The Experts below are selected from a list of 225 Experts worldwide ranked by ideXlab platform

Sarah L. Berga - One of the best experts on this subject based on the ideXlab platform.

  • Salivary cortisol reflects serum cortisol : analysis of circadian profiles
    Annals of Clinical Biochemistry, 2007
    Co-Authors: Lorah D. Dorn, Joseph F. Lucke, Tammy L. Loucks, Sarah L. Berga
    Abstract:

    Background: Technical hurdles limit the characterization of key Hormonal Rhythms. Frequent sampling increases detection of changes in magnitude or circadian and ultradian patterns, but limits feasi...

  • Salivary cortisol reflects serum cortisol: analysis of circadian profiles.
    Annals of clinical biochemistry, 2007
    Co-Authors: Lorah D. Dorn, Joseph F. Lucke, Tammy L. Loucks, Sarah L. Berga
    Abstract:

    Technical hurdles limit the characterization of key Hormonal Rhythms. Frequent sampling increases detection of changes in magnitude or circadian and ultradian patterns, but limits feasibility for clinical or research settings. These caveats are particularly pertinent for cortisol, a hormone that displays a prominent circadian rhythm and whose magnitude is tightly regulated in the absence of biobehavioural challenge. Ideally, one would like to obtain samples non-invasively from a matrix of interest at frequent intervals. While many investigations have reported a high correlation between serum and salivary cortisol assays, the degree to which salivary cortisol reflects the circadian patterns of circulating cortisol concentrations has not been established across a 24 h period. We obtained hourly serum and salivary samples over a 24 h period in nine adults in an inpatient setting. The circadian patterns for serum and salivary cortisol were analysed by harmonic regression. For all but two subjects (both on oral contraceptives), the salivary cortisol concentration was synchronous with the serum concentration, indicating that the salivary assay could be substituted for the serum assay to assess circulating rhythmicity across the 24 h time frame. This statistical model has distinct improvement over the correlational approach of examining serum and saliva cortisol relationships. Saliva cortisol appears to represent serum cortisol across the 24 h period, except for those on oral contraceptives.

Lorah D. Dorn - One of the best experts on this subject based on the ideXlab platform.

  • Salivary cortisol reflects serum cortisol : analysis of circadian profiles
    Annals of Clinical Biochemistry, 2007
    Co-Authors: Lorah D. Dorn, Joseph F. Lucke, Tammy L. Loucks, Sarah L. Berga
    Abstract:

    Background: Technical hurdles limit the characterization of key Hormonal Rhythms. Frequent sampling increases detection of changes in magnitude or circadian and ultradian patterns, but limits feasi...

  • Salivary cortisol reflects serum cortisol: analysis of circadian profiles.
    Annals of clinical biochemistry, 2007
    Co-Authors: Lorah D. Dorn, Joseph F. Lucke, Tammy L. Loucks, Sarah L. Berga
    Abstract:

    Technical hurdles limit the characterization of key Hormonal Rhythms. Frequent sampling increases detection of changes in magnitude or circadian and ultradian patterns, but limits feasibility for clinical or research settings. These caveats are particularly pertinent for cortisol, a hormone that displays a prominent circadian rhythm and whose magnitude is tightly regulated in the absence of biobehavioural challenge. Ideally, one would like to obtain samples non-invasively from a matrix of interest at frequent intervals. While many investigations have reported a high correlation between serum and salivary cortisol assays, the degree to which salivary cortisol reflects the circadian patterns of circulating cortisol concentrations has not been established across a 24 h period. We obtained hourly serum and salivary samples over a 24 h period in nine adults in an inpatient setting. The circadian patterns for serum and salivary cortisol were analysed by harmonic regression. For all but two subjects (both on oral contraceptives), the salivary cortisol concentration was synchronous with the serum concentration, indicating that the salivary assay could be substituted for the serum assay to assess circulating rhythmicity across the 24 h time frame. This statistical model has distinct improvement over the correlational approach of examining serum and saliva cortisol relationships. Saliva cortisol appears to represent serum cortisol across the 24 h period, except for those on oral contraceptives.

Tammy L. Loucks - One of the best experts on this subject based on the ideXlab platform.

  • Salivary cortisol reflects serum cortisol : analysis of circadian profiles
    Annals of Clinical Biochemistry, 2007
    Co-Authors: Lorah D. Dorn, Joseph F. Lucke, Tammy L. Loucks, Sarah L. Berga
    Abstract:

    Background: Technical hurdles limit the characterization of key Hormonal Rhythms. Frequent sampling increases detection of changes in magnitude or circadian and ultradian patterns, but limits feasi...

  • Salivary cortisol reflects serum cortisol: analysis of circadian profiles.
    Annals of clinical biochemistry, 2007
    Co-Authors: Lorah D. Dorn, Joseph F. Lucke, Tammy L. Loucks, Sarah L. Berga
    Abstract:

    Technical hurdles limit the characterization of key Hormonal Rhythms. Frequent sampling increases detection of changes in magnitude or circadian and ultradian patterns, but limits feasibility for clinical or research settings. These caveats are particularly pertinent for cortisol, a hormone that displays a prominent circadian rhythm and whose magnitude is tightly regulated in the absence of biobehavioural challenge. Ideally, one would like to obtain samples non-invasively from a matrix of interest at frequent intervals. While many investigations have reported a high correlation between serum and salivary cortisol assays, the degree to which salivary cortisol reflects the circadian patterns of circulating cortisol concentrations has not been established across a 24 h period. We obtained hourly serum and salivary samples over a 24 h period in nine adults in an inpatient setting. The circadian patterns for serum and salivary cortisol were analysed by harmonic regression. For all but two subjects (both on oral contraceptives), the salivary cortisol concentration was synchronous with the serum concentration, indicating that the salivary assay could be substituted for the serum assay to assess circulating rhythmicity across the 24 h time frame. This statistical model has distinct improvement over the correlational approach of examining serum and saliva cortisol relationships. Saliva cortisol appears to represent serum cortisol across the 24 h period, except for those on oral contraceptives.

Joseph F. Lucke - One of the best experts on this subject based on the ideXlab platform.

  • Salivary cortisol reflects serum cortisol : analysis of circadian profiles
    Annals of Clinical Biochemistry, 2007
    Co-Authors: Lorah D. Dorn, Joseph F. Lucke, Tammy L. Loucks, Sarah L. Berga
    Abstract:

    Background: Technical hurdles limit the characterization of key Hormonal Rhythms. Frequent sampling increases detection of changes in magnitude or circadian and ultradian patterns, but limits feasi...

  • Salivary cortisol reflects serum cortisol: analysis of circadian profiles.
    Annals of clinical biochemistry, 2007
    Co-Authors: Lorah D. Dorn, Joseph F. Lucke, Tammy L. Loucks, Sarah L. Berga
    Abstract:

    Technical hurdles limit the characterization of key Hormonal Rhythms. Frequent sampling increases detection of changes in magnitude or circadian and ultradian patterns, but limits feasibility for clinical or research settings. These caveats are particularly pertinent for cortisol, a hormone that displays a prominent circadian rhythm and whose magnitude is tightly regulated in the absence of biobehavioural challenge. Ideally, one would like to obtain samples non-invasively from a matrix of interest at frequent intervals. While many investigations have reported a high correlation between serum and salivary cortisol assays, the degree to which salivary cortisol reflects the circadian patterns of circulating cortisol concentrations has not been established across a 24 h period. We obtained hourly serum and salivary samples over a 24 h period in nine adults in an inpatient setting. The circadian patterns for serum and salivary cortisol were analysed by harmonic regression. For all but two subjects (both on oral contraceptives), the salivary cortisol concentration was synchronous with the serum concentration, indicating that the salivary assay could be substituted for the serum assay to assess circulating rhythmicity across the 24 h time frame. This statistical model has distinct improvement over the correlational approach of examining serum and saliva cortisol relationships. Saliva cortisol appears to represent serum cortisol across the 24 h period, except for those on oral contraceptives.

Andries Kalsbeek - One of the best experts on this subject based on the ideXlab platform.

  • circadian Rhythms in glucose and lipid metabolism in nocturnal and diurnal mammals
    Molecular and Cellular Endocrinology, 2015
    Co-Authors: Pawan Kumar Jha, Andries Kalsbeek, Etienne Challet
    Abstract:

    Most aspects of energy metabolism display clear variations during day and night. This daily rhythmicity of metabolic functions, including hormone release, is governed by a circadian system that consists of the master clock in the suprachiasmatic nuclei of the hypothalamus (SCN) and many secondary clocks in the brain and peripheral organs. The SCN control peripheral timing via the autonomic and neuroendocrine system, as well as via behavioral outputs. The sleep-wake cycle, the feeding/fasting rhythm and most Hormonal Rhythms, including that of leptin, ghrelin and glucocorticoids, usually show an opposite phase (relative to the light-dark cycle) in diurnal and nocturnal species. By contrast, the SCN clock is most active at the same astronomical times in these two categories of mammals. Moreover, in both species, pineal melatonin is secreted only at night. In this review we describe the current knowledge on the regulation of glucose and lipid metabolism by central and peripheral clock mechanisms. Most experimental knowledge comes from studies in nocturnal laboratory rodents. Nevertheless, we will also mention some relevant findings in diurnal mammals, including humans. It will become clear that as a consequence of the tight connections between the circadian clock system and energy metabolism, circadian clock impairments (e.g., mutations or knock-out of clock genes) and circadian clock misalignments (such as during shift work and chronic jet-lag) have an adverse effect on energy metabolism, that may trigger or enhancing obese and diabetic symptoms.

  • Temporal organization of the 24-h corticosterone rhythm in the diurnal murid rodent Arvicanthis ansorgei Thomas 1910
    Brain research, 2004
    Co-Authors: Linda A.w. Verhagen, Paul Pévet, Michel Saboureau, Bruno Sicard, Béatrice Nesme, Bruno Claustrat, Ruud M. Buijs, Andries Kalsbeek
    Abstract:

    Abstract Arvicanthis ansorgei is a diurnal murid rodent from sub-Saharan Africa. The present study reports on the temporal organization of one of the major Hormonal Rhythms, i.e. the adrenal steroid hormone corticosterone, in an attempt to characterize further the diurnal nature of this species. The data were obtained by means of two different physiological methods: blood sampling and intracerebral microdialysis. The results show a 12-h rhythm of corticosterone release with peak values close to the light–dark (ZT10) and dark–light transition (ZT22–24), which is clearly different from that in a nocturnal animal. Both corticosterone peaks are closely correlated with the occurrence of two major bouts of running wheel activity. As far as we are aware, this is the first demonstration of a Hormonal rhythm with a clear crepuscular appearance (peak values around dusk and dawn). In conclusion, these data show that also in a rodent with a diurnal/crepuscular activity pattern, the tight association between the daily corticosterone peak and the onset of activity is maintained. In addition, intracerebral microdialysis is a suitable technique to measure Hormonal Rhythms when repeated blood sampling is not possible.

  • Rhythms of inhibitory and excitatory output from the circadian timing system as revealed by in vivo microdialysis
    Progress in brain research, 1996
    Co-Authors: Andries Kalsbeek, Ruud M. Buijs
    Abstract:

    Publisher Summary The inhibitory effects of vasopressin (VP) and GABA released from suprachiasmatic nuclei (SCN) terminals in the paraventricular nucleus (PVN)/DMH area form an important aspect in the circadian control of corticosterone and melatonin release, respectively. In addition, the experimental results reviewed in the chapter make clear that the SCN control of both Hormonal Rhythms also contains a stimulatory signal. A circadian rhythm is then created by allowing a stimulatory input to the Hormonal system during the secretion trough of the inhibitory transmitter. Using partial SCN-lesioned, hamsters provide with fetal SCN transplants of tau -mutant hamsters. In conclusion, microdialysis has proven to be an important research tool for the exploration of circadian secrets, and, perhaps in the future, it may even be helpful in unraveling the (circadian) secrets of the human brain.