Pharmacology, Toxicology and Environmental Health Commons^™

Investigating The Toxicity And Accumulation Of 2,4-Dichlorophenoxyacetic Acid (2,4-D) And Glyphosate In Eisenia Fetida, Caitlin Lazurick, Nicole Lidzbarski, Rachel Owings, Jeff Brotherton, Edna Steele

Journal of the South Carolina Academy of Science

Glyphosate, the main ingredient in Roundup^®, is the most widely used herbicide in the world. It is also used in combination with another effective herbicide, 2,4-D, in the formulation called Enlist Duo^®. The EPA approved the use of Enlist Duo^® on certain crops including those genetically modified to be resistant to both herbicides. The predicted significant increase in the use of these herbicides raised concerns from the general public because both compounds have been classified as possibly or probably carcinogenic. Since herbicides are applied directly to vegetation, the safety of organisms that come in contact …

Exopolysaccharides Regulate Calcium Flow In Cariogenic Biofilms, Monika Astasov-Frauenhoffer, Muth M. Varenganayil, Alan W. Decho, Tuomas Waltimo, Olivier Braissant

Faculty Publications

Caries-associated biofilms induce loss of calcium from tooth surfaces in the presence of dietary carbohydrates. Exopolysaccharides (EPS) provide a matrix scaffold and an abundance of primary binding sites within biofilms. The role of EPS in binding calcium in cariogenic biofilms is only partially understood. Thus, the aim of the present study is to investigate the relationship between the calcium dissolution rates and calcium tolerance of caries-associated bacteria and yeast as well as to examine the properties of EPS to quantify its binding affinity for dissolved calcium. Calcium dissolution was measured by dissolution zones on Pikovskaya’s agar. Calcium tolerance was assessed …

Hmgb1-Rage Pathway Drives Peroxynitrite Signaling-Induced Ibd-Like Inflammation In Murine Nonalcoholic Fatty Liver Disease, Varun Chandrashekaran, Ratanesh K. Seth, Diptadip Dattaroy, Firas Alhasson, Jacek Ziolenka, James Carson, Franklin G. Berger, Balaraman Kalyanaraman, Anna Mae Diehl, Saurabh Chatterjee

Faculty Publications

Recent clinical studies found a strong association of colonic inflammation and Inflammatory bowel disease (IBD)-like phenotype with NonAlcoholic Fatty liver Disease (NAFLD) yet the mechanisms remain unknown. The present study identifies high mobility group box 1 (HMGB1) as a key mediator of intestinal inflammation in NAFLD and outlines a detailed redox signaling mechanism for such a pathway. NAFLD mice showed liver damage and release of elevated HMGB1 in systemic circulation and increased intestinal tyrosine nitration that was dependent on NADPH oxidase. Intestines from NAFLD mice showed higher Toll like receptor 4 (TLR4) activation and proinflammatory cytokine release, an outcome strongly …

Complete Genome Sequence Of Vibrio Gazogenes Atcc 43942, Phani M. Gummadidala, Michael E. Holder, Jacqueline L. O’Brien, Nadim J. Ajami, Joseph F. Petrosino, Chandrani Mitra, Yung Pin Chen, Alan W. Decho, Anindya Chandaa

Faculty Publications

Vibrio gazogenes ATCC 43942 has the potential to synthesize a plethora of metabolites which are of clinical and agricultural significance in response to environmental triggers. The complete genomic sequence of Vibrio gazogenes ATCC 43942 is reported herein, contributing to the knowledge base of strains in the Vibrio genus.

Microbial Extracellular Polymeric Substances (Epss) In Ocean Systems, Alan W. Decho, Tony Gutierrez

Faculty Publications

Microbial cells (i.e., bacteria, archaea, microeukaryotes) in oceans secrete a diverse array of large molecules, collectively called extracellular polymeric substances (EPSs) or simply exopolymers. These secretions facilitate attachment to surfaces that lead to the formation of structured ‘biofilm’ communities. In open-water environments, they also lead to formation of organic colloids, and larger aggregations of cells, called ‘marine snow.’ Secretion of EPS is now recognized as a fundamental microbial adaptation, occurring under many environmental conditions, and one that influences many ocean processes. This relatively recent realization has revolutionized our understanding of microbial impacts on ocean systems. EPS occur in a range …

A Comparison Of Imputation Algorithms For Modeling Water Quality, Carter Alexander Allen

Senior Theses

This project addresses the need for predictive modeling tools to forecast expected concentrations of fecal bacteria in recreational waters in the Charleston, SC area. Data was provided by Charleston Waterkeeper, a water quality monitoring organization that has been measuring Enterococcus faecalis concentrations at 15 recreational sites since 2013. The data contain a non-negligible number of censored and missing observations, so three distinct imputation methods were developed and compared in terms of their effect on final predictive model characteristics. The best performing method relied on drawing samples from a truncated normal distribution to replace censored values, and using a partial model …

Tgf-Beta Triggers Rapid Fibrillogenesis Via A Novel T Beta Rii-Dependent Fibronectin-Trafficking Mechanism, Archana Varadaraj, Laura M. Jenkins, Priyanka Singh, Anindya Chanda, John Snider, N.Y. Lee, Ayelet R. Amsalem-Zafran, Marcelo Ehrlich, Yoav I. Henis, Karthikeyan Mythreye

Faculty Publications

Fibronectin (FN) is a critical regulator of extracellular matrix (ECM) remodeling through its availability and stepwise polymerization for fibrillogenesis. Availability of FN is regulated by its synthesis and turnover, and fibrillogenesis is a multistep, integrin-dependent process essential for cell migration, proliferation, and tissue function. Transforming growth factor β (TGF-β) is an established regulator of ECM remodeling via transcriptional control of ECM proteins. Here we show that TGF-β, through increased FN trafficking in a transcription- and SMAD-independent manner, is a direct and rapid inducer of the fibrillogenesis required for TGF-β–induced cell migration. Whereas TGF-β signaling is dispensable for rapid fibrillogenesis, stable …

Mercury Bioaccumulation In Three Popular Subsistence And Recreational Estuarine Fishes From Southeastern U.S.A., Taylor Cannon

Theses and Dissertations

A rising concern in recent years has occurred over the presence of methylmercury in seafood, particularly fishes, and its impact on human health. However, fish also provide many health benefits, including improved cardiovascular health and neurodevelopment. Because fishes are the main source of methylmercury exposure to humans, and are such an integral part of the human diet, understanding the risks versus the benefits of fish consumption is imperative in allowing the public to make healthy, educated choices. One way that state and federal governments attempt to do this is through issuing fish consumption advisories. Unfortunately, these advisories do not always …

Altered Gut Microbiome In A Mouse Model Of Gulf War Illness Causes Neuroinflammation And Intestinal Injury Via Leaky Gut And Tlr4 Activation, Firas Alhasson, Suvarthi Das, Ratanesh K. Seth, Diptadip Dattaroy, Varun Chandrashekaran, Caitlin N. Ryan, Luisa S. Chan, Traci Testerman, James Burch, Lorne J. Hofseth, Ronnie Horner, Mitzi Nagarkatti, Prakash Nagarkatti, Stephen M. Lasley, Saurabh Chatterjee

Faculty Publications

Many of the symptoms of Gulf War Illness (GWI) that include neurological abnormalities, neuroinflammation, chronic fatigue and gastrointestinal disturbances have been traced to Gulf War chemical exposure. Though the association and subsequent evidences are strong, the mechanisms that connect exposure to intestinal and neurological abnormalities remain unclear. Using an established rodent model of Gulf War Illness, we show that chemical exposure caused significant dysbiosis in the gut that included increased abundance of phylum Firmicutes and Tenericutes, and decreased abundance of Bacteroidetes. Several gram negative bacterial genera were enriched in the GWI-model that included Allobaculum sp. Altered microbiome caused significant decrease …

A Study Of Hepatic Purinergic Receptor X7 Molecular Mechanisms In Ectopic Intestinal Inflammation In Environmental Nafld, Varun Chandrashekaran

Theses and Dissertations

Due to the increased consumption of unhealthy foods rich in sugar and fat along with a highly sedentary lifestyle the prevalence of obesity has steadily increased in the United States and the rest of the world. In America about one third of the adult population is obese putting them at a greater risk for diseases such as cancer, cardio-vascular disorders, inflammation and metabolic diseases such as diabetes and non-alcoholic fatty liver disease (NAFLD). NAFLD can be classified into two major categories non-alcoholic fatty liver (NAFL) and non-alcoholic steato-hepatitis depending on the extent of damage which ranges from simple fat accumulation …

Prenatal Methylmercury Exposure Through Rice Consumption In Rural China, Chuan Hong

Theses and Dissertations

Background: Methylmercury is one of the most toxic forms of mercury, which severely afflicts the developing fetus. Methylmercury exposure occurs not only through fish consumption but also through rice consumption. However, rice does not contain the same beneficial micronutrients that fish/shellfish has. Therefore, prenatal methylmercury exposure through maternal rice consumption may potentially increase adverse health effects on the developing fetus.

Objectives: The purpose of this dissertation was to investigate the magnitude of prenatal methylmercury exposure through rice consumption and the relationship between maternal mercury biomarkers and birth outcomes.

Methods: A total of 398 pregnant women were recruited at parturition in …