Esperanza Olivares

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The effects of a melatonin agonist, S-20098, included in the diet were tested on a specific effect of aging in hamsters: the marked decline in the phase shifting effects of a 6-h pulse of darkness on a background of constant light. In contrast to young hamsters, old hamsters fed with the control diet showed little or no phase shifts in response to a dark(More)
Abnormal timing in the circadian system is reported in endogenous depression. Gepirone, a 5HT1A receptor partial agonist, has anxiolytic and antidepressant properties. We determined whether gepirone was able to modify the functioning of the circadian system. Single i.p. injections of gepirone in hamsters induced phase-advances in the circadian activity(More)
S-20098 has potent and specific agonist properties on melatonin receptors both in vitro and in vivo. Behavioral studies on rodents already showed that repeated intraperitoneal administration of S-20098 could dose-dependently alter the functioning of the circadian clock. To determine whether single administration of S-20098 could alter the circadian rhythms(More)
With the goal to establish a model that relates birth weight to placenta weight, adjusted for the most documented predictors of birth weight, 300 live newborns were studied, all were products of single gestation. Inclusion criteria were newborns with gestational age of 37 weeks or older according to the date of last menstruation, whose mothers did not have(More)
This report demonstrates the feasibility of using deuterium (2H) and phosphorus (31P) nuclear magnetic resonance (NMR) spectroscopy to make multiple simultaneous determinations of changes in cerebral blood flow, brain intracellular pH, and phosphorylated metabolites for individual animals. In vivo spectra were obtained from the brains of newborn piglets(More)
BACKGROUND AND PURPOSE Our investigation sought to determine whether neonatal brain ischemic vascular and metabolic effects were altered by repeated episodes of ischemia. METHODS We studied twelve piglets using in vivo magnetic resonance spectroscopy to obtain multiple, simultaneous measurements of cerebral blood flow and phosphorylated metabolites from(More)
Using 'jet lag' paradigms involving phase shifts in the light-dark (LD) cycle, we studied the effects of S-20098 on the circadian clock of a diurnal rodent. Arvicanthis mordax, entrained to a regular LD cycle, were subjected to advance shifts (i.e. 4, 6 or 8 h) in the LD cycle and injected with vehicle or the melatonin agonist S-20098 (20 mg/kg) the day of(More)
Anti-Di(a) is a clinically significant red cell antibody known to cause hemolytic disease of the newborn. Here, we report on a case of mild hemolytic disease of the newborn caused by Di(a) antibody. The mother had three prior pregnancies with no history of blood transfusion. She delivered a preterm 35-week-old female newborn by cesarean section. The neonate(More)