1. Department of Anesthesia, Stanford University School of Medicine and Beckman Center for Molecular and Genetic Medicine, Stanford, California 94305-5117
2. Department of Veterans Affairs, Palo Alto VA Health Care System, Palo Alto, California, 94304
3. Stockholm Bioinformatics Center and Center for Biomembrane Research, Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden