Intrinsically photosensitive retinal ganglion cells (ipRGC) signal environmental light level to the central circadian clock and contribute to the pupil light reflex. It is unknown if ipRGC activity is subject to extrinsic (central) or intrinsic (retinal) network-mediated circadian modulation during light entrainment and phase shifting. Eleven younger persons (18-30 years) with no ophthalmologic...

BACKGROUND Measurements of heart rate variability (HRV) are increasingly used as markers of cardiac autonomic activity. AIM To examine circadian variation in heart rate and HRV in children. SUBJECTS A total of 57 healthy infants and children, aged 2 months to 15 years, underwent ambulatory 24 hour Holter recording. Monitoring was also performed on five teenagers with diabetes mellitus and s...

Objective. To determine circadian variation in the onset of placental abruption. Methods. A retrospective study involving 115 placental abruptions, divided into four subgroups based on initial symptoms comprising abdominal pain, vaginal bleeding, both abdominal pain and bleeding, or other symptoms. The time of the initial symptom was considered the disease onset. We analyzed the frequency of di...

1. Cameron MA, Baker LA, Maalouf NM et al. Circadian variation in urine pH and uric acid nephrolitiasis risk. Nephrol Dial Transplant 2007; 22: 2375–2378 2. Robert M, Roux JO, Bourelly F et al. Circadian variation in the risk of urinary calcium oxalate stone formation. Br J Urol 1994; 74: 294–297 3. Voogel AJ, Koopman MG, Hart AA et al. Circadian rhythms in systemic hemodynamics and renal funct...

BACKGROUND WHITE COLLAR-1 (WC-1) mediates interactions between the circadian clock and the environment by acting as both a core clock component and as a blue light photoreceptor in Neurospora crassa. Loss of the amino-terminal polyglutamine (NpolyQ) domain in WC-1 results in an arrhythmic circadian clock; this data is consistent with this simple sequence repeat (SSR) being essential for clock f...

BACKGROUND Circadian variation in blood pressure (BP), which is commonly blunted among patients with chronic kidney disease (CKD), has been associated with increased cardiovascular risk. The causes of this blunted circadian variation remain incompletely understood. METHODS We hypothesized that physical activity is a determinant of circadian BP variation. Accordingly, we studied 101 patients w...

The importance of natural gene expression variation for human behavior is undisputed, but its impact on circadian physiology remains mostly unexplored. Using umbilical cord fibroblasts, we have determined by genome-wide association how common genetic variation impacts upon cellular circadian function. Gene set enrichment points to differences in protein catabolism as one major source of clock v...