• Impact of Myeloid Cell NF-κB Signaling on Glioblastoma Growth

      Venugopal, Natasha; Howard, Shelby; Achyut, Bhagelu; Jain, Meenu; Arbab, Ali; Bradford, Jennifer W.; Department of Biological Sciences (2017-03)
      Cancer consists of malignant tumor cells as well as supporting, non-cancerous cells that make up the tumor stroma. Tumor-associated macrophages (TAMs), a critical component of the stroma, can be present in very large numbers in a variety of cancers, and can lead to tumor progression through promotion of tumor inflammation, angiogenesis, invasion, and metastasis. Canonical nuclear factor-kappaB (NF-κB) pathway activity is very important in normal immune function, synaptic plasticity, and memory, and aberrant NF-κB activity is associated with autoimmune disease, and importantly, cancer. Previous studies have been reported about the importance of tumor cell associated NF-κB signaling in cancers. As myeloid cell NF-κB signaling may also be important in promoting cancers, we have been utilizing the p65fl/fl/LysMCre transgenic animal model, which lacks p65 protein in cells of the myeloid lineage, to study the impact of myeloid cell derived NF-κB signaling in glioblastoma (GBM), an extremely aggressive brain cancer. This transgenic model has a very efficient deletion of p65 protein and drastically reduced NF-κB signaling in bone marrow derived macrophages (BMDMs), but brain residing microglia do not have significantly lower p65 levels as compared to control microglia. Even with this finding, p65fl/fl/LysMCre mice implanted with syngeneic GBM cells have significantly reduced GBM tumor burden than LysMCre control mice, as measured by magnetic resonance imaging. This result underscores the potential importance of bone marrow cells that migrate to the tumor site and significantly contribute to GBM growth. This work also indicates the potential benefits of targeting myeloid specific NF-κB signaling in GBM patients.
    • Influence of Rainfall on Mosquito Abundance

      Haibach, Nicole; Laymon, Kelsey; Wolff, Liam; Pruitt, Carson; Flite, III, Oscar P.; Department of Biological Sciences (2017-03)
      Some species of mosquitoes, known as container-inhabiting mosquitoes, breed in temporary pools of water typically filled after rainstorms. Some examples of this are tires, trash, and anything that can collect water from a rain event. This study seeks to further understand container-inhabiting mosquito abundance and the connection to rainfall. Mosquitoes were collected at 14 sites in Richmond County, GA on a biweekly basis between January to December 2016. These sites were surveyed using two types of traps, Centers for Disease Control and Prevention (CDC) Light trap and a CDC gravid trap. In addition to rainfall, the 7-14 day incubation period of the mosquito life cycle was considered to assess antecedent rainfall window for the correlation analysis. For the previous 7-14 day total precipitation, we found good correlation for one known container-inhabiting species and poor correlation for two other known species. Culex quinquefasciatus, had the best correlation (R2 = 0.71) while the other two species, Aedes albopictus (R2= -0.005) and Culex salinarius (R2= 0.024) had weak correlations. We conclude that differences between correlations were likely due to the reliance of breeding within containers for C. quinquefasciatus than for the other two species, which have more diverse breeding habitat preferences.
    • Method Development for Separation and Quantification of Niacin and its Metabolites in Human Blood Plasma

      Sutherland, Kevin D.; Gibbs, Alexandra J.; Department of Chemistry & Physics (2017-03)
      A high performance liquid chromatography (HPLC) assay for the detection of Niacin (nicotinic acid/vitamin B3), nicotinamide, and nicotinuric acid in human blood plasma was developed. The method used a C18 stationary phase with a mobile phase of 0.1% formic acid in water with varied methanol for chromatographic separation. UV absorbance detection was used in conjunction with mass spectrometry. Samples were prepared by mixing with methanol containing niacin D-4 internal standard, vortexing under vacuum, adding an aqueous formic acid buffer to reconstitute the dried pellet, followed by centrifugation at 15000g. Linearity was assessed and LLD (lower limit of detection) was determined. The elution order was niacin, nicotinamide, and finally nicotinuric acid. No issues with the calibration for nicotinuric acid were encountered, however there was significant interference from nicotinuric acid on the nicotinamide calibration. Currently new methods to limit the interferences are being researched.
    • Mosquito Abundance and Land Use in Varying Median Income Census Blocks in Richmond County, Georgia

      Wolff, Liam; Laymon, Kelsey; Pruitt, Carson; Haibach, Nicole; Flite, III, Oscar P.; Department of Biological Sciences (2017-03)
      Mosquitoes pose a major health hazard to humans globally as primary vectors for disease transmission. Many species of mosquito rely on standing water pooled in open containers to breed. These are often found in items such as old, unused tires associated with lower income properties. This study sought to determine whether lower income census blocks in Richmond County correlated to increased mosquito abundances. For this project, we compared mosquito abundance, land use, and median household income throughout Richmond County. Centers for Disease Control (CDC) light and gravid traps were deployed January 2014 to December 2016 at 18 different trapping locations of varying median household incomes between an annual salary of $16,000 and $55,000. Data from the United States Census Bureau was compared to land use data from the USGS National Land Cover Database. Results indicated a positive correlation (R2=0.7905) between median annual income and mosquito abundance overall. However, the percentage of mosquitoes that were container breeders did not correlate well against median household income (R2=0.0664). This could be because some container breeders utilize other habitats for breeding. Looking at one strictly container-reliant species, Culex quinquefasciatus, indicated a strong connection (R2=0.9022) between abundance and lower income census blocks.
    • Novel Chemical Entities for the Treatment of Human Colorectal Cancer

      Plotkin, Alexander; Lovett, Ilene; Calkins, Joe; Peppers, Anthony; Lee, Jacob; Lebedyeva, Iryna; Department of Chemistry & Physics (2017-03)
      Ceramide plays a key role in human colorectal tumor cell death and proliferation. Current approach for ceramide-based therapy is aimed at the development of ceramide structural mimetics as cytotoxic agents. It has been recently discovered that ceramide plays an essential role in Fas-mediated apoptosis of tumor cells. Fas is a death receptor expressed on the surface of the colorectal cancer cell. FasL is the physiological ligand of Fas and is expressed on the surface of activated T cells. The Fas-FasL pathway participates in the cancer immune surveillance. It has been proved that although Fas is silenced in the majority of tumor cells, low level of Fas is still expressed on tumor cell surface and ceramide effectively increases Fas oligomerization and therefore increases tumor cell sensitivity to FasL-induced cell death. Based on this discovery several structural mimetics of ceramide have been developed as potential enhancers of Fas-mediated apoptosis of human colon cancer cells. These compounds increase human colon carcinoma cell sensitivity to FasL-induced tumor cell death by tumor-specific T cells in vitro.
    • Political Apathy Among Colleges Students

      Zicari, Dominic; Department of Political Science (2017-03)
      Young Americans are often stereotyped as one of the most politically disconnected demographics in the country. Low rates of voter turnout help characterize this age group as indifferent and apathetic. This makes the voting behavior of young people an incredibly important topic of study for political scientists. This is especially true in the wake of the 2016 presidential election. This research focused on American citizens aged 18-24. The research aimed to determine whether political apathy among this age group has increased or decreased since 2012. The study consisted of a comparison of responses from two different surveys. Data from the first survey was drawn from a nationwide telephone poll conducted by the Center for Information and Research on Civic Learning and Engagement (CIRCLE). This survey was conducted shortly after the 2012 presidential election. This data was compared to an identical survey administered online to a sample of students at Augusta University following the 2016 presidential election. Differences in sample sizes limited the ability to analyze comparisons between the two surveys. However, analysis of the 2016 dataset points to a low sense of political apathy among students sampled at Augusta University.
    • Progress City - An Honors Thesis Exhibition

      Conway, Baillie; Department of Art (2017-03)
      The purpose of this project is to explore the way sculpture can visually represent history. Progress City is an art exhibition that focuses specifically on the time period during which America transitioned from an industrial to a service-based economy (1950s - 1970s) and the effects this departure had on cities throughout the Southeast. The exhibition comprises a series of twelve buildings with sides featuring screen printed images of actual abandoned and dilapidated structures. Each building reflects an industry or trade that was once considered vital to the growth of southern communities. These buildings are juxtaposed alongside a collection of found objects that have either a direct or indirect correlation to businesses that once occupied the actual structures. For example, a series of empty food packaging boxes from the 1950s are set alongside a structure featuring screen printed images of an abandoned market facade. By juxtaposing the found objects, now considered outdated, alongside a corresponding abandoned building, the viewer is able to see first-hand the effects progress has had on southern cityscapes.
    • The Structural and Functional Properties of a Splice Variant of ADCY7 Gene in Human Pancreatic Cancer

      Liao, Kristie; Jhanji, Nancy; Department of Biological Sciences (2017-03)
      Alternative splicing of mRNA precursors is a regulated process of gene expression in eukaryotic cells. It provides cells with the opportunity to create protein isoforms of different functions from a single gene. Cancer cells often take advantage of this process to produce proteins that promote growth and survival. Cyclic adenosine monophosphate (cyclic AMP) is a second messenger that has shown to suppress migration and invasion of pancreatic ductal adenocarcinoma cells. Cyclic AMP is formed from cytosolic ATP by the enzyme adenylyl cyclase (AC). There are ten isoforms of ACs; nine are anchored in the plasma membrane and one is soluble. Our goal was to find alternative splice variants of transmembrane AC isoforms in pancreatic cancer. We found a possible splice variant of type VII adenylyl cyclase (ADCY7) in human healthy pancreatic, adjacent non-tumor, tumor tissues, two pancreatic cancer cell lines HPAC and PANC-1, epithelial duct cell line PDEC, but not in isolated human pancreatic acini (the exocrine part of the pancreas). Further research will be carried out to study the structural and functional properties of the splice variant of human ADCY7.
    • Structural, Kinetic and Functional Properties of CAP1/AC Complexes

      Mehrotra, Simran; Department of Biological Sciences (2017-03)
      The major cause of death in pancreatic cancer is due to metastases; therefore, it is important to study the mechanism by which the pancreatic cancer cells migrate and invade. This would help advance therapeutics and ultimately help prolong survival. Adenylyl cyclase-associated protein 1 (CAP1) is a scaffold protein that is involved in the regulation of actin microfilament formation, which ultimately leads to cell migration and invasion. CAP1 binds to G-actin inhibiting polymerization. We first tested whether CAP1 binds to adenylyl cyclase (AC) by performing co-immunoprecipitation. We found that CAP1 not only interacts with G-actin, but also with a number of AC isoforms: AC1, AC3, AC4 and AC7. Further studies need to be done to determine how CAP1/AC/G-actin interact and the impact of these interactions on the invasive behavior of pancreatic cancer cells.