- Prostaglandin E2-mediated anabolic effect of a novel inhibitor of phosphodiesterase 4, XT-611, in the in vitro bone marrow culture. Miyamoto, K., Suzuki, H., Yamamoto, S., Saitoh, Y., Ochiai, E., Moritani, S., Yokogawa, K., Waki, Y., Kasugai, S., Sawanishi, H., Yamagami, H. J. Bone Miner. Res. (2003)