Advances in oral anticoagulation therapy - What's in the pipeline?

Approximately 900,000 people are affected by some sort of venous thromboembolic (VTE) event every year in the United States. VTE diagnosis used to mean treatment with medications that required routine lab monitoring for safety and efficacy. Activated factor X (FXa) inhibition has emerged as a convenient pathway for management of VTE and currently three FXa inhibitors are available for anticoagulation management - rivaroxaban, apixaban, and edoxaban. Continued development of medications utilizing this pathway may offer advantages via novel pharmacokinetic or pharmacodynamic properties that may minimize the adverse effects associated with traditional anticoagulant therapy. This review summarizes the available information regarding pharmacokinetic, pharmacodynamic, and early safety and efficacy data for three factor Xa inhibitors being developed - darexaban, betrixaban and nokxaban. The studies reviewed in this article suggests that three newer agents possess the potential for promise based on early phase I and II trials.

Vesicular transport of sulfatide in the myelinating mouse brain. Functional association with lysosomes?

Sulfatide synthesis and its subcellular distribution kinetics was followed in the myelinating brain of 17-day-old mice. Pulse-labeling-chasing conditions were achieved by an intraperitoneal injection of (35S)sulfate followed 2 h later by a second injection of a high dose of unlabeled sulfate. At 1, 2, 3, 4, and 6 h after the (35S)sulfate injection, the brains were removed, homogenized, and subcellular fractions were obtained by differential and discontinuous sucrose gradient centrifugation (Eichberg, J., Whittaker, V. P., and Dawson, R. M. (1964) Biochem. J. 92, 91-100). The microsomal membranes were further subfractionated (Siegrist, H. P., Burkart, T., Wiesmann, U. N., Herschkowitz, N. N., and Spycher, M. A. (1979) J. Neurochem. 33, 497-504) into light myelin, plasma membranes, Golgi vesicles, endoplasmic reticulum membranes, and heavy vesicles associated with acid hydrolase activities. The [35S]sulfatide-labeling kinetics was measured in all subcellular fractions. The results indicate that sulfatides are synthesized in the Golgi-endoplasmic reticulum complex and transferred in vesicles at least partially associated with lysosomes to the myelin membranes. The association of sulfatides with lysosomes could explain the existence of the previously described labile pool of newly synthesized sulfatides (Burkart, T., Hofmann, K., Siegrist, H. P., Herschkowitz, N. N., and Wiesmann, U. N. (1981) Dev. Biol. 83, 42-48) and also could be a form of vesicular transport to the myelin.