Abstract: Diagnostic and therapeutic compositions in the form of complexes for enhancing transmembrane transport of a diagnostic or therapeutic agent and methods for their use. The complexes contain the &agr;, &ggr;, or bis isomers of folate receptor-binding analogs of folate, a metal chelated by a ligand, and in one embodiment, a chemotherapeutic agent.

Abstract: A twist valve for use in a fluid delivery system is provided for selectively allowing fluid flow and blocking fluid flow therethrough. The twist valve is in communication with a pre-filled flexible container and includes a proximal part and a distal part each having a fluid inlet and a fluid outlet. The proximal and distal parts are equipped with cylindrical helical surfaces which allow them to move toward or away from each other when a twisting force is applied to them. The fluid outlet of the proximal part is blocked with a stopper in the distal part when the twist valve is in the closed position, and is unblocked by the stopper when the twist valve is in the open position.

Abstract: Diagnostic and therapeutic compositions in the form of complexes for enhancing transmembrane transport of a diagnostic or therapeutic agent and methods for their use. The complexes contain the .alpha., .gamma., or bis isomers of folate receptor-binding analogs of folate, a metal chelated by a ligand, and in one embodiment, a chemotherapeutic agent.