Gait Velocity in RA Exhibits Significant Diurnal Variation

2011 ◽  
Vol 10 (5) ◽  
pp. 2
Author(s):  
SARA FREEMAN
Keyword(s):  
Diurnal Variation ◽  
Gait Velocity ◽  
Significant Diurnal Variation

The effects of exercise stress testing, diurnal variation and temporal decline on circulating progenitor cells

2010 ◽  
Vol 103 (02) ◽  
pp. 419-424 ◽  
Author(s):  
Vellore Karthikeyan ◽  
Shahirose Jessani ◽  
Patrick Goon ◽  
Timothy Watson ◽  
Eduard Shantsila ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Diurnal Variation ◽  
Stress Testing ◽  
Endothelial Damage ◽  
Significant Decline ◽  
Exercise Stress ◽  
Post Exercise ◽  
Blood Samples ◽  
Male Age ◽  
Significant Diurnal Variation

SummaryEndothelial damage/dysfunction is involved in numerous cardiovascular disease processes. Given that the mature endothelial cells have limited capacity for self regeneration, circulating progenitor cells (CPCs) may modulate the balance between vascular damage and regeneration. The three aims of the present study were 1) to define the influence of exercise treadmill testing (ETT) on peripheral CPC levels; 2) to assess the diurnal variation of CPC counts; and 3) to investigate the rate of temporal decline in CPCs once ex vivo. The dynamics of CPC count changes following an ETT were assessed on consecutive 20 patients referred to our ‘rapid-access’ chest pain clinic (70% male, age 69.9 ± 7.8) with venous blood samples taken pre-exercise, immediately post-exercise and at 30 minutes post-exercise. Diurnal variation in CPCs was assessed in 13 stable in-hospital patients (46% male, age 69.1 ± 7.5 years) with blood samples were taken five times every 6 hours. To investigate the temporal decline, blood samples from 12 patients (58.3% male, age 69.9 ± 7.9 years) were reprocessed for CPC counts at 4 hours and at 24 hours after sample collection. Plasma levels of von Willebrand factor (vWf) and soluble E-selectin (sE-selectin) were assessed by ELISA. CPCs were enumerated with flow cytometry as CD34+, CD133+, CD45dim events. Exercise led to significant increases in vWF and sE-selectin levels, but no significant influence on CPC counts were observed. Baseline CPC numbers demonstrated a negative correlation with vWf (r=-0.551, p=0.012) and sE-selectin levels (r=-0.494, p=0.027). CPC counts showed a significant diurnal variation, being significantly higher at 12 a.m. compared to 12 p.m. (p=0.046) and 6 p.m. (p=0.023). A 4 hour delay in sample preparation did not affect CPCs counts, but there was a significant decline in CPC recovery when sample processing was delayed by 24 hours (p<0.05). Routine exercise stress testing does not significantly affect CPC counts. Peripheral CPC levels showed a significant diurnal variation. Delays in sample preparation for CPC counts should be avoided as they may influence the accuracy of the test by resulting in a significant decline in CPC recovery. Thus, various factors may affect accuracy of CPC enumeration that may limit their role as a reliable clinical marker and biomarker of endothelial damage.

scholarly journals Gait velocity exhibits more than 50% diurnal variation in Rheumatoid Arthritis: the divign study

2010 ◽  
Vol 3 (S1) ◽  
Author(s):  
Michael Backhouse ◽  
David Pickles ◽  
Hannah Mathieson ◽  
Lucy Edgson ◽  
Paul Emery ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Diurnal Variation ◽  
Gait Velocity

Diurnal Variation in Choroidal and Retinal Thickness of the Early Treatment of Diabetic Retinopathy Study Macular Subfields Determined Using Swept-Source Optical Coherence Tomography

2015 ◽  
Vol 233 (3-4) ◽  
pp. 192-197 ◽  
Author(s):  
Yong-Seop Han ◽  
Hyung-Bin Lim ◽  
Soo-Hyun Lee ◽  
Jung-Yeul Kim
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Diurnal Variation ◽  
Early Treatment ◽  
Retinal Thickness ◽  
Intraclass Correlation ◽  
Optical Coherence ◽  
Swept Source ◽  
A Prospective Study ◽  
Significant Diurnal Variation

Purpose: To describe diurnal variation in choroidal thickness (CT) and retinal thickness (RT) of the nine Early Treatment of Diabetic Retinopathy Study (ETDRS) macular subfields determined using swept-source optical coherence tomography. Methods: A prospective study was conducted on 24 healthy Korean volunteers who underwent two sequential measurements of a randomly selected eye at 9 a.m., 1 p.m., and 6 p.m. The radial scan mode was used. To determine the repeatability and reliability, we applied intragrader agreement using the intraclass correlation coefficient (ICC). Results: Significant diurnal variation in CT was observed. The highest mean CT was found at 9 a.m. The lowest mean CT occurred at 1 p.m. There was excellent intragrader agreement, with the ICC ranging from 0.961 to 0.997. There was no significant diurnal variation in RT. Conclusion: There was significant diurnal variation in CT. The choroid was thinner at 1 p.m. than at 9 a.m. and 6 p.m.

scholarly journals Avalanche Activity on the Vaughan Lewis Icefall, Alaska

1968 ◽  
Vol 7 (51) ◽  
pp. 441-448 ◽  
Author(s):  
Alfred C. Pinchak
Keyword(s):  
Diurnal Variation ◽  
Direct Observation ◽  
Relative Frequency ◽  
Inverse Relationship ◽  
Early Morning ◽  
Cooling Period ◽  
Significant Diurnal Variation

AbstractAvalanche data were obtained by direct observation of the Vaughan Lewis Icefall. Magnitude, time and location of each ice fall were recorded and the resulting data were analyzed statistically. An inverse relationship was found between the relative frequency and the magnitude of the avalanches. A significant diurnal variation in avalanche rate was also detected. During the early morning hours the avalanche rate reached a maximum. No secondary increase in the avalanche frequency was observed during the evening cooling period. The data indicated that a given ice fall results in an increased probability of an ice fall occurring shortly thereafter. After approximately 4 min the effect of a given avalanche no longer correlates with succeeding avalanches.

Diurnal and Inter-Colony Variation in Pollen Collection from Different Seed Crops by Honeybees (Apis melifera L.)

1973 ◽  
Vol 4 (2) ◽  
pp. 100-104 ◽  
Author(s):  
Morten Helt Poulsen
Keyword(s):  
Diurnal Variation ◽  
White Clover ◽  
Red Clover ◽  
Pollen Collection ◽  
Pollen Sources ◽  
Seed Crops ◽  
Different Sources ◽  
Field Beans ◽  
Significant Diurnal Variation

AbstractA total of 2207 pollen collectors were trapped from five honeybee colonies at different times of day and grouped according to the pollen sources: red clover, white clover, field beans, crucifers, other species. Significant diurnal variation in amount of pollen collected from the different sources was found and the percentage of pollen collected from red clover, white clover and field beans respectively varied significantly between the five colonies.

EFFECT OF OESTRADIOL-17β EXPOSURE ON THE SPONTANEOUS SECRETION OF GONADOTROPHINS IN CHRONICALLY GONADECTOMIZED RATS

1977 ◽  
Vol 73 (3) ◽  
pp. 455-462 ◽  
Author(s):  
S. R. HENDERSON ◽  
CHRISTINE BAKER ◽  
G. FINK
Keyword(s):  
Diurnal Variation ◽  
Female Rats ◽  
Gonadotrophin Secretion ◽  
Significant Difference ◽  
Spontaneous Secretion ◽  
Significant Diurnal Variation

SUMMARY The effect of oestradiol-17β (administered in Silastic capsules) on gonadotrophin secretion in long-term gonadectomized rats has been investigated. In female rats, a daily afternoon surge of LH occurred which could be blocked by administering sodium pentobarbitone at 13.00 h. This, together with the fact that there was no significant difference between the LH-response to LH-releasing factor in the morning compared with the afternoon, supports the view that the LH surges are due to a neural rhythm. There was no significant diurnal variation in plasma FSH concentration, but an apparent diurnal variation was disclosed by administering sodium pentobarbitone on alternate days. There was no diurnal variation in plasma gonadotrophin concentrations in male animals implanted with an oestradiol capsule, or in animals of either sex bearing empty capsules.

scholarly journals Sudden Commencements and Impulses in Kodaikanal magnetograms -their hourly frequency

MAUSAM ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 209-212
Author(s):  
B. SRINIVASAMURTHY
Keyword(s):  
Diurnal Variation ◽  
Harmonic Analysis ◽  
Local Time ◽  
Secondary Minimum ◽  
Frequency Curve ◽  
Secondary Maximum ◽  
Sudden Commencements ◽  
Significant Diurnal Variation

The diurnal variation in the frequencies of sudden commencements (SCs) and sudden impulses (SIs) at Kodaikanal (10.2°N, 77.5°E) is analysed from the data for the period 1949-1957.The hourly frequency curve of SCs and SIs (combined) has little resemblance to the curve obtained by Newton from his analysis of Greenwich-Abinger record. The results of harmonic analysis show a nearly semi-diurnal trend the distribution of storm sudden commencements (SSCs); this, however, is small. The hourly frequencies of SIS  show s significant diurnal variation with an afternoon maximum and a forenoon maximum and a secondary minimum around 18h local time and a secondary maximum around 08h. These results are also compared with those obtained by Ferraro Parkinson and Unthank.

scholarly journals Aged organic aerosol in the Eastern Mediterranean: the Finokalia Aerosol Measurement Experiment – 2008

2010 ◽  
Vol 10 (9) ◽  
pp. 4167-4186 ◽  
Author(s):  
L. Hildebrandt ◽  
G. J. Engelhart ◽  
C. Mohr ◽  
E. Kostenidou ◽  
V. A. Lanz ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Eastern Mediterranean ◽  
Source Region ◽  
Bulk Composition ◽  
Organic Aerosol ◽  
Aerosol Measurement ◽  
Two Factors ◽  
Measurement Experiment ◽  
Total Sulfate ◽  
Significant Diurnal Variation

Abstract. Aged organic aerosol (OA) was measured at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiment-2008 (FAME-2008), which was part of the EUCAARI intensive campaign of May 2008. The site at Finokalia is influenced by air masses from different source regions, including long-range transport of pollution from continental Europe. A quadrupole aerosol mass spectrometer (Q-AMS) was employed to measure the size-resolved chemical composition of non-refractory submicron aerosol (NR-PM1), and to estimate the extent of oxidation of the organic aerosol. Factor analysis was used to gain insights into the processes and sources affecting the OA composition. The particles were internally mixed and liquid. The largest fraction of the dry NR-PM1 sampled was ammonium sulfate and ammonium bisulfate, followed by organics and a small amount of nitrate. The variability in OA composition could be explained with two factors of oxygenated organic aerosol (OOA) with differing extents of oxidation but similar volatility. Hydrocarbon-like organic aerosol (HOA) was not detected. There was no statistically significant diurnal variation in the bulk composition of NR-PM1 such as total sulfate or total organic aerosol concentrations. However, the OA composition exhibited statistically significant diurnal variation with more oxidized OA in the afternoon. The organic aerosol was highly oxidized, regardless of the source region. Total OA concentrations also varied little with source region, suggesting that local sources had only a small effect on OA concentrations measured at Finokalia. The aerosol was transported for about one day before arriving at the site, corresponding to an OH exposure of approximately 4×1011 molecules cm−3 s. The constant extent of oxidation suggests that atmospheric aging results in a highly oxidized OA at these OH exposures, regardless of the aerosol source.

DEVELOPMENT OF THE CIRCADIAN RHYTHM OF CORTISOL IN THE GILT FROM WEANING UNTIL PUBERTY

1988 ◽  
Vol 68 (4) ◽  
pp. 1105-1111 ◽  
Author(s):  
F. D. EVANS ◽  
R. J. CHRISTOPHERSON ◽  
F. X. AHERNE
Keyword(s):  
Circadian Rhythm ◽  
Diurnal Variation ◽  
Key Words ◽  
Biologically Active ◽  
Total Cortisol ◽  
Adrenal Axis ◽  
Gradual Development ◽  
Cortisol Levels ◽  
Afternoon Peak ◽  
Significant Diurnal Variation

In order to characterize the development of the adrenal axis by monitoring development of the circadian rhythm of cortisol, 10 gilts were blood-sampled serially for 24 h every 4 wk from 4 to 28 wk of age. Age at first estrus for sampled animals (199.6 ± 5.3 d, mean ± SEM) was not different (P > 0.05) from that of another group of 10 control gilts not blood sampled (203.4 ± 6.8 d). Cortisol profiles at 4 wk of age did not show a significant diurnal variation. At 8 and 12 wk, the profile showed the development of an afternoon trough. At 16 wk, an afternoon peak was present. At 20 and 24 wk, the continued development of peaks and a well-formed trough were evident and by 28 wk of age the profile was characterized by a large morning peak, small afternoon peak and an evening trough. Mean levels of total cortisol at 4, 8, 12, 16, 20, 24 and 28 wk were 25.3 ± 2.2, 37.4 ± 4.1, 40.1 ± 3.5, 26.8 ± 2.8, 20.6 ± 2.6, 38.3 ± 3.6 and 24.8 ± 2.9 ng mL−1, respectively. Profiles of biologically active cortisol appeared to closely mirror total cortisol profiles. Total cortisol levels at 8, 12 and 24 wk of age were higher (P < 0.05) than at other ages. These results indicate that in the gilt the circadian rhythm of cortisol undergoes gradual development reaching adult profiles at or shortly before first estrus. Key words: Adrenal, circadian rhythm, cortisol, cortisol binding globulin, development, gilt

Reduced peak, but no diurnal variation, in thrombin generation upon melatonin supplementation in tetraplegia

2015 ◽  
Vol 114 (11) ◽  
pp. 964-968 ◽  
Author(s):  
Anders Dahm ◽  
Grethe Skretting ◽  
Marie-Christine Mowinckel ◽  
Annicke Stranda ◽  
Bjarne Østerud ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Thrombin Generation ◽  
Study Groups ◽  
Sleep Cycle ◽  
Healthy Individuals ◽  
Time To Peak ◽  
Cat Assay ◽  
Increased Risk ◽  
Significant Diurnal Variation

SummaryTetraplegic patients have increased risk of venous thrombosis despite anti-thrombotic prophylaxis. Moreover, they have blunted plasma variations in melatonin and altered diurnal variation of several haemostatic markers, compared with able-bodied. However, whether healthy individuals and tetraplegic patients, with or without melatonin, display abnormalities in thrombin generation during a 24-hour (h) cycle, is unknown. We therefore used the Calibrated Automated Thrombogram (CAT) assay to examine diurnal variations and the possible role of melatonin in thrombin generation. Six men with long-standing complete tetraplegia were included in a randomised placebo-controlled cross-over study with melatonin supplementation (2 mg, 4 consecutive nights), whereas six healthy, able-bodied men served as controls. Ten plasma samples were collected frequently during a 24-h awake/sleep cycle. No significant diurnal variation of any of the measured CAT indices was detected in the three study groups. Whereas endogenous thrombin potential (ETP) was independent (p > 0.05) of whether the tetraplegic men received melatonin or placebo, melatonin decreased (p = 0.005) peak values in tetraplegia compared with those given placebo. Able-bodied men had lower (p = 0.019) ETP and Lag-Time (p = 0.018) compared with tetraplegics receiving placebo. Neither the Time-to-Peak nor the Start-Tail was affected (p > 0.05) by melatonin in tetraplegia. In conclusion, indices of thrombin generation are not subjected to diurnal variation in healthy able-bodied or tetraplegia, but peak thrombin generation is reduced in tetraplegic men receiving oral melatonin.

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