Washington Chromatography Discussion Group (WCDG) meets monthly from September to May. Meetings are free and include a light dinner & social hour followed by a seminar.
Wednesday, February 19, 2020
Institute for Bioscience and Biotechnology Research (IBBR)
9600 Gudelsky Drive, Rockville, MD
6:00 PM – Dinner & Social
6:50 PM – Jie Li (Univ. of Maryland College Park) 2019 Guiochon Student Award Recipient
7:00 PM – Alexander Zestos (American University)
Speaker: Alexander Zestos (American University)
Title: LC-MS/MS Method for Neurochemical Detection in Biological Samples
Abstract: We have pioneered a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay that can detect 24 neurochemicals simultaneously from microdialysate samples in freely behaving animals. The method utilizes a 4-minute gradient to detect important neurotransmitters such as dopamine, serotonin, norepinephrine, and others. This assay is immensely important in monitoring neurotransmitters in microdialysate fractions under specific behavioral and pharmacological stimuli. The method has been further developed to detect over 17 compounds at high pressures in a 2-minute gradient or over 70 compounds with a 20-minute gradient. We have applied this method to study the effects of therapeutics for cocaine abuse. Previous work has shown that protein kinase C (PKC)-β inhibitors, enzastaurin and ruboxistaurin, have attenuated amphetamine-stimulated dopamine efflux and hyperlocomotion using in vivo microdialysis and LC-MS/MS for detection. More recently, the administration of CNS permeant PKC inhibitor 6c was also shown to attenuate amphetamine-stimulated dopamine over flow and reach the brain at robust concentrations as detected by the LC-MS/MS assay. The microdialysis-LC-MS/MS experiments have also shown similar effects of the protein kinase C inhibitors on cocaine-stimulated dopamine overflow and other monoamines. Just recently, the method has been applied to measure the dynamics of glutamate and GABA (in addition to several other neurotransmitters) before, during, and after epileptic seizures to determine novel biomarkers for epileptogenesis and ictogenesis. Lastly, we have measured the release of acetylcholine from beige fat adipocytes with our LC-MS/MS assay to help understand the importance of nicotinic acetylcholine receptor signaling in thermogenesis and the adaptation to cold temperatures.
Bio: Dr. Alexander G. Zestos is a bioanalytical chemist who uses electrochemical and chromatographic techniques for neurotransmitter analysis. He received his B.S./M.S. in Chemistry at the College of William and Mary in Williamsburg, VA. He obtained a Ph.D in Chemistry at the University of Virginia in Charlottesville, VA in 2014. He was also a postdoctoral research fellow at the University of Michigan from 2014-2017 where he was mentored by Prof. Robert T. Kennedy. Since 2017, he has been an Assistant Professor of Chemistry at American University. Prof. Zestos has published over 20 papers in prestigious journals such as Nature Medicine, ACS Applied Materials and Interfaces, Analytical Chemistry, and others with his research being highlighted in several media platforms. He has won numerous accolades and awards such as the Best Paper Award at the SPE ANTEC Conference, and was named a finalist for the 2018 and 2019 Csaba Horváth Young Scientist Award at HPLC 2018 and 2019 in Washington, D.C. and Milan, Italy respectively. Recently, he was named as an Emerging Investigator by the Royal Society of Chemistry for one of his latest publications. He serves as a Manager for the Chemical Society of Washington in addition to being the Faculty Editor of the Catalyst, a student run science publication at American University. He also serves as a guest researcher at NIST in the Biophysics Group in the Microsystems and Nanotechnology Division and at the National Institute of Mental Health in the NIH. He leads an interdisciplinary bioanalytical chemistry group that uses several electrochemical and chromatographic assays to improve neurotransmitter analysis. His research is funded through the NIH BRAIN Initiative and the National Science Foundation. He serves as a reviewer for the Center for the Scientific Review at the NIH, a referee for several journals, and will be the new editor of The Chemist through the American Institute of Chemists.
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