SAMUELW. GREENHOUSE

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Melatonin secretion was measured from rainbow trout (Salmo gairdneri) pineal organs maintained individually under flow-through whole organ culture (superfusion) conditions. Radioimmunoassay of perfusate fractions collected during controlled photic conditions demonstrated that melatonin secretion in vitro remained basal during the photophase and underwent(More)
The light/dark cycle influences the rhythmic production of melatonin by the trout pineal organ through a modulation of the serotonin N-acetyltransferase (NAT) activity. In static organ culture, cyclic AMP (cAMP) levels (in darkness) and NAT activity (in darkness or light) were stimulated in the presence of forskolin, isobutylmethylxanthine, or theophylline.(More)
Tumorigenesis in humans and experimental animals appears to involve the activation of ras protooncogenes for a number of organ systems and seems to be important to the development of the metastatic phenotype in several model systems. Clinically, the presence of activated ras protooncogenes has been reported to be a negative prognostic factor in the(More)
The pineal body of lower vertebrates is saccular and directly photoreceptive. The pineal gland of mammals is parenchymal and not directly photoreceptive. The parenchymal morphology of snake pineal raises questions of direct photoreceptivity of snake pineal and of correspondence of molecular homology with morphological homology. S-antigen and rhodopsin are(More)
The initial spermatozoon-egg interaction of mammalian fertilization is mediated by the zona pellucida, an extracellular matrix composed of three glycoproteins (ZP1, ZP2, ZP3). These proteins are sufficiently conserved between human and mouse to form chimeric zonae pellucidae, and genetically engineered mice in which the endogenous mouse ZP3 has been(More)
Administration of citrovorum factor (CF) or pteroylglutamic acid (FA) may reduce the lethal toxicity for mice of the antimetabolite 4-aminopteroylglutamic acid (aminopterin). The mortality response is dependent upon the relative dose level of FA or CF administered with the aminopterin and is influenced by the temporal relationships of administration of the(More)
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