2016
Comparison of symmetric dimethylarginine with creatinine, cystatin C and their eGFR equations as markers of kidney function
El-Khoury JM, Bunch DR, Hu B, Payto D, Reineks EZ, Wang S. Comparison of symmetric dimethylarginine with creatinine, cystatin C and their eGFR equations as markers of kidney function. Clinical Biochemistry 2016, 49: 1140-1143. PMID: 27452178, DOI: 10.1016/j.clinbiochem.2016.07.009.Peer-Reviewed Original ResearchConceptsGlomerular filtration rateKidney functionCystatin CEGFR equationsWidespread clinical useIothalamate clearanceEGFR formulasFiltration rateSymmetric dimethylargininePlasma specimensAdult populationStrong markerAbstractTextClinical useEndogenous markerCreatinineLiquid chromatography-tandem mass spectrometry methodChromatography-tandem mass spectrometry methodFurther studiesDimethylarginineRoche Cobas 8000MarkersCatabolic productsCobas 8000
2012
Highly sensitive and selective measurement of underivatized methylmalonic acid in serum and plasma by liquid chromatography-tandem mass spectrometry
Yuan C, Gabler J, El-Khoury JM, Spatholt R, Wang S. Highly sensitive and selective measurement of underivatized methylmalonic acid in serum and plasma by liquid chromatography-tandem mass spectrometry. Analytical And Bioanalytical Chemistry 2012, 404: 133-140. PMID: 22618327, DOI: 10.1007/s00216-012-6099-z.Peer-Reviewed Original ResearchConceptsLC-MS/MS methodSample preparationMS methodAnion exchange solid phase extractionChromatography-tandem mass spectrometry methodLiquid chromatography-tandem mass spectrometry methodNegative electrospray modeSuccinic acidOrganic acid columnStrong anion-exchange solid-phase extractionSolid-phase extraction
2011
A simple and fast liquid chromatography–tandem mass spectrometry method for measurement of underivatized l-arginine, symmetric dimethylarginine, and asymmetric dimethylarginine and establishment of the reference ranges
El-Khoury JM, Bunch DR, Reineks E, Jackson R, Steinle R, Wang S. A simple and fast liquid chromatography–tandem mass spectrometry method for measurement of underivatized l-arginine, symmetric dimethylarginine, and asymmetric dimethylarginine and establishment of the reference ranges. Analytical And Bioanalytical Chemistry 2011, 402: 771-779. PMID: 22124751, DOI: 10.1007/s00216-011-5462-9.Peer-Reviewed Original ResearchConceptsFast liquid chromatography–tandem mass spectrometry methodAnalytical cycle timeChromatography-tandem mass spectrometry methodLiquid chromatography-tandem mass spectrometry methodMinimum sample preparationMass spectrometry methodLiquid chromatography-tandem mass spectrometryChromatography-tandem mass spectrometryAsymmetric dimethylarginineSymmetric dimethylarginineLC-MS/MS methodMass spectrometerFormic acidSpectrometry methodMass spectrometrySilica columnProtein precipitationSample preparationInternal standardAmmonium acetateMS methodGlomerular filtration rateAnalytesNitric oxide synthaseΜM