Life Sciences Commons^™

Lactobacillus Crispatus Produces A Bacteridical Molecule That Kills Uropathogenic E. Coli, Katherine Diebel

Master's Theses

As many as 1 in 2 women will have at least one urinary tract infection (UTI) in their lifetime. UTIs can cause complications in pregnancy and decrease quality of life, and their treatment and prevention are expensive. Uropathogenic E. coli (UPEC) is the primary cause of UTI. The probiotic and bactericidal capacities of gut and vaginal Lactobacillus isolates have been studied, but the same attention has not been paid to urinary strains. These urinary isolates of L. crispatus appear to have a greater killing capacity against UPEC and this bactericidal activity does not depend on the cells themselves, consistent with …

Investigation Of A Ubiquitous Spore Surface Protein, Justyna Kordzikowska

Master's Theses

All bacterial spores are comprised of concentric shells. All spores are encased in a layer called the coat. Some spores have an additional layer outside of the coat called the exosporium. Presumably, this morphological variation is an adaptation to variation in the environments in which these species can be found. However, spores from species with and without exosporia can often be found in the same niche. We hypothesize, therefore, that spores with and without exosporia share a common surface protein. Bacillus anthracis possess a well characterized surface protein called BclA. A BclA homologue is also present on the surface of …

Characterization Of Il-22-Producing Cells In The Human Thymus And The Mechanism By Which Il-22 Expression Is Modulated By Thymic Epithelial Cells., Nadine N. Morgan

Master's Theses

Thymic epithelial cells (TECs) are indispensable for T cell development and maturation. Therefore, damages to the thymic epithelial cells are detrimental to thymic function and immune response. In young healthy individuals, TECs have a high regenerative potential and are capable of renewal from serious damage; however, the molecular mechanism of this recovery is unclear. A recent study has shown that IL-22-producing ILCs are present in the mouse thymus and can regenerate thymic epithelial cells following radiation induced injuries. However, it is unknown whether IL-22-producing cells are also found in the human thymus. Thus, the goal of this study is to …

Early Round Goby (Neogobius Melanostomus) Invasion Into Lake Michigan Tributaries And Competitive Interactions With Two Native Benthic Fishes., Margaret Ann Malone

Master's Theses

The round goby is a prolific invasive species and is currently spreading into Great Lake tributary streams. There is a high potential for negative impacts on native benthic fishes in these stream habitats and the aim of this study is to assess the impacts of the round goby on two native darter species in particular (johnny darter and blackside darter). I review the history of round goby invasion in the Great Lakes and summarize hypotheses of the invasive characters of the round goby. Using game theory, I provide a G-function approach to understanding the outcomes of the round goby invasion …

Investigating The Regulatory Mechanisms By Which Arabinose And Sypa Control Biofilm Formation In Vibrio Fischeri, Sheila Paris

Master's Theses

Biofilms are surface-associated microbial communities surrounded by an extracellular matrix. Through biofilm formation, many pathogens and symbionts are able to colonize, survive, and persist in their host. A model system used to study biofilm formation is the symbiotic bacterium Vibrio fischeri, which colonizes its host, the squid Euprymna scolopes. Complex signaling between the squid and the bacteria is essential for the proper regulation of biofilm formation as well as for persistent colonization.

The signal(s) that promote host-relevant biofilm formation are as-yet unknown, but recently it was discovered that the sugar, L-arabinose, serves as a unique signal to promote biofilm formation …

Phosphodiesterase Inhibition As A Mechanism Of Ion Channel Modulation By Celecoxib, Christina Jean Robakowski

Master's Theses

The overall objective of this thesis work is to determine the mechanism by which celecoxib modulates Kv7 potassium channels in vascular smooth muscle cells. The central hypothesis of the project is that celecoxib modulates Kv7 potassium channels in vascular smooth muscle cells through inhibition of phosphodiesterase 4 (PDE4, which catalyzes the breakdown of cyclic adenosine monophosphate (cAMP)), thereby activating a cAMP/protein kinase A (PKA) signaling pathway. The aims of this thesis targeted different points in the cAMP/PKA pathway with pharmacological interventions using whole cell perforated patch clamp electrophysiology and biochemical methods.

The data suggest multiple mechanisms by which celecoxib could …

The Role Of C-Abl Kinase In Hcc Development, Lennox Chitsike

Master's Theses

Hepatocellular Carcinoma is the second most lethal cancer after pancreatic cancer. Unresectable HCC tumors carry a poor prognosis and few treatment options are available. The dismal prognosis is mainly due to limited therapy options and molecularly targeted therapy is deemed as solution. Here, we report a novel role of c-Abl in HCC development. We provide evidence of c-Abl activation in human HCC samples compared to normal liver. Using genetic and pharmacological tools, we show that c-Abl plays a vital role in HCC progression in vitro and in vivo. We have identified Axl as an effector in processes mediated by c-Abl. …

Assessing The Success Of Outreach At Preventing The Movement Of Aquatic Invasive Species In Illinois, Ellen Anne Cole

Master's Theses

Overland transport of recreational boats is the major vector of dispersal for aquatic invasive species among North American waterbodies. These species have large economic and ecosystem impacts, and understanding their movement is essential to understanding the biodiversity and functioning of aquatic ecosystems across the continent. I surveyed Illinois boaters to determine patterns of recreational boat movement and the consistency with which boaters perform actions to prevent the spread of invasive species. Although most boaters perform these actions, a large minority do not and the network for invasive species spread on recreational boats still connects most waterbodies. Next, I interviewed managers …

Chronic Toxicity Of Binary Metal Mixtures Of Cadmium-Zinc And Cadmium-Nickelon Daphnia Magna, Edgar Ramiro Perez

Master's Theses

This study characterizes binary-metal mixture effects of cadmium (Cd2+) + zinc (Zn2+) and Cd2+ + nickel (Ni2+) on Daphnia magna. Although acute studies have shown protective Ni2+ (Traudt et al. 2016) and Zn2+ effects (Meyer et al. 2015) against Cd2+ toxicity, no study has fully characterized a protective effect on D. magna at several endpoints (survival, reproduction, growth, and accumulation) on a chronic study. In this study, the titration design was selected to characterize the 21 day (21-d) chronic effects of the binary-metal mixtures on survival, growth, reproduction, and metal accumulation in D. magna. Using this design, increasing concentrations of …

Regulation Of Gonad Morphogenesis In Drosophila Melanogaster By Broad Complex, Tramtrack And Bric À Brac Transcription Factors, Diane Silva

Master's Theses

During embryogenesis, primordial germ cells (PGCs) and somatic gonadal precursor cells (SGPs) migrate and coalesce to form the early gonad. A failure of SGPs and PGCs to form a gonad with the proper architecture not only affects germ cell development, but also can result in infertility. We have characterized the phenotypes of two genes, longitudinals lacking (lola) and ribbon (rib), required for the coalescence and compaction of the embryonic gonad in Drosophila melanogaster. Both rib and lola are expressed in the SGPs and to a lesser extent in the PGCs of the developing gonad, and genetic interaction analysis suggests these …

A Study Of Immune-Regulation Of Microbiota Supernatant On Macrophage Function, An N. Nguyen

Master's Theses

The diverse human microbial ecosystem colonizes many different body sites. The gastrointestinal (GI) tract, especially, is a major region that that harbors a complex microbial community composed of trillions of commensal bacteria. Interactions between the commensal bacteria and the host immune system begin at birth and continue through the human lifespan. In the gut, commensal bacteria help the host to ensure the maintenance of intestinal homeostasis as well as the mucosal barrier structure through host stimulation of mucus and antimicrobial molecules. The secretion of these host factors functions to inhibit pathogenic invasion and maintain the population of commensal bacteria. The …

Organismal Composition And Photosynthetic Traits Of Biological Soil Crusts In Prairie Ecosystems Ofthe Great Plains, Brendon C. Mccampbell

Master's Theses

Biological soil crusts (BSCs) are soil-surface microecosystems composed of a close association of algae, cyanobacteria, fungi, lichens, and non-vascular plants with soil particles. BSCs have several ecological functions including carbon fixation, nitrogen fixation, nutrient relations, soil stabilization, water relations, and floral community development, which make them extremely important in many of the ecosystems where they occur. While BSCs have been studied throughout the American West, little work has been done in the Great Plains region where they are less prominent among the dominant vascular plant communities. This study examined organismal composition and photosynthetic traits of BSCs in four ecosystems within …

A Comparison Of Small Mammal Communities Among Three Habitats In Western North Dakota, Samantha R. Pounds

Master's Theses

There is recent oil and natural gas development within western North Dakota, which makes it imperative to update outdated and incomplete small mammal records. Small mammals are vital components to many ecosystems, including grasslands. Small mammals contribute to grazing, seed dispersal, and provide food for other animals. I surveyed small mammals in three habitats, grassland, badland, and wet meadow, in the summers of 2014 and 2015 in western North Dakota. In 2014, I surveyed in 8 badland and 10 grassland habitats and in 2015 I surveyed in 1 badland, 13 grassland, and 4 wet meadow habitats, with 1 transect per …

Aquatic Insect Community Structure And Secondary Production In Southcentral Alaska Streams With Contrasting Thermal And Hydrologic Regimes, Samantha D. Hertel

Master's Theses

Streams along the Copper River Delta, southcentral Alaska, exhibit contrasting thermal and hydrologic variability associated with being primarily groundwater-fed (GWF) or surface water-fed (SWF). Groundwater-fed streams are predictable both thermally and hydrologically year round, whereas SWF streams are unpredictable and exhibit more variable thermal and hydrologic regimes. These differences may strongly influence aquatic insect community structure and secondary production. Four streams, two GWF and two SWF, were sampled twice monthly from late April 2013 through August 2013 and once seasonally in fall (September) and early winter (November). Aquatic insect community structure differed markedly in both hydrologic types. Taxa richness was …

Adams As Potential Regulators Of Stem Cell Quiescence In The Olfactory Epithelium, Elaine Elizabeth Orendorff

Master's Theses

I demonstrate that a member of the protein family A Disintegrin and Metalloprotease (ADAM), ADAM23, is expressed in the olfactory epithelium (OE) and may inhibit neural progenitor cell (NPC) proliferation. I generated a list of ten gene candidates and selected ADAM23 for further study, based on its conserved protein structure and accumulating evidence for its role in cell cycle progression of proliferative cells. I next determined ADAM23 protein localization using immunohistochemistry and measured both mRNA and protein expression post-lesion with RT-qPCR and Western blot. ADAM23 is expressed in multiple cell types of the OE, including glial Sustentacular (Sus) cells and …

Role Of Pkc Delta In Uv Radiation Dna Damage Repair, Gargi Patil

Master's Theses

DNA damage caused by ultraviolet radiation (UV), such as cyclobutane pyrimidine dimers (CPD), is repaired by the nucleotide excision repair (NER) pathway. When NER is defective, DNA damage is not repaired, leading to mutations and skin cancer. After DNA damage, the cell cycle is halted at various checkpoints to allow time for repair of the damage and maintain genomic integrity, however little is known about the coordination between NER DNA damage repair and cell cycle halting at checkpoints after DNA damage. Protein kinase C δ (PKCδ) plays major role in apoptosis and maintains the G2/M checkpoint in response to UV …

A Bioluminescence Sensor Of Nlrp3 Inflammasome Activation, Michael Alexander Winek

Master's Theses

The innate immune system is many organisms first line of defense against pathogenic insult or tissue damage. This defense strategy is intent on restoring homeostasis upon perturbation. Upon activation of the innate immune system in humans, an oligomeric protein complex termed the “Inflammasome” forms in myeloid cells. The canonical output of activation of any subset of inflammasome is Caspase-1-mediated secretion of pro-inflammatory cytokines IL1β and IL18. Chronic or uncontrolled inflammasome activation is at the core of myriad economically burdening diseases. In many of these diseases, endogenous factors chronically engage the innate immune system. To study these diseases in in vivo, …

Defining The Role Of A Putative Peptidase In Staphylococcus Aureus Quorum Sensing And Pathogenesis, Chelsea Rose White

Master's Theses

The pathogenic bacterium Staphylococcus aureus encounters a variety of immune cells that restrict bacterial growth and dissemination during infection. However, S. aureus counters these immune cell functions by producing myriad virulence factors that facilitate evasion of host defenses. Therefore, it is important to understand S. aureus-immune cell interactions and the virulence factors that perturb normal immune function to promote pathogenesis. In a genetic screen designed to identify S. aureus secreted factors that modulate macrophage activity our lab identified a transposon insertion mutant in the gene SAUSA300_1984, encoding a putative membrane spanning peptidase. To investigate the role of 1984 in pathogenesis, …

Lipoate Metabolism In Staphylococcus Aureus Pathogenesis, Maria Azul Zorzoli

Master's Theses

Lipoate is an essential cofactor of several proteins involved in cellular energy homeostasis and catabolism. Lipoate metabolism has been linked to pathogenesis in some microbial species, but its role in Staphylococcus aureus infections had not been explored. In this thesis, we tested the hypothesis that lipoate acquisition mechanisms promote S. aureus infectivity. We used a bacterial genetics approach to elucidate the biological function of the S. aureus genes involved in lipoate metabolism. Our findings allowed us to propose a model for lipoic acid de novo biosynthesis and salvage pathways in S. aureus. Moreover, we detail hitherto undescribed genetic arrangements of …