, tertiary, and quaternary. The interactions amongst the structural components of a protein give rise to its unique characteristics. The four helix bundle motif is a common structural trait in a variety of binuclear proteins. In this study, PyMOL, a molecular visualization system, was used to analyze binuclear proteins that possess a four helix bundle. Images of proteins containing dicopper, diiron, and dimanganese sites were captured. The images were compiled into figures for each individual protein. After creating the figures, each protein was further …

Aggregatibacter Actinomycetemcomitans Exploits And Modulates The Immune Response By Human Neutrophils For Survival In The Anaerobic Environment., Hazel Ozuna

Electronic Theses and Dissertations

Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative facultative anaerobe and an opportunistic oral pathogen, strongly associated with localized periodontitis and other inflammatory diseases. Periodontitis is a chronic inflammation of the periodontium resulting from the inflammatory response of the host towards the dysbiotic microbial community present at the gingival crevice. The host immune response creates a hostile environment for microorganisms; therefore, it is important for Aa to be able to regulate the necessary genes to survive and thrive in such an environment. Aaexpresses several virulence factors such as a cytolethal distending toxin (Cdt), lipopolysaccharide (LPS) and leukotoxin A (LtxA), …

Investigation Of Iron Homeostasis In Colon Tumorigenesis, Hyeoncheol Kim Ph.D.

Chemistry and Chemical Biology ETDs

Iron is essential part of the human metabolism. It is a catalytic co-factor for many proteins, but it generates harmful reactive oxygen species in human body. Also, many irons metabolic genes are changes in human cancer cells compared to normal cells, leading to iron accumulation in cancer cells especially in colorectal cancer.

Due to iron’s significant role in colorectal cancer promotion, much research is focused on its role in colorectal cancer genesis. But some important metabolic aspects are not fully addressed and researched. One key aspect of iron on colorectal cancer cell progression is hemin iron. Much research warned hemin …

Cellular And Molecular Alterations Associated With Ovarian And Renal Cancer Pathophysiology, Ravneet Kaur Chhabra

USF Tampa Graduate Theses and Dissertations

Elucidating molecular alterations underlying tumor development and chemoresistance are critical to expand our understanding of the disease pathophysiology. This dissertation is focused on analyzing the cellular and molecular alterations associated with LPA-induced chemoresistance in clear cell renal cell carcinoma (ccRCC) cells and chronic iron-induced deregulation of miRNA expression in fallopian tube secretory epithelial cells (FTSECs).

Kidney cancer is one of the ten most common cancers worldwide with <15% survival rate at advanced stage (American Cancer Society). ccRCC is the most common type of kidney cancer and is described as a metabolic disease characterized by deregulated lipid metabolism leading to increased intracellular lipid droplets [9, 10]. The current molecular-targeted treatment strategies involve VEGF/VEGFR and mTOR inhibition [9, 12]. However, there are limitations to these approaches leading to the reduced efficacy and/or increased resistance in ccRCC cells [13, 14]. Therefore, it is important to decipher the factors involved in compromising the chemosensitivity in these cells.

Lysophosphatidic acid (LPA), a bioactive phospholipid, was previously reported to increase resistance against Sunitinib (VEGFR/PDGFR inhibitor) in ccRCC cells and to increase migration and invasion in various tumors [15-17]. In Chapter 3 of …

Copper-Mediated Regulation Of A Traditional Iron Uptake System In Uropathogenic Escherichia Coli., George Lwanga Katumba

Arts & Sciences Electronic Theses and Dissertations

Transition metals constitute an important part of the host-pathogen interface. Iron is an essential nutrient that functions as a cofactor for numerous bacterial and host proteins, as either a ligand for oxygen in carrier proteins or an enzyme catalytic site due to its natural redox properties. As part of the innate immune response, infected hosts sequester iron from pathogens to limit their growth, a phenomenon known as nutritional immunity. On the other hand, copper ions are deployed at infection sites as a potent antimicrobial agent to kill bacteria. The ability to survive within multiple, often harsh, microenvironments is fundamental to …

Investigation Of Dissimilatory Iron Reduction By Exophiala Hkrs030, Zachary Burton

All Theses

Iron (Fe) is the fourth most abundant element in the Earth’s crust and is an essential component in many biological processes. While highly abundant, free iron is not readily available to biological systems since most iron is present in the earth’s crust in the form of ferrous (Fe2+) and ferric (Fe3+) iron minerals. Because of this limited availability, bacteria, plants and fungi have developed diverse ways to safely assimilate and store iron. Bacteria and some fungi have the ability to dissimilate iron. Dissimilatory iron reduction (DIR) is where Fe3+ is reduced to Fe2+ without the cell assimilating the Fe2+ and …

Partial Expression Of The Vbss Gene In Rhizobium Leguminosarum Atcc 14479 And In-Silico Analysis Of The Vbs Gene Cluster In Various Microorganisms, Afreen Siddiqui

Undergraduate Honors Theses

Iron is extremely important for many organisms. Despite its abundancy, it exists in insoluble forms that makes its usability difficult. Some organisms secrete siderophores, low molecular weight compounds, that can chelate iron and convert it into usable forms for cells. One such organism, Rhizobium leguminosarum, is a nitrogen fixing symbiont proteobacteria that infects leguminous plants. The genome of Rhizobium leguminosarum ATCC 14479, which infects the red clover, Trifoli pratense, has previously been completely sequenced in our lab. Our lab has identified several genes in this strain involved in the biosynthesis of a siderophore, vicibactin. The protein product of one of …

Use Of Supplemental Iron For The Enhancement Of Physical Performance In Competitive Non-Anemic Female Athletes, Annalese M. Lamke

All Electronic Theses and Dissertations

Background: Iron has been a commonly prescribed supplement for female athletes to take, but there is little evidence to support if iron supplementation can help improve non-anemic female, athlete’s performance. There is still a lack of unity to determine whether iron can be beneficial to a female athlete during their competitive season regardless of their blood iron status. Purpose: The purpose of this literature review is to determine the impact of iron supplementation on physical performance in competitive non-anemic female athletes. Results: Seventeen articles were selected after following evaluation procedures utilizing the PEDro Scale, CASP, and the Critical Appraisal of …

Targeting Transferrin Binding Protein A For Vaccine Development In Neisseria Gonorrhoeae, Ashley Greenawalt

Theses and Dissertations

Neisseria gonorrhoeae, the causative agent of the sexually-transmitted infection gonorrhea, has recently been labeled a superbug. With dwindling treatment options, there is urgent need for a gonococcal vaccine. TonB-dependent transporters (TDTs) are important gonococcal virulence factors that allow the gonococcus to pirate metals directly from host proteins. The TDTs, TbpA and TbpB, are promising vaccine targets because both proteins are expressed and highly conserved in gonococcal strains, and they are not subject to high-frequency antigenic variation. Because the Tbps bind to host protein as their natural function, our immune system does not recognize them as foreign antigens; thus, immunogenicity is …

Comparing Capabilities Of Shewanella Oneidensis Mr-1 And The Microbial Community Of Iron Caves To Reduce Fe(Iii), Aaron Douglas Pham

Williams Honors College, Honors Research Projects

Caves are generally formed by the erosion and/or dissolution of rock and its subsequent removal by water. Iron ore caves (IOCs) form despite being hosted by relatively insoluble and weathering-resistant rock. Due to the discovery of a microbial community behind the walls of these caves, it was hypothesized that these bacteria could be responsible for speleogenesis. Iron ore exists in an oxidized (Fe(III)) state, but reduced (Fe(II)) form is soluble. It was further reasoned that the bacteria might be able to reduce Fe(III) through direct metabolic activity, which uses iron as an electron acceptor. Here we show that cave microorganisms …

Synthesis And Characterization Of Synthetic Urban Melt Glass, Rebecca Kristien Lowe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Melt glass formed from the explosion of a nuclear device is a unique post-detonation material that can aid in the ensuing forensics investigation. Trapped in the melt glass are chemical and isotopic signatures that can provide diagnostic and source information about the weapon by comparison with documentation of previous detonations. A nuclear terrorist attack would likely take place in an urban environment and as such, the melt glass formed would consist of a complex matrix including urban materials like cement and glass, activation products from the large neutron flux that will be seen, and fission products from the detonation. The …

Comparing And Linking Organic Carbon And Iron In Soil And Headwater Stream In A Pasture And A Forest Catchment In A Central Appalachian Region, West Virginia, Lili Lei

Graduate Theses, Dissertations, and Problem Reports

Continued global warming and surface water brownification are two main environmental issues which have attracted attention and are related to soil organic carbon (SOC) cycling. Iron oxides differ in reducibility and thus have essential roles in regulating SOC preservation and remineralization in soil and transport of dissolved organic carbon (DOC) from soil to surface water. In the central Appalachian region, anthropogenic disturbances are increasing, which leads to major issues of soil degradation and depletion of SOC concentrations. Cropland and pasture soils are subject to intense disturbances compared to the forest soil, which may lead to differences in SOC fractions and …

Determination Of Iron-Reducing Bacterial Activities In Lake Sediments., Alexandra Kahn

Williams Honors College, Honors Research Projects

Algal blooms are growing rampantly in lacustrine systems due to an increase of phosphorus, a nutrient for algae. Phosphorus is being released into the environment causing overpopulation and eutrophication which damages the ecosystem. The availability of phosphorus is affected by the solubility of iron which is regulated through iron reducing and iron oxidizing bacteria. Phosphorus adheres to insoluble Fe(III), which prohibits algae from utilizing it, while phosphorus does not attach to soluble Fe(II) and therefore it remains available to algae. The purpose of this study was to determine how bacteria influence iron solubility and what are the ideal environmental conditions …

The Chelation Of Metal Ions By Vicibactin, A Siderophore Produced By Rhizobium Leguminosarum Atcc 14479, Joshua Stinnett

Undergraduate Honors Theses

Vicibactin is a small, high-affinity iron chelator produced by Rhizobium leguminosarum ATCC 14479. Previous work has shown that vicibactin is produced and secreted from the cell to sequester ferric iron from the environment during iron-deplete conditions. This ferric iron is then transported into the cell to be converted into ferrous iron. This study uses UV-Vis spectroscopy as well as ion trap-time of flight mass spectroscopy to determine that vicibactin does form a complex with copper(II) ions, however, at a much lower affinity than for iron(III). Stability tests have shown that the copper(II)-vicibactin complex is stable over time. The results of …

Investigating The Proteinaceous Regulome Of The Acinetobacter Baumannii, Leila G. Casella

USF Tampa Graduate Theses and Dissertations

Acinetobacter baumannii is an opportunistic pathogen that overtime has evolved into one of the most problematic pathogens due to its ability to overcome antibiotic pressures and harshly environments in the host and hospital environments. In this context, its genomic evolution due to its capacity to acquire genes that contribute to its pathogenic and antibiotic resistance nature has been the subject of research in the last decades providing with the identification of several proteins aiding in the process of pathogenicity. Although these findings have contributed to our understanding of A. baumannii pathogenic traits, the regulatory network that control their expression are …

Iron Deficiency Anemia And Difficulty Concentrating In A Nationally Representative Sample Of School-Aged Children In The United States., Elizabeth Jennifer Voyles

Graduate Research Theses & Dissertations

The worldwide prevalence of iron deficiency anemia (IDA) among school-aged children is estimated to be 40%. Anemia has been associated with varying degrees of impaired cognitive functioning due to iron’s role in maintaining the neurochemical environment of the prefrontal cortex (PFC). However, limited research is available related to the prevalence of IDA and its resulting adverse effects on cognitive functioning in school-aged children in the United States. Data from two National Health and Nutrition Examination Surveys (NHANES) from 2013-2016 were analyzed to assess the relationship between iron deficiency anemia and difficulty concentrating in 1758 children, ages 5-15 years old. Hemoglobin …

Investigating Iron Metabolism In Subarachnoid Hemorrhage Patients, Alexander A. Maynard, Gardenia Pacheco

Williams Honors College, Honors Research Projects

Subarachnoid hemorrhage (SAH) is a stroke characterized by bleeding into the subarachnoid space of the brain, typically resulting in high mortality rate.⁸ Delayed cerebral ischemia (DCI), characterized by vasospasms induced arterial constriction, occurs in roughly one third of the surviving patients.²⁰ The development of DCI and neurodegeneration could be linked to metabolic pathology that occurs after SAH, specifically iron induced changes in redox status. The oxidized environment induced by iron has the potential to functionally affect the ferroxidase ceruloplasmin (Cp), which is linked to neurodegeneration.¹⁵ Global LC-MS based metabolomics data revealed alterations in metabolism in the CSF …

Micronutrient Status And Telomere Length In Adult Men And Women., Christy S. Maxwell

Doctoral Dissertations

Background: Telomeres are the noncoding nucleotide sequences at the end of eukaryotic chromosomes, serving to protect DNA during mitotic division. Given their guanine-rich structure, telomeres are highly susceptible to oxidative damage often mediated by inflammation. Recently, telomere attrition and dysfunction have been associated with age-related diseases, including cardiovascular disease, type 2 diabetes, Alzheimer’s disease, and certain cancers. Several modifiable risk factors have also been associated with shortened telomere length, including physical inactivity, obesity, stress, smoking, and poor diet. Objective: We examined the relations between vitamin B₁₂ status, folate status, and iron status, relative to telomere length in …

Lead, Copper, And Iron In University Tap Water, Alison Mclendon

Honors Theses

This study observed concentrations of lead, copper, and iron in university tap water over an eight-week span during and between the summer and fall semesters. First draw and 30s flush samples were taken after overnight stagnation from the Honor House, College Hall, J. B. George Building, and International Center bathrooms and analyzed with an inductively-coupled plasma mass spectrometer (ICPMS). There was no obvious correlation between time in the semester and metal concentrations. Relative iron levels rose and fell at the same time in all buildings, but there was little correlation between buildings for lead and copper concentrations. The Honor House …

The Effects Of Site-Directed Mutagenesis On Hemerythrin-Like Protein Rv2633c, Kelly M. Rosch

Honors Undergraduate Theses

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, one of the top ten causes of death worldwide. One of the genes upregulated in Mtb during macrophage infection is rv2633c, but the structure and function of its gene product remain unknown. Preliminary research has indicated that Rv2633c is a hemerythrin-like protein that exhibits catalase activity and binds two iron atoms using an HHE domain. Additionally, Rv2633c appears to exist as a dimer. The purpose of this project is to identify specific residues outside of the HHE domain that contribute to the protein's iron-binding ability and/or catalase activity, …

Mri T2 Signal Changes Indicate Tau Pathophysiology In A Murine Alzheimer's Disease Model, Rajan Deep Adhikari

Theses and Dissertations

Pathogenesis, diagnosis and treatment, the essential domains in medical practice, seem helpless to address Alzheimer's disease (AD). With a huge mortality rate, it is looming and threatening the socioeconomic barrier. Despite many different studies, the pathogenesis of AD remains inconclusive. However, growing numbers of studies suggest oxidative stress to contribute to the initiation and progression of AD. We propose an iron hypothesis: iron mediated oxidative damage by reactive oxygen species (ROS), which induces protective roles of amyloid beta and hyper-phosphorylated tau (HP-tau) to sequester iron and limit the disease. We propose to study such mechanism using transgenic mice models for …

Characterizing Ferroportin Trafficking In Macrophages During Phagocytosis, Tayler J. Farrell

Electronic Thesis and Dissertation Repository

Macrophages are important mediators of innate immunity and nutritional immunity via modulation of essential nutrients like iron during bacterial infection. Ferroportin (Fpn), an iron-exporting protein, is found on the plasma membrane of macrophages and, if not modulated during phagocytosis, would transport iron into phagosomes and supply phagocytosed bacteria with iron. Interestingly, the fate of Fpn during phagocytosis and bacterial infection remains unknown. We generated a Fpn-GFP fusion protein and, using fluorescence microscopy, demonstrated that, during phagocytosis in RAW264.7 macrophages, Fpn is removed from phagosomes containing IgG-coated beads or Staphylococcus aureus. Further, Fpn is present on Rab5-containing phagosomes but absent …

Antibiotic Resistance Genes In Minnesota Soil Bacteria From Areas Of High And Low Ferric Iron, Gunner L. Drossel, Presley Martin Phd

Departmental Honors Projects

Naturally-occurring antibiotic resistance genes in soil bacteria represent a potentially important reservoir of genes that could contribute to antibiotic resistance of human pathogens. It has been reported that over 40 genes in bacterial genomes are controlled by concentrations of ferric iron. We examined the effect of soil metal content on the level of resistance to two antibiotics, ampicillin (Amp) and tetracycline (Tet), and the presence of multiple genes that code for efflux pump-mediated resistance. These pumps act to export toxins (e.g. heavy metals and antibiotics, perhaps). Because of this, growth in heavy metal-contaminated soils might select for antibiotic resistance. Ninety-six …

Contributions Of Gene Copy Number Variation To Genome Evolution And Local Adaptation Of The Cyanobacterium Acaryochloris, Amy L. Gallagher

Graduate Student Theses, Dissertations, & Professional Papers

Acaryochloris is a recently discovered genus of cyanobacteria, unique in its use of an uncommon chlorophyll as its major photosynthetic pigment, and in its peculiar genome dynamics. Members of this genus exhibit increased genic copy number variation (CNV), which is thought to be primarily derived from gene duplications and horizontal gene transfer (HGT). Acaryochloris provides an ideal system to explore mechanisms behind maintenance of gene duplicates and the influence of CNV in local adaptation. Here, I propose a mechanism for retention of gene duplicates of the bacterial recombinase, RecA, in Acaryochloris genomes and provide preliminary evidence that these paralogs are …

Documentation Of Siderophore Activity, Metal Binding, And Its Effect On Symptomatology Of Cercospora Leaf Blight Caused In Soybean By Cercosporin From Cercospora Cf. Flagellaris, Brian Michael Ward

LSU Doctoral Dissertations

Cercospora leaf blight of soybean (Glycine max) is a serious problem in the mid-south of the United States and is present in most soybean-growing regions of the world. The causal organisms, Cercospora kikuchii, C. cf. flagellaris and C. cf. sigesbeckiae, utilize the photo-activated toxin cercosporin as the primary pathogenicity factor. The disease has historically been understood to progress from a purpling or bronzing of the leaves to a blight in which tissue dies. Previous literature showed possible binding of cercosporin to metals and previous work in our group showed possible use of minor element nutrition in the plant to reduce …

Iron Acquisition Strategies Employed By Staphylococcus Lugdunensis, Jeremy R. Brozyna

Electronic Thesis and Dissertation Repository

Iron is crucial for many cellular processes including DNA synthesis and respiration. The majority of iron in mammals is in heme within hemoproteins, inside cells, or transported through circulation by the glycoprotein transferrin, which constitutes the greatest iron source in serum. Limiting iron availability is an important facet of nutritional immunity to help prevent infection.

Staphylococcus lugdunensis is a human skin commensal and opportunistic pathogen capable of causing a variety of infections, including particularly aggressive endocarditis. It is an emerging pathogen with elevated virulence compared to other species of coagulase-negative staphylococci. The versatility of S. lugdunensis to infect multiple niches …

Iron Regulation Of Macrophage Responses To Uropathogenic E. Coli, Nana Kwame Owusu-Boaitey

Arts & Sciences Electronic Theses and Dissertations

Uropathogenic E. coli (UPEC) are the principal cause of urinary tract infections (UTIs), one of the most common infections globally. Given the rising incidence of antibiotic resistance among UPEC strains, there is an increasing need to better understand the host response to UPEC and to develop ways to harness the bladder innate immune response that clears infection. In response to infection, the host attempts to limit the ability of UPEC to access iron, a metal critical to UPEC survival. Innate immune cells known as macrophages are known to regulate iron homeostasis through the production of pro-inflammatory cytokines, though it remains …

Molybdenum And Iron Interactions As Micronutrients For Growth Of A Freshwater Cyanobacterium, Microcystis Aeruginosa, Yan Xu

Electronic Thesis and Dissertation Repository

The cyanobacterium M. aeruginosa is an important bloom former in freshwater environments. We investigated the growth, photosynthesis and toxin contents of two toxic strains of M. aeruginosa, CPCC 299 and CPCC 300, under a combination of nitrogen supply (nitrate or ammonium) and depleted or replete Molybdenum (Mo) and/or Iron (Fe) concentrations. When Mo and Fe were supplied at growth-replete levels, M. aeruginosa grew equally well on nitrate and ammonium. Reducing Fe dramatically reduced growth rate efficiency when the cells were supplied with nitrate, but not with ammonium. In contrast, the removal of Mo from the medium did not impair …

Escherichia Coli Iron Acquisition Paradigms And Host Responses In The Human Urinary Milieu, Robin Reid Shields-Cutler

Arts & Sciences Electronic Theses and Dissertations

Urinary tract infections (UTIs) are some of the most common bacterial infections worldwide and are increasingly complicated by high antibiotic resistance and recurrence rates. Explanations for the marked individual differences in UTI susceptibility remain incomplete. In this thesis we show that urinary colonization by uropathogenic E. coli (UPEC) is influenced by urine composition and the activity of an important innate immune protein, siderocalin (SCN; also called lipocalin 2 or neutrophil gelatinase-associated lipocalin/NGAL). During UTI, host factors limit the availability of iron, an essential nutrient for the invading pathogen. In response, UPEC modify the urinary environment with metal binding siderophores, some …