Undergraduate Research Program

2003 Program | 2003 Abstracts | 2003 Plenary Session

2003 Summer Research Symposium Poster Abstracts

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Syntheses, Characterization, and Electrochemical Studies of a series of dioxo-Mo(VI) centers with a thiol coordination

Jonathan J. Miller, Raghvendra S. Sengar, and Partha Basu*

Department of Chemistry and Biochemistry, Duquesne University Molybdenum is the only element in the second period of the d-block elements which is essential for all life forms. According to Hille's classification1, mononuclear molybdenum enzymes can be divided into three families, one of which is the Sulfite Oxidase (SO32-) family of enzymes, which has a [MoO2]2+ unit coordinated by a cysteine sulfur in its fully-oxidized form. The eukaryotic nitrate reductases also have a similar coordination environment. To understand the effect of cysteine coordination, we have synthesized complexes of the general formula LMoO2 (o-S-C6H4-X), where L = hydrotris (3, 5-dimethyl) pyrazolyl borate ligand2 and X = CONHCH3; NHCOCH3; CON(CH3)2; NH2; COOH. The ortho-substituted 'X'-groups are designed to harbor H-bonding between the S-atom and the NH group3. The redox behavior (one-electron) will be discussed.

Measuring the Conformational Properties of 1, 2, 3, 6, 7, 8-hexahydropyrene

Philip J. Morgan, David W. Pratt University of Pittsburgh

The compound 1, 2, 3, 6, 7, 8-hexahydropyrene (HHP) is known to exist as interconvertible chair and boat conformers. The process of the dynamical interconversion of the two conformers, chair and boat, using high-resolution and low resolution electronic spectroscopy will be studied. Once the high-resolution electronic spectrum is obtained, the energy of each conformer and the rotational constants will be calculated. Line broadening in the spectra will also permit the determination of barriers to the process of dynamical interconversion between the two conformers. High level ab initio calculations will also be performed to calculate the theoretical energies, rotational constants, and dipole moments of the two conformers.

The Effects of Trauma during Invasive Measurements in the Brain

Katie Bohovic and Adrian C. MichaelDepartment of Chemistry, University of Pittsburgh

Microdialysis probes are widely used to monitor neurotransmitters in the brain. The probes are large in comparison with the neuronal cells and their processes, raising concern about the effects of trauma caused by the insertion of the probe into living tissue. The extent and magnitude of the effects of trauma on the outcome of neurotransmitter measurements is not yet clearly understood. I am testing the hypothesis that the inclusion of a substance known to decrease trauma will affect the outcome of the neurotransmitter measurements. The addition of ethyl pyruvate into the perfusion causes a great change in the measured concentration of the neurotransmitter dopamine. This provides evidence that trauma is indeed an issue that must be considered when using microdialysis techniques.

Oral Presentation

A Novel Polycaprolactone/Collagen Composite as a Biomaterial for Nerve Guide Fabrication

Jade Leung, R. Waddell, *K. Marra, and J. DoctorDuquesne University, *Depts. Of Surgery & Bioengineering, McGowan Institute for Regenerative Medicine, University of Pittsburgh

Polycaprolactone (PCL) is a biomaterial with applications in nerve guide fabrication for nerve regeneration. We are evaluating three types of polycaprolactone: "plain" PCL, laminin-coated PCL, and a composite of PCL and CultiSpher collagen beads. PC12 cells derived from a rat pheochromocytoma attach to discs of polycaprolactone as indicated by cell staining using DAPI, a fluorescent stain for nuclei. Further, PC12 cells that attach to discs of the three types of polycaprolactone will proliferate on this biomaterial, and, when induced with nerve growth factor, will differentiate and extend neurites as indicated by FITC staining of the actin cytoskeleton. When comparing the three types of polycaprolactone, the PCL/CultiSpher composite provides a statistically significant increase in PC12 cell attachment, proliferation, and differentiation, as well as viability (assessed by live/dead staining). These results indicate that the polycaprolactone/CultiSpher composite may prove to be an effective material for nerve guide fabrication.

Toward a "Green" Synthesis of Adipic Acid

Katherine Mullaugh University of Pittsburgh, Department of Chemical and Petroleum Engineering

The current industrial production of adipic acid, a precursor to the widely used material nylon-6,6, results in the emission of the greenhouse gas nitrous oxide. Approximately 2.2 million metric tons of adipic acid are produced each year worldwide and the resulting emission of N2O is a sizable contributor to global warming and ozone depletion. Thus, a "greener" synthetic route to this important reagent is desirable. In 1998 Noyori and coworkers showed that it was possible to use aqueous hydrogen peroxide to oxidize cyclohexene directly to adipic acid in the presence of a tungstate catalyst and phase transfer ligand. Previous work in our group has shown that cyclohexene can undergo epoxidation to cyclohexene oxide with aqueous H2O2 under basic conditions in supercritical carbon dioxide. We hope to extend this work and employ this system to further oxidize cyclohexene to adipic acid in a more environmentally friendly manner

DNA Bending by Unnatural Guanine Nucleotides

Ryanne Forcht, S. Mueller, S. M. Firestine, J. Evanseck Duquesne University, Department of Chemistry & Biochemistry

An experimental effort has been undertaken to investigate the effect of insertion of sterically demanding groups in DNA. The insertion has been accomplished by chemical modification of a nucleotide with the unnatural guanine derivative 2-fluoro-2'-deoxyinosine. Reaction of the unnatural residue occurs such that a t-butyl or adamantanamine substrate is oriented into the minor groove at one of two specified positions. The insertion causes a degree of steric strain that is relieved by bending. An unmodified 27-mer d(5'-CGCATCGCATGTATGCGGCGCATAAGA-'3) of DNA and complement have been synthesized by standard phosphoamidite chemistry and purified by 13% denaturing polyacrylamide gel electrophoresis. Purification conditions for modified DNA via high pressure liquid chromatography are currently being developed.

Why Can't the Sox Ever Win? The Quest to Clone the Transcription Factor EcSox17 in Eleutherodactylus coqui, a Direct-Developing Frog

Sean Williamson, Richard ElinsonDuquesne University, Dept of Biological Sciences

Traditional frogs develop digestive organs from the yolky cells of the egg, while birds and reptiles have non-cellular yolk for nutrition only. Eleutherodactylus coqui, a tree frog, has a more birdlike development and may lie somewhere between. To find out, my goal is to isolate Sox17, a marker for digestive tissues. DNA was synthesized complementary to E. coqui neurula RNA. PCR (polymerase chain reaction) with degenerate primers produced fragments of promising length, which when sequenced, gave a 261 base-pair segment with 75% identity to Xsox17, the clawed-frog counterpart. Nucleotide sequence gaps suggest that the clone is authentic, since the DNA-binding domain of the protein is maintained despite reading-frame changes. A larger product from 3' RACE (rapid amplification of cDNA ends) will be analyzed next by cloning and sequencing. The EcSox17 clone should provide a tool to distinguish tissue-forming cells from nutritional ones.

Osteoblast Attachment to a Novel Biocompatible Microchip For Use in Assessing Bone Mineral Density

Sara Otaibi, Christa Heyward, *Paul Campbell, J.Doctor Department of Biological Sciences, Duquesne University, *Institute for Complex Engineered Systems, CMU

Bone Mineral Density is the measure of the amount of calcium in a specific region of a bone. It is an important diagnostic tool used to identify patients at risk of a bone fracture or osteoporosis. The Complementary Metal Oxide Semiconductor (CMOS) sensor, with built in strain gauges that move in response to stress on the bone, will permit medical clinicians to directly quantitate bone mineral density. The CMOS sensor determines bone mineral density based on biomechanical properties and may prove to be superior to current methods. My research focused on in vitro testing of the interaction between CMOS sensors and cells that have the potential to differentiate into osteoblasts. Preliminary studies show that MG-63 cells, isolated from a human osteosarcoma, attach to and remain viable, on the CMOS sensor, as assessed by several staining procedures and scanning electron microscopy. Further research will investigate which surface topography on the CMOS sensor promotes the greatest cellular attachment, proliferation, and differentiation of adult stem cells and MG-63 cells.

INVESTIGATION OF A RYDBERG COMPLEX, NeNO+ùe-, USING PENNING IONIZATION ELECTRON SPECTROSCOPY

Lisa S. Park and Peter E. Siska University of Pittsburgh, Department of Chemistry

The Penning ionization (PI) of nitric oxide by metastable (excited) neon, Ne* + NO?Ne + NO+ + e-, is observed using electron spectroscopy. In this experiment, electrons excite a beam of neon gas to its 3P2 and 3P0 states, which is then collided at 90Æ with a beam of nitric oxide. The electron spectrometer detects relative numbers of electrons ejected from the collision products at a range of kinetic energies, from -0.2 to 8.0 eV. Energies of detected electrons indicate the states of products being formed. The appearance of a novel species, the "Rydberg" complex, NeNO+?e-, is anticipated. This species, a molecular ion with an excited, loosely attached electron, might then dissociate into PI products or into associative ionization products, NeNO+ + e-. The expected "signature" of the new complex has not yet been seen. Future studies will be carried out at higher kinetic energy with expectations of seeing evidence for the formation of a Rydberg complex.

Studies Toward a Functional Template for Tissue Engineering

Amanda Valco University of Pittsburgh

The use of polymers in tissue engineering is not a new concept. Known biodegradable polymers include poly(e-caprolactone), poly(glycolic acid), and poly(ethylene glycol). Unfortunately, none of these polymers include functional groups to which essential growth factors could be attached to aid in tissue growth and repair. In this series of experiments, studies were carried out to synthesize the lactone monomer 2-oxo-morpholine-4-carboxylic acid tert-butyl ester from N,N-bis-(2-hydroxy-ethyl)-carbamic acid tert-butyl ester. Procedures varied with some procedures attempting the synthesis in one step while others followed a two step scheme utilizing the lactol intermediate 2-Hydroxy-morpholine-4-carboxylic acid tert-butyl ester, which was later to be oxidized to the lactone. Procedures included use of the Fetizon reagent, o-iodoxybenzoic acid, and Dess-Martin reagent. Future work includes the ring opening polymerization of the lactone intermediate to produce a polymer containing a main chain protected amine which would provide an avenue to functionalize the polymer.

Carbon Dioxide Permeable Membranes Formed from Amino-Functional Polymers

Travis Martin, Robert Enick University of Pittsburgh, Benedum Hall

The objective of this research was to evaluate the CO2 permeance and selectivity of amino-functional polymers. Amine groups incorporated into the backbone of the polymer chain increase the solubility of carbon dioxide in the membrane by forming polymer bound zwitterions within the membrane while not strongly influencing diffusivity. Enhanced carbon dioxide solubility will therefore probably result in enhanced carbon dioxide permeability (the product of solubility and diffusivity). Due to the low polymer melting point and the nature of the CO2:amine interaction, the membranes are well suited to the low temperature (20-100 oC) separation of carbon dioxide from a gas mixture. The first class of polymers being examined is water-soluble polymers including poly(vinylamine) homopolymers, poly(vinylamine-vinylalcohol) co-polymers, and blends of poly(vinylamine) and poly(vinylamine-vinylalcohol) co-polymers. The second class of polymers includes oil-soluble polymers such as poly(vinylbenzylethylenediamine) that may be more resilient membrane material for wet gas mixtures.

Identification of Genes Regulated by CspE in Escherichia coli

Amber Pryzbylski, John Arigo, Nancy Trun Duquesne University, Department of Biological Sciences

CspE is a small protein found in Escherichia coli that is known to participate in chromosome condensation. It is also known to regulate genes and has been shown to upregulate the rscA gene. We are interested in determining which other genes are regulated by CspE. lplacMu53 phage was used to create random lacZ operon fusions in genes of the E. coli chromosome. The fusions that respond to CspE were identified by fusions that respond to CspE were identified by monitoring their b-galactosidase activity in the presence of CspE. The l phage fusion was induced out of the chromosome by UV induction. The fusion DNA will be extracted from the phage. We hope to sequence the fusions and thereby identify which genes are regulated by CspE.

Synthesis of Novel Crown Ethers

Kristy M. Wolfel and Balazs Hargittai Saint Francis University

Many practical reagents in organic synthesis are soluble in water due to their ionic nature, but this also makes them insoluble in organic solvents. Since many organic syntheses are performed in organic solvents, crown ethers may play an important role by making many insoluble substances soluble in a wide range of reactions. These cyclic polyethers can coordinate metal ions in non-polar solvents. The metal ions therefore are separated from their anions, forming salts that are soluble in the organic solvents and are highly reactive. In our research we are attempting to synthesize crown ethers containing multiple adjacent tetrahydrofuran rings. This poster presents the initial results of the first two steps of the crown ether synthesis.

Evaluation of the role of proline on the folding of a-conotoxins

Amy K. Croskey and Balazs Hargittai Saint Francis University

Evaluation of the role of disulfide bridges plays an important part in understanding the concept of protein folding. We are exploring how slight changes in the sequence of several small peptides affect their folding properties. These peptides are multiple disulfide bridge-containing a-conotoxins, a-conotoxins GI, GII (found in Conus Geographus), SI, SIA (Conus Striatus), and MI (Conus Magus), and their analogs. These are all thirteen-fourteen amino acid containing peptide amides having four cysteine residues. These four residues can form to two disulfide bridges, leading to three possible regioisomers. The amino acid in position 9 of these peptides plays an important role in the biological characteristics of these compounds. In our studies we have been investigating the effects of different amino acids, primarily proline, in this position on the folding of the peptides. Proline's cyclic nature may impose steric constraints for the folding of the peptides.

Synthesis of a Novel Cyclic Amino Acid and Incorporation into Peptide Sequences

Andrew Farabaugh and Balazs Hargittai Saint Francis University

The shape a protein takes after undergoing the folding process determines the function this protein will perform. Folded peptide chains are held in place by various inter- and intramolecular interactions. One type of these interactions are disulfide bridges. We are interested in looking at how slight changes in the sequence of several small disulfide-rich peptides (our studies focus on the family of a-conotoxins) affect their folding properties and their biological characteristics. In this study we are attempting to synthesize a novel cyclic amino acid, 4-(2-aminoethyl)-L-proline, that may promote the specific folding of the peptide chains, and at the same time play a role in its affinity for particular receptor protein targets.

The Synthesis of Silyl Transfer Reagents

Heidi J. Frazee and Joseph J. Grabowski University of Pittsburgh, Department of Chemistry

The unique capabilities of the flowing afterglow are being used to investigate the formation of a novel reagent ion and its reaction with volatile organic compounds (VOCs) found in breath. The objective is to identify an efficient synthetic route to a highly selective and rapid reaction for VOC analysis. The identified method will be used to identify a complex mixture of VOCs quantitatively using pseudo-first-order-kinetics and previously measured rate coefficients (and branching ratios if necessary). The initial ion examined is protonated hexamethyldisiloxane. The trimethylsilyl group has been referred to as a "big" proton that can readily transfer like a proton. The proton transfer reaction of tertiary-butyl cation with hexamethyldisiloxane has been characterized as forming only the desired product, but is disappointingly slow (Eff ~ 1%). Additional routes that should lead to the desired ion will be reported, as will be initial studies of a designed "representative list" of breath VOCs.

DNA Folding Measured by Viscosity of Escherichia coli Nucleoids

Steven Arnstein Duquesne University, Dept of Biological Sciences

Many factors influence the condensation and conformation of the E. coli nucleoid. Some of the known factors include DNA binding proteins, RNA-DNA interaction, and general DNA folding. The E. coli nucleoid is known to decondense when incubated with intercalating agents, heat, proteases, RNases, DNases, and camphor. In these experiments, we are investigating the use of viscosity as a quantitative measure of DNA folding. The viscosity of the nucleoids has been measured at various DNA concentrations. These values will then be compared to the viscosity of nucleoids treated with a range of ethidium bromide concentrations. The viscosity of nucleoids treated with the decondensing agents listed above will also be measured. Future experiments will involve measuring the viscosity of nucleoids in mutant strains of E. coli and the affect of decondensing agents on these nucleoids.

Fabrication of Bioactive Soft Tissue Scaffolds by Multiple Nozzle Electrospinning

Hann-Chung E. Wong University of Pittsburgh, Chemical Engineering, Cellomics Center

Electrospinning offers a means to generate tissue engineering scaffolds composed of nanoscale fibers. Previously, we demonstrated the ability to electrospin strong elastic scaffolds composed of biodegradable poly(ester urethane)ureas designed for soft tissue applications. The objective of this work is to introduce multiple nozzles into the electrospinning apparatus, by which it may be possible to fabricate a multilayer, multicomponent scaffold suitable for cellular growth and tissue replacement. Biodegradable poly(ester urethane)ureas and other polymers together with extracellular matrix proteins such as collagen are dissolved in appropriate solvents and then electrospinning takes place from separate injectors onto a rotating collector plate. Electrospinning parameters such as polymer concentration, applied voltage magnitude and injector-to-tip distance are varied. Scaffolds are characterized by differential scanning calorimetry, gel permeation chromatography and tensile testing. In vitro degradation is also evaluated for electrospun biodegradable polyurethane. Multiple-nozzle electrospinning presents a novel and efficient means of creating soft tissue scaffolds.

UvrD- A study of its expression patterns

Hawa Abubakar, Nancy Trun Duquesne University, Dept of Biological Sciences

UvrD is a DNA helicase located on the leading strand during DNA replication. It functions in methyl directed mismatch repair as well as uvrABC excision repair. UvrD has also been implicated in replication of the bacterial chromosome during DNA replication. Studies have shown that E coli can survive a single mutation of either Rep or UvrD but a double mutation of Rep and UvrD is lethal. Beginning with a PCR fragment of chromosomal DNA, the objectives of this project are to create a fusion between the uvrD promoter region and the lacZ gene. The fusion will be used to carry out studies of uvrD expression including lacZ activity assays, site directed mutagenesis and an examination of what proteins regulate UvrD. Using a fusion of the rep promoter and lacZ that had been previously constructed, we will compare and contrast uvrD and rep expression patterns under a variety of environmental conditions.

Chemistry of Excited Neon

*Constance Young, Peter Siska, Keerti Gulati University of Pittsburgh, Chemistry Department

Excited atom chemistry is the study of atoms whose valence electron shell has been disturbed to produce an excited configuration and a more reactive atom. The ground state noble gases are not reactive with other atoms and studies of their chemistry have been limited. Noble gases are unique because their valence shells are completely filled. After exciting the noble gases, they become more reactive than any ground state atom. Our electron beam gun in a vacuum chamber excites the atom which then reacts with other atoms or molecules. In my experiment, I am reacting excited neon (Ne*) with hydrogen (H2). Ne* + H2 ¶ Ne + H2+ + e-. This reaction is called Penning Ionization. The vacuum chamber is equipped to do many things before and after collision in order to provide accurate data. We use a quadrupole mass spectrometer to detect the charged species. We will present the angular distribution of the H2+, NeH2+, and NeH+ products. We will use this to derive the energy distribution and to discuss and analyze the dynamics of the reactions.

Utilization of Fructose Frames in the Fabrication of Multi-Channeled Nerve Guides

Emily M. Kowalik and Kacey G. Marra University of Pittsburgh, Division of Plastic Surgery

In this study, porous, biodegradable nerve guides with single or multiple longitudinally aligned channels were made from poly(caprolactone) (PCL) and collagenous microcarriers (CultiSpher-Gs). These conduits have potential to promote nerve regeneration by supporting Schwann cells, retaining important lumenal growth factors, enhancing neuroglial cell attachment, and guiding the direction of axonal growth. A novel technique involving a Styrofoam Assembly with Wires (SAW; for single-channeled) or an Elevating SAW (ESAW; for multi-channeled) produced fructose frames, which molded the guides. This technique allows for easy alteration of channel number and diameter by exploiting the relationships between temperature, viscosity, and wire-coating thickness of molten fructose. The single-channeled guides had an average OD of 3.08±0.07 mm and ID of 1.94±0.08 mm. The multi-channeled guides had an average OD of 3.40±0.3 mm and IDs of 0.178±0.01 mm. The reproducibility, speed, non-toxicity, and simplicity of the fructose framing technique shows its potential for neural tissue engineering applications.

Effects of postural changes on genioglossal muscle activity in awake cats

Katie Wilkinson, Heather Arendt, Lucy Cotter, Dave Mays, Chris Olsheski, and Bill Yates University of Pittsburgh, Departments of Otolaryngology and Neuroscience

Postural changes can cause the tongue to fall back and obstruct the airway, necessitating a protrusion of the tongue by the genioglossus to keep the airway patent. Genioglossal activity was measured in awake cats before and during nose-up and ear-down tilts. For all tilt directions, the change in genioglossal activity during 60Æ tilt was significantly larger than that during 20Æ tilt, suggesting that postural changes in awake animals produce modulation of genioglossal activity. The genioglossal responses were complex, in that muscle activity increased in some animals while decreasing in others. This complexity most likely results from the multi-compartmental nature of the genioglossus muscle. Peripheral vestibular lesions were performed on these animals and it remains to be determined whether removing vestibular inputs will abolish the genioglossal response to tilt.

An Investigation of Attitudes of General Chemistry Students in Science versus Engineering Programs (A Pilot Study)

William McClendon University of Pittsburgh

Many majors require students to take General Chemistry courses at the University of Pittsburgh. There are two student populations that are the target of this study: students taking Chemistry 0120 (science majors) and students in Chemistry 0970 (engineering majors). This paper will compare attitudes toward chemistry for both populations and for selected subgroups within each population. Student surveys administered in Spring 2003 constitute the major source of data for this study. This data includes hours spent toward chemistry, total hours spent toward classes, workload perception, and perception of chemistry's relevancy to students' major. Two of the major discoveries were that the student population here studies more than the national average and that engineering students studied less than the author expected, based on anecdotal evidence and discussions with students. In addition, the survey results were used to create a modified survey form and protocol.

A Computational Model of Calcium Pyrophosphate Dihydrate Crystals

Kimberly Zanotti, Pranav Dalal, Andrzej Wierzbicki, Jeffry D. Madura Duquesne University, Dept of Chemistry & Biochemistry Calcium pyrophosphate dihydrate (CPPD) crystals can often be found in joints that are afflicted by pseudogout (a form of arthritis). The presence of CPPD crystals leads to the rupturing of the lysosome phospholipid membrane, thus causing pseudogout to develop. The interactions between the CPPD crystal and the lysosome phospholipid membrane that lead to the membrane's rupture are thoroughly analyzed using computational modeling techniques. We placed a majority of the efforts towards developing force field parameters for the CPPD crystal. These parameters will be employed in unconstrained molecular dynamics simulations in which the crystal will be placed at a lipid-water interface.

Candidate Gene Screening for the Cerulean Cataract Locus on 17q24-q25.

S.R. Clarke, B.W. Rigatti Department of Ophthalmology, University of Pittsburgh Cerulean cataracts are autosomal dominant, early-onset cataracts. Through linkage analysis we mapped a locus to 17q24-q25 and are now selecting and screening lens expressed candidate genes (CGs) within 17q24-q25 for mutations and SNPs (single nucleotide polymorphisms). CGs screening includes testing for expression in the human lens via BLAST against NEIBank, designing PCR (polymerase change reaction) primers to amplify all CG exons, and sequencing amplified exons. Sequenced exons are then analyzed for mutations and SNPs. Four genes, Pro0478, LOC56270, RAB40B, LOC339159, have been screened to date. We detected sequence variations in Pro0478, SNPs in LOC56270 and RAB40B, and no variations in LOC339159. Other CGs are currently under investigation and linkage analysis using new SNPs will further narrow the critical region allowing for screening of CGs currently not in NEIBank lens library.

Separation of Fatty Acids and Amides Using Various Forms of Thin-Layer Chromatography

Leigh Ann DiCicco Duquesne University, Dept of Chemistry & Biochemistry Simple and inexpensive, thin-layer chromatography (TLC) is a process by which organic molecules, such as fatty acids and amides, can be separated based upon polarity. The technique is widely used to visualize cellular components, and provides a suitable foundation for more precise methods of quantification. The principle objective in this study was to separate a given saturated fatty acid and its mono-, di-, and tri-unsaturated forms from one another. In order to achieve good separation, it was necessary to find a combination of polar and non-polar solvents that corresponded to the polarities of the saturated and unsaturated fatty acids. However, success was limited due to the very small polarity differences between the molecules which were caused by the increasing number of unsaturated sites. Argentation-TLC, which uses the reactive properties of silver ion, was also tested on the free fatty acids, given its success in separating fatty acid methyl esters. At this time, progress continues in hopes of find a feasible method for fatty acid separation. Should success with acids be achieved, separation of the corresponding amides should follow.

Differentiation of Adipose-Derived Stem Cells into Neural Progenitor Cells

Lauren E. Kokai, Bradley M. Tebbets, Jennifer M. Bennett, John S. Doctor, and Kacey G. Marra University of Pittsburgh, Division of Plastic Surgery, Duquesne University, Dept of Biological Sciences There are two types of stem cells known that are capable of undergoing neuronal differentiation in vitro and in vivo. These are stem cells from embryonic tissue and adult brain. Because these cells are difficult to obtain, efforts have been made to induce autologous adult stem cells to differentiate toward neuronal cells. Adipose derived stem cells (ADSCs) hold great clinical potential as ideal stem cells that can be induced to differentiate into cells of neural lineage. We investigated several methods to induce ADSCs to differentiate into early neural progenitor cells. Treatments included combinations of isobutylmethylxanthine (IBMX), indomethacin, insulin, hydrocortisone, valproic acid, butylated hydroxyanisole, and epinephrine. Cells with morphology closest resembling early neuronal cells were induced with IBMX, indomethacin and insulin. Future studies include western blot and immunocytochemistry analysis of cells with neuronal characteristics. Utilization of these cells in tissue engineering applications is being studied.

CO2 Sequestration: The solubility of Carbon Dioxide in Brines

Paulette Cazoe, Thomas J. Dick, Jeffry D. Madura Duquesne University, Dept of Chemistry & Biochemistry Carbon dioxide sequestration is the process of capturing CO2 and removing it from the environment. One method to sequester the CO2 is in brine aquifers. Studies suggest that the solubility is controlled by the interaction of the CO2 with the water and that ions affect the local structure of water around the CO2. Thus the effect would be more pronounced at higher concentrations of ion and thus would influence the CO2 solubility. Additionally the behavior of methane clathrate formation was observed to use as a future model for carbonate formation. Computational experiments were used to model the CO2 - H2O interaction at different levels of theory/basis sets. From this analysis, varying concentrations of brine solution can be evaluated as functions of temperature and concentration.

ftsW: Not A Filamentous Temperature Sensitive Wonder

Peter Bidey and Joseph R. McCormick Duquesne University, Dept of Biological Sciences Streptomyces coelicolor is a Gram-positive, filamentous, sporulating, soil bacterium that is a genetic marvel because null mutants survive without key cellular division genes that most organisms must possess to live. ftsW has been found to be essential in the rod-shaped bacteria, Eshcherichia coli, but has not been studied in the filamentous bacteria, S. coelicolor. It is believed that ftsW has two major functions in cell division: stabilization of the FtsZ-ring and to interact with FtsI. With this in mind, I tested to see if ftsW was dispensable in S. coelicolor. Using a cosmid containing ftsW and a mutagenic PCR product, I was able to introduce the insertion-deletion mutation into ftsW using an in vivo recombination strategy. Subsequently, the mutation was transferred to the chromosome. Using a low-copy-number plasmid, containing ftsW, I was able to demonstrate genetic complementation of the mutation. Finally, the presence of the mutation was verified by Southern blot hybridization proving that ftsW is truly not a filamentous, temperature sensitive, wonder because in S. coelicolor, ftsW is not essential for growth and viability.

Use of the Green Fluorescent Protein to Decipher Cellular Division of Streptomyces coelicolor

A.J. Szabo, Joseph R. McCormick Duquesne University, Department of Biological Sciences It has long been known that bacteria reproduce by binary fission. What is not known, however, is exactly how this is accomplished. My research is designed to build tools that will help answer this question. It is believed that a specific protein machine forms when the cell divides. The role of each protein involved in this machine is yet to be determined. I am attempting to solve this riddle by using the Green Fluorescent Protein (GFP) as a molecular tag for several of the proteins thought to be involved in cell division in the filamentous bacterium Streptomyces coelicolor. I am attempting to make a plasmid that will contain the region coding for GFP, which can be fused to the coding region for the division protein in question. For ease, the preliminary cloning steps will be carried out in Escherichia coli. Once the actual plasmid is created it can then be used to transform S. coelicolor. This protein tag will allow us to visualize the subcellular localization of each cell division protein by fluorescence microscopy of live cells. This valuable tool will undoubtedly shed light on the process of bacterial cell division.

Comparison of Pre- and Post-operative Kinematic Data in Ankle Joint Replacement Patients

Kelly Donahue and Mark C. Miller Duquesne University - The Kristen McMaster Motion Analysis Laboratory Patients undergo ankle joint replacement surgery to restore normal lower extremity function. In order to determine the kinematic benefits of the surgery, the ankle and knee joint ranges of motion (ROM) of eight unilateral ankle patients were recorded prior to and one year following ankle joint replacement. Six cameras were used to track reflective markers on lower extremity bony landmarks to facilitate the calculation of ankle and knee joint angles, walking speed, and step length. The results compared operated to unoperated and pre-operative to 1-year post-operative conditions. Pre-operative ankle stance and swing ROM increased significantly from operated to unoperated trials. Post-operative data showed that both operated swing phase ROM and operated step length were significantly lower than that of the unoperated side. There was a significant increase from pre-op to post-op trials in both operated ankle plantar flexion at heel strike and operated step length.

Analysis of Potential Division Mutants in Streptomyces coelicolor

Mary Ryan and Joseph McCormick Duquesne University, Department of Biological Sciences Streptomyces coelicolor is a simple filamentous, soil-dwelling bacterium, which is amenable to genetic alteration. Mutations in known division genes inhibit the cell's ability to divide correctly. These mutants often exhibit what is known as a blue-halo phenotype, characterized by the overproduction of the blue-pigmented antibiotic actinorhodin. New mutants were previously isolated by screening for colonies with blue haloes. My research involves analyzing the novel blue-halo phenotype mutants using a genetic complementation strategy. This process will insert a complete division and cell wall cluster from a cosmid into the chromosome to determine if a mutation lies within the division and cell wall cluster, the region of the chromosome containing many known division genes. We are most interested in mutations that identify unknown genes.

Preparation of a Photoaffinity-Labeled Laulimalide Derivative to Determine Binding Mechanism

Annette Welty University of Pittsburgh Laulimalide (1) is a natural product isolated from the marine sponge Cacospongia mycofijiensis. The compound exhibits potent anticancer activity arising from its ability to stabilize tubulin-derived microtubules, thereby rendering cell mitosis impossible. This project focuses on the preparation of a photoaffinity-labeled laulimalide derivative 2 for elucidation of the protein sequence responsible for laulimalide binding in tubulin. The photoaffinity label 3 to be incorporated in modified laulimalide derivatives has been prepared (eq 1). Current efforts are focused on preparing the upper half synthon 4 required for completing the synthesis of PAL-laulimalide 2 (eq 2). Ensuing protein binding studies will assay the ability of 2 to function as an effective surrogate for the native protein ligand

Osteoblast Attachment and Proliferation on a Tri-calcium Phosphate Bone Void Filler

Green, Ross, Quidwai, H, *Campbell, P, Doctor, J., Duquesne University, Department of Biological Sciences *Bone Tissue Engineering Center, Carnegie Mellon University ChronOS granulat (ChronOS II) is a FDA approved highly porous calcium tri-phosphate bone void filler that can be used to fill cavities that are left after bone surgeries in which a large portion of damaged or unhealthy bone is removed. MG 63 cells are derived from a human osteo-sarcoma and are widely used for in vitro analysis of ostoeblast function. ChronOS II was seeded at various concentrations of MG 63 cells to assess attachment and proliferation. We quantified the number of attached and proliferated cells within a one-week period using the fluorescent DNA binding CyQuant assays. In addition the morphology of attached cells will be observed using Scanning Electron Microscopy. Further studies include repeating various experiments, using human Adult Mesenchymal Stem Cells (hAMSCs) as well as MG 63 cells, and using other FDA approved bone void fillers.

Examination of methods of forming open-porous structures through spinodal decomposition and CO2 foaming

Todd Crosby University of Pittsburgh The objective is to research methods of forming open-celled structures. Applications of these structures include biological scaffolds for cell regeneration, as well as numerous uses in the food industry. One method is spinodal decomposition forming co-continuous morphologies in two component blends. The second method is through foaming. This is an open-ended project in its early stages of development. The system chosen for spinodal decomposition was a gelatin/dextran mixture. There is extensive information on this protein/polysaccharide biopolymer blend. However, there is limited information on the modulus and tensile strength of this system as a function of time, concentration, and porosity. The second path is to start with an aqueous solution of gelatin as a gel and foam the substance using CO2. This is advantageous because there is only one component. Various moduli and stiffness of gels will be tested during the foaming process.

Biohybrid Lung Development: Endothelial Cell Attachment to Microporous Hollow Fibers

Celena Daniels University of Pittsburgh, Department of Chemical and Petroleum Engineering, (under the direction of Dr. William Wagner and Alexa Polk) To prevent thrombogenesis and plasma weeping, endothelial cells are seeded on siloxane coated microporous hollow fibers (MHF). The MHF are modified by fibronectin (Fn) adsorption and radio frequency glow discharge (RFGD) to promote endothelial cell attachment. Modules have been created from multiple wraps of modified MHFs around a Teflon core, and placed in seeding tubes. Seeding tube designs are being evaluated to further increase endothelial cell retention and growth. The lid design containing a permeable membrane provided gas transfer that a solid lid design did not. The time for placing the MHF module inside a bioreactor, with cells, is being determined. In addition, the shear and gas transfer effects on ECs will be accessed, once the MHF module is in the bioreactor. Furthermore, endothelial cells are being compared to HepG2 cells (a liver carcinoma cell line) to compare cell growth rates.

The Evaluation of Non-fluorous CO2-philic Polymers and Surfactants

Loveland Jones, Xin Fan, Servi Kilic, Tugba Oz University of Pittsburgh, Department of Chemical and Petroleum Engineering Efforts have been made to develop inexpensive, highly CO2-soluble surfactants and polymers for various chemical and petroleum engineering applications. These polymers and surfactants (composed primarily of only carbon, hydrogen and oxygen) would be more practical, affordable, and biodegradable than the highly fluorinated, CO2 soluble compounds developed in the past. During this research, the solubility of commercially available nonionic and ionic surfactants with hydrocarbon- or oxygenated hydrocarbon-based tails were analyzed. These surfactants were CO2 soluble because the highly branched alkane or oligomeric poly(propylene oxide) tails are known to be CO2-philic. Progress was also made in synthesizing a polymer from the reductive acetylation of an acyclic ester. This polymer combines the attributes of the two most CO2 soluble non-fluorous polymers, poly(propylene oxide) and poly(vinyl acetate). Its solubility in CO2 has yet to be determined.

Isolation of similar metalloid reductase proteins in Sulfurospirillum barnesii and Sulfurospirillum arsenophilum

Elisabeth Hesse Duquesne University, Dept of Biological Sciences Sulfurospirillum barnesii and Sulfurospirillum arsenophilum are epsilon proteobacteria that respire arsenate. Previous work has identified a 48 kDa putative metalloid reductase polypeptide in S. barnesii. Antibodies to this protein also reacted with proteins from S. arsenophilum. The purpose of this work was to clone and sequence the gene encoding the 48 kDa protein from S. arsenophilum and to design new PCR primers based on the sequence of the gene in S. barnesii to produce an amplicon suitable for use in a heterologous expression system in Escherichia coli. The gene from S. arsenophilum had a 60% identity with the one from S. barnesii. The amplicon from S. barnesii was also inserted into E. coli for expression using the TOPO pcR C7 system (Invitrogen Inc., Carlsbad CA). Western blot analysis confirmed the production of the 48 kDa protein by E. coli, and activity assays were performed to assess the metalloid reductase activity in these cells.

The purification of the copper chaperone CopZ in E. hirae.

Nicole A. Spardy and Charles T. Dameron Duquesne University, Department of Chemistry and Biochemistry The element copper is necessary for proper functioning of all organisms, and is utilized in the catalysis of the transfer of electrons within a system. Cellular metabolism is a sensitive process, regulated by copper chaperones which control the trafficking of copper to the correct proteins. Previous research has shown that there are a limited number of such chaperones, and that each is utilized by a specific copper-dependent protein. Identifiable structures of these special metal guides contain metal binding motifs (MXCXXC) and stacked beta-sheets. One such copper chaperone that has been identified is CopZ located in the cop operon of the Gram-positive bacterium Enterococcus hirae. This 8 kDa protein functions by delivering copper (I) to the Zn (II) CopY complex, which then consequently releases the operon's repressor (CopY) from the DNA. I propose to purify the copper-chaperone CopZ through the use of size-exclusion chromatography.

The Synthesis and Characterization of Hydortris (3-isopropylpyrazole-1-yl) borate

Jeremy W. Snodgrass, Brian Kail, and Partha Basu Duquesne University, Department of Chemistry and Biochemistry Molybdenum containing enzymed are important in different chemical transformations in the environment. Molybdenum is the only 4d element which is essential to all life forms. In humans failure to synthesize the molybdenum cofactor means development of a fatal metabolic disorder. Many of these enzymes function via atom transfer chemistry. The focus of this research is directed towards the synthesis of the Molybdenum containing complex LMoO(OPh)(OPEt3), where L=Hydrotris (3-isopropylppyrazole-1-yl) borate. By following procedures from Young and Trofimenko we synthesized isopropyl pyrazole and the ligand KHB(3-iPrPz)3 to begin synthesis of the larger Molybdenum containgin complex. Future work will include research on the larger complex LMoO(OPh)(OPEt3). By synthesizing the larger complex we will be able to better understand serine coordination.

Catalytic Deactivation in a Reversible-Flow Reactor

Anthony Mitri University of Pittsburgh Chemical Engineering REU Catalytic partial oxidation of methane to synthesis gas (a mixture of H2 and CO) was investigated over Pt, Ni, Ir, and Rh monolith supported catalysts. The differences between reversible-flow and autothermal steady-state reactor operations were considered by determining respective catalyst deactivation trends, as well as by varying inlet flow variables (volumetric flow-rate and methane to oxygen ratio). Catalyst deactivation was considered to be a complex interplay between coke formation, sintering, and metal volatilization. EDX (energy dispersive X-ray) analysis was used to examine respective metal concentration gradients in both the inert zones and monolith supported metal catalysts. With variation in the volumetric flow-rate and methane to oxygen ratio, for each of the catalysts, inlet flow conditions were determined such that methane conversion and syngas yields were optimal. Changing the catalyst support to a silicon-based wafer, with deposited Pt, was also investigated. SEM (scanning electron microscopy) was used to determine the arrangement and quantity of Pt present on the silicon wafer.

Developing Web Tools For Data Mining And Analysis Of SAGE Data

Kristin Wheeler1,5 and Panayiotis V. Benos2,3,4 1Bioengineering and Bioinformatics Summer Institute, 2Center for Computational Biology and Bioinformatics, 3Department of Human Genetics, 4University of Pittsburgh Cancer Institute, University of Pittsburgh, 5Department of Computer Science, Grambling State University Novel techniques for studying the gene expression, like microarrays and SAGE, require new databases to store and exploit these data. Also, the need for tools to traverse and analyze the information has increased. UniGene is a collection of all currently known/predicted expressed sequences, including mRNA of genes, ESTs and gene predictions. The focus of this project is to develop a web tool that will exploit this information and produce various SAGE tag sets according to user-specified criteria. This tool could be used for searching UniGene collection, or other gene expression datasets, for genes that match specific criteria. The search will return the name of the organism, the length of the sequence, and the position where the tag was found. Genomic information in this context gives a simplistic reference for gene expression patterns. We will test this tool on the human genome.

No Title Perry, Tamika L., Deglau, Timothy E., Wagner, William University of Pittsburgh, Chemical/ Petroleum Engineering Coronary artery disease (CAD), a chronic disease in which the coronary arteries are hardened and narrowed by fatty plaque deposits; reduces oxygen-rich blood flow needed for function. Untreated, CAD can gradually worsen and lead to cardiac arrest. Balloon Angioplasty, a standard effective treatment, has been opposed for its temporary results (restenosis) and damage to artery walls. The objective of the project was targeted delivery of endothelial cells and microspheres in an effort to prevent the reinstatement of plaque to damaged vascular tissues. Cultured human coronary artery EC's were incubated with 10mM poly(ethylene glycol)-biotin [NHS-PEG-biotin]; used to covalently attach to amine groups of proteins exposed to damaged vascular tissue, as well as the 2mg/mL fluorescent Neutravidin. The EC's were then analyzed with quantitative flow cytometry to determine the number of PEG-biotin molecules per EC. Bovine carotid artery segments were tested with the parallel plate perfusion chamber in an effort to stimulate flow over the arterial wall.

ò No Title Mary Pham University of Pittsburgh The use of cell scaffolds will likely be employed in the field of tissue engineering. These scaffolds would provide a base structure for the adhesion and growth of cells before implantation, and would gradually transfer mechanical stress to the cells while biodegrading. These scaffolds would need to be flexible and strong, with the ability to biodegrade non-toxically and promote cell adhesion and growth. A group of poly (ester-urethane) ureas have been synthesized to meet this need. Surface modifiers and chain extenders used in the synthesis took into account the requirement of non-toxic biodegradation as well as promotion of cell adhesion and growth. Thermal properties of these polymer films were measured using differential scanning calorimetry and molecular weight was measuring using high performance liquid chromatography. Human umbilical vein endothelial cells were cultured and grown on several of these polymer films. Adhesion and viability were measured.

The Hattler Catheter Michael Plachta University of Pittsburgh, McGowan Center for Regenerative Medicine Exchange of blood gases through the lungs is essential to survival. Though several methods for inducing respiration and sustaining life are currently available to combat respiratory failure, they have rash inadequacies. The need for improved methods led to development of the Hattler Catheter. The catheter, when inserted into the vena cave, supplements gas exchange independent of the lungs. The Hattler Catheter utilizes holofibers as an exchange membrane for blood gasses. The bundle of fibers surrounds a balloon, which is rapidly inflated and deflated. This pulsing maximizes gas exchange by increasing longitudinal blood flow across the fibers and minimizing laminar flow barriers. A pneumatic system, which oscillates pressure in the catheter balloon, drives pulsation. A mathematical model representing the system was created that system components could be evaluated and performance optimized by simulation, not experimentation. My duties include determination of several unknown system parameters required for the models computations.

Effect of arterial hemodynamics on porcine internal jugular veins

Stuart H Weiler, Mohammed S El-Kurdi, Douglas W. Hamilton, David A Vorp University of Pittsburgh The most common treatment for coronary artery stenosis is bypass grafting with saphenous vein. 90% of these grafts stenose within 10 years. Intimal hyperplasia (IH) is the long-term failure response. IH is characterized by de-adhesion, migration, and proliferation of smooth muscle cells (SMC). The focus of this work was de-adhesion of SMCs. Six 24-hour ex-vivo paired-perfusions (arterial vs venous) were performed with porcine veins. The veins were fixed, cryosectioned, and immunostained for tenascin-C (TNC), mitogen inducible gene-2 (Mig-2), and integrin linked kinase (ILK). TNC disassembles focal adhesions, while Mig-2 and ILK maintain adhesions. Results indicated an upregulation of TNC, and downregulation of Mig-2 and ILK under arterial conditions. Protein expression will be quantified via western blotting. Longer experiments will be performed to assess possible transient changes in gene expression. Immunostaining and western blotting will also be performed for two other molecules involved in focal adhesion disassembly, thrombospondin and SPARC.

An Experimental Study of Heat Transfer in Tumbled Granular Materials

Justin Yanko and J.J. McCarthy University of Pittsburgh Heat transfer in even the simplest particle flows is poorly understood. Thermal Particle Dynamics (TPD) was used to model a tumbler mixer at different rotation rates and fill levels. The model indicated that the bulk temperature within the drum varies in a logarithmic fashion. The bulk temperature was higher at greater rotation rates when the drum was half-filled, but when the drum was less than half-filled, higher rotation rates produced lower bulk temperatures. The model also showed that the rate of heat transfer was generally faster as the fill level decreased. We develop an experimental method to evaluate the heat transfer of this system, so that we may study the heat conduction in granular media undergoing slow flow in a rotating drum. It is hypothesized that the experimental measurements will support the results of the model.

Ab Initio and Density Functional Study of Aviation and Vehicular Fuel Components with a Nitrile Rubber Polymer

Edward G. Franklin, J. DeChancie, & J.D. Evanseck* Duquesne University, Contribution from the Center of Computational Sciences & National Energy Technology Laboratory Analyses of methane and carbon dioxide interactions with a nitrile rubber polymer have been performed using quantum mechanical methods. Second-order Múller-Plesset theory (MP2) with the 6-31G(d) basis set provides a realistic structural and energetic description of the intermolecular interactions, yielding CS symmetry for the nitrile and carbon dioxide complex and C1 symmetry for the nitrile-methane system. The calculated MP2 binding energy of the nitrile and carbon dioxide system is approximately 1.5 kcal/mol stronger than that of the nitrile-methane complex. Density functional theory utilizing the B3LYP/6-31G(d) level of theory does not provide an accurate electronic description of either system. The data suggests the possibility of selective component binding along with a possible means of CO2 sequestration, which may have environmental significance. This study may also be applicable to studies pertaining to poor O-ring swelling properties observed in Fischer-Tropsch derived fuels.

Staudinger Synthesis of Glycosyl Amides Using DPPE

Sara Duncan, Shawn McKee and Peter Norris* Youngstown State University, Department of Chemistry Glycosyl amides are found in biomolecules such as nucleic acids and glycoproteins. The chemical construction of the amide is possible using a modified Staudinger method, which employs a glycosyl azide, a suitable phosphine and a carboxylic acid derivative. One of the drawbacks of using readily available PPh3 in this chemistry is that the byproduct Ph3P=O is often difficult to remove. To avoid this problem we have investigated the use of bis(diphenylphophino)ethane (DPPE) in place of PPh3 and found that reaction purification is much easier. This presentation will detail our studies on the application of DPPE to the synthesis of various glycosyl amides as well as NMR studies into the mechanistic progress of the reaction.

Glycosyl Triazole Synthesis Using Microwave Heating

Robin Hurt, Tracey Meyers and Peter Norris Department of Chemistry, Youngstown State University The Huisgen 1,3-dipolar cycloaddition between azides and acetylenes has been described as an almost perfect reaction for coupling preformed building blocks together to create new materials [1]: the reaction is perfect in terms atom economy, the building blocks are usually simple to create, and the cycloaddition usually occurs by simply heating the reaction mixture. With a long term view to constructing new glycopolymers by "clicking" together preformed carbohydrate-derived azides and acetylenes we have been investigating the use of microwave heating to speed up the cycloaddition chemistry. This poster will detail the utility of this method in the construction of various glycosyl triazole derivatives

Developing an Efficient Monte Carlo Algorithm to Calculate Population Ratios in a Symmetric Double-Well Potential Energy Surface

Steve Ascencio and Kenneth D. Jordan University of Pittsburgh, Department of Chemistry The Monte Carlo method, named after the city famous for gambling, is an algorithm used for calculating properties of systems of particles with complicated potential energy surfaces. One such algorithm is currently employed to calculate the population ratio of a single particle in a symmetric double-well potential. However, the predicted 50% ratio is not found at low temperatures. MathCAD and C++ programs are being used to explore and improve the algorithm in order to achieve the necessary results. This improved algorithm can then be applied to systems with much more complicated potential surfaces than the symmetric double-well.

Using quantitative fluorescence detection PCR for rtPCR of a rare transcription factor and its targets in the fly.

Lindsey Aspden and Erin Predis Duquesne University, Dept of Biological Sciences The gene lozenge is involved in cell differentiation for the primordial eye of Drosophila melanogaster. Lozenge, functioning as a transcription factor, acts as an inhibitor or activator of a variety of other genes. It has been previously reported that a gene called prospero is regulated by lozenge. We hypothesize that the activation of prospero expression by Lozenge occurs transcriptionally and can be demonstrated by quantitative reverse transcriptase PCR. The lzmr1 mutant has been shown to express significantly lower levels of lozenge as compared to normal. By utilizing real-time PCR to compare the levels of expression of prospero in normal and lzmr1 mutants, we have shown that lower prospero levels correspond to decreased lozenge expression. Experimental details of quantitative fluorescence detection PCR and various control experiments will be discussed.

"Sequencing the R Box"

Stephanie Gullace Duquesne University, Department of Biological Sciences The maize r1 locus encodes a transcription factor that regulates the production of anthocyanin, a red pigment in plants. r1 haplotypes can consist of one to five homologous genes in direct or inverted arrangements. Although the regulatory regions of r1 genes are very dissimilar, a 51 base pair motif (called the R box) appears in both inverted repeat and direct repeat genes at the 5' start of transcription. This R box has homology to known transcription factor binding sites. Using the Polymerase Chain Reaction, I amplified a 350 base pair segment containing the R box from haplotypes found throughout the world. I will sequence the DNA and compare the sequences to known R box sequences. Comparisons of the sequences will be used in phylogenetic analysis of r1 genes.

Near-Infrared Dyes as a Means of Detecting Latent Fingerprints

Sarah Blanning, Mitch Johnson Duquesne University, Dept of Chemistry & Biochemistry Current methods that utilize laser induced fluorescence (LIF) in the visible region of the spectrum often result in poor image quality due to inherent fluorescence of the surface or native fluorophores present in the material. A proposed method causes fluorescence in the near-infrared (NIR) region (>790nm), thereby eliminating most nonspecific background fluorescence because few materials fluoresce when excited by NIR light. Each sample was fumed with cyanoacrylate, stained with the NIR dye Patonay-3, rinsed with ethanol, and visualized with a diode laser at 788nm to produce an emission at 810nm. The resulting print was then photographed using CCD camera. This procedure made the fingerprint easily visible on surfaces that would have fluoresced when excited by either UV light or an argon-ion laser. Therefore, NIR-LIF is a viable alternative when current fingerprinting techniques fail.

A Method of Computing Foot Progression Angles in Tibial Osteotomy Patients

Gail Siewiorek and Mark C. Miller Duquesne University Foot progression angles are one method of evaluating gait and a surgical procedure that improves patients' leg alignment, such as a tibial osteotomy, may affect the foot progression angle. In order to have accurate data that is comparable to other studies, review of the scientific literature found an accepted definition of the angle and a normative foot progression angle. Experimentally, reflective markers on bodily landmarks were tracked as eight tibial osteotomy patients walked along an instrumented walkway until three trials of kinematic data were collected via PEAK5 software, both pre-operatively and post-operatively. A MATLAB program written for this experiment included an anthropometric correction of the landmark locations to the accepted normative sites. For each patient, averaged midstance angles were computed and a t-test was performed to test for statistical significance. Preliminary results suggested that a tibial osteotomy had no effect on the foot progression angle.

Innie or Outie?: Determining the Topology of the Arsenate Reductase of Bacillus selenitireducens

Kimberly Boelte Duquesne University, Dept of Biological Sciences Bacillus selenitireducens is a haloalkaliphilic bacterium that has been shown to respire arsenate using a membrane bound arsenate reductase. As B. selenitireducens is a Gram positive bacterium, there was some question as to whether the catalytic site of the arsenate reductase faced the cytoplasm or the peptidoglycan layer. Artificial electron donors were used in spectrophotometric assays to determine activities for arsenate reduction, from which were calculated specific activities. Using methyl viologen and benzyl viologen, artificial electron donors with different permiabilities to the cell membrane, the specific activities for arsenate reduction were determined and compared in whole cells and cell lysates. Methyl viologen was also used to determine the specific activities for arsenate reduction in samples treated with detergent and samples that were permiabilized through lysozyme treatment.

The Effects of Melatonin on Proliferation of Human MT1-Chinese Hamster Ovary Cells and Suprachiasmatic Nucleus 2.2 Cells

Aksana Vasilyeva, Nagarjun Konduru, Paula A. Witt-Enderby Duquesne University, Department of Pharmacology and Toxicology Previous studies have shown that melatonin decreases cell proliferation and transformation, making it a potential anti-cancer agent. However, only three concentrations of melatonin (1 µM, 10 µM, and 100 µM) were used to demonstrate this. The purpose of this study was to expand the number of concentrations and observe the effects of melatonin on the proliferation of Chinese Hamster Ovary cells transfected with human MT1 receptors and Suprachiasmatic Nucleus 2.2 cells that endogenously express the MT1 receptors. The cells were treated with melatonin concentrations ranging from 0.1 pM to 100 µM. The effects of melatonin were studied by direct cell count and by measuring protein levels after a 24-hour incubation period. The results of the study show that melatonin increases cell proliferation at 10 nm and 100 nM. At concentrations of 0.1 pM, 1 pM, 10 pM, 100 pM, 1 nM, 1 µM, 10 µM, and 100 µM melatonin has an inhibitory effect.

EFFECTS OF SOLUTION COMPOSITION ON ADSORBED CYTOCHROME C ELECTROCHEMISTRY

Jelena Petrovic, Jianjun Wei, Hungjun Yue, Rose A. Clark, and David H. Waldeck University of Pittsburgh, Dept of Chemistry, Saint Francis University Dept of Chemistry, Math, and Phys. Sciences Cytochrome c (cyt c) is a redox protein that can be found in the mitochondria of all living organisms where it plays an important role in the process of creating cellular energy. Due to its biological importance as well as small size, availability, and ease of handling, cyt c has been studied extensively. Many studies, primarily in solution, have investigated how its redox chemistry changes with the environment of the protein. In the present research, the redox properties of cyt c adsor

Synthesis of Substituted Bicyclic Molecules: Potential Protein-Protein Interaction Inhibitors

Melanie Grubisha Duquesne University, Department of Pharmacology and Toxicology In the herpes simplex virus, it is known an interaction between the two proteins, UL30 and UL42, is required for successful DNA replication. Biochemical analysis has elucidated specific regions of UL30 and UL42 that, in combination with x-ray crystal analysis, has provided a valuable breakdown of the interaction. Using this information, synthetic molecules were designed to act as inhibitors of this interaction. The bicyclic structure of these inhibitors has key points that can be substituted with various functional groups to produce a molecule paralleling the structure of UL30 This poster will describe the preliminary synthesis of one of these bicyclic inhibitors.

Wood Permeability of Pennsylvanian White Oaks

John Worgul, Paul Kolesar, Bruce Beaver Duquesne University, Department of Chemistry & Biochemistry In wine production many factors come into play that shape the way a wine will taste. The period spent aging in an oak barrel has a significant effect on the wine before being aged in a bottle. It has been shown that the oak allows the wine to exhibit characteristics described as woody, vanilla, toasted, coconut and has a significant effect on bouquet. These effects can be attributed to cis- Oak Lactone (cis-b-methyl-g-octalactone). During aging Oak lactone leaves the wood to enter the solution where it will affect the wine. By measuring the permeability of the wood (through elligitannin concentrations) it is possible to classify trees that may be more desirable for destination of a cooperage. By knowing the permeability and Oak lactone concentration of particular trees it is possible to conduct further experiments by comparing these differences and the effects of the quality of the solution to produce better wine.

Using Mutants to Determine the Role of Primary Structure in the Site-Specific Oxidation of Proteins.

Justin A. Pruneski, Michael A. SerraYoungstown State University, Department of Chemistry Reactive oxygen species (ROS) are a group of highly reactive molecules derived from molecular oxygen (O2). They are often formed by the reaction of metal ions with hydrogen peroxide. When produced, these molecules cause oxidative damage to important biomolecules, such as proteins, in the immediate vicinity of their production. Therefore, the damage is thought to be site-specific, and may depend on the protein's primary structure. In order to determine the role primary structure plays in this type of oxidation, two site-directed mutants have been prepared using the polymerase chain reaction: N77-H77 and a double mutant H15-S15 + N77-H77. The mutant genes will then be transformed into the yeast Pichia pastoris in order to express the mutant proteins in quantities sufficient for study.

Purification, Isolation, and Analysis of Oxidized Hen Egg White Lysozyme

Ben Kutay, Mike Serra Youngstown State University, Department of Chemistry Reactive oxygen species (ROS) are a class of molecules produced by the reduction of molecular oxygen. To study the oxidative damage to proteins caused by ROS, which have been linked to nearly a hundred health problems, the model system of hen egg white lysozyme (HEW) was chosen. ROS can be generated by metal catalyzed oxidation (MCO) systems, which utilize transition metal ions to generate highly reactive species such as the hydroxyl radical.The purification of the oxidized HEW lysozyme is carried out using cation exchange chromatography in which the five most prominent peaks are collected. Further purification of the oxidized protein peaks, which are structurally similar, is accomplished through the use of hydrophobic interaction chromatography (HIC). The purified oxidized forms will be characterized by mass spectrometry, which will identify the extent of the oxidative damage to the lysozyme.

Structure-based design of tumor vaccines

Matthew A. Joseph1, Jeffrey R. Kovacs1, Tugba G. Kucukkal2, Jeffrey D. Evanseck2, and Wilson S. Meng1 Duquesne University, Division of Pharmaceutical Sciences & Department of Chemistry & Biochemistry The purpose of this study was to identify more potent analogues of GVYDGREHTV (wt), an HLA-A2.1-restricted T cell epitope derived from MAGE-A4. MAGE-A4 is a tumor-associated antigen that is overexpressed in melanoma. One limiting-factor of the wt epitope as a tumor vaccine is its poor stabilization of HLA-A2.1. Our goal was to study the effects of peptide/HLA-A2 stabilization and T-cell receptor (TCR) usage by mutating the peptide at the 7th position from a downward pointing glutamic acid to alanine (E7A). Our hypothesis was that by changing the amino acid at the 7th position, it would be possible to control the flexibility of the arginine at position 6 (pR6), and that by controlling the flexibility of pR6, the peptide could possible engage a greater variety of TCRs. Methods: Peptide binding was determined with T2 cells and TCR-Vb usage was determined with HLA/2Kb-Tg mice. Results. Molecular modeling showed that by mutating the glutamic acid to alanine the H-bonding scheme the glutamic acid had with the water in the HLA-A2 groove was lost. Molecular dynamics simulations revealed that pR6 is more flexible in E7A than in the wt peptide. Flow cytometry showed that there was no distinguishable binding difference between wt and E7A.

Regulation of Copper Levels in Cells

Dahlia Ashford and Charles T. Dameron Duquesne University, Department of Chemistry & Biochemistry Copper is necessary for normal cellular metabolism, it is used as a cofactor for vital enzymes involved in biological processes and is essential in its usage for electron transfer processes. However, copper is also toxic when there is an excess amount in the cells. In the Gram-positive bacterial system Enterococcus hirae (E. hirae) cellular copper levels are regulated by the encoding of four genes: copY, copZ, copA, and copB. CopY encompasses a copper responsive repressor protein that controls the transcription of all cop genes according to cellular concentrations of Cu(I). CopZ encodes a copper chaperone required to route copper through the cell and to shield the cytoplasm from the toxic effects of the Cu(I) ion. CopA and copB encode P-type copper ATPases. CopA imports Cu(I) and copB exports the Cu(I).

The Genetic Analysis of Putative Cell Division Gene sqnB in Streptomyces coelicolor A(3)2

Angela Verdoni, Jennifer Bennett, and Joseph McCormick Duquesne University, Department of Biological Sciences Streptomyces coelicolor A(3)2 is a filamentous soil bacterium with a developmentally complex life cycle. Beginning as a substrate mycelium, S. coelicolor differentiates into aerial filaments which eventually divide into chains of spores. The fts genes in S. coelicolor control cell division, and a mutation in any one of these genes results in either a partial or complete block of cell division. FtsQ is a protein that is essential in the division process, potentially recruiting other proteins to the site where cell division occurs. A null mutation in the ftsQ gene results in virtually no sporulation (division). A strain with a mutation (sqnB; suppressor of Q null) has been isolated in which sporulation has been restored. In this study we attempt to identify the location of sqnB through the means of genetic mapping experiments. We are also interested in whether sqnB has the ability to suppress mutations in other cell division genes, or if it is specific for a deletion of ftsQ. Discovering the ability of sqnB to suppress other division phenotypes may offer answers as to whether or not SqnB is a novel cell division protein.

USING MOSSBAUER SPECTROSCOPY FOR OBSERVING NANOMETICAL HEMATITE AND NANOCOMPOSITES

Zachary Bruno, Monica Sorescu Duquesne University, Department of Physics he phases and hyperfine interactions of nano-hematite after varying times of mechanochemical activation and different alloys of the nanocomposite spring magnet (Nd2Fe14B) at different annealing times and temperatures have been studied by means of emission Mossbauer emission spectra. For the nano-hematite it was found that after longer times of mechanochemical activation the hematite phase was virtually removed from the compound to be replaced by phases of magnetite and a-Fe. For the spring magnets it was found that the concentration of a-Fe changed for each alloy after different annealing times and temperatures.

QM/MM Simulations of the Diels-Alder Free Energy Profile in Molten Sodium Chloride Salts

Joshua Plumley, O.Acevedo, J. DeChancie, J.D. Evanseck* Duquesne University, Contribution from the Center of Computational Sciences and the Department of Chemistry & Biochemistry Free energy profiles for the Diels-Alder reaction between cyclopentadiene and methyl acrylate have been computed in molten sodium chloride at 1000 ÆC. A combined quantum and molecular mechanical (QM/MM) hybrid Hamiltonian has been employed for Monte Carlo simulations. The QM/MM approach features AM1 as an effective Hamiltonian to describe the bond making and breaking process of the Diels-Alder reaction, while the OPLS force field is used for the molten sodium chloride. Becke three- parameter density functional theory with the non-local correlation of Lee, Yang and Parr with the 6-31G(d) basis set has been used to test the predicted structures and energies from AM1 calculations. The computed results provide molecular insight into how highly ionic environments influence the stereoselectivity and rates of chemical reactions.

Determining binding of a novel TNFa-derived peptide in mouse splenocytes

Karl Anderson, Steve M. Firestine, and Wilson S. Meng Duquesne University, Division of Pharmaceutical Sciences The goal of this study is to investigate whether pTNF (YTYQGKL), a peptide derived from tumor necrosis factor alpha (TNFa) identified by us recently, can bind to murine splenocytes. We have previously determined that pTNF binds to antigen presenting cells, including mouse dendritic cells. The putative molecular target of pTNF is tumor necrosis factor receptor-2 (TNFR2), a membrane-bound receptor is up-regulated in tissues undergoing inflammation. Methods: Cells were harvested from female C57BL/6 mice and red blood cells were removed prior to binding assays. Binding experiments were performed at 4C with a fluorescein-tagged pTNF and analyzed using flow cytometry and fluorescence-imager. Results: We confirmed expression of TNFR2 on the lymphocytes, and observed binding of pTNF to a significant fraction of the cells. We have also screened a panel of novel small organic molecules for their capacity to compete with pTNF for binding sites on splenic cells. Conclusion: Data obtained from these experiments shall pave the way for discovery of novel agents for modulation of inflammatory mechanisms.

Computational Investigation of the Acetonitrile Anion with Explicit Solvents

Andrea M. Goncher, Jeffry D. Madura Duquesne University, Department of Chemistry & Biochemistry, Center For Computational Sciences Nitriles play an important role in synthetic chemistry. When probing nitrile anions, a change in reaction stereo- selectivity occurs when the solvent and the counter ions are changed. We have chosen to use the acetonitrile anion to study the effects of solvent on the anion structure and counter-ion position. Analysis using ab initio and DFT methods showed that C-lithiation was preferred over N- lithiation in the gas phase, however N-lithiation is preferred when 2 -3 solvent molecules were added. These calculations were extended to systems containing chiral centers. PCM calculations were also performed on the anion and explicit solvents where the model defines the solute cavity as the union of a series of interlocking atomic spheres. Five and six membered rings containing the nitrile anion were studied to observe the anion structure and used to predict the product stereochemistry upon addition of a methyl cation.

Electrodsorption of Dendrimers on Titanium Oxide Nanopartices Kern B. Wilson, J. D. Evanseck, Shahed U.M. Khan Duquesne University Dept of Chemistry & Biochemistry Dendrimers are highly branched, porous, multifunctional molecules that pose the potential for significant increase of contact area between CO2(g) and amines. The aim of this research is to determine the percentage of nitrogen that is adsorbed by electroadsorption of dendrimeric compounds on Titanium nanoparticles (260 m2/g). The dendrimer compounds are polypropylenimine hexadecamine dendrimer generation 3( DAB-Am-16). Dendrimers from generation 2 and 1 have been investigated as well. Electroadsorption has been carried out using 0.001M dendrimer in 0.01M HCl under potential control. Maximum adsorption of nitrogen was found to be 2% per gram of the titanium oxide (TiO2) by XPS (X-ray photoelectron spectroscopy) analysis, where dendrimer-16 was electroadsorbed under 0.4 V versus Ag/AgCl electrode. FTIR results also indicate adsorption of the dendrimer on TiO2 surface. Ab intito calculations have been carried out to investigate the structural and energetic behavior of secondary and tertiary amines with CO2, N2 and other flue gases.

DNA Aptamers for Fluorescent Chemical Sensors Renee Allen University of Pittsburgh Cellular DNA is typically found in a double stranded a-helical structure and functions as a storage macromolecule of genomic information. Single stranded DNA has been synthesized and shown to be capable of binding ligands and small molecules, forming complex folding structures, and functioning as their RNA and protein counterparts by catalyzing reactions. These functional single stranded DNA are known as aptamers. We are using in vitro selection techniques to select for DNA aptamers that bind to 1-(4-methoxyphenyl)piperazine (MPP). A synthesized single stranded DNA pool with ~1013 different random sequences is selected against a resin with an attached MPP. Aptamers that bind to this molecule can then be applied to selection with a MPP substituted 2,7-dichlorofluorescein that will function as a fluorescent sensor to localize the respective aptamers in vivo.

Evaluation of CultiSphers as a Cellular Vehicle for Adipose-Derived Stem Cells Bradley M. Tebbets, Lauren E. Kokai, Jennifer M. Bennett, John S. Doctor, Kacey G. Marra University of Pittsburgh, Division of Plastic Surgery, Duquesne University, Dept of Biological Sciences CultiSphers (collagenous microcarriers) have the potential to act as cellular vehicles for soft tissue and nerve regeneration using adipose-derived stem cells (ADSCs). The attachment, proliferation and differentiation of ADSCs on CultiSphers were determined in vitro using spinner flasks. DAPI, a fluorescent nuclear stain, was used to determine the number of ADSCs attached to the CultiSphers. 24 hours after the ADSCs and CultiSphers were added to the spinner flask, unattached ADSCs were washed away to observe subsequent proliferation of ADSCs on CultiSphers. ADSCs viability on CultiSphers was quantified by dye exclusion (Trypan Blue) using light microscopy. After two weeks of culture in the spinner flasks, adipogenic differentiation media was added to the ADSCs. ADSCs differentiation was observed using Oil Red O, a lipid-specific stain. Additionally, neuronal differentiation media will be added to ADSCs on CultiSphers to produce neuronal progenitor cells.

Characterization of transgenic mouse line expressing Cre recombinase Stephen T. Magill, Carol X.-Q. Chen, Yong-Jian Liu University of Pittsburgh School of Medicine, Department of Neurology and the Department of Neurobiology The loss of dopaminergic neurons in the nigro-striatal pathway is the pathological hallmark of Parkinson's disease (PD); however, the pathogenesis remains unknown. Cytosolic dopamine (DA) has been shown to be toxic. In the brain it is packaged into vesicles by vesicular monoamine transporter 2 (VMAT2). Inactivation of VMAT2 may increase cytosolic DA levels. We are developing a conditional VMAT2 knockout mouse using Cre recombinase/loxP mediated excision to generate an in vivo DA toxicity model of PD. This mouse will be created by crossing a floxed VMAT2 mouse with a Cre mouse showing brain-specific expression after addition of the inducer, doxycycline. Here we characterize the Cre mice using „-Gal staining, immunohistochemistry and Western blotting. Our preliminary results for this line of mice show Cre expression in the brain and increased expression with doxycycline treatment. Generation of the Cre mice is needed to create the conditional VMAT2 knockout mouse.

CHARMM ANALYSIS OF BRANCHED-CHAIN FATTY ACIDS IN RELATION TO CAPILLARY ELECTROPHORESIS Osi Iyalomhe, Mitch Johnson, Jeffrey Evanseck Duquesne University, Department of Chemistry & Biochemistry Capillary electrophoresis (CE), a sensitive separation technique, has been applied to separating a series of unbranched fatty acids. However the hypothesis exists that a fatty acid's shape, dynamics in separation medium, degree of unsaturation and branching, as well as chain length, may have an effect on its resolution using CE. The CHARMm program has been used to carry out computational and molecular dynamics studies on branched-chain fatty acids, 2-methyl hexanoic acid and 3,5,5-trimethyl hexanoic acid, in a box of 695 waters. Results will be used as an aid in interpreting experimental data derived from the CE separation of these acids.

Trigeminal ganglion neuronal activity during normal and hypertensive blood pressures David W. Matthews, Michael Shoykhet, Daniel J. Simons University of Pittsburgh School of Medicine, Department of Neurobiology The rat vibrissae-barrels circuit, a well-characterized somatosensory system, mediates responses to deflections of whiskers. Each whisker follicle is contained within two sub-epidermal sinuses, which together form a follicle-sinus complex (FSC). The FSC contains an intricate microvasculature and mechanoreceptors from 150-200 myelinated axons of the primary afferent neurons in the trigeminal ganglion (TG). To understand the potential biophysical relationship between these mechanoreceptors and the vast microvasculature, we used single-cell electrophysiology to record the extracellular responses of TG neurons to whisker deflection at normal and hypertensive blood pressures (BPs). Counterintuitively, increased BP was consistently correlated with fewer neuronal spikes in response to a single whisker deflection. These findings suggest that TG neurons may use a distinct encoding mechanism according to the physiological state of the rat.

Studying Quantum Dots in Lipid Bilayers Sarah Rugheimer University of Pittsburgh Quantum Dots are semiconductor nanocrystals that range in size from 3-9nm. I am studying these dots in soft media such as gels and lipid bilayers. QDs have the potential inside the vesicle membrane to make a voltage sensitive probe. Through gel electrophoresis we will separate dots of different sizes. Decreased fluorescence has been a problem we hope to solve in the formation of the gel with the quantum dots.

Measuring Perfusion Using MRI Paula Myers University of Pittsburgh Perfusion Magnetic Resonance Imaging (MRI) measures the rate at which blood is delivered to tissue. The measure of perfusion acts as an indicator of tissue health. Applications of this imaging include diagnosis of chronic disease and the study of microvascular changes associated with functional cerebral activation. An influential advantage of MRI is that it has no ionization radiation as in x-ray techniques. Further development of techniques in MRI enable us with new ways to study the brain in great detail. Arterial spin labeling (ASL) is a noninvasive perfusion MRI technique that uses radio frequency (RF) to invert the arterial spins (magnetization). A control image (spins not inverted) is also obtained. The perfusion is proportional to the difference (control -label) image. Analyzing the perfusion difference requires the evaluation of several terms each representing different factors of (ASL). The linear velocity term will be the main focus of this experimental evaluation. We will simulate blood using a water mixture that has the same properties as blood. The velocity will be analyzed by evaluating the fluid as it flows through a mechanical phantom using MRI.

Physics Simulation Software for the ATLAS Detector Zaheer Parpia University of Pittsburgh The Standard Model of elementary particles attempts to define all fundamental forces and their carrier particles. However, gravitational interaction and mass are not defined in the model.There are several experiments currently being designed to help us answer some of these questions. The main goal of the LHC ( Large Hadron Collider) is going to be discovering and studying the properties of the so called Higgs boson, an elusive elementary particle responsible for generation of masses of all elementary particles. The Standard Model requires that at least one such important particle must exist. The ATLAS detector is being designed to record data from the collision.To be able to carry out the simulation at the University of Pittsburgh, various simulation and computational tools need to be first configured. Once ready, physics studies with ATLFAST that include studies of two photon decay of the most likely Higgs candidate or some supersymmetry (SUSY) production process can be carried out.

Identification of New QSOs to Better Understand Foreground Components of the Universe Lisa Kelly (advised by Dr. David Turnshek) University of Pittsburgh, Department of Physics and Astronomy Quasi-stellar objects (QSOs), are thought to be supermassive black holes surrounded by luminous accretion disks. High redshift QSOs are oftentimes used in studies to determine the foreground components of the Universe. This includes gaseous clouds and other components that would affect the luminosity of something behind them. However, an insufficient number of background QSOs are known. Some of the promising candidates for new QSOs are among two categories: those behind nearby galaxies that have a very large angular size to permit the possibility of several bright background QSOs close to the galaxy's center, and QSOs that lie within an arcmin of each other. New data from Sloan Digital Sky Survey color images suggest that new searches for quasars behind galaxies will be a successful endeavor. This project consists of observing QSO candidates for seven nights using the 2.1 m telescope at the Kitt Peak National Observatory in Arizona.

A study of the material properties of Ultra High Molecular Weight Polyethylene (UHMWPE) Jasper Harris University of Pittsburgh, Department of Mechanical Engineering When looking at total-joint replacement the major concern is the wear being applied. Wear is responsible for a range of negative consequences such as fracturing of the material, ultra high molecular weight polyethylene (UHMWPE), the body reacting to debris due to wear, and possibly replacement. Therefore our objective is to study the properties of ultra high molecular weight polyethylene, the material used in total-joint replacement, in order gain a better understanding of its ability to resist wear. There will be several different approaches taken in order to achieve our objective. One approach is to determine how the direction of wear being applied affects the strength of ultra high molecular weight polyethylene. Hypothetically, when wear is applied in the same direction as the molecular chains our material becomes stronger and wear is retarded. The opposite takes place in the other directions. Another approach is to find out how well does the material resist wear when it is processed through extrusion. The intent of this research is to obtain true stress-strain curves in order to verify our previous hypothesis.

Controlling Molecular Self-assembly at Interfaces Jasmine Star Yuko Ma University of Pittsburgh Molecules can self-assemble into sophisticated structures on a surface. Understanding and controlling these molecular arrangements is imperative in developing nanometer scale molecular sensors and computational devices. I have used Scanning Tunneling Microscopy to investigate the structures and dynamic properties of these systems in the hope of learning how to manipulate the variables, such as functional groups, electric fields, adsorbate-substrate interactions, that control the self-assembly. Even the simplest systems, e.g. HOPG (highly oriented pyrolytic graphite) are surprisingly complex. Most published STM images only resolve every second surface atom on HOPG, Our high-resolution images of HOPG show unusual three-fold symmetry and MoirØ pattern in the arrangement of carbon atoms. These patterns reveal ALL the surface atoms and are probably caused by the electronic perturbation from the underlying graphite layer. The self-assembled structures of liquid crystal 8CB on HOPG and eicosanol on gold are imaged and corresponding molecular patterns are deduced.

The Large-Scale Clustering of Quasars Nick Allen University of Pittsburgh Quasars are the most luminous sources in the universe, can be seen to great distances, have a compact volume, and are likely powered by accretion onto supermassive black holes. In this study, quasars will be used to study the large-scale distribution of matter in the universe. The data are drawn from the Sloan Digital Sky Survey. Quasars in the survey are identified using spectra. The spectra have been automatically classified using a computer algorithm which fails approximately ten percent of the time, causing contamination in the data. I have inspected thousands of spectra in order to assign proper classification. I will use the clean sample to investigate large-scale quasar clustering. My study will help determine how clustering in general has evolved throughout the history of the universe.

Thymine Hydroxylase: Gene Isolation from a cDNA Library Melisa Kundracik* and Jeffrey A. Smiley Youngstown State University, Department of Chemistry Thymine hydroxylase is an enzyme involved in the rare thymidine salvage pathway, which is used to convert thymine to uracil in pyrimidine base synthesis. This pathway is found in few organisms, among them Neurospora crassa, Aspergillus nidulans, and Rhodotorula glutinis. Specifically, thymine hydroxylase catalyzes three oxidative steps in the middle of the pathway converting thymine to uracil-5-carboxylic acid [Iso-orotate (IOA)]. The gene for thymine hydroxylase has not yet been isolated. The purpose of this study is to isolate this gene from a cDNA library for the yeast Rhodotorula glutinis via hybridization and labeling with a digoxigenin (DIG) antibody probe. After isolation of the gene, it will be amplified by PCR, expressed in E. coli clones, and the protein will be overproduced for further study.

Synthesis and Reactions of Bis(2,2,2-trifluoroethyl)phosphonoalkynes John R. Miller, Jared F. Mike, Ankit B. Patel, John A. Jackson* Youngstown State University, Department of Chemistry Improved methods of synthesis and purification of bis(2,2,2-trifluoroethyl)phosphonoalkynes have been developed. Conjugate addition to bis(2,2,2-trifluoroethyl)phosphonoalkynes using a number of various nucleophiles such as cuprates, enolates, and hydrides were explored. The utility of bis(2,2,2-trifluoroethyl)phosphonoalkynes as dienophiles in cycloaddition reactions has also been investigated.

Acid and Temperature Dependence of Pyrrole-2-Carboxylate Decarboxylation and Integration into the Physical Chemistry Laboratory Kelly Hutchinson,* Howard Mettee, Stacey Lowery Bretz, Jeffrey Smiley Youngstown State University, Department of Chemistry The focus of this research is to design a collaborative learning physical chemistry laboratory experiment in kinetics. Both the effects of acid concentration and temperature on the rate of decarboxylation of pyrrole-2-carboxylate (P2C) have been investigated. The reaction of P2C has been found to be acid catalyzed, to be pseudo first order rate, and to have a higher activation energy at lower acid concentrations (higher pH). This experiment requires students to work in small groups to obtain different parts of the data and then collaborate as a whole class by sharing their data to discover how both the rates and activation energies change as a function of both acid concentration and temperature.

Cloning and Expression of Two Genes in the Tryptophan Degradation Pathway for the Study of ACMS Decarboxylase Katie Muzevich*, Vanessa Ho and Jeffrey Smiley* Miami University and Department of Chemistry, Youngstown State University Involved in tryptophan metabolism in mammals is an unconventional decarboxylase, amino carboxymuconate semialdehyde decarboxylase (ACMSD), which cleaves a carboxyl group from 2-Amino-3-carboxymuconate-6-semialdehyde (ACMS). This reaction can only occur after the previous metabolite, 3-Hydroxyanthranilate (3HA), is oxidized and the ring of 3HA is opened, forming a carboxyl and an aldehyde group. We intend to study the unusual mechanistic aspects of ACMSD, as the structure of the substrate is atypical. The substrate ACMS is neither commercially available nor is it stable at room temperature, as it spontaneously forms quinolinate, a precursor to NAD+ and NADP+. Consequently, ACMS must be obtained via enzymatic conversion of commercially available 3HA to ACMS by 3-Hydroxyanthranilate-3,4-dioxygenase (3HAO), which was cloned from yeast and expressed successfully in a yeast expression system. As ACMSD is not present in yeast, it is being cloned from the known mouse sequence and will be expressed in E. coli.

Iso-Orotate Decarboxylase: The Non-Enzymatic Reaction as a Model for the Enzymatic Mechanism Craig R. Smith, Daniel A. Landfried, Vincient R. Barnes, and Jeffrey A. Smiley Youngstown State University, Department of Chemistry Iso-Orotate Decarboxylase (IDCase) completes the thymidine salvage pathway in which thymidine is converted to uracil, via the enzymatic decarboxylation of iso-orotate. To elaborate upon the mechanism of the enzymatic reaction, the non-enzymatic reaction has been studied in regards to the dependence upon pH, temperature, ionic concentrations, and the presence of multiple potential catalysts. Preliminary results suggest that two mechanisms exist, one which dominates at moderate pH, and a second that is hydroxyl dependent, occurring at an elevated pH. The secondary reaction occurs more rapidly and has a lower activation than the reaction at moderate pH, which suggests a hydroxyl dependent mechanism. The addition of 1 mM sodium thiomethoxide increased the rate of reaction, supporting the hypothesis that the reaction occurs with addition of a nucleophile presumably adding to C6. Further studies will examine isotope effects of both a deuterated substrate along with a carboxyl 13C labeled substrate.

A Comparison of the Hopewell (1803) and Mill Creek Furnaces (1835) Sarah Dellinger and Daryl W. Mincey Youngstown State University The evolution of steel is of great historical and anthropological interest. During the summers of 1975, 1976, and 1977, archaeological excavations were carried out by Dr. John R. White and volunteers at the Eaton (Hopewell) Furnace. This furnace, near Youngstown, Ohio, is believed to be the earliest blast furnace west of the Allegheny Mountains dating back to 1803. Dr. White has recently discovered another furnace in Mill Creek Park dating back to 1835. Samples from the Hopewell and Mill Creek Furnaces were obtained, and their chemical composition will be analyzed to determine differences in the raw materials and processes that occurred. The ppm concentrations of Mn, P, S, Ni, Cr, Mo, C, Si, and Ti will be described. Standard steel samples have been used as controls. The iron samples from both furnaces will be liquefied through the process of acid microwave digestion and analyzed with an ICP emission spectrometer.

Differences in Expectations between Teachers and Learners of University Chemistry Nathaniel Grove* and Stacey Lowery Bretz University of Pittsburgh at Johnstown and Department of Chemistry, Youngstown State University Students' expectations for learning chemistry in the university classroom affect their attitudes and ultimately their overall success in general chemistry. To measure these expectations, a modified version of the MPEX (Maryland Physics Expectations) survey was administered. The modifications were made to better reflect the differences between the disciplines of physics and chemistry. Respondents were asked to read 36 statements about learning chemistry and to rate their level of agreement or disagreement with each. Because the expectations of entering university students were of particular interest, the survey was given to incoming BS/MD students. Also of interest were any differences in expectations between such recent high school graduates and the expectations of their teachers, i.e., high school chemistry teachers. Accordingly, the survey was administered to area high school teachers participating in summer research experiences in the chemistry department. Findings from the survey analysis will be presented, along with directions for future research.

PREPARATION AND X-RAY DIFFRACTION STUDIES OF INORGANIC NITRIDE-FLUORIDES Harry Seibel* and Tim Wagner Youngstown State University, Department of Chemistry A relatively unexplored area of solid state chemistry is the study of inorganic nitride-fluoride materials. Fewer than forty inorganic nitride-fluoride compounds have been previously reported, compared to tens of thousands of inorganic oxides, nitrides and fluorides. The main reason for this is probably due to the extreme air-sensitivity of many of the nitride-fluorides already reported, making them relatively difficult to prepare and characterize. Recent advances in X-ray diffraction methods now make the characterization of N-F compounds much more feasible. The present study, which is part of a larger effort at YSU, focuses on the preparation and X-ray characterizations of: Ba2NF, BaCuNF, Y2NF3, and BaMnNF2. The final results of the first single crystal preparation and quantitative structure analysis of Ba2NF will be presented, which indicate that Ba2NF has the rocksalt-type structure of BaO. Preliminary results on the preparation and analyses of the other target compounds will also be presented.

Tylosin and Its Effects on the Antibiotic Resistance in Bacillus subtilis Franciska Kiraly* and Thomas D. Kim Walsh University and Department of Chemistry, Youngstown State University With the expanded use of antibiotics and biocidal agents released into the environment, increased evidence of antibiotic resistance has been found within certain types of bacteria. This resistance is evident in the changes to a bacterium's protein sequence, which can be visualized through a two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Tylosin, one such broad-spectrum antibiotic frequently used for its anti-inflammatory properties, is used as the antibiotic under study. By exposing two strains of Bacillus subtilis to the Tylosin, 2-D PAGE's have been performed to identify if the Tylosin has any effect on the protein sequence of the B. subtilis. If proteins vary between the control and the exposed bacteria, these proteins will be isolated and sent to the University of Cincinnati to be analyzed using mass spectrometry and access the amino acid sequence. This could then be used as an aid in understanding how antibiotic resistance is formed.

Synthesis and Characterization of Organometallic Nanowires Robert Wilcox* and Allen D. Hunter Youngstown State University, Department of Chemistry The goal of our research is to synthesize and characterize organometallic Nanowires, organometallic compounds with conjugated backbones. Molybdenum and tungsten dinitrogen complexes will be linked by di-isonitrile bridges. To get distinct compounds instead of mixtures of variable chain length, the Nanowires will be capped at the ends. For the synthesis of bi and trimetallic complexes the outer metal dinitrogen units will be first capped on one side with a carbonyl group. These will then be connected with each other either using a di-isonitrile or a bis(di-isonitrile)metal unit as the bridge.

Synthesis of Various Bidentate Phosphine Ligands Nathan J. Takas, Allen D. Hunter Youngstown State University, Department of Chemistry Current research has led to an interest in compounds with high Non Linear Optical (NLO) properties. Expected to be among the highest NLO responses are conjugated organometallic complexes. Many metals desirable for use in these complexes must be ligated to limit the geometries of the final product to rigid-rod, straight chain conformations (favorable for NLO responses). Dppe is a common bidentate ligand with the downfall of lower than desirable solubilities of its metal complexes. Thus a series of dppe analogs were synthesized to allow for greater solubility of the metal complexes and chains. The following were synthesized: 1,2-diphosphinoethane, 1,2 diphosphinobenzene, as well as dppe derivatives with substitutions of methyl, ethyl, or methoxy groups in the para position of the phenyl rings.

Analysis of Components in Wine by Gas Chromatography- Mass Spectrometry and High Performance Liquid Chromatography Jazerie Williams*, Tunde Meyers, Roland Reisen, Daryl Mincey Central State University and Youngstown State University The composition and concentration of various materials in wine can dramatically affect its aroma and taste. Such materials include carboxylic acids, sugars, alcohols, terpenes, ketones, and esters. We will report a method for determining carboxylic acids in wines from the Lake Erie region of the United States. Solid-phase microextration (SPME) was combined with gas chromatography/mass spectrometry (GC/MS) and automated sample handling to produce excellent sensitivity and reproducibility. The use of a method produced at Cleveland State University will also be used in comparison to a validated method produced at Youngstown State University using HPLC.

Modulation of E. coli RNase P Function by the Peptide Antibiotic Viomycin Stephanie Spence, Subhashish Kr. Chakraborty and Soumitra Basu University of Pittsburgh, Center for Pharmacogenetics, School of Pharmacy The goal of this project is to study viomycin mediated modulation of RNase P function. The emergence of antibiotic resistance makes it important to identify new targets and develop original drug molecules. RNase P, a ribonucleoprotein complex is a ubiquitous ribozyme, which cleaves the leader sequence from pre-tRNAs, producing mature tRNAs, molecules essential for an organism's survival. RNase P structure differs in humans and bacteria, making it an excellent drug target. We hypothesized that the RNA-protein electrostatic interaction in RNase P may be inhibited by the basic peptide viomycin. To study the modulation of RNase P function, an in vitro assay was used where E. coli RNase P was incubated in the presence of pre-tRNA at various concentrations of viomycin and the cleavage patterns of pre-tRNA was monitored. Viomycin mediated inhibition of RNase P function was found to be concentration dependent. The mechanism of inhibition is currently being explored.

Computational Insights into the Actin Family of Proteins William Hawse, Alpay Temiz, Lee-Wei Yang, Holly Goodson and Ivet Bahar Dept of Biophysics, Johns Hopkins University, Center for Computational Biology & Bioinformatics, Department of Molecular Genetics & Biochemistry, University of Pittsburgh, Department of Chemistry/Biochemistry, University of Notre Dame Members of the actin family have well-defined cytoskeletal functions. More recently, actin related proteins (ARPs) have been associated with nuclear activities. To better understand evolutionary and functional relationships in this family, we performed a phylogenetic analysis. Our analysis shows that at least four additional ARP subfamilies are conserved from humans to yeast, and all are implicated in nuclear functions. The strong evolutionary conservation of these proteins suggests that ARPs and actin play fundamental roles in nuclear processes. Homology modeling results suggest that all ARPs share the core actin ATP binding cleft and that some of the ARPs share additional commonalities with actin. In addition to the evolutionary study, the Gaussian Network Model (GNM) was used to predict the molecular dynamics of the ARP2/3 complex and highlight modes of motion that are responsible for the function and regulation of the ARP2/3 complex.

Analysis And Identification Of Possible Subfamilies In The Methionine S-Sulfoxide Reductase Family Of Enzymes Jeffrey M. Kidd and Hugh B. Nicholas Jr. Bioengineering and Bioinformatics Summer Institute, Center for Computational Biology and Bioinformatics, University of Pittsburgh, Case Western Reserve University, Department of Biology, Biomedical Initiative, Pittsburgh Supercomputing Center A sequence analysis of the methionine S-sulfoxide reductase (MsrA) family of enzymes identified several potential subfamilies. The methionine residues of proteins are easily oxidized to a mixture of the R- and S-isomers of methionine sulfoxide. The peptide methionine sulfoxide reductase family of enzymes is responsible for the reduction of oxidized methionine residues in proteins back to methionine. MsrA, which catalyzes the reduction of the S-isomer of methionine sulfoxide, has recently been a target of investigation. The family contains a strongly conserved active site and several mechanisms of action have been proposed. It has been suggested that the MsrA family contains distinct subfamilies that may have different reaction pathways. The 187 MsrA sequences identified by a database search were analyzed and subdivided into mutually exclusive groups. The nature of the possible subfamilies was determined and molecular modeling techniques were used to investigate the subfamilies' implications on the proposed reaction mechanisms.

Transcription Factor Binding Sites Of HHV8 Jennifer Dietrich1,5 and Panayiotis V. Benos2,3,4 1Bioengineering and Bioinformatics Summer Institute, 2Center for Computational Biology and Bioinformatics, 3Department of Human Genetics, 4University of Pittsburgh Cancer Institute, University of Pittsburgh, 5Department of Computer Science, Southern Methodist University Human Herpes Virus-8 is a recently discovered human virus and little is known about its transmission. Due to HHV8's role in developing Kaposi's Sarcoma, HHV8 is being heavily investigated. The life cycle of HHV8 is characterized by two phases: the latent and the lytic. Transition between these two phases heavily depends on ORF50. Thus, the analysis of the promoter of ORF50 for patterns of human transcription factors could potentially reveal interesting interactions between host and parasite. My research involves the identification of genes with similar expression patterns to ORF50 and subsequent analysis for identification of novel promoter elements and/or comparison with known elements in the TRANSFAC database. During the process, operons in the viral genome will be identified, so the promoter set will be more accurate.

Ab Initio Calculations Of A Series Of Alcohols For Use In Large-Scale Molecular Dynamics Simulations Paul Gera1,2, Alexander C. Saladino3 and Pei Tang3 1Bioengineering and Bioinformatics Summer Institute, Center for Computational Biology and Bioinformatics, University of Pittsburgh, 2Departments of Biology and Computer Science, Elizabethtown College, 3Departments of Anesthesiology and Pharmacology, University of Pittsburgh The effects of alcohol and general anesthetic molecules on the central nervous system have been known for more than a century, yet the molecular mechanisms of their actions remain unsolved. Recent advances in large-scale molecular dynamics simulations have made it possible to reveal the interaction details of these molecules with potential protein targets. In the present study, ab initio calculations were performed on a series of n(normal)-alcohols (C2 - C12) at the hybrid B3LYP level with the 6-311G basis set using the Gaussian 98 program. The geometric parameters and dipole moments have been determined. These alcohol molecules are ready for applications in further molecular dynamics simulations.

Ab Initio Modeling To Develop CHARMM Force Fields For Novel Sequence Specific DNA Bending Agents Scott Geyer1,2, Anne Loccisano3 and Jeffrey Evanseck3 1Bioengineering and Bioinformatics Summer Institute, Center for Computational Biology and Bioinformatics, University of Pittsburgh,2Department of Chemistry, University of Virginia, 3Departments of Chemistry and Biochemistry, Duquesne University Controlling the transcription process has benefits in disease treatment and gene research. DNA bending can up or down regulate transcription. The addition of bending agents to sequence specific binding molecules may provide a way to control certain transcription processes. Molecular Dynamics studies are being done using CHARMM to investigate the effects of different steric groups on the binding of a polyamide chain and the bending of the DNA. To create an accurate CHARMM force field to describe DNA bending agents, ab initio modeling has been carried out on model compounds of the polyamide using Gaussian 98/03. Optimization and frequencies were done at the B3LYP / 6-31G(d) level for the model compounds. Comparisons of the optimized structures, theoretical frequency and IR absorption calculations to experimental data have been made. Torsion energies were calculated and graphed against CHARMM results for model compounds at 15 degree increments. These results were used to modify the CHARMM force field.

Analysis And Design Of Discodermolide Analogues That Target Tubulin Jennifer Greene1,2*, John Jara1,3*, and Billy Day4 1Bioengineering and Bioinformatics Summer Institute, Center for Computational Biology and Bioinformatics, University of Pittsburgh, 2Department of Biological Sciences, University of Maryland, Baltimore County, 3Department of Biological Sciences, University of Texas at El Paso, 4 Departments of Chemistry and Pharmaceutical Sciences, University of Pittsburgh Proper assembly and disassembly of tubulin and its superstructure of microtubules are necessary for cell division, making it a good anticancer target. Analogues of new microtubule stabilizers were synthesized and analyzed for biological activity. Computational molecular models of the lead compounds were built for structure-activity relationship analyses and docking to the model of tubulin obtained by electron crystallography. After analysis, analogues were modeled using a visualization and computational program called MOE (Molecular Operating Environment). All analogs modeled were energy minimized and analyzed to create new models to be tested for biological activity, including possible displacement of paclitaxel-a microtubule stabilizing drug, microtubule stabilization activity, and growth inhibition for cancer cell lines. MOE was also used to dock discodermolide and the newly created analogs to the crystal structure of tubulin. The goal is to make hypothetical models of analogues to be synthesized and tested to discover active but synthetically more accessible analogues.*Both authors contributed equally to this work.

Conformations Of Proteins On Lattice Models Natalie Kantz1,4, Jiangbo Miao5, Judith Klein-Seetheraman6 and Hagai Meirovitch2,3 1Bioengineering and Bioinformatics Summer Institute, 2Center for Computational Biology and Bioinformatics, 3Department of Molecular Genetics and Biochemistry, University of Pittsburgh, 4Departments of Computer Science and Biology, Queens College, City University of New York, 5Department of Computer Science, Carnegie Mellon University,6Department of Pharmocology, University of Pittsburgh The optimization of lattice model algorithms that define the conformational space available to proteins is proposed. These lattice model algorithms include the Simple Cubic (SC) lattice model and the Face-Centered Cubic (FCC) lattice model. The models are based on two way (?, ?) rotation of the Ca backbone of the protein to generate all conformations for a given number of iterations. Subsequently the conformations are evaluated according to the best fit of protein backbone to the lattice. According to the resulting conformations, the implementation of a three way (?, ?, ?) rotation and the step size increment of these angles optimizes the SC and FCC lattice model algorithms.

Linguistic Analysis Of Endosymbiosis Ken Ober1,2 and Judith Klein-Seetharaman3 1Bioengineering and Bioinformatics Summer Institute, Center for Computational Biology and Bioinformatics, University of Pittsburgh, 2Department of Biology, Bard College, 3Department of Pharmacology, University of Pittsburgh Medical School Application of language technologies to protein sequences from entire genomes has indicated that genomes may be viewed as representations of different languages or dialects. Specifically, n-grams, peptide subsequences of length n, have been identified that can serve as genome "signatures" by being over represented in some organisms but rare or absent in others. Here, we tested if such genome signatures are preserved when one organism is engulfed by another organism, an event that has been proposed to be the origin for chloroplasts in plants. We compared the amino acid compositions of the protein sequences of plastids and cyanobacteria, the class of organisms that most closely resembles the endosymbiont that gave rise to plastids. The signatures for the cyanobacteria and the plastids were then analyzed to quantify how much of a change in signature was necessary for the endosymbiosis event to succeed.

Biological Importance Of The Most Discriminative N-grams In A Family Of Proteins. Mehrdad Seyed Safavian1,4, Dror Tobi2 and Ivet Bahar2,3 1Bioengineering and Bioinformatics Summer Institute, 2Center for Computational Biology and Bioinformatics, 3Department of Molecular Genetics and Biochemistry, University of Pittsburgh, 4Department of Computer Science, Xavier University Protein folding prediction is an old and challenging problem that is still the focus of much research. Many approaches have been taken to solve this problem. In this study, we took the n-gram frequency approach to detect patterns of repeating n-grams in the G Protein Coupled Receptor (GPCR) protein family within the PIR-PSD database, and created vectors of the most discriminative n-grams of this family. As expected, the cosine values between the vectors belonging to the GPCR family members were higher than cosine values between the GPCRs and the rest of the proteins in the database. We compared these results with a more refined group of only GPCRs classified as Vertebrate Rhodopsin in PIR-PSD, and even to a further refined group of those that only exist in humans. Finally, we examined the position of the most discriminative n-grams in tertiary structure to learn about their function.

A Mathematical Model Of Stress Fracture In Human Bone

Elisa A. Sandvik1,2, Demian Nave3, Arthur Wetzel3, David Deerfield3 1Bioengineering and Bioinformatics Summer Institute, Center for Computational Biology and Bioinformatics, University of Pittsburgh,2Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 3Biomedical Initiative, Pittsburgh Supercomputing Ctr.

Stress fracture is a common injury among dancers, runners, and trainees in the military. It is the result of fatigue failure of bone. Microcracks form from everyday constant and cyclic loading of the human skeleton. Normally, bone remodeling removes those small cracks at a certain rate. When the bone remodeling rate cannot keep up with the microcrack formation rate, fatigue damage accumulates, and eventually, a stress fracture occurs. It can be a painful experience. The system of equations that governs microcrack formation and bone remodeling is graphically modeled using MATLAB's Simulink software package. A simulation is executed with appropriate loading values. The instability of the system is illustrated by plots of damage, porosity, activation frequency, and microstrain with time. All simulations show the delicate balance between damage formation and removal, and the point in one specific case where damage formation overloads the system and creates fatigue failure.

Tubulin Polymerization Dynamics Modeling

David Sivakoff1,2 and G. Bard Ermentrout31Bioengineering and Bioinformatics Summer Institute, Center for Computational Biology and Bioinformatics, University of Pittsburgh, 2Departments of Mathematics and Psycology, University of Maryland, College Park,3Department of Mathematics, University of Pittsburgh

Tubulin dimers polymerize into microtubules, which are an integral part of the cytoskeleton and many cellular processes of most eukaryotes. Each microtubule undergoes long periods of polymerization relative to short periods of rapid depolymerization (catastrophe). Microtubules within a system oscillate between these two phases in order to produce a dynamic instability for the overall system. We have proposed several models for microtubule oscillations based on the effects of free tubulin concentration and diffusion, the rates of polymerization and depolymerization, and the frequency of catastrophe. We used XPP, an ordinary differential equation (ODE) software, to visualize and modify the various ODE, partial differential equation (PDE), and stochastic models that we devised. Our goal is to derive a model that describes the oscillations of an individual microtubule, and maintains dynamic instability in a system of coupled microtubules.

Modeling the effect of anticancer drug 9-NC on human colon xenografts in scid mice.

Shilpa Reddy University of Pittsburgh, Department of Chemical Engineering

Camptothecin, an herbal component from a Chinese tree, has been known to have properties that interfere with the function of topoisomerase enzymes, which enable DNA replication in cells. Clinical studies have observed cell cycle arrest by apoptosis in rapidly dividing cells exposed to camptothecin analogues.Using data from experiments done on mice implanted with HT29 human colon xenografts, a model was developed to predict the effect of the drug 9-Nitrocamptothecin in tumor growth in those mice. First a cell cycle model of tumor cell growth without the drug was developed. The drug, metabolite, and the delayed response of the cells were then added as parameters to the function that was used to predict uncontrolled tumor growth. These parameters and errors were optimized to create a better fit of the simulated model to the actual data in order to determine an accurate rate at which the drug affects rapidly dividing tumor cells.

Detection of hepatic vitellogenin mRNA as a biomarker for endocrine disruption in tiger salamanders

Lisa Mangus, Kyle Selcer Duquesne University, Department of Biological Sciences

Vitellogenin is the egg yolk precursor protein produced by the liver of female oviparous vertebrates under estrogen stimulation. Vitellogenin can be used as a biomarker for exposure of animals to environmental estrogens, which are chemical agents capable of disrupting endocrine pathways. These compounds may have deleterious effects on humans and wildlife. Our lab has been developing assays to measure hepatic vitellogenin mRNA in various aquatic vertebrates after stimulation by estrogenic agents. Using degenerate primers designed from known vitellogenin sequences of various amphibian and fish species, an RT-PCR assay was conducted on control and estrogen- treated male tiger salamanders (Ambystoma tigrinum). The cDNA obtained from estrogen-treated males was sequenced, compared to the known Xenopus laevis (African clawed frog) vitellogenin sequence, and found to have strong homology. New primers, designed based on the A. tigrinum sequence, should be useful in further studies of environmental estrogens and vitellogenesis in A. tigrinum and other species of salamanders

Disrupting the formation of an unknown protease responsible for the degradation of CspA and CspB.

Ian D. Ferguson, Dr. Nancy J. Trun Duquesne University, Department of Biological Science

In Escherichia coli there are a series of nine proteins that are denoted the cold shock like proteins. Eight of these proteins have been cloned; they are cspA, cspB, cspC, cspE, cspF, cspG, cspH, and cspI. We have transformed E. coli strains with clones of each gene to induce production of all these in the presence of arabinose, cspA, cspB, cspC, cspE, cspG, and cspI clones will produce mRNA in these strains. We have found that the Lon protease will degrade CspC, CspE, CspG, and CspI. It is not know however what degrades CspA and CspB. The goal of these experiments is to randomly insert transposons, in the cell's chromosome, in order to disrupt the production of the unknown protease. We have shown that CspC, CspE, CspG, and CspI, when overproduced, will activate the promoter for the rcsA gene. We will use this assay to detect insertions that disrupt the protease that degrades CspA and CspB and allow for activation of the rcsA promoter.

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