Abstract: A catheter having a therapeutic agent chemically bonded to a substrate on its exterior surface using a linker which photolytically releases the agent upon exposure to light energy at an appropriate wavelength. The linker is attached to the substrate via a complementary chemical group, with the opposing end containing an aromatic ring with a nitro group in the ortho position relative to a methyl or ethyl group which is functionalized to accept a complementary bond to the therapeutic agent. The substrate may include materials such as glass, polyamide, polyester, polyolefin, polypropylene, polyurethane, or latex. The therapeutic agent may include peptides, proteins, steroids, carbohydrates, nucleotides, or other aliphatic or heterocyclic products, and may be bonded to a molecular lattice or meshwork to accommodate a high molecular concentration per unit area and the inclusion of ancillary compounds such as markers or secondary emitters.

Abstract: A method is disclosed for extraction, concentration, and bioassay measurement of the concentration of bioactive parathyroid peptides in biological or other fluids. Parathyroid peptides are extracted from the fluid by a support-antibody matrix specific to the N-terminal region. The bioassay is directed to the extracted parathyroid peptides. The volume of the medium containing the extracted parathyroid peptides and tissue, cells or tissue extracts with adenylate cyclase-coupled parathyroid hormone receptors may be chosen to be significantly less than the volume of biological or other fluid being assayed.

Abstract: A method for the radioimmunoassay of parathyroid hormone in mammalian serum. The method is an improvement on previous double antibody radioimmunoassays in that spurious assay results caused by the nonspecific interaction of serum proteins with the labeled peptide is eliminated by the labeling of a specific portion of either human or bovine parathyroid molecule. The 65-84 portion of human or bovine parathyroid hormone, as radioactively labeled, is incorporated in the assay as the labeled peptide. A chicken antibody with a high affinity for the 65-84 portion of human parathyroid hormone is incorporated in the assay as the first antibody. The invention further pertains to compounds useful in practicing the method, namely X.sup.64 -hPTH.sup.65-84 and Y-X.sup.64 -hPTH.sup.65-84 wherein X is either histidyl, tyramyl, histamyl, or tyrosyl, and wherein Y is either .sup.125 I or .sup.131 I.

Abstract: A method for the radioimmunoassay of parathyroid hormone in mammalian serum. The method is an improvement on previous double antibody radioimmunoassays in that spurious assay results caused by the nonspecific interaction of serum proteins with the labeled peptide is eliminated by the labeling of a specific portion of either human or bovine parathyroid molecule. The 65-84 portion of human or bovine parathyroid hormone, as radioactively labeled, is incorporated in the assay as the labeled peptide. A chicken antibody with a high affinity for the 65-84 portion of human parathyroid hormone is incorporated in the assay as the first antibody. The invention further pertains to compounds useful in practicing the method, namely X.sup.64 -hPTH.sup.65-84 and Y-X.sup.64 -hPTH.sup.65-84 wherein X is either histidyl, tyramyl, histamyl, or tyrosyl, and wherein Y is either .sup.125 I or .sup.131 I.