Abstract: The present invention provides a compound of formula (I): PtIV(N3)2X1X2Y1Y2, wherein X1 and X2 are the same or different and each one is a group NR1R2R3 wherein R1, R2 and R3 are the same or different and each can be any one of H and optionally substituted alkyl, aryl, aralkyl, acyl, cycloalkyl, heterocyclyl, alkenyl, aralkenyl, alkinyl, cycloalkenyl, or X1 and X2 together represent a group R1R2NR4NR1R2 wherein R1 and R2 have the same meaning as before, and R4 represents an optionally substituted divalent, saturated or unsaturated, alkyl chain, an optionally substituted divalent, saturated or unsaturated cycloalkyl or an optionally substituted divalent aryl, or R4 or two or more of R1, R2, R3 and R4 and the respective N atom(s) to which they are linked, represent an optionally substituted heterocyclyl having at least one ring containing said N atom(s); and Y1 and Y2 are the same or different or when cis together represent a divalent moiety Y3, wherein at least one of Y1 and Y2, or Y3, is a substantially labil

Abstract: A polysaccharide chemically joined to a nitroxyl spin label (NSL) compound has use for the preparation of an NMR diagnostic composition. An agent for modifying H.sub.2 O relaxation times in NMR diagnosis may comprise a polysaccharide to which is chemically linked both an NSL compound and an organic complexing agent to which is complexed a paramagnetic metal ion, such as Gd(III) or Cu(II). Polysaccharides include dextran, starch and cellulose. The preferred NSL compound is 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl.

Abstract: Pharmaceutical compositions and a method for inhibiting the growth of tumor cells by administering a tumor cell growth-inhibiting amount of a bis[bis (diphenylphosphino)hydrocarbon]-, bis[bis(diethylphsophino) hydrocarbon]-, bis[bis(diphenylphosphine-deithylphosphino) hydrocarbon]gold(I), silver(I) or copper(I) complex or a tris[bis(diphenylphosphino)ethane] dicopper(I) complex to an animal afflicted with said tumor cells.

Abstract: Complexes formed between (a) an amino di- or poly-phosphonate in which phosphonate groups comprise separate carbon atoms and (b) a paramagnetic metal ion such as Gd.sup.3+, have calcified tissue seeking properties which make them useful as contrast agents for investigating bone metabolism by NMR scanning. Two preferred poly-phosphonates are ethylenediamine tetramethylphosphonate and meta-xylene-diamine tetramethylphosphonate.