Localization and structural characterization of insulin-like growth factor receptors in mammalian retina.

Insulin-like growth factors (IGFs) are peptide mitogens, structurally related to insulin, whose biological actions in the CNS are incompletely known. The retina is largely uncharacterized with respect to IGF receptors. We, therefore, studied IGF receptors in bovine and murine retinal tissues by immunohistochemistry, autoradiographic localization, and affinity labeling.

Calibration of [14C]plastic standards for quantitative autoradiography of [125I]labeled ligands with Amersham Hyperfilm beta-max.

The densitometric response of Hyperfilm beta-max (HFBM) to [14C]plastic standards was calibrated to tissue-equivalent concentrations of [125I]. Plastic sections with standard concentrations of [125I] and [14C] were apposed to HFBM for 1, 3, 5, and 9 days, with liver and muscle slices (20 microns thick) labeled with [125I]insulin. The relative optical densities (ROD = log 10 [1/gray level x 256(-1)] produced by [125I]- and [14C]plastic standards were converted to equivalent tissue [125I] concentrations (dpm/mm2).

Milk progesterone enzyme immunoassay: modifications and a field trial for pregnancy detection in dairy cows.

A milk progesterone enzyme immunoassay was modified to shorten the antibody:antigen incubation time and tested in a field trial. Coupling the antibody to paper fibers at pH 7 increased the binding activity of the paper-antibody conjugate to allow incubation for 3 h at room temperature with no significant loss of competitive binding of progesterone. The relationship between progesterone concentrations measured by the modified and original enzyme immunoassays was r = .