Circadian variation

FIGURE 3.1. Circadian Variations in Oral Temperatures and Alertness for Six Process Workers (Monk and Embrey, 1981). 

FIGURE 3.3. Circadian Variations in Errors Made by Process Workers... 

A link between 5-HT release and increased waking is supported by evidence from in vivo microdialysis of cats and rats. This has confirmed that the extracellular concentration of 5-HT in all brain regions studied to date is lower during both SWS and REM sleep than in the awake state (see Portas, Bjorvatn and Ursin 2000). Interestingly, if behaviour is maintained at a constant level, the activity of 5-HT neurons does not show circadian variation although 5-HT turnover in the brain areas to which they project... 

Garcia-Borreguero D., Larrosa O., Saiz T. et al. (2001). Circadian variation in neuroendocrine response to the administration of L-dopa in patients with restless legs syndrome a pilot study. Sleep 24(suppl.), (A16-A17). 

Kawano Y., Kawasaki T., Kawazoe N. et al. (1990). Circadian variations of urinary dopamine, norepinephrine, epinephrine and sodium in normotensive and hypertensive subjects. Nephron 55(3), 277-82. 

Sowers J. R., Vlachakis N. (1984). Circadian variation in plasma dopamine levels in man. J. Endocrinol. Invest. 7(4), 341-5. 

Ayers, N. A., Kapas, L. Krueger, J. M. (1996). Circadian variation of nitric oxide synthase activity and cytosolic protein levels in rat brain. Brain Res. 707, 127-30. 

Tunctan, B., Weigl, Y., Dotan, A. et al. (2002). Circadian variation of nitric oxide synthase activity in mouse tissue. Chronobiol. Int. 19, 393-404. 

The serum L-PGDS/p-trace concentration shows a circadian variation with a nocturnal increase, which is suppressed during total sleep deprivation but not affected by deprivation of REM sleep (Jordan et ah, 2004). Whether or not L-PGDS is a dual-function protein in vivo and is involved in the production of PGD2 as well as in the transport of PGD2 or some other compound(s) remains to be elucidated. 

Williams MB. Circadian variation in rat brain AP-1 DNA binding activity after cholinergic stimulation modulation by lithium. Psychopharmacology (Berlin), 1995 122 363-368. 

Spieler, R.E., A.C. Russo, and D.N. Weber. 1995. Waterborne lead affects circadian variations of brain neurotransmitters in fathead minnows. Bull. Environ. Contam. Toxicol. 55 412-418. 

Singleton, C and Marsden, C. A. (1981) Circadian variation in the head twitch response produced by 5-methoxy-N,N-dimethyltryptamine and p-chloroamphetamine in the mouse. 

Goo RH, Moore JG, Greenberg E, Alazraki NP. Circadian variation in gastric emptying of meals in humans. Gastroenterology 1987 93 515-518. 

Kumar D, Wingate D, Ruckebusch Y. Circadian variation in the propagation velocity of the migrating motor complex. Gastroenterology 1986 91 926-930. 

According to Chandler (C4), there is no circadian variation, but one should keep in mind that the distribution of Lp(a) over the different lipid fractions after a meal differs from the distribution in fasting serum samples (B11, E8). 

Circadian variations in basal conditions Absence or presence of an effect compartment The PK model of absorption and disposition and the parameters to be estimated Inclusion or exclusion of specific patient data... 

Harris, B.E., Song, R., Soong, S.J., et al. (1990) Relationship between dihydropyrimidine dehydrogenase activity and plasma 5-fluorouracil levels with evidence for circadian variation of enzyme activity and plasma drug levels in cancer patients receiving 5-fluorouracil by protracted continuous infusion. Cancer Res. 50,197-201. 

A circadian variation in serum acid phosphatase has been reported in patients with prostatic carcinoma and phosphatase activity determined with phenyl phosphatase as substrate (DIO). The nocturnal values decreased 25-50% of the highest day time activity. The highest values were observed from 9 am to 3 pm and the lowest between 9 pm and 3 am. In one patient observations were made at hourly intervals. The peak of 14.2 King-Armstrong units was observed at 11 am and the lowest activity, 6.4 units, at midnight. Orchiectomy did not eliminate the variation. 

Androderm - Following application to nonscrotal skin, testosterone is continuously absorbed during the 24-hour dosing period. Daily application of 2 systems at approximately 10 00 p.m. results in a serum testosterone concentration profile that mimics the normal circadian variation observed in healthy young men. Maximum concentrations occur in the early morning hours with minimum concentrations in the evening. 

The Walter Reed Army Institute of Research s Department of Behavioral Biology has developed a field-deployable version of a commercial Psychomotor Vigilance Task (PVT) that has been widely used in sleep research. The software runs on handheld PDAs running the Palm Operating System (Palm OS). It is modeled after the simple reaction time task of Wilkinson and Houghton,57 as modified by Dinges and Powell.58 The Palm OS version incorporates additional stimulus, feedback, control, and data options developed by Dr. Thome. In laboratory studies, performance on the PDA task has been shown to be sensitive to time-on-task fatigue effects, sleep deprivation, and circadian variation.18 Field studies have utilized the PVT to measure the efficacy of caffeine gum as a sleep loss countermeasure. 

Richardson GS, Carskadon MA, Orav EJ, Dement WC. Circadian variation of sleep tendency in elderly and young adult subjects. Sleep 1982 5 (suppl) 82-94. 

Figure 3 Mean PVT reaction times (msec) and false starts (errors of commission) during 88 hr of total sleep deprivation and 88 hours of sleep deprivation with two 2-hour nap opportunities each day. Subjects in the total sleep deprivation (TSD) group (n = 13) are represented by the open circles. Subjects in the 88-hr sleep deprivation plus two 2-hr nap opportunities (NAP) group (n = 15) are represented by the closed squares. Nap opportunity periods were at 02 45-04 45 and 14 45-16 45 each day. The top panel illustrates mean reaction times ( s.e.m.) for each test bout across the experimental protocol. Subjects in the NAP group demonstrated little variation in reaction times across the experimental period, while subjects in the TSD group experienced significant impairment in performance, reflected in the increasing reaction times as time awake increased, with circadian variation in performance capability evident. The bottom panel illustrates mean number of errors ( s.e.m.) per test bout across the experimental protocol. A similar pattern of performance degradation in this variable was evident for both the NAP and TSD groups. (From Ref. 44.)...

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