Student Research Experiences – Spring 2016

Investigating Immunotoxic Effects of Pyrethroids

Christopher Carr, MPH Candidate

During my first year as a Masters of Public Health student in Epidemiology at the Rollins School of Public Health, I had the opportunity to work as a graduate research assistant in Dr. Malu Tansey’s lab.

Dr. Tansey’s lab investigates how neuroinflammatory and immune system responses alter gene-environment interactions and how these responses play a role in the risk of neurodegenerative and neuropsychiatric disease. Over the past year I worked on a project that is focused on studying the immunotoxic effect pyrethroids have in vitro. Pyrethroids are an ingredient in common household pesticides that have been linked to acute toxicity in humans. It is hypothesized that exposure to these compounds synergizes with a hyper-responsive immune system to increase risk for late-onset Parkinson’s Disease. This is based on the finding that homozygosity (GG) at a non-coding single-nucleotide polymorphism (SNP) in HLA DRA in the MHC II gene cluster is associated with increased risk for Parkinson’s Disease. Since this SNP is located in the MHC II locus there is an implication that antigen presentation is a potential mechanism through which immune responses link genetic susceptibility and environmental exposure to Parkinson’s disease.

Our lab is coordinating with Emory’s Department of Neurology to obtain human blood. I have had the opportunity to design my own experimental conditions that test different concentrations of pyrethroids and their impact on monocytes and T-cells. My specific tasks involve isolating monocytes and T-cells from human blood using Ficoll-Paque Density Centrifugation and CD14+ and CD3+ paramagnetic beads. I also run flow cytometry on the cells I have isolated and stained. This spring I have been looking at how different pyrethroid concentrations affect cell surface receptor protein (HLA-DR and HLA-DQ) induction in Interferon Gamma stimulated monocytes and T-cell proliferation.

The Intersection of Environmental Health and Epidemiology

Emma Rosen, MSPH Candidate

As a first year MSPH student in the Departments of Environmental Health and Epidemiology, I had the opportunity to work in the lab of Dr. Michele Marcus. This experience allowed me to more fully explore both of these fields and their interaction.

Dr. Marcus follows a large cohort of Michiganders who were exposed to a group of flame retardants, Polybrominated Biphenyls (PBB), following an agricultural disaster in the 1970s. Forty years after the original contamination incident, Dr. Marcus and her team continue to investigate various health outcomes among different generations — those directly exposed, those exposed in utero or via breast milk, and the grandchildren of those originally exposed.

Working with Dr. Marcus’ team allowed me to gain exposure to many aspects of conducting an epidemiologic study; throughout the year, I assisted with writing a grant proposal, communicating with participants, helping disseminate study findings to the affected communities, and reviewing and collating data from a previous study.

My main task for the year, however, was to prepare a large dataset for further analyses. Working with the raw data from participants – both quantitative and qualitative – allowed me to apply skills I had learned in my classes and further my competencies with the statistical analysis software, SAS. In addition, working on this study provided real instances of epidemiological concepts that had only been discussed previously in classes. Being able to identify different biases or determine the best modeling technique based on the actual study data further cemented my understanding of epidemiological principles.

My work with Dr. Marcus has been so valuable in my development as a public health practitioner that I decided to continue my work with the team for my Masters thesis. Using the dataset that I prepared, I will evaluate the association of PBB exposure and prevalence of autoimmune conditions among those in the Michigan PBB Cohort.

Assessing the Impact of Dietary Patterns on Redox Status

Erika Bettermann, MPH

During my first year as an MPH student at Rollins School of Public Health in the Department of Epidemiology, I worked with Dr. Thomas Ziegler and Dr. Jessica Alvarez in Emory’s Department of Medicine.  I was hired as a data analyst to work with a database of health indicators of over 700 Emory University employees.  This database has developed from the Emory-Georgia Tech Center for Health Discovery and Well Being for health-focused research and education to measure risks and deviations from health.

The goal of my specific project was to examine the influence of changes in macronutrient intake and other dietary factors on systemic redox status (glutathione and cysteine redox pools).  The database included variables of specific macronutrient intake as well as Food Frequency Questionnaire indicators.  From these, I developed diet scores (Healthy Eating Index, Mediterranean Diet Score, and Dietary Approaches to Stop Hypertension).  Throughout the year, I performed a variety of analyses to determine correlations between diet and plasma redox status.

This project allowed me to collaborate with a variety of faculty across Emory’s campus in the Department of Medicine, Department of Nursing, and Department of Epidemiology.  I was also able to enhance my skills in data analytics.  We found correlations between dietary pattern and BMI with redox status.  This summer, I am working to develop a paper for publication of my results.  We hope that our results will further the research and knowledge surrounding the importance of diet in improving redox levels and overall health status.

Using Analytical Chemistry to Study Children’s Environmental Health

Meghan Stuart, MSPH

I began working in Dr. Dana Barr’s lab within a few weeks of beginning my MSPH at Rollins in Fall 2014. Immediately I was able to begin working on some great studies! The first one I started with was extracting and measuring BPA in meconium from newborn infants. This study also involved measuring phthalate levels in meconium as well, though I was only involved with the BPA portion. With this study I was able to add to my analytical foundations by learning new extraction and quantification techniques.

Spring 2015 brought my work with a couple new studies. For one study, we were charged with extracting pesticide metabolites from the urine of pregnant mothers. The purpose of this study was to determine the association between pesticide exposure and autism outcomes in offspring among an exposed cohort of women. This was a different extraction procedure than BPA which led to me learning many new foundational skills from this as well.

I continued to work with Dr. Barr through Summer 2015 and into the fall as well. During this time, we were extracting and analyzing phthalates and BPA in urine for a group up at Harvard. This was a more challenging study. We only had very small sample volumes so efficiency and accuracy was essential. If you made a mistake, there was not enough sample left to run the sample again. I was the main lead on this study and thoroughly enjoyed working on it. By the end of the summer, we had analyzed hundreds of samples.

Working for Dr. Barr and her lab group was one of the best learning experiences I’ve had. The work I did in this lab and the skills I developed taught me not only techniques in the laboratory setting, but also taught me management, writing, and organizational skills that helped me outside the lab as well. It was truly a wonderful experience.