Disclosed herein are organic molecules to which are covalently bonded a sialyl-Le.sup.x determinant and a sulfated determinant, at least one of these determinants being positioned at a non-naturally occurring site on the molecule. Also disclosed are particular P-selectin ligands and P-selectin ligand-antibody fusions. These molecules, ligands, and fusion proteins find use in methods of reducing or protecting against inflammation and extravasation-dependent adverse reactions, such as organ damage and clotting (for example, associated with adult respiratory distress syndrome or ischemic myocardial injury).