BAUMANN FAMILY SCHOLARSHIP
2000 - 2001 Winners
Sonya Tran and Steven Zahn
Sonya Tran's Research Proposal (November, 2000):
In Spring 2000, under the guidance of Dr. Gary Michels, I began working with human osteosarcoma cells. During the initial stages, I acquired the requisite skills and techniques employed in the study of these cells. Over the summer, I began to test the effects of adriamycin on the osteosarcoma cells. Adriamycin is a chemotherapeutic drug that interrupts the cell cycle during G2 of interphase, effectively inhibiting cell growth. The research I am currently conducting involves finding the lowest concentration at which osteosarcoma cells detect adriamycin. Once a relationship between the concentration of adriamycin and % cell survival has been established, I will test the mechanism
by which the adriamycin interacts with the cells.
Adriamycin has both polar and nonpolar properties, which allows us to predict that it will interact with the cellular membrane. However, it also has a planar aromatic ring and a positive charge, which are elements of a molecule that suggest interaction with DNA inside the cell. To test whether adriamycin acts at the level of the cell surface or has direct interaction with the DNA of
the cells, I will bind the adriamycin to agarose beads and then treat the cells. The adriamycin-agarose complex is too large and prevents the drug from entering the cell. Thus, if adriamycin interacts with cell DNA, then no effects should be observed. However, if adriamycin acts only at the cell surface, then the attached agarose beads will not impede the cytotoxic effects
of the drug and the cells will die. Once this research is complete, I will present my results at the poster session in Spring 2001.
The research for this study will be conducted on diamines and polyamines (collectively referred to as polyamines) in food matrices. Aliphatic polyamines are prominent within biological systems and are major indicators of spoilage in food. The goal of this research is to develop a sensitive analytical method for the determination of biological polyamines in food. Due to the fact that polyamines are highly polar and contain no native chromophore, the method of analysis used high performance liquid chromatography (HPLC) with pulsed electrochemical detection (PED). This summer, the work I performed included analysis of standard solutions of the polyamines being detected and then modifications to the method so that it could be applied to the quantitation of the polyamines in food samples. This also included modification of the waveform used in PED and determination of the limits of detection for the various polyamines being evaluated. Other experiments I conducted were done to study the effects of varying mobile phase constituents on the baseline and how baseline disturbance could be minimized in the presence of gradient eluents.
Sonya Tran's Research Report
Steven Zahn's Research Proposal:
Once the preliminary method was developed, I applied it to food samples such as fish, fruit and meat. Recovery efficiencies were determined for specific polyamines and were found to be greater than 90% in our method. Sampling preparation was minimal and limited to homogenization of the sample in an acidic solution followed by centrifugation and then syringe-filtering prior to injection.
My future work in this project will include further modification of the sample preparation procedure and simplifying it while also trying to minimize the baseline disturbances with the HPLC detector. The current method of homogenization in acidic solutions produces a large disturbance in the baseline during the first minute of separation. We suspect that this is probably due to a large shift in pH at the detector, since the typical eluent used is highly alkaline (pH>13). Further studies will test basic and neutral conditions that will provide the same degree of isolation of the polyamines from their food matrix and yield less baseline disturbance. I will also attempt several versions of recovery efficiency studies in order to duplicate the few studies that have been produced already. Following these and other necessary final analyses of the polyamines and their method of detection, the remainder of the research will be spent on preparing a conclusive paper that will be presented for publication.
The research conducted by Dr. Dobberpuhl and myself will be presented at the St. Albertís Day Chemistry Research Seminar in the manner of a poster presentation. I also plan to present this at the Nebraska Academy of Sciences Student Section Meeting in the spring of 2001.
Steven Zahn's Research Report
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