1. Department of Biochemistry and Molecular Biology, Mayo Clinic, Biomedical Mass Spectrometry Facility, Rochester, Minnesota, USA
2. Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota, USA
3. Department of Ophthalmology, Mayo Medical School, Mayo Clinic, Rochester, Minnesota, USA
4. Department of Pharmacology and Clinical Pharmacology Unit, Mayo Clinic, Biomedical Mass Spectrometry Facility, Department of Biochemistryand Molecular Biology, Rochester, Minnesota, USA