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Thanks for stopping by. Douglas Toal, PhD, is a clinical scientist with over 25 years of experience in translational research, clinical laboratory operations and diagnostic assay development. He has worked alongside other scientist to pioneer the clinical application of metabolomics for the screening of inborn errors of metabolism and rare disease. Additionally, his teams have developed and validated small molecule assays for conditions like prediabetes and chronic kidney disease. In the area of cell biology and genomics, Dr. Toal has led efforts to introduce innovative clinical diagnostic assays for the identification of Alzheimer's disease, hospital-acquired infections, and other serious infectious diseases. Dr. Toal completed his doctorate in the microbiology at the University of Oklahoma where he studied intercellular communication in soil bacteria. He completed post-doctoral fellowship training at the Mayo Clinic in Rochester, Minnesota. He is board certified in Medical and Public Health Microbiology by the American Board of Medical Microbiology. Selected publications are listed below
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SELECT PUBLICATIONS
Clinical Metabolomics for Inborn Errors of Metabolism
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Advances in Clinical Chemistry, 2022: 107, 79-138
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Metabolism is a highly regulated process that provides nutrients to cells and essential building blocks for the synthesis of protein, DNA and other macromolecules. In healthy biological systems, metabolism maintains a steady state in which the concentrations of metabolites are relatively constant yet are subject to metabolic demands and environmental stimuli...
Assessment of the Effects of Repeated Freeze Thawing and Extended Bench Top Processing of Plasma Samples Using Untargeted Metabolomics​
Metabolomics 2021, 17,31
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Clinical metabolomics has utility as a screen for inborn errors of metabolism (IEM) and variant classification in patients with rare disease. It is important to understand and characterize preanalytical factors that influence assay performance during patient sample testing...
Global Biochemical Analysis of Plasma, Serum, and Whole Blood Collected Using Various Anticoagulant Additives
PLoS One, 2021 8;16(4)
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Analysis of blood for the evaluation of clinically relevant biomarkers requires precise collection and sample handling by phlebotomists and laboratory staff. An important consideration for the clinical application of metabolomics are the different anticoagulants utilized for sample collection. Most studies that have characterized differences in metabolite levels in various blood collection tubes have focused on single analytes.
Precision of a Clinical Metabolomics Profiling Platform for Use in the Identification of Inborn Errors of Metabolism
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Lisa Ford, Adam D Kennedy, Kelli D Goodman, Kirk L Pappan, Anne M Evans, Luke A D Miller, Jacob E Wulff, Bobby R Wiggs, III, John J Lennon, Sarah Elsea, Douglas R Toal
The Journal of Applied Laboratory Medicine, Volume 5, Issue 2, March 2020, Pages 342–356
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The application of whole-exome sequencing for the diagnosis of genetic disease has paved the way for systems-based approaches in the clinical laboratory. Here, we describe a clinical metabolomics method for the screening of metabolic diseases through the analysis of a multi-pronged mass spectrometry platform. By simultaneously measuring hundreds of metabolites in a single sample, clinical metabolomics offers a comprehensive approach to identify metabolic perturbations across multiple biochemical pathways.
Validation of a Metabolite Panel for a More Accurate Estimation of Glomerular Filtration Rate Using Quantitative LC-MS/MS
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Tiffany A Freed, Josef Coresh, Lesley A Inker, Douglas R Toal, Regis Perichon, Jingsha Chen, Kelli D Goodman, Qibo Zhang, Jessie K Conner, Deirdre M Hauser, Kate E T Vroom, Maria L Oyaski, Jacob E Wulff, Gudný Eiríksdóttir, Vilmundur Gudnason, Vicente E Torres, Lisa A Ford, Andrew S Levey
Clinical Chemistry, 2019 Mar;65(3):406-418
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Clinical practice guidelines recommend estimation of glomerular filtration rate (eGFR) using validated equations based on serum creatinine (eGFRcr), cystatin C (eGFRcys), or both (eGFRcr-cys). However, when compared with the measured GFR (mGFR), only eGFRcr-cys meets recommended performance standards. Our goal was to develop a more accurate eGFR method using a panel of metabolites without creatinine, cystatin C, or demographic variables.
Metabolomics in the Clinic: A Review of the Shared and Unique Features of Untargeted Metabolomics for Clinical Research and Clinical Testing
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Adam D. Kennedy, Bryan M. Wittmann, Anne M. Evans, Luke A.D. Miller, Douglas R. Toal, Shaun Lonergan, Sarah H. Elsea, Kirk L. Pappan
Journal of Mass Spectrometry, 2018; 53:1143–1154
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Metabolomics is the untargeted measurement of the metabolome, which is composed of the complement of small molecules detected in a biological sample. As such, metabolomic analysis produces a global biochemical phenotype. It is a technology that has been utilized in the research setting for over a decade. The metabolome is directly linked to and is influenced by genetics, epigenetics, environmental factors, and the microbiome—all of which affect health...
Identification of an Endogenous Organosulfur Metabolite by Interpretation of Mass Spectrometric Data
Qibo Zhang*, Lisa A. Ford, Anne M. Evans, and Douglas R. Toal
Organic Letters, 2018; 20, 7:2100-2103
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The chemical structure of x11564, a new endogenous organosulfur metabolite, was elucidated by de novo interpretation of mass spectrometric data. The structure was confirmed by comparison to a synthetic standard. Metabolite x11564 is structurally related to intermediates in the methionine salvage pathway...
Structure Elucidation of Metabolite x17299 by Interpretation of Mass Spectrometric Data
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Qibo Zhang, Lisa A. Ford, Anne M. Evans, Douglas R. Toal
Metabolomics, June 2017; 13,92
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A major bottleneck in metabolomic studies is metabolite identification from accurate mass spectrometric data. Metabolite x17299 was identified in plasma as an unknown in a metabolomic study using a compound-centric approach where the associated ion features of the compound were used to determine the true molecular mass.
LC-MS/MS Method for Quantitation of Seven Biomarkers in Human Plasma for the Assessment of Insulin Resistance and Impaired Glucose Tolerance
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Qibo Zhang, Lisa A Ford, Kelli D Goodman, Tiffany A Freed, Deirdre M Hauser, Jessie K Conner, Kate E T Vroom, Douglas R Toal
Journal of Chromatography B, 2016; 1038:101-108
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Early detection of insulin resistance (IR) and/or impaired glucose tolerance (IGT) is crucial for delaying and preventing the progression toward type 2 diabetes. We recently developed and validated a straightforward metabolite-based test for the assessment of IR and IGT in a single LC–MS/MS method...
Multidrug-Resistant Organism Colonization in a High-Risk Pediatric Patient Population
Infection Control & Hospital Epidemiology, 2016; 37(5), 615-616​
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Multidrug-resistant organisms (MDROs) present substantial clinical and financial burdens to patients and hospitals. In pediatric patients undergoing cancer or hematopoietic stem cell treatment, information is needed to characterize...
Analytical Performance of Multiplexed Screening Test for 10 Antibiotic Resistance Genes from Perianal Swab Samples
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G Terrance Walker, Tony J Rockweiler, Rossio K Kersey, Kelly L Frye, Susan R Mitchner, Douglas R Toal, Julia Quan
Clinical Chemistry, 2016; 62(2):353-359
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Multiantibiotic-resistant bacteria pose a threat to patients and place an economic burden on health care systems. Carbapenem-resistant bacilli and extended-spectrum β-lactamase (ESBL) producers drive the need to screen infected and colonized patients for patient management and infection control...
Laboratory Diagnosis of Central Nervous System Infections with Herpes Simplex Virus by PCR Performed with Cerebrospinal Fluid Specimens
P. S. Mitchell, M. J. Espy, T. F. Smith, D. R. Toal, P. N. Rys, E. F. Berbari, D. R. Osmon, and D. H. Persing
Journal of Clinical Microbiology, Nov. 1997 p. 2873-2877
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Until recently, the laboratory diagnosis of central nervous system (CNS) infections with herpes simplex virus (HSV) has been limited by poor sensitivity and/or specificity. We assessed the diagnostic utility of PCR for detection of HSV in over 2,100 specimens referred to the Mayo Clinic from August 1993 to May 1996...
Branched-chain Fatty Acids: The Case for a Novel Form of Cell-Cell Signalling During Myxococcus Xanthus Development​
Molecular Microbiology, 1995: 16(2), 171-175​
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Metabolism is a highly regulated process that provides nutrients to cells and essential building blocks for the synthesis of protein, DNA and other macromolecules. In healthy biological systems, metabolism maintains a steady state in which the concentrations of metabolites are relatively constant yet are subject to metabolic demands and environmental stimuli...
The esg Locus of Myxococcus Xanthus Encodes the E1α and E1ß Subunits of a Branched-Chain Keto Acid Dehydrogenase​
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Douglas R. Toal, Sandra W. Clifton, Bruce A Roe, John Downard
Molecular Microbiology, 1995: 16(2), 177-189​
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The esg locus of Myxococcus xanthus appears to control the production of a signal that must be transmitted between cells for the completion of multicellular development DNA sequence analysis suggested that the esg locus encodes the E1 decarboxylase (composed of E1α and E1β subunits) of a branched-chain keto acid dehydrogenase (BCKAD) that is involved in branched-chain amino acid (BCAA) metabolism...