R L Somers

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The retina contains specific high-affinity receptors for insulin-like growth factor-I (IGF-I). Although IGF-I binding was observed in photoreceptor outer segments, the level of this binding was only 10% of that found in whole retina or mixed preparations of rod outer (ROS) and inner (RIS) segments. The higher IGF-I binding activity in RIS and(More)
Rhodopsin kinase, an enzyme involved in photochemical transduction in the retina, has been found in the mammalian pineal gland in amounts equal to those in the retina; other tissues had 7 percent of this amount, or less. This finding suggests that, in mammals, rhodopsin kinase functions in the pineal gland and other tissues to phosphorylate rhodopsin-like(More)
Rhodopsin kinase, once thought to be a retinal enzyme, was recently found at high levels in the pineal gland. In the present study the developmental pattern and the regulation by environmental lighting of this enzyme in both tissues was studied in the rat. Enzyme activity was present in the neonatal pineal gland several days earlier than in the retina, and(More)
The structural components involved in transduction of extracellular signals as diverse as a photon of light impinging on the retina or a hormone molecule impinging on a cell have been highly conserved. These components include a recognition unit or receptor (for example, the beta-adrenergic receptor (beta AR) for catecholamines or the 'light receptor'(More)
Antiserum against the alpha subunit of bovine rod-outer-segment transducin was used in an immunocytochemical study that identified the protein in retina (human, baboon, owl monkey, cow, rat, quail, newt, frog, salmon, eel, and lamprey), pineal organ (quail, newt, frog, salmon, eel, and lamprey), and parapineal organ (salmon and lamprey). No reaction was(More)
Treatment results of leptomeningeal metastasis are reported in 33 breast cancer patients. They were divided into three groups: group 1, 19 patients, received intraventricular methotrexate (MTX) with doses based on CSF MTX levels; group 2, 6 patients, received whole brain radiation followed by a course of MTX given by lumbar punctures; group 3, 8 patients,(More)
Taking advantage of the capability of GTP binding protein to bind GTP, we purified the catalytic subunit (G alpha) of bovine rod GTP binding protein by nucleotide-affinity chromatography on Blue Sepharose CL6B. Purified G alpha was essentially free of bound guanine nucleotide and activated by photoactivated rod membranes. Circular dichroism spectra(More)