James Shoemaker, M.D.
Screening children for inborn errors of metabolism using gas chromatography-mass spectrometry and evaluation of special nutritional needs in children with Down's syndrome.
Office: DRC, Room 431
Phone: (314) 977-9230
M.D., 1981, Ph.D., 1984, University of Illinois at Urbana-Champaign
Our clinical activities include screening for inborn errors of metabolism in children by quantifying chemicals in body fluids by gas chromatography-mass spectrometry. We developed a new method of sample preparation which allows carbohydrates and amino and organic acids to be detected in the same sample. Our current research is concerned with the evaluation of special nutritional needs in children with Down syndrome and the diagnosis of vitamin deficiency by quantitation of urinary metabolites after an oral dose of amino acids and other food constituents.
- Dicarboxylic acid excretion in normal formula-fed and breastfed infants.
Anderson M, Eliot K, et al. Nutr Clin Pract. (2016) May 6 [Epub ahead of print].
- Estimation of glucose utilization in a type 2 diabetes mellitus patient on insulin analogs with tumor hypoglycemia induced by IGF-II.
Code S, Albert SG, et al. Growth Horm IGF Res. (2016) 26:8-10.
- Urinary organic acids quantitated in a healthy north Indian pediatric population.
Kumari C, Singh A, et al. Indian J Clin Biochem. (2015) 30(2):221-9.
Misidentification of propionic acid as ethylene glycol in a patient with methylmalonic acidemia.
James D. Shoemaker, Robert E. Lynch, Joseph W. Hoffmann, and William S. Sly.
J. Pediatr. 120(3):417-421, 1992 (PMID 1538288).
My first significant publication was the result of my involvement in the case of a mother, who was initially incarcerated on charges of murder because high levels of ethylene glycol were present in her child's blood. However, upon further analysis by the Metabolic Screening Laboratory, the child was found to have methylmalonic acidemia, an inborn metabolic disorder resulting in increased propionic acid, which can be mistaken for ethylene glycol by the chromatographic techniques commonly used by clinical laboratories. Our analysis, which used combined gas chromatography-mass spectrometry techniques, was able to distinguish between the products of ethylene glycol metabolism and those associated with metabolic abnormalities. As a result, the mother was exonerated of all charges.
The story can also be seen on YouTube (viewed over 3175 times): Deadly Formula
Involvement of lipids in ferriprotoporphyrin IX polymerization in malaria.
Coy D. Fitch, Guang-Zuan Cai, Yi-Feng Chen, James D. Shoemaker.
Biochim. Biophys. Acta 1454(1):31-37, 1999 (PMID 10354512).
My next significant publication is my most-cited, with 114 citations. Here I identified linoleic acid as the substance that promoted polymerization of ferriprotoporphyrin IX or FP. The ability of malaria parasites to sequester FP from hemozoin in an insoluble and non-toxic form is an important adaptation, which allows them to digest hemoglobin while avoid FP toxicity. The research was done in collaboration with Coy Fitch, M.D., of the Department of Internal Medicine at SLU.
One-step metabolomics: carbohydrates, organic and amino acids quantified in a single procedure.
James D. Shoemaker.
J. Vis. Exp. Jun 25(40):e2014, 2010 (20613709).
Urinary organic acids quantitated in a healthy north Indian pediatric population.
Chandrawati Kumari, Ankur Singh, Siddharth Ramji, James D. Shoemaker, Seema Kapoor.
Indian J. Clin. Biochem. 30(2):221-229, 2015 (25883433).
I choose two related publications for my final entry. The first is a video publication that explains how to do One Step Metabolomics, a procedure I introduced that has now been done over 20,000 times for diagnostic purposes in the Metabolic Screening Lab. It is significant because it provides a more specific test for screening of rare genetic disorders and identification of suspected inborn errors of metabolism. The "urease" process allows for removal of urea from the fluid being tested, permitting most other water soluble metabolites to be dehydrated and processed via chromatography and mass spectrometry. The method has been cited 91 times. The video can be viewed on the Jove site
The second is my "favorite" publication because it shows the global impact of One Step Metabolomics as used by investigators in New Delhi, who invited me to speak there, and in Hyderabad, Bangalore, and Mumbai in 2012 and 2013, to promote screening for inborn errors using our method. It is significant because knowing the concentrations of organic acids in the general healthy pediatric population can aid in the correct diagnosis of metabolic abnormalities, since these values vary depending on environment, food consumption, and genotype, as well as other various factors.