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McNair Scholar 2016Jackie Penaloza

Jackie Penaloza is a senior at the University of Minnesota, Twin Cities, majoring in mathematics with a specialization in physiology and a minor in biology. Her research interest are modeling diseases to gain an insight on the development of a disease and effects of current and new therapeutic drugs. Ms. Penaloza plans on getting her Ph.D. in bioengineering.

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My dream is to further research on diabetes mellitus and other diseases that affects underrepresented groups, in order to improve health care to those that show a history of being ignored in our society. I also want to be a supportive professor to students, through innovative teaching techniques, that ensures students with diverse learning styles can succeed and become novel researchers.

Research project

A mathematical model to simultaneously calculate growth and death rates of cells undergoing oxidative stress

Abstract: An increasing number of Americans are diagnosed with diabetes mellitus each year. The ultimate goal of this study is to find the best ways to evaluate beta cell proliferation and death in an in vitro model of beta cell death due to oxidative stress. The model system used was a mouse beta cell (βTC-6) line and hydrogen peroxide as a source of oxidative radicals to trigger. The hypothesis of this study is that cell growth and death are occurring at the same time and it is necessary to quantify both processes to fully understand the beta cell death in diabetes. Standard trypan blue dye exclusion assays were performed initially and sigmoidal growth curves were established for live and dead cells. However, the number of cells that could be counted was not sufficient to obtain accurate quantification of cell death. For this reason, another exclusive assay with fluorescent 7-Amino-Actinomycin (7-AAD) dye was used with flow cytometry. Flow cytometry, unlike trypan blue staining, collects a larger cell sample, thus increasing accuracy and facilitating both live and dead cell counts. A positive control of ethanol used as a toxin to validate this assay. However, the cytoplasmic enzyme lactate dehydrogenase (LDH) was measured in cell culture medium to estimate the number of cells that has been lysed, releasing cytoplasmic contents. Based on these results, a mathematical model can be established to evaluate the quality of the potential cell insults active during the progression of diabetes, and identify novel drug inhibitors. Download poster. [PDF]

Faculty profile

Meri T. Firpo is an assistant professor for the Stem Cell Institute, Department of Medicine, Division of Endocrinology and Diabetes. Dr. Firpo attended Cornell University of Graduate School of Medicine and received a Ph.D. in Cell Biology and Genetics in 1992. Her research interest include, stem cells and transplantation therapies specifically for diabetes. Dr. Firpo has a variety of publications in well know journals and has been awarded distinguishable awards. This is the first year that Dr. Firpo has been a McNair faculty mentor.