Keith S. Heller

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In hamsters, changes in ambient photoperiod lead to alterations in the circadian rhythm of pineal melatonin secretion and subsequent changes in reproductive function. The present study examined whether photoperiod also alters 24-h rhythms in neuropeptide mRNA levels in the SCN of Siberian hamsters. In situ hybridization and quantitative autoradiography were(More)
H ayes Martin died on Christmas Day 1977. I was a fellow on the head and neck service at Memorial Hospital, New York, New York, at that time. I never met Dr Martin because he had been an invalid for many years. I felt his influence constantly, though, because my teachers, my attending physicians, had all been his students, his fellows, or his colleagues. Dr(More)
BACKGROUND The incidence of well-differentiated thyroid cancer (WDTC) is increasing rapidly. Many authors feel that this increase is due to over-diagnosis and that one of the contributing factors is the increasing use of various imaging studies. The rate of obesity has also been increasing in the United States. It has been suggested that patients with an(More)
These studies used quantitative in vitro autoradiography to investigate whether endogenous or exogenous melatonin modulate specific 2-[125I]iodomelatonin binding sites in the pars tuberalis or suprachiasmatic nuclei of Siberian hamsters. Saturation analyses were conducted on tissue sections from hamsters that were pinealectomized, exposed to constant(More)
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