Helen I'anson

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This study records the length of hospital stay of 50 total knee arthroplasty patients involved in an accelerated postoperative rehabilitation protocol, and a control group of patients undergoing routine rehabilitation. This protocol involved modifications to normal knee replacement procedure, including infiltration of bupivacaine and adrenaline to the(More)
A transient increase in serum progesterone concentrations (to 1 ng/ml for 1-2 days) is observed in the majority of ewes before the first estrous cycle of the breeding season. To determine whether such a brief antecedent rise in progesterone ensures initiation of a full-length cycle by the next LH surge, synthetic GnRH was administered for 3 days to 24(More)
We tested the hypothesis that hindbrain catecholamine (norepinephrine or epinephrine) neurons, in addition to their essential role in glucoprivic feeding, are responsible for suppressing estrous cycles during chronic glucoprivation. Normally cycling female rats were given bilateral injections of the retrogradely transported ribosomal toxin, saporin,(More)
Growth retardation induced by dietary restriction results in hypogonadotropism, and thus, puberty is delayed. The present studies determined 1) whether reduced LH secretion in the growth-retarded condition is due to a reduction in the frequency and/or in the amplitude of GnRH secretion, and 2) whether the mechanism regulating LH secretion is being actively(More)
The present study determined whether exposure to gonadal steroids in utero dictates the postnatal control of gonadotropin secretion in the lamb. There is a marked sex difference in the timing of neuroendocrine sexual maturation in sheep; while male lambs undergo a reduction in sensitivity to inhibitory gonadal steroid feedback by 10 weeks of age, females(More)
Estrogen-dependent enhancement of glucoprivic-induced luteinizing hormone (LH) suppression is hypothesized to be due to increased estrogen receptor alpha (ERalpha)-immunoreactive (ir) cells in specific brain nuclei in a manner similar to fasting. ERalpha expression in various brain areas was determined in ovariectomized rats after systemic 2-deoxy-D-glucose(More)
The objective of this study was to determine whether the previously observed effects of photoperiod on body weight in Siberian hamsters were due to changes in the daily patterns of locomotor activity, energy expenditure, and/or feeding behavior. Adult males were monitored through a seasonal cycle using an automated comprehensive laboratory animal monitoring(More)
Growth retardation induced by dietary restriction in the lamb results in a low GnRH pulse frequency, and thus, puberty is delayed. In our experimental model, in which ovariectomized lambs are maintained at weaning weight (approximately 20 kg BW), hypothalamic GnRH is present and releasable, suggesting that central mechanisms limit the release of GnRH during(More)
The present study aims to clarify the role of fatty acids in regulating pulsatile LH secretion in rats. To produce an acute central lipoprivic condition, mercaptoacetate (MA), an inhibitor of fatty acids oxidation, was administered into the fourth cerebroventricle (4V) in ad libitum fed ovariectomized (OVX) rats (0.4, 2, and 10 micromol/rat) with or without(More)