Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Evaluations were made of the diurnal variations of tremor power at rest, after fatigue and after mass loading, and plasma norepinephrine in patients with familial essential tremor and normal subjects. Diurnal tremor power rhythms for both essential and physiological tremor pursued identical temporal profiles. Plasma norepinephrine levels followed a congruent diurnal pattern with later peak values than the peak values of tremor power. Sympathetic nervous system activity is unlikely to be the cause of diurnal tremor power variation. The consistent diurnal rhythm of tremor power may affect dosage schemes of tremorolytic drugs.
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PMID:Diurnal variation of essential and physiological tremor. 188 May 13

The predictive value of patients' characteristics with regard to subsequent success of antidepressant therapy was investigated in a prospective study. Starting from the amine-deficiency hypotheses the sample was randomized and 30 patients were treated with maprotiline, 30 with clomipramine. Sociodemographic data, data about the immediate history of the illness and also most of the psychopathological symptoms before the start of treatment have no predictive capacity. Predictors of a subsequent response to clomipramine proved to be: positive reaction to sleep deprivation, decrease in MAO activity as a result of sleep deprivation, absence of signs of fatigue in the EEG after the first infusion, a serum concentration of at least 75 ng clomipramine/ml serum or 30 ng desmethyl-clomipramine/ml serum on the 7th day of treatment. A negative response to sleep deprivation, an increase in MAO activity as a result of sleep deprivation, the appearance of signs of fatigue (vigilance index) in the EEG after the first infusion as well as obvious autonomic symptoms before the start of treatment are indicative of a response to maprotiline. Diurnal variations of mood point rather to a general responsiveness to antidepressants without preference for a particular antidepressant. The results of this study provide theoretical reasons why unchangeable characteristics of patients, so-called 'static variables', can be of only slight predictive value. In contrast, changeable characteristics, so-called 'dynamic variables', such as reaction to sleep deprivation, EEG changes resulting from the first infusion, etc., could be of predictive value.
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PMID:Biological predictors of success of antidepressant drug therapy. 362 43

Six Holstein cows were sampled hourly for 24 h for plasma concentrations of hormones and metabolites. Cows were sampled at about 2 wk prepartum, at 3 wk postpartum, during a ketonemia induced by feed restriction to 54% of ad libitum intake, and after a recovery period. They were fed long alfalfa hay postpartum. The onset of lactation caused concentrations of growth hormone, glucagon, acetoacetate, beta-hydroxybutyrate, and total amino acids of plasma to increase and those of glucose and insulin to decrease. Feed restriction exacerbated changes at 3 wk postpartum except for total amino acids and glucagon, which both decreased to prepartal concentrations. Resumption of ad libitum feeding caused most hormones and metabolites to return to prepartum concentrations. Diurnal variations in response to feeding twice daily were most evident for growth hormone, free fatty acids, and total amino acids. The 3-wk postpartum and ketonemic periods gave the greatest responses to feeding. Molar ratios of insulin to glucagon and insulin to growth hormone tended to decrease at 3 wk postpartum and decreased further in ketonemia, demonstrating hormonal adaptations to decreased energy intake during lactation. Lactation ketosis results from more than severe energy deficit.
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PMID:Glucagon, insulin, growth hormone, and some blood metabolites during energy restriction ketonemia of lactating cows. 388 31

Associations between tinnitus and craniomandibular disorders (CMD) were investigated in an epidemiological sample, in tinnitus patients, and in patients attending a 'CMD-clinic'. Natural course of tinnitus was explored in a longitudinal epidemiological study of an elderly population. Several findings indicating a relatively strong relationship between CMD, tinnitus and subjective hearing loss were noted. This relationship seemed to be independent of objectively assessed degree of hearing loss, occupational noise exposure, general morbidity, medication or socioeconomic status. The prevalence of frequent headaches and fatigue or tenderness in jaw muscles was higher in tinnitus patients than would be expected if these conditions were unrelated. About one third of the individuals affected by tinnitus reported influence on tinnitus by jaw movements or pressure on the temporomandibular joint (TMJ). Diurnal bruxism and jaw fatigue appeared to be related to fluctuating tinnitus, vertigo, and hyperacusis. Stomatognathic and biofeedback treatment seemed to be able to reduce or eliminate tinnitus in some patients. Relatively low severity of tinnitus, normal hearing, fluctuating tinnitus, and some signs and symptoms of CMD are believed to constitute predictors of successful treatment outcome. Substantial longitudinal fluctuations with a high occurrence of spontaneous remissions of tinnitus were found in elderly people.
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PMID:Tinnitus and craniomandibular disorders--is there a link? 850 98

Diurnal variation in the P300 component of the human cognitive event-related potential (ERP) was examined. The P300 component is considered to be a measure of neuroelectric activity related to cognitive functions such as attention allocation and information processing. Nine diurnally active healthy male subjects whose sleep-wake rhythms were synchronized prior to the experiment were studied. The P300 components oral temperature, heart rate, left- and right-hand grip strength, reaction time, subjectively rated sleepiness, attention level, and fatigue were measured at 08:00, 11:00, 14:00, 17:00, and 20:00. Significant diurnal variations in P300 latency, P300 amplitude, oral temperature, heart rate, left- and right-hand grip strength, subjectively rated sleepiness, and attention level were observed. The P300 latency at 08:00 was significantly longer than at 11:00, 17:00, and 20:00, while the P300 amplitude at 08:00 was significantly greater than at 17:00 and 20:00. The P300 latency was correlated positively with subjectively rated sleepiness and negatively correlated with subjectively rated attention level. These results suggest the existence of diurnal variation in human cognitive functions.
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PMID:Diurnal variation in the P300 component of human cognitive event-related potential. 1102 14

Approximately 30% of breast cancer survivors report persistent fatigue of unknown origin. We have previously shown that cancer-related fatigue is associated with alterations in immunological parameters and serum cortisol levels in breast cancer survivors. The current study examined the diurnal rhythm of salivary cortisol in fatigued and non-fatigued breast cancer survivors. Salivary cortisol measures were obtained from breast cancer survivors with persistent fatigue (n=13) and a control group of non-fatigued survivors (n=16). Participants collected saliva samples upon awakening and at 1200, 1700, and 2200 h on two consecutive days. Diurnal cortisol slope for each day was determined by linear regression of log-transformed cortisol values on collection time and analyzed using multi-level modeling. Fatigued breast cancer survivors had a significantly flatter cortisol slope than non-fatigued survivors, with a less rapid decline in cortisol levels in the evening hours. At the individual patient level, survivors who reported the highest levels of fatigue also had the flattest cortisol slopes. Group differences remained significant in analyses controlling for demographic and medical factors, daily health behaviors, and other potential confounds (e.g. depressed mood, body mass index). Results suggest a subtle dysregulation in hypothalamic-pituitary-adrenal axis functioning in breast cancer survivors with persistent fatigue.
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PMID:Diurnal cortisol rhythm and fatigue in breast cancer survivors. 1535 46

This study used electronic diaries to examine patterns of mood and physical symptoms within and across days in two independent samples of cancer patients. Twenty-three breast cancer survivors (post-treatment) and 33 ovarian cancer survivors (on chemotherapy) recorded mood and physical symptoms 4 times daily for 7 consecutive days. A series of repeated-measures multilevel models using SAS Proc Mixed were calculated to estimate the degree to which physical symptoms (e.g., pain, fatigue, and nausea) were associated with participants' moods. Across days, mood vectors with a pleasantness component (i.e., happy-sad and calm-anxious) and mood vectors with an arousal component (i.e., active-passive and peppy-tired) were significantly associated with physical symptom severity. Specifically, breast cancer survivors with greater fatigue and pain reported more negative moods (eta2 < or = 0.33). Ovarian cancer survivors with greater fatigue (eta2 < or = 0.35), pain (eta2 < or = 0.04), and nausea (eta2 < or = 0.04) also reported more negative moods. Diurnal analyses showed that happy-sad (eta2 < or = 0.16), active-passive (eta2 < or = 0.27), and peppy-tired moods (eta2 < or = 0.33) were significantly negatively associated with fatigue at each of the four daily assessment times in both samples. Although correlational, our findings are consistent with previous studies suggesting that variations in both pleasant and aroused mood covary with changes in real-time physical symptom reports.
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PMID:Mood states associated with transitory physical symptoms among breast and ovarian cancer survivors. 1670 84

The aim of this study was to examine the supposed influence of pedal rate on the diurnal fluctuation of the time to exhaustion from high-intensity exercise. Eleven male cyclists performed three tests at 06:00 h and three at 18:00 h at a free pedal rate (FPR) and two imposed pedal rates (80% and 120% of the FPR). They performed the tests until exhaustion using a power output corresponding to 95% maximal power (Pmax). Time to exhaustion, rectal temperature, oxygen consumption (.VO2), M. quadriceps, vastus medialis, M. biceps femoris electromyographic Root Mean Square activity rise (RMS slope), and blood lactate concentration were measured. The mean time to exhaustion recorded at 18:00 h (270.6+/-104.8 sec) was greater than at 06:00 h (233.9+/-84.9 sec). The time to exhaustion was significantly greater when the pedal rate was imposed at 80% versus 120% FPR. The blood lactate concentration and absolute core temperature at the point of exhaustion were significantly higher during tests done at 18:00 h. There was no diurnal variation in core temperature increase, .VO2, and RMS slope. The time-of-day effect for every variable did not depend on pedal rate. Diurnal variations in maximal aerobic endurance cannot be explained by a change in aerobic metabolism or in muscular fatigue. The origin of the diurnal variation in the time to exhaustion is likely to lie in greater participation in anaerobic metabolism. Also, the influence of temperature on neuromuscular functioning as an explanation for the diurnal variation in performance cannot be excluded in this study. The hypothesis on the basis of which pedal rate would influence diurnal variations in time to exhaustion in cycling was not validated by this research.
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PMID:The effect of pedal rate and time of day on the time to exhaustion from high-intensity exercise. 1705 Feb 14

Football (soccer) training and matches are scheduled at different times throughout the day. Association football involves a variety of fitness components as well as psychomotor and game-related cognitive skills. The purpose of the present research, consisting of two separate studies, was to determine whether game-related skills varied with time of day in phase with global markers of both performance and the body clock. In the first study, eight diurnally active male association football players (19.1+/-1.9 yrs of age; mean+/-SD) with 10.8+/-2.1 yrs playing experience participated. Measurements were made on different days at 08:00, 12:00, 16:00, and 20:00 h in a counterbalanced manner. Time-of-day changes in intra-aural temperature (used as a marker of the body clock), grip strength, reaction times, flexibility (markers of aspects of performance), juggling and dribbling tasks, and wall-volley test (football-specific skills) were compared. Significant (repeated measures analysis of variance, ANOVA) diurnal variations were found for body temperature (p<0.0005), choice reaction time (p<0.05), self-rated alertness (p<0.0005), fatigue (p<0.05), forward (sit-and-reach) flexibility (p<0.02), and right-hand grip strength (p<0.02), but not left-hand grip strength (p=0.40) nor whole-body (stand-and-reach) flexibility (p=0.07). Alertness was highest and fatigue lowest at 20:00 h. Football-specific skills of juggling performance showed significant diurnal variation (p<0.05, peak at 16:00 h), whereas performance on the wall-volley test tended to peak at 20:00 h and dribbling showed no time-of-day effect (p=0.55). In a second study, eight diurnally active subjects (23.0+/-0.7 yrs of age) completed five test sessions, at the same times as in the first study but with a second session at 08:00 h. Test-re-test comparisons at 08:00 h for all components indicated good reliability. Intra-aural temperature showed a significant time-of-day effect (p<0.001) with mean temperature at 16:00 h (36.4 degrees C) higher than at 08:00 h (35.4 degrees C). There was no significant effect of chronotype on the temperature acrophase (peak time) (p>0.05). Diurnal variation was found for performance tests, including sit-and-reach flexibility (p<0.01) and spinal hyper-extension (p<0.05). Peaks occurred between 16:00 and 20:00 h and the daytime changes paralleled the temperature rhythm. Diurnal variation was also found for football-specific tests, including dribbling time (p<0.001, peak at 20:00 h) and chip test performance (p<0.01), being more accurate at 16:00 h (mean error=0.75 m) than at 08:00 h (mean error=1.01 m). Results indicate football players perform at an optimum between 16:00 and 20:00 h when not only football-specific skills but also measures of physical performance are at their peak. Body temperature peaked at a similar time, but positive mood states seemed to peak slightly earlier. While causal links cannot be established in these experiments, the results indicate that the diurnal variation of some aspects of football performance is affected by factor(s) other than body temperature alone.
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PMID:Diurnal variation in temperature, mental and physical performance, and tasks specifically related to football (soccer). 1761 48

Anesthesia and surgery are associated with fatigue and sleep disorders, suggestive of disturbance of the circadian rest-activity rhythm. Previous studies on circadian rhythm disturbance were focused on patients undergoing general anesthesia associated with surgery. This does not permit one to draw valid conclusions about the effects of general anesthesia per se on circadian rhythms. Our study was set up to determine the impact of a hypnotic dose of propofol on the circadian rest-activity rhythm in humans under real-life conditions. Seventeen healthy subjects scheduled to receive light propofol anesthesia for ambulatory colonoscopy were investigated. Their rest-activity rhythms were assessed using actigraphic monitoring. Diurnal rest was increased, whereas nocturnal sleep was unchanged in the days following anesthesia. Nonparametric analyses showed a decrease in the strength of coupling of the rhythm to stable environmental zeitgebers and increase of fragmentation of the rhythm after anesthesia. Light general anesthesia itself impairs synchronization of the circadian rest-activity rhythm to local time in patients by acting directly on the circadian clock.
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PMID:Desynchronization of daily rest-activity rhythm in the days following light propofol anesthesia for colonoscopy. 1880 35


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