1. Department of Process Research, Merck Research Laboratories, Merck & Co., 466 Devon Park Drive, Wayne, Pennsylvania 19087, Department of Bioprocess R&D, Merck Research Laboratories, Merck & Co., Rahway, New Jersey 07065, Department of Process Research, Merck Research Laboratories, Merck & Co., Rahway, New Jersey 07065, and Department of Molecular Systems, Merck Research Laboratories, Merck & Co., West Point, Pennsylvania 19486