The Clinical Mass Spectrometry Core collaborates with investigators from across the NIDDK Clinical Research Program, NIDDK basic research program and collaborating institutes to conduct stable isotope tracer studies (human and mammalian sources) and quantitative small molecule LC-MS and GC-MS. Clinical stable isotope studies include, but are not limited to, doubly labeled water, 6,6-D2-Glucose, D5-glycerol, 13C-palmitate. Doubly labeled water is used to measure total energy expenditure. Whereas the other labeled compounds are typically for metabolic studies. Metabolic studies with stable isotopes cover a vast range. Currently we measure labeled glucose, glycerol, and free fatty acids. The lab will advise, develop and validate novel research assays in collaboration with on-going clinical research projects and actively seeks new areas for collaboration with staff from across the NIH community. The most common projects nowadays involve mass spectrometry quantitation, by GC-MS but especially by LC-MS, of many drugs, metabolites, or small molecule compounds. Beside quantitation, we have identified unknown metabolite or even contaminants, which provided new avenues for investigation.

Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
U.S. National Inst Diabetes/Digst/Kidney
Zip Code
Sylvetsky, Allison C; Walter, Peter J; Garraffo, H Martin et al. (2017) Widespread sucralose exposure in a randomized clinical trial in healthy young adults. Am J Clin Nutr 105:820-823
Carmona-Rivera, Carmelo; Purmalek, Monica M; Moore, Erica et al. (2017) A role for muscarinic receptors in neutrophil extracellular trap formation and levamisole-induced autoimmunity. JCI Insight 2:e89780
Sylvetsky, Allison C; Bauman, Viviana; Blau, Jenny E et al. (2017) Plasma concentrations of sucralose in children and adults. Toxicol Environ Chem 99:535-542
Fothergill, Erin; Guo, Juen; Howard, Lilian et al. (2016) Persistent metabolic adaptation 6 years after ""The Biggest Loser"" competition. Obesity (Silver Spring) 24:1612-9
Howard, Louisa C; Liu, Chia-Ying; Purdy, Julia B et al. (2016) Lipolytic Rate Associated With Intramyocardial Lipid in an HIV Cohort Without Increased Lipolysis. J Clin Endocrinol Metab 101:151-6
Sylvetsky, Allison C; Gardner, Alexandra L; Bauman, Viviana et al. (2015) Nonnutritive Sweeteners in Breast Milk. J Toxicol Environ Health A 78:1029-32
Hall, Kevin D; Bemis, Thomas; Brychta, Robert et al. (2015) Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity. Cell Metab 22:427-36
Chang, Yun C; Khanal Lamichhane, Ami; Garraffo, H Martin et al. (2014) Molecular mechanisms of hypoxic responses via unique roles of Ras1, Cdc24 and Ptp3 in a human fungal pathogen Cryptococcus neoformans. PLoS Genet 10:e1004292
Yadav, Hariom; Lee, Ji-Hyeon; Lloyd, John et al. (2013) Beneficial Metabolic Effects of a Probiotic via Butyrate-induced GLP-1 Hormone Secretion. J Biol Chem 288:25088-97