Pharmacology, Toxicology and Environmental Health Commons^™

Effect Of Environmental Factors On The Aggregation Behavior Of Silver Nanoparticles In The Aquatic Environment, Kamelia Afshinnia

Theses and Dissertations

Understanding the environmental factors that affect the fate and effects of engineered nanoparticles (ENPs) in the environment is crucial for NP risk assessment. Silver nanoparticles (Ag NPs) readily transform in the environment, which alters their properties and subsequently their transport, fate, and toxicity. The overall aim of this dissertation was to evaluate the effects of Ag NPs physicochemical properties (e.g., size, surface charge, surface coating) and water chemistry (e.g., buffer concentration, organic ligands, natural organic matter) in controlling Ag NPs colloidal stability. This aim was achieved by systematically 1) review and rationalize many studies that investigated the aggregation kinetics of …

Application Of Polymer-Coated Magnetic Nanoparticles For Oil Separation, Seyyedali Mirshahghassemi

Theses and Dissertations

Oil spills and storm water runoffs can have serious impact on the environment with potentially major economic impacts. Given the limitation of current oil clean-up technique, the application of nanotechnology for oil remediation has been widely studied showing a promising avenue of research. This dissertation reports a cheap, facile and cost-effective nanotechnology-based oil clean-up technique that has been optimized for effectiveness and feasibility and reduced adverse environmental impacts. The synthesized polyvinylpyrrolidone (PVP)-coated magnetic nanoparticles (NPs) have been characterized using different techniques and the oil removal efficiency investigated under a wide range of environmentally relevant conditions. Based on the characterization data, …

Inhibition Of Aflatoxin Biosynthesis With Vibrio Gazogenes, Phani Madhuri Gummadidala

Theses and Dissertations

Aflatoxin, a mycotoxin, is one of the world’s most potent carcinogen. It contaminates major food products such as milk, grains, nuts, corn, etc., leading to greater than $ 1 billion in economic losses and when ingested causes hepatocellular carcinoma (HCC). It is the primary risk factor for 75% HCC cases in the developing world and 3% HCC cases in developed world. Most common methods used in agriculture to reduce aflatoxin contamination are expensive, time consuming and have low efficiency with limited success rates where as biological controls were proven to be most effective in inhibiting aflatoxins and aflatoxin producing fungi. …

Understanding The Impact Of Land Use On Microbial Water Quality To Support Decisions For A Future Land Use Plan, Mohammed Tawfiq Aljassim

Theses and Dissertations

May River meandering through the Town of Bluffton, South Carolina has been known for its high level of water quality. The May River is one of the major sources of shellfish harvesting in South Carolina. Due to the non-point source pollution of fecal coliform, the water quality of the May River became degraded. As a result, shellfish harvesting classification in the May River was downgraded for the first time in its history. The rapid growth of the Town has led to a change in land use, which might be related to the increased levels of fecal coliform in the stream …

Environmental Impacts On Enterococcus In Shem Creek, South Carolina, And Characterization Of Changing Land Use, Maria Elizabeth Zubizarreta

Theses and Dissertations

Zoning and land-use practices have a direct influence on hydrologic systems and can impact water resources. Linkages between change in land uses and degradation of water quality in stream and watershed environments have been well established. Shem Creek, located in Mount Pleasant, SC, has a history of fecal indicator bacteria levels that exceed the Environmental Protection Agency’s recreational water quality standards. With recent coastal population and development trends, proper management and the sustainability of beach and estuary environments are a rising public health concern. The objective of this study is to determine what climatic and water quality parameters are associated …

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 …

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 …

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 …

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 …

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 …

Aflatoxin-Exposure Of Vibrio Gazogenes As A Novel System For The Generation Of Aflatoxin Synthesis Inhibitors, Phani M. Gummadidala, Yung Pin Chen, Kevin R. Beauchesne, Kristen P. Miller, Chandrani Mitra, Michelle Velez-Martinez, Peter D. R. Moeller, John L. Ferry, Alan W. Decho, Anindya Chanda

Faculty Publications

Aflatoxin is a mycotoxin and a secondary metabolite, and the most potent known liver carcinogen that contaminates several important crops, and represents a significant threat to public health and the economy. Available approaches reported thus far have been insufficient to eliminate this threat, and therefore provide the rational to explore novel methods for preventing aflatoxin accumulation in the environment. Many terrestrial plants and microbes that share ecological niches and encounter the aflatoxin producers have the ability to synthesize compounds that inhibit aflatoxin synthesis. However, reports of natural aflatoxin inhibitors from marine ecosystem components that do not share ecological niches with …

The Ecorep Program At The University Of South Carolina: How To Engage Students In On-Campus Environmental Activities, Veronica Dorothy Farrell

Senior Theses

This senior thesis focused on determining how much the undergraduate student population is aware about current environmental problems, their impression of them, and how they act accordingly. In addition, through completion of this thesis I hoped to understand what motivates students to participate in events on campus in order to more effectively increase awareness or sustainable behaviors. Specific interest was placed on the students at the University of South Carolina. I oriented this research for one environmental organization at the University of South Carolina in particular, known as EcoReps. EcoReps are peer leaders that strive to educate students about environmental …

Xenoestrogens From Household Plastics Bind Estrogen Receptors And Affect Cell Proliferation, Susan G. Hurley, Brett R. Lackey, Patricia L. Tate, Sandra L. Gray

Journal of the South Carolina Academy of Science

Xenoestrogens are “foreign” chemicals or compounds that interact with estrogen receptors as either agonists or antagonists to interfere with endocrine system function. Xenoestrogens include phytoestrogens, pesticides, industrial by- products and synthetic estrogens. In this study, consumer plasticware, including baby bottles and food storage containers, were found to release xenoestrogenic compounds that bound to ERα and ERβ and affected cell proliferation.

Thromboxane A2 And Tp Receptors: A Trail Of Research, Well Traveled, Perry V. Halushka Phd, Md

Journal of the South Carolina Academy of Science

This article was written is response to a request from the editor-in-chief as a result of my receiving the Governor’s Award in Scientific Awareness. My goal is to provide a glimpse into a 40 plus year research career that was predominately focused on the role of thromboxane A₂ and its receptor (TP) in physiologic and pathophysiologic processes in the cardiovascular system. It also enumerates the lessons learned along the way that may lead to a productive research career. Those lessons were; Perseverance, Think out of the box, Challenge the dogma, Take risks, Failure is not a bad thing, Focus, …

Citrate Coated Silver Nanoparticles With Modulatory Effects On Aflatoxin Biosynthesis In Aspergillus Parasiticus, Chandrani Mitra

Theses and Dissertations

The manufacture and usage of silver nanoparticles has drastically increased in recent years (Fabrega et al. 2011a). Hence, the levels of nanoparticles released into the environment through various routes have measurably increased and therefore are concern to the environment and to public health (Panyala, Peña-Méndez and Havel 2008). Previous studies have shown that silver nanoparticles are toxic to various organisms such as bacteria (Kim et al. 2007), fungi (Kim et al. 2008), aquatic plants (He, DorantesAranda and Waite 2012a), arthropods (Khan et al. 2015), and mammalian cells (Asharani, Hande and Valiyaveettil 2009) etc. Most of the toxicity studies are carried …

Nanotechnology In The Real World: Redeveloping The Nanomaterial Consumer Products Inventory, Marina E. Vance, Todd Kuiken, Eric P. Vejerano, Sean P. Mcginnis, Michael F. Hochella Jr., David Rejeski, Matthew S. Hull

Faculty Publications

To document the marketing and distribution of nano-enabled products into the commercial marketplace, the Woodrow Wilson International Center for Scholars and the Project on Emerging Nanotechnologies created the Nanotechnology Consumer Products Inventory (CPI) in 2005. The objective of this present work is to redevelop the CPI by leading a research effort to increase the usefulness and reliability of this inventory. We created eight new descriptors for consumer products, including information pertaining to the nanomaterials contained in each product. The project was motivated by the recognition that a diverse group of stakeholders from academia, industry, and state/federal government had become highly …

Anion-Responsive Metallopolymer Hydrogels For Healthcare Applications, Jiuyang Zhang, Jing Yan, Parasmani Pageni, Yi Yan, Adam Wirth, Yun-Ping Chen, Yali Qiao, Qian Wang, Alan W. Decho, Chuanbing Tang

Faculty Publications

Metallopolymers combine a processable, versatile organic polymeric skeleton with functional metals, providing multiple functions and methodologies in materials science. Taking advantage of cationic cobaltocenium as the key building block, organogels could be simply switched to hydrogels via a highly efficient ion exchange. With the unique ionic complexion ability, cobaltocenium moieties provide a robust soft substrate for recycling antibiotics from water. The essential polyelectrolyte nature offers the metallopolymer hydrogels to kill multidrug resistant bacteria. The multifunctional characteristics of these hydrogels highlight the potential for metallopolymers in the field of healthcare and environmental treatment.

When Nanoparticles Meet Biofilms—Interactions Guiding The Environmental Fate And Accumulation Of Nanoparticles, Kaoru Ikuma, Alan W. Decho, Boris T. Lau

Faculty Publications

Bacteria are essential components of all natural and many engineered systems. The most active fractions of bacteria are now recognized to occur as biofilms, where cells are attached and surrounded by a secreted matrix of “sticky” extracellular polymeric substances. Recent investigations have established that significant accumulation of nanoparticles (NPs) occurs in aquatic biofilms. These studies point to the emerging roles of biofilms for influencing partitioning and possibly transformations of NPs in both natural and engineered systems. While attached biofilms are efficient “sponges” for NPs, efforts to elucidate the fundamental mechanisms guiding interactions between NPs and biofilms have just begun. In …

Engineering Nanoparticles To Silence Bacterial Communication, Kristen P. Miller, Lei Wang, Yung-Pin Chen, Perry J. Pellechia, Brian C. Benicewicz, Alan W. Decho

Faculty Publications

The alarming spread of bacterial resistance to traditional antibiotics has warranted the study of alternative antimicrobial agents. Quorum sensing (QS) is a chemical cell-to-cell communication mechanism utilized by bacteria to coordinate group behaviors and establish infections. QS is integral to bacterial survival, and therefore provides a unique target for antimicrobial therapy. In this study, silicon dioxide nanoparticles (Si-NP) were engineered to target the signaling molecules [i.e., acylhomoserine lactones (HSLs)] used for QS in order to halt bacterial communication. Specifically, when Si-NP were surface functionalized with β-cyclodextrin (β-CD), then added to cultures of bacteria (Vibrio fischeri), whose luminous output depends upon …

Upregulation Of Mir21 And Repression Of Grhl3 By Leptin Mediates Sinusoidal Endothelial Injury In Experimental Nonalcoholic Steatohepatitis, Sahar Pourhoseini, Ratanesh K. Seth, Suvarthi Das, Diptadip Dattaroy, Maria B. Kadiiska, Guanhua Xie, Gregory A. Michelotti, Mitzi Nagarkatti, Anna Mae Diehl, Saurabh Chatterjee

Faculty Publications

Sinusoidal endothelial dysfunction (SED) has been found to be an early event in nonalcoholic steatohepatitis (NASH) progression but the molecular mechanisms underlying its causation remains elusive. We hypothesized that adipokine leptin worsens sinusoidal injury by decreasing functionally active nitric oxide synthase 3 (NOS)3 via miR21. Using rodent models of NASH, and transgenic mice lacking leptin and leptin receptor, results showed that hyperleptinemia caused a 4-5 fold upregulation of hepatic miR21 as assessed by qRTPCR. The upregulation of miR21 led to a time-dependent repression of its target protein Grhl3 levels as shown by western blot analyses. NOS3-p/NOS3 ratio which is controlled …

High-Content Screening In Zebrafish Embryos Identifies Abamectin As A Potent Neurotoxicant, Tara Diane Raftery

Theses and Dissertations

During development, the nervous system is a sensitive target for chemical exposure in both humans and animal models, and early life-stage exposures can lead to long-term effects on motor activity, sensory function, and cognition. Currently, there are minimal to no developmental neurotoxicity (DNT) data available for thousands of chemicals used in commerce, and it is impractical to screen these chemicals in rodent models using the existing DNT test guideline, as this test is costly, time- and animalintensive, and low-throughput. Therefore, there is a recognized need to use alternative non-mammalian models to support screening and prioritization of chemicals for DNT testing, …

Bacterial Communication And Its Role As A Target For Nanoparticle-Based Antimicrobial Therapy, Kristen Publicover Miller

Theses and Dissertations

The goal of this dissertation is to establish the environmental and public health importance of alternative forms of antimicrobial therapy, specifically those that utilize nanotechnology to combat quorum sensing-controlled bacterial infections. Quorum sensing (i.e. chemical communication) is an inherent characteristic that is essential to bacterial pathogenesis and biofilm formation (where most infections occur). A thorough review of the literature has been conducted to establish an understanding of the state of nanotechnology research as it relates to combatting bacterial infections. This synthesis, provided in Chapter 1, demonstrates how the chemical and structural designs of nanoparticles can be manipulated to specifically target …

Toxicity Of Engineered Nanomaterials And Their Transformation Products Following Wastewater Treatment On A549 Human Lung Epithelial Cells, Yanjun Ma, Subbiah Elankumaran, Linsey C. Marr, Eric P. Vejerano, Amy Pruden

Faculty Publications

Here we characterize the toxicity of environmentally-relevant forms of engineered nanomaterials (ENMs), which can transform during wastewater treatment and persist in aqueous effluents and biosolids. In an aerosol exposure scenario, cytotoxicity and genotoxicity of effluents and biosolids from lab-scale sequencing batch reactors (SBRs) to A549 human lung epithelial cells were examined. The SBRs were dosed with nanoAg, nano zero-valent iron (NZVI), nanoTiO2 and nanoCeO2 at sequentially increasing concentrations from 0.1 to 20 mg/L. Toxicities were compared to outputs from SBRs dosed with ionic/bulk analogs, undosed SBRs, and pristine ENMs. Pristine nanoAg and NZVI showed significant cytotoxicity to A549 cells in …

Characterization Of Particle Emissions And Fate Of Nanomaterials During Incineration, Eric P. Vejerano, Elena C. Leon, Amara L. Holder, Linsey C. Marr

Faculty Publications

As the use of nanotechnology in consumer products continues to grow, it is inevitable that some nanomaterials will end up in the waste stream and will be incinerated. Through laboratory-scale incineration of paper and plastic wastes containing nanomaterials, we assessed their effect on emissions of particulate matter (PM) and the effect of incineration on the nanomaterials themselves. The presence of nanomaterials did not significantly influence the particle number emission factor. The PM size distribution was not affected except at very high mass loadings (10 wt%) of the nanomaterial, in which case the PM shifted toward smaller sizes; such loadings are …