OBJECTIVE To review the literature on the circadian rhythm of blood pressure during pregnancy. DATA SOURCES Computerized searches on MEDLINE, CINAHL, and MIRLYN. STUDY SELECTION Selected studies from 1 969 to 1997 were evaluated. DATA EXTRACTION Data were extracted and information was organized under the following areas: definition of and the interconnection between circadian rhythm and b...

Hypothalamic-pituitary-adrenal (HPA) axis functioning is characterized by the baseline production of cortisol following a circadian rhythm, as well as by the superimposed production of cortisol in response to a stressor. However, it is relatively unknown whether the basal cortisol circadian rhythm is associated with the cortisol stress response in children. Since alterations in cortisol stress ...

The clock mechanism for circatidal rhythm has long been controversial, and its molecular basis is completely unknown. The mangrove cricket, Apteronemobius asahinai, shows two rhythms simultaneously in its locomotor activity: a circatidal rhythm producing active and inactive phases as well as a circadian rhythm modifying the activity intensity of circatidal active phases. The role of the clock g...

Two prominent timekeeping systems, the cell cycle, which controls cell division, and the circadian system, which controls 24-h rhythms of physiology and behavior, are found in nearly all living organisms. A distinct feature of circadian rhythms is that they are temperature-compensated such that the period of the rhythm remains constant (approximately 24 h) at different ambient temperatures. Eve...

Circadian rhythm sleep disorders are common in clinical practice. The disorders covered in this review are delayed sleep phase disorder, advanced sleep phase disorder, free-running, irregular sleep-wake rhythm, jet lag disorder and shift work disorder. Bright light treatment and exogenous melatonin administration are considered to be the treatments of choice for these circadian rhythm sleep dis...

The symptoms of allergic rhinitis show marked day-night changes that are likely to be under the control of the circadian clock, but the mechanism of this control is poorly understood. Because most peripheral tissues have endogenous circadian clocks, we examined the circadian rhythm of the clock gene product PERIOD2 (PER2) in the nasal mucosa of male mice using a luciferase reporter and demonstr...

We apply performance analysis techniques to a biological modelling problem, that of capturing and reproducing the Circadian rhythm. A Circadian rhythm provides cells with a clock by which to regulate their behaviour. We consider two distinct stochastic models of the Circadian rhythm – one unbounded and the other bounded. We consider a fluid approximation of the models, and, by conversion to a s...