My efforts have been keenly focused on the development of bioanalytical methods to measure endogenous and exogenous small-molecules and proteins from an assortment of biological fluids and tissue extracts. Of late, I have been building a number of methods to support the analytical microbiology efforts of our team here at BCM/TCH, and the efforts of collaborators affiliated with outside institutions. As a member of the TCH-Microbiome Center, I apply LC-MS/MS-based methods to support an assortment of bio-medically relevant projects that include: 1) examine if specific microbes (i.e., Bifidobacterium dentium, Bacteroides ovatus, and others) possess specific metabolic pathways necessary to produce a targeted set of neurotransmitters and short-chain fatty acids in in vitro culture; ii) examine if these same microbes are capable of modulating neurotransmitter production in our in vitro intestinal organoid models, and in our in vivo gnotobiotic mouse models of the mammalian gut-brain-axis; and, iii) performing biomarker discover in a number of pediatric liver and gastroenterology-related diseases.

I currently work in the Microbiome Center at Texas Children's Hospital. I have been working on developing a rapid LC-MS/MS-based in vitro method to fingerprint the Antimicrobial Resistance (AMR) profiles of standard and clinically relevant Klebsiella pneumonia (K pneumonia) isolates. The method utilizes sub-Minimum Inhibitory Concentration (MIC) levels of commonly prescribed antibiotics (e.g., carbapenems) to probe for hydrolytic activity of potentially expressed beta-lactamase enzymes. Additionally, I am working towards adapting my expertise in targeted LC-MS/MS analysis to quantitate biologically relevant small-molecules in microbiological laboratory (e.g., SCFAs, bile acids, and potential bacteria-host signaling molecules). I am currently working on methods for quantifying these analytes in the following samples: stool, bio-reactor, and bacteria media and cell pellets. Furthermore, I am currently working on developing my skills in proteomics, metaproteomics, and proteomic-based bioinformatics. Finally, I am working closely with our in-house clinical microbiologists to gain an understanding on how to work with pathogenic micro-organisms safely and in accordance with BSL2 safety requirements (e.g., bacterial incubation and expansion, inoculation, and how to assess the log phase of bacteria growth (lag, expansion, and stationary).

Adjunct Faculty in the Department of Pharmacy Practice and Translational Research

In this role, I review manuscripts undergoing peer review, invite candidates to peer review articles, and make accept/revise/reject decisions based on anonymous peer reviewer recommendations. Further, I recruit peer reviewers and content for the journal.

I assist the editorial staff of the journal by providing input and feedback on website content, peer-review processes, and journal formatting.

I am a member of the MSACL Scientific Committee Member for the OMICs Steering Committee for the 2024-MSACL National Meeting

In this voluntary role, I assist the Society by co-coordinating the presented content of the Metabolomics Interest Group Workshop at the annual ASMS National Meeting - this is a 2-year appointment.

Developed targeted LC-MS/MS methods on a Sciex 6500 QTrap for the following projects:Quantitative lipidomics method for the quantitation of eicosanoids, (S)-HETEs, cysteinyl leukotrienes, lipoxins, prostaglandins, thromboxanes, and platelet-activating factors present in cell, plasma, or serum samples.Quantitative metabolomics methods: i) measurement of ~50 metabolites from diverse chemical classes from cell-based biological extracts; ii) measurement of transsulfuration pathway metabolites for an on-going clinical oncology study to screen for potential biomarkers present in human serum and plasma.Quantitative methods for the quantitation of therapeutic compounds: i) simultaneous assessment of PK/PD parameters and tissue distribution of an investigational NNMT inhibitor in the serum and tissues of mice; and ii) assessment of PK parameters an antibiotic in plasma or serum collected from critically ill pediatric burn patients.

Developed targeted Low-Resolution LC-MS/MS (LR-LC-MS/MS) on an Agilent 6460 tandem mass spec, or High-Resolution, Accurate-Mass (HRAM-LC-MS)) methods on a Thermo Scientific OrbiTrap Fusion mass spec for the following projects:Quantitative metabolomics methods: i) measurement of 36 amino acids and amino acid derivatives in various biological matrices; ii) determination of the position and degree of carbon-13 isotope tracer incorporation into the amino acids alanine, proline, glutamine, and glutamate in mosquitoes fed bloodmeal with [1,2-13C2]-glucose; and iii) measurement of the isotopolog population distributions of carbon-13 isotope tracer incorporation into approximately 43 targeted metabolites using HRAM-LC-MS.Quantitative methods for the quantitation of therapeutic compounds: i) assessment of L-Asparaginase PD in mice treated with commercial or novel in-house derived mutants of the enzyme-drug; ii) assessment of the loading of an immunogenic peptide into a novel adjuvant for the development of an anti-cancer vaccine; and iii) assessment of the tissue exposure of the radioprotectant drug, WR-1065, in the jujenum, duodenum, liver, pancreatic tumors, and plasma of mice treated with the prodrug, WR-2721 (Amifostine).Performed preventative maintenance and monthly calibration of the LC-MS/MS system. Trained junior staff on the operational use of the laboratory software and hardware.

I worked as a Senior Research Scientist in the Methods Development (MD) group in the Bioanalytical Sciences Division of WorldWide Clinical Trials (WCT) located in Austin, Texas. In this role, I was able to accomplish the following tasks: 1) Developed approximately 20 LC-MS/MS bioanalytical methods for the quantitation of pharmaceuticals and metabolites in plasma harvested from humans, rats, and beagles; 2) performed full GLP-level validations on two bioanalytical methods; 3) evaluated new MD technologies for increasing throughput during the development and production phases of our bioanalytical workflows (e.g. Shimadzu SIL-20AC HT; Shimadzu MPX2 2-channel multiplexed LC system; and SPEWare ALDIII SPE screening robot); 3) served as the MD laboratory supervisor and laboratory safety officer to ensure that all MD staff complied with operational and EH&S SOP's. My secondary role was focused on the composition and execution of Operations Qualification (OQ) and Performance Qualification (PQ) scripts to complete the validation packages for new technology initiatives at WCT. I took a leadership role in the following validation projects: 1) authored and executed PQ scripting for the validation of Analyst 1.6.1 for the operation of a single AB Sciex mass spectrometer in a regulated production environment; 2) I co-authored the replicate IQ/PQ for the deployment of Analyst 1.6.1 on 19 additional API-4000 and API-5000 mass spectrometers in a regulated production environment; 3) co-authored the validation plan and SOP for the deployment of Thermo-Fisher Scientific Aria LX-2 2-channel Multiplexing LC Systems in a regulated environment; 4) authored the OQ and PQ for the control and operation of a CTC PAL autosampler (w/ DLW) by Analyst 1.6.1; 5) Authored and executed the PQ for a single Aria LX-2 2-channel Multiplexing LC System in a regulated environment; 6) authored and executed the replicate PQ for four additional Aria LX-2 2-channel Multiplexing LC Systems.

Developed LC-MS/MS methods to measure the tissue-level biotin status indicators 3-hydroxyisovaleric acid and 3-hydroxyisovaleryl carnitine in human plasma and urine.Conducted biomarker research and managed past and on-going clinical sample analysis performed at the Arkansas Department of Health, Public Health Laboratories.