P Caglar has received her BS and MS (combined degree) in Chemical Engineering in 1973 from Chemical Engineering Department of Hacettepe University in Ankara, Turkey. She received her PhD in Analytical Chemistry from Chemistry Department of Hacettepe University in 1980. She is currently a Professor of Analytical Chemistry. She awarded by “TUBITAK and British Council Fellowship” at University of Machester DIAS for 4 months in 1987, “Fulbright Fellowship” at Rensselear Polytechnic Institute, Department of Chemistry in Troy, NY for a year in 1990, and “Visiting Professorship” at University of Virginia, Department of Chemistry in Charlottesville, VA for a year in 2001-2002. Her current research interests are design, development and application of fiber-optic chemical sensors and biosensors, novel sensors based on capillary electrophoretic microchip systems using fiber optics. She has over 70 papers published in refereed journals.
In this study, we propose a simple, fast, low cost extraction method based on dispersive-liquid-liquid microextraction (DLLME) and GC-MS analysis for the determination of 17β-estradiol (E2) and diethylstilbestrol (DES) in water. The main parameters affecting DLLME process such as the kind of extraction solvent, dispersive solvent,volume of the extraction and the dispersive solvent, extraction time and ionic strength were optimized. This method involves the rapid injection of an appropriate mixture of extraction solvent (100 μL chloroform) and dispersive solvent (1.00 mL acetonitrile) to water samples. After centrifugation of formed cloudy solution, sedimented phase was evaporated. Prior to GC-MS analysis samples were derivatized. The correlation coefficient of the calibration curve was higher than 0.994. The linear range was from 1 to 20 ng mL−1 for diethylstilbestrol (DES) and 1 to 10 ng mL-1 for 17β-estradiol (E2). The detection limits of DES and E2 were 0.42 ng mL1 and 0.71 ng mL-1,respectively. The recoveries of the method for DES and E2 from well water samples at spiking levels of 5 ng mL−1 ere 101.6% and 93.4%, respectively.
Jared Selman is currently a Forensic Science – Chemistry major at St. Mary’s University. Over summer 2016, he worked with Dr. José Tormos-Mélendez as part of the Summer Undergraduate Research Program supported by a departmental Welch grant awarded to the Department of Chemistry and Biochemistry at St. Mary’s University. His summer work consisted in obtaining the first crystal structure of mammalian PAO. He learned essential lab techniques and research methodologies that will prepare him for gr\aduate studies. After graduate school, he hopes to launch a career as a forensic scientist. He also hopes to one-day work as a high school science teacher. Inspired by the teachers who challenged and prepared him for college, he seeks to educate the next generation of upcoming leaders.
Human polyamine oxidase (hPAO) is a flavoprotein that catalyzes the oxidation of polyamine metabolites. Polyamines are important for cell growth and proliferation1. It has been shown that if polyamine synthesis is inhibited, cell growth is limited2. Recent studies have found a link between increased polyamine levels and hydrogen peroxide in cancer cells3. The catabolism of polyamines produces peroxides, which in high levels can enhance cancer cell growth4,5. Understanding polyamine metabolism can lead to advancements in cancer therapy. To better understand hPAO and its links as a target for cancer therapy, we need to have a better understanding of the chemical and structural specificities of hPAO. Sequence alignment has identified a conserved histidine residue in the active site of PAO and it has been found to play a role in polyamine metabolism6. Previous studies have shown that mammalian PAO prefers the N1-acetylated substrate over the non-N1-cetylated substrates6. Currently there are crystal structures for the maize and yeast PAO, but they are only 20% identical to mammalian PAO6. Therefore, in order to better understand the chemical and structural specificities of PAO we have attempted to obtain the first crystal structure of a mammalian PAO. Here in, we present two different purification methods for the crystallization of hPAO. Samples were submitted for crystallization trials at the X-Ray Core facility at the Department of Biochemistry in the University of Texas Health Science Center at San Antonio.