Search results for "circadian"
showing 10 items of 363 documents
Red cell sorbitol concentration in relation to short- and medium-term variation of plasma glucose.
1989
To evaluate the time course of changes in red cell sorbitol (RCS) concentration in relation to variations of plasma glucose levels, RCS was determined in 7 normal subjects during i.v. glucose infusion (IVGTT); in 6 hyperglycemic insulin-dependent diabetic subjects while glycemia was normalized with Biostator GC 115 and in 4 diabetic patients in previously poor metabolic control, in whom normal glycemia was obtained in 8–10 days by intensive insulin therapy. During IVGTT, plasma glucose levels increased with significant differences from baseline at 5, 10, 16, 25, 60, 100 and 160 min and returned to basal levels after 3h; RCS concentration showed small and insignificant increases. During i.v.…
Alterations in circadian rhythm of serum thyrotropin in critically ill patients.
1992
To evaluate the 24-h pattern of serum thyrotropin (TSH) in critically ill patients, we measured serum concentrations of TSH in blood samples collected every 2 h for 24 h from nine patients (six with malignancy, two with liver cirrhosis, one with chronic renal failure), who had subnormal levels of both triiodothyronine (T3) and thyroxine (T4), in the absence of history, symptoms or signs of thyroid disease. Analysis of the data, performed using a second-order inferential statistical methodology for rhythmometry (cosinor method), demonstrated that critically ill patients still had daily oscillations of serum TSH which significantly adapted to the function approximating the circadian rhythms (…
Deficient pulsatile thyrotropin secretion in the low-thyroid-hormone state of severe non-thyroidal illness
1994
Custro N, Scafidi V, Gallo S, Notarbartolo A. Deficient pulsatile thyrotropin secretion in the low-thyroid-hormone state of severe non-thyroidal illness. Eur J Endocrinol 1994;130:132–6. ISSN 0804–4643. Twenty-four-hour thyrotropin (TSH) profiles in eight severely ill patients were compared with those of six healthy subjects. The profiles were assessed using the cosinor method to evaluate circadian variations and using the Pulsar algorithm to analyze episodic secretion. In the normal subjects, the typical periodicity of TSH secretion showed a mean level in the rhythm (mesor) of 2.03 mU/l, The amplitude (half the extent of rhythmic change in the cycle) was 0.58 mU/l; the acrophase (the delay…
Evaluation of 24-hour gastric acidity in patients with hepatic cirrhosis.
1996
Data from previous studies on gastric acid secretion in patients with hepatic cirrhosis are controversial, due, at least in part, to the possible interference of liver failure and altered gastric mucosal microcirculation on the pharmacological action of the substances used to stimulate the parietal cell. For this reason, we wished to investigate the circadian pattern of gastric acidity by means of continuous 24-hour pH monitoring, which permits measurement of pH fluctuations in a nearly physiological manner and does not require any pharmacological stimulus.Forty-nine patients with liver cirrhosis of different aetiology were recruited for this study. They underwent 24-hour gastric pH-metry w…
[Cardiac arrhythmias in hypertensive subjects with and without left ventricular hypertrophy compared to the circadian profile of the blood pressure].
1990
To evaluate possible correlations between cardiac arrhythmias and circadian pattern of blood pressure (BP) and of heart rate (HR), we studied 2 groups of 20 males with stable arterial hypertension of mild to moderate entity, with (Group I) or without (Group II) left ventricular hypertrophy (LVH). In patients with LVH the mean age (56 vs 46 years), the duration of the hypertensive state (48.1 vs 15.7 months), the thickening of interventricular septum (IVS; 13.7 vs 9.6 mm) and of the posterior wall of the left ventricle (13.2 vs 9.2 mm) and the mass of LV (149.8 vs 99.7 g/m2) were significantly greater (p less than 0.01). On the contrary, the 2 groups did not show significant differences conc…
Inter-individual variation of the urinary steroid profiles in Swedish and Norwegian athletes.
2020
The steroidal module of the Athlete Biological Passport (ABP) aims to detect doping with endogenous steroids, e.g. testosterone (T), by longitudinally monitoring several biomarkers. These biomarkers are ratios combined into urinary concentrations of testosterone and metabolically related steroids. However, it is evident after 5 years of monitoring steroid passports that there are large variations in the steroid ratios complicating its interpretation. In this study, we used over 11000 urinary steroid profiles from Swedish and Norwegian athletes to determine both the inter- and intra-individual variations of all steroids and ratios in the steroidal passport. Furthermore, we investigated if th…
Blood Pressure Response to Physical Activity in Hypertensive Subjects at Different Times of the Day
1976
1. Active orthostasis causes a fall of systolic blood pressure in the morning; this fall was more extensive in severe arterial hypertension. 2. Everyday physical activity produces a marked rise of systolic blood pressure, which is higher at noon and in the evening than in the morning; the hypertensive response is somewhat greater in WHO II and III, than in WHO I, grades of hypertension. 3. In studies on blood pressure behaviour in hypertensive subjects the circadian variability not only of the blood pressure at rest but also of the blood pressure response to various stimuli has to be considered.
Clock genes beyond the clock: CLOCK genotype biases neural correlates of moral valence decision in depressed patients
2007
Gene polymorphisms in the mammalian biological clock system influence individual rhythms. A single nucleotide polymorphism (SNP) in the 3' flanking region of CLOCK (3111 T/C; rs1801260) influenced diurnal preference in healthy humans and caused sleep phase delay and insomnia in patients affected by bipolar disorder. Genes of the biological clock are expressed in many brain structures other than in the 'master clock' suprachiasmatic nuclei. These areas, such as cingulate cortex, are involved in the control of many human behaviors. Clock genes could then bias 'nonclock' functions such as information processing and decision making. Thirty inpatients affected by a major depressive episode under…
The effects of post-awakening light exposure on the cortisol awakening response in healthy male individuals.
2019
Abstract Background It is assumed that the expression of the cortisol awakening response (CAR) is modulated by light exposure during the peri-awakening period. While initial evidence supports this principal effect, the specific role of the spectral composition of light (brightness and wavelength) is still incompletely understood. Method Two counterbalanced within-subject experiments were conducted in a standardized sleep laboratory setting to investigate the effect of light intensity (study I; two days: dim vs. bright light) and spectral composition (study II; three days: red vs. blue vs. green light) on the CAR. Across studies, light exposure was conducted for one-hour post-awakening and t…
Cortisol and trait anxiety as relevant factors involved in memory performance in people with drug-resistant epilepsy
2018
People with drug-resistant epilepsy are exposed to unpredictable and uncontrollable seizures, which can be considered as a chronic stress condition. Additionally, these patients present memory deficits and a high prevalence of depression and anxiety. Cortisol, the main stress hormone, has a modulatory role on memory in healthy individuals and patients with emotional disorders, but its role in memory and emotional processes remains unclear in people with epilepsy. This study analyzes the differences in cortisol levels in people with epilepsy with high and low memory performance, and the relationships among cortisol levels, epilepsy-related factors, memory, anxiety, and depression. Fifty-two …