Jaycinth Blackman

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To define the roles of circadian rhythmicity (intrinsic effects of time of day independent of the sleep or wake condition) and sleep (intrinsic effects of the sleep condition, irrespective of the time of day) on the 24-h variation in glucose tolerance, eight normal men were studied during constant glucose infusion for a total of 53 h. The period of study(More)
Abnormalities in fasting lipid and lipoprotein levels are known to occur in obesity and other hyperinsulinemic states. However, postprandial lipoprotein metabolism has not been studied systematically in obese subjects using sensitive techniques to distinguish between triglyceride-rich lipoprotein particles derived from the intestine and the liver. In the(More)
Ultradian "oscillations" or "pulses" of insulin secretion with periods around 120 min occur in man. It is not known whether glucose plays an active role in generating these oscillations, or if an intrapancreatic pacemaker generates oscillations in insulin secretion that entrain glucose passively. To determine if the frequency of pulses of insulin secretion(More)
Previous studies have shown that hyperinsulinism is associated with hyperandrogenism in patients with the polycystic ovary syndrome, a form of functional ovarian hyperandrogenism (FOH). Although many studies have documented insulin resistance and hyperinsulinemia in polycystic ovary syndrome, the relative roles of insulin secretion and clearance in the(More)
To determine the magnitude and direction of phase shifts of human circadian rhythms occurring within 1 day after a single exposure to bright light, plasma thyrotropin, melatonin, and cortisol levels and body temperature were monitored for 38 h in 17 men who were each studied two times, once during continuous dim light conditions and once with light(More)
To determine whether a single episode of physical activity is capable of inducing rapid phase shifts in human circadian rhythms, 17 subjects were studied two times under constant routine conditions, once in the absence of stimulus and once with a 3-h nighttime pulse of exercise interrupting the constant routine conditions. The profiles of plasma cortisol,(More)
To define the spontaneous diurnal variations in glucose regulation during fasting in noninsulin-dependent diabetes (NIDDM), we measured circulating levels of glucose, insulin, C-peptide, GH, cortisol, and glucagon at 15-min intervals in 11 patients with untreated diabetes and 7 matched control subjects studied during a 24-h period. The rates of insulin(More)
OBJECTIVE To evaluate the utility of a semipermeable polymeric membrane dressing for the treatment of chronic diabetic foot ulcers. RESEARCH DESIGN AND METHODS Nineteen subjects with either insulin-dependent diabetes mellitus (IDDM) or non-insulin-dependent diabetes mellitus (NIDDM) and foot ulcers were randomly assigned to the polymeric dressing or(More)
Fourteen poorly controlled insulin-dependent diabetes mellitus (IDDM) patients (HbA1c 11 +/- 0.5%) with a mean +/- SE duration of disease of 15 +/- 2 yr were studied to evaluate the hypoglycemic threshold for cognitive dysfunction under insulin-induced hypoglycemia. The P300 event-related potential, a measure of cognitive function, and reaction time (RT) in(More)
Nineteen healthy adult volunteers were studied to define the nature of and threshold for the cognitive dysfunction that occurs during insulin-induced hypoglycemia. The P300 cerebral event-related potential is an electrophysiological correlate of cognitive decision-making processes that can be measured in response to either an auditory or visual stimulus.(More)