Matthew Blahna
Prerna Bhargava
Haiming Cao, Ph.D.
Meg Gustafson
Erin Johnson, Ph.D.
David Kim, Ph.D.
Jun Kawasaki
Li Ye
Matthew Blahna: Entering 1st year HSPH predoctoral student in the Biological Sciences in Public Health (BPH) program. Matt has a BS and MPH degrees from the University of Michigan. His efforts have been largely focused on population dynamics responsible for the emergence of antimicrobial resistant pathogens. His previous thesis work in the MPH program at UMichigan examined the dissemination of virulence factors and antibiotic resistance genes among uropathogenic E. coli and he is first author of a paper reporting the distribution of trmethoprim-sulfamethoxazole resistance genes among uropathogens in Europe and Canada. He also is coauthor on a paper examining the population dynamics of a newly proposed uropathogenic E coli clonal group and he is finishing work with researchers at the Center for Molecular and Clinical Epidemiology of Infectious Disease to utilize microarray technology for gene discovery in pathogenic and commensul E coli. Recognizing that his "goals require a mulit-disciplinary and inter-departmental education" he applied to our to obtain basic biological research training since his goals "require the utilization of molecular biology laboratory techniques, epidemiological surveys and nonlinear systems models".
Prerna Bhargava: Prerna Bhargava is an entering predoctoral student in the Biological Sciences in Public Health (BPH) program. She has recently graduated from Brandeis University and has been active in bench research on genetic instability. Her studies at Brandeis also involved legal issues as a minor, so she has past interdisciplinary training in her “passion for biochemical research, patient advocacy, and the law”. We believe Prerna will be an outstanding trainee to be supported by our program.
Haiming Cao, Ph.D. (Biochemistry, University of Nevada-Reno): Postdoctoral fellow co-mentored by Drs. Gokhan Hotamisligil and Alexander Ivanov at Harvard School of Public Health. Fatty acid binding proteins play critical roles in inflammatory and metabolic responses. Using gene expression profiling, Haiming is studying mouse models deleted in the fatty acid binding protein aP2 and mal1 to characterize the effects of diet induced obesity on adipocyte gene expression. He will also collaborate with the HSPH proteomics core, under the supervision of Dr. Ivanov, to identify protein interactions and potential post-translational modification of fatty acid binding proteins. These studies will eventually be extended to use ‘lipidomics’ in order to characterize the content of lipid bodies and how these organelles are regulated by fatty acid binding proteins. Haiming’s project combines state-of-the-art high throughput analytical techniques to address outstanding questions about metabolic syndrome.
Meg Gustafson: HSPH predoctoral student, 2nd year BPH program. Meg has begun to study the role of Stamp 1 and 2 proteins in cellular metabolism. Stamp2, a six-transmembrane protein with oxido-reductase capabilities, has been shown to be necessary for proper insulin signaling in adipose tissue. However, little is known about its mechanism of action. Stamp1 is a highly homologous family member with a different tissue profile, predominantly expressed in the brain and prostate, and present at lower levels in the kidney, spleen, and white adipose tissue. Its function is as yet unidentified. Cell culture and mouse models are the primary tools used to investigate the metabolic functions of the Stamp molecules and their importance in maintaining appropriate insulin signaling.
Erin Johnson, Ph.D. (Medical Sciences, Medical College of Ohio): Post-doctoral fellow co-mentored by Drs. Marianne Wessling-Resnick and Megan Murray. Erin's project is to investigate the relationship between reticuloendothelial iron status (specifically regulated by the iron export protein, ferroportin) and intracellular Mycobacterium tuberculosis (M.tb) growth and infection. Conducting experiments with a pathogen such as M.tb requires extensive BL3 level training. Erin is in the process of finishing this training and will be able to operate independently following completion of the final skills test. While training, Erin also conducted several experiments with the BL2 level Mycobacterium bovis-BCG aimed at discerning a role for ferroportin in modulating intracellular mycobacterial growth. These preliminary experiments helped to develop a novel immunofluorescence-based approach for quantifying intracellular bacteria using scanning cell microscopy. The results suggest that ferroportin is a negative regulator of intracellular mycobacterial growth. Erin was also a co-author on a paper exploring a similar role for ferroportin in regulating the growth of Salmonella, another obligate intracellular pathogen. In addition to performing bench work, Erin is also participates in weekly group meetings held by Dr. Murray. These meetings are conducted to discuss and coordinate active tuberculosis epidemiology studies being carried out in both South Africa and Peru. An ultimate goal is to translate findings on disease progression and human genetic variation into a model system for cell culture studies.
Jun Kawasaki: Entering 1st year HSPH predoctoral student in the Biological Sciences in Public Health (BPH) program. Jun has a BA in Biology from Grinnell College and enters our program with a keen interest in cancer research. She seeks to pursue questions about signal transduction pathways critical for tumor development from both cellular and clinical aspects, using genetic and molecular approaches. Her undergraduate research studies focused on nutritional products that have chemopreventive and chemotherapeutic effects, and her findings were recently presented at the Experimental Biology 2006 meeting, which she was invited to attend last April. Jun’s broad interests fit in well with the interdisciplinary nature of our program.
David Kim, PhD (Environmental Sciences and Engineering, The University of North Carolina at Chapel Hill): Postdoctoral fellow co-mentored by Drs. Thomas Smith (Harvard School of Public Health) and Guido Guidotti (Harvard College). In the last decade, a number of important discoveries have been made regarding the role of membrane proteins (i.e., transporters). Transporters are expressed at higher concentrations in the epithelium of the stomach, intestines, kidneys, liver, and brain. They can restrict the access of many compounds to the central nervous systems, decrease the bioavailability of drugs, and limit the transport of teratogens to the fetus. Despite the overall significance of transporters, their role in determining the pharmacokinetic behavior of environmental toxicants is poorly understood. The objectives of David’s study are (1) to identify environmental toxicants that can potentially interact with transporters, and (2) to examine the relative importance of transporters for the bioavailability of environmental toxicants. The hypothesis behind David’s project is that transporters will decrease the toxicity of environmental contaminants by restricting uptake into the systemic circulation and increasing clearance. David will implement computational tools to examine the structural and functional properties of chemicals that interact with transporters. He will use the results from this analysis to develop quantitative structure-activity relationship (QSAR) models that are predictive of pharmacokinetic parameters, such as the maximum efflux rate. David will also develop a quantitative description (i.e., physiologically-based pharmacokinetic model) of the interaction between chemicals and transporters, and use this description to predict the bioavailability of chemicals. The results of David’s project will contribute to a better understanding of and ability to predict individual risks from exposures to environmental toxicants.
Weidong Tian, Ph.D. (Bioinformatics, Washington University): Postdoctoral fellow co-mentored by Drs. Fritz Roth and Heather Nelson. Weidong’s project takes advantage of the fact that non-melanoma skin cancer, which is the most frequently diagnosed malignancy in humans, can serve as a model for understanding genetic susceptibility to cancer. Working with Dr. Fritz Roth, Weidong plans to develop a principled candidate gene approach applying a fully integrated probabilistic model for predicting genes potentially involved in skin cancer development. His work in this area will greatly benefit from the co-mentorship of Dr. Heather Nelson, who has strong expertise in epidemiology and the biology of skin cancer. She has developed a large population-based case control study of skin cancer in New Hampshire, and with access to DNA from this population, Weidong can directly test the association between variants in candidate genes and case status in Dr. Nelson’s epidemiologic study. Variation in genes that modify UV exposure, as well as those involved in DNA damage response and repair are known to affect individual susceptibility to skin cancer, thus we viewed this particular research project to be in keeping with our training goal for interdisciplinary research in molecular biology, epidemiology, and biostatistics in a team-oriented environment with the prospect of developing a novel candidate gene approach to mapping complex traits.
Li Ye: Entering 1st year HSPH predoctoral student in the Biological Sciences in Public Health (BPH) program. He graduated from Tsinghua University with a BS degree in Biological Sciences this June. He has twice received a First Prize Scholarship for academic excellence from Tsinghua University, and was a Gold Medal winner in the National Biology Olympiad of China in 2002. He is seeking to apply his talents to systems biology, and in his statement he indicated that he was attracted to our program because of its "integrated multidisciplinary approaches÷.not only [have we] covered essential issues such as genetic basis, stress responses and metabolic regulation of diseases, but also investigated them at the mechanism level as well as in the context of population studies".