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

1. The effect of different levels of ventricular pressure upon the prevalence of ventricular arrhythmias has been studied in 42 rat hearts by using the isolated working heart model. 2. The results have shown that there is an increased prevalence of arrhythmia at the highest levels of pressure tested in hearts from both normal and hypertensive rats. In hearts from normal rats total ectopic counts were 304 at 140 mmHg and 150 at 60 mmHg (P less than 0.05). In hearts from hypertensive rats total ectopic counts were 4217 at 180 mmHg and 2179 at 100 mmHg (P less than 0.05). 3. Hearts from hypertensive rats demonstrated significantly more ectopic activity than hearts from normal rats at all test pressures. Median values for ectopic counts for each study period were 68 in hearts from hypertensive rats and seven in hearts from normotensive rats (P less than 0.001). 4. There was evidence that the increased arrhythmia observed was not due to ischaemia or fatigue, and it seems likely that these effects of raised pressure are due to its effect on ventricular wall stress. The differences between various pressures were relatively small, but do suggest that a sustained increase in ventricular wall stress is arrhythmogenic. 5. This small arrhythmogenic effect over the relatively short period of these studies may be of much greater significance when considered in the context of the prolonged periods for which the diseased heart may be subjected to raised wall stress.
 ...
PMID:Effect of different levels of briefly sustained ventricular pressure on arrhythmia in the isolated working rat heart. 166 75

Six male college students were tested under two experimental conditions; amphetamine and no amphetamine. Each subject was tested three times under each condition. A double-blind placebo-controlled approach was employed and on six consecutive Fridays the subjects received either a placebo or 15 mg of Dexedrine per 70 kg of body weight 2 hours prior to testing. The physiological components tested were strength, muscular power, running speed, acceleration, aerobic power, and anaerobic capacity. Other variables evaluated were pre-exercise and maximum heart rates, respiratory exchange ratio and time to exhaustion. Data analysis revealed significant increases in knee extension strength, acceleration, anaerobic capacity, time to exhaustion, and pre-exercise and maximum heart rates. The most revealing results were in the area of increased time to exhaustion during the Vo2max test presumably due to higher lactic acid tolerance, thus a possible rationale to substantiate the theory that this drug has the ability to mask fatigue. It may also be possible that the biochemical actions of the drug alter fatigue processes directly. The results demonstrate that amphetamines have no effect on aerobic power, but further research will be necessary to clarify the drug's influence on muscular power-dominated movements.
 ...
PMID:The effect of amphetamines on selected physiological components related to athletic success. 739 5

Today's battleground requires round-the-clock air support. Modern aircraft systems enable tactical aircraft to be flown in all weather conditions, day or night, and for prolonged periods. U.S. Air Force Tactical Air Command (TAC) aircrew who deployed to the Southwest Asia Area of Responsibility (SWA AOR) for Operation Desert Shield/Desert Storm were retrospectively surveyed to determine the extent and effectiveness of dextroamphetamine use in support of sustained flying operations. Surveys were sent in May 1991 to each tactical squadron that participated in Desert Storm. Of pilots who were surveyed, 65% used amphetamines during the deployment to the SWA AOR and/or during Operation Desert Storm. Pilots who used amphetamines in air operations described it as "occasional." The most frequent indications for amphetamine use were "aircrew fatigue" and "mission type." Of pilots who used amphetamines, 58-61% considered their use beneficial or essential to operations. Dextroamphetamine (5 mg every 4 h) was used effectively and without major side effects in tactical flying operations. Amphetamine use enhanced cockpit performance and flight safety by reducing the effect of fatigue during critical stages of flight.
 ...
PMID:The use of amphetamines in U.S. Air Force tactical operations during Desert Shield and Storm. 748 18

A promising countermeasure for fatigue in sustained aviation operations is stimulant administration. However, well-controlled, aviation-relevant studies of the efficacy of medications such as Dexedrine are virtually nonexistent. In this investigation, flight performance, mood, and alertness were evaluated in 10 UH-60 pilots during sleep deprivation periods under Dexedrine or placebo. Relative to placebo, Dexedrine improved flight performance during straight-and-levels, climbs, descents, right turns, and a left-descending turn, with tendencies toward better performance during the left turns and the instrument landing system approach. Dexedrine markedly reduced subjective feelings of fatigue, confusion, and depression while increasing feelings of vigor. Central nervous system arousal was enhanced by Dexedrine relative to placebo. No significant side effects occurred, although Dexedrine was associated with mild asymptomatic increases in heart rate and BP. Thus, Dexedrine appears effective for the short-term sustainment of aviator performance during sustained operations. However, future work should investigate the efficacy of stimulants for longer-term use (e.g., more than 40 h of continuous wakefulness).
 ...
PMID:An in-flight investigation of the efficacy of dextroamphetamine for sustaining helicopter pilot performance. 940 55

To determine in clinical practice which rheumatoid arthritis (RA) clinical status variables are most associated with a change in disease modifying antirheumatic drug (DMARD) therapy, we studied 26,240 observations from 1905 RA patients occurring over 25 years. Variables included tender joint count, erythrocyte sedimentation rate (ESR), grip strength, visual analog scale for pain, global severity, fatigue and sleep, Health Assessment Question functional disability scale (HAQ), anxiety, depression and morning stiffness. Only the tender joint count required a physician. Observations at which a change in DMARD therapy occurred were compared to those where a change did not occur using generalized estimating equations (GEE) and classification and regression tree analysis (CART). Tender joint count, pain, global severity, and ESR were the 4 variables most strongly predictive of DMARD change. CART modeling indicated a special role for fatigue and sleep disturbance in some patients. These data add support in clinical practice for the ACR core set and the DAS set of variables. In addition, they validate the use of these variables in a practice setting. We suggest a minimum set of evaluations comprising: joint count, ESR or CRP, measures of pain and/or severity, a fatigue scale (fatigue being a surrogate for sleep disturbance), and a measure of function such as the HAQ or modified HAQ. Because only joint count requires physician participation, these evaluations are practical for the clinic, and allow quantitative measurement of RA status. With the use of quantile charts, the comparative status of RA and the change in RA status can be determined easily.
 ...
PMID:Evaluation and documentation of rheumatoid arthritis disease status in the clinic: which variables best predict change in therapy. 1146 86

This study determined whether dexamphetamine improved symptoms and quality of life in patients with chronic fatigue syndrome. The setting was a specialized clinic within a tertiary referral hospital. This was a 6-week parallel-group, placebo-controlled trial with random allocation. There was a 2-week dose-adjustment phase and a 4-week stable treatment period. Outcome measures were the Fatigue Severity Scale, the Medical Outcomes Study 36-item Short-Form Health Survey, and two patient-determined outcomes. Ten patients were randomly assigned to dexamphetamine, and 10 were assigned to placebo. Fatigue Severity Scale scores improved in nine of 10 dexamphetamine and four of 10 placebo patients. The change in mean score was statistically significant. There were large but statistically nonsignificant changes in scores for the Short-Form Health Survey domains vitality and physical functioning. Dexamphetamine may be useful in the management of chronic fatigue syndrome; a larger and longer trial is justified by these results.
 ...
PMID:A pilot randomized controlled trial of dexamphetamine in patients with chronic fatigue syndrome. 1251 36

The aim of this study was to assess disability, psychological distress and quality of life in Polish breast cancer survivors with arm lymphedema. One thousand sets of questionnaires consisting of WHO-DAS II, GHQ-30, EORTC QLQ-C30 and QLQ-BR23 were sent to members of the Polish Federation of Breast Cancer Survivors Clubs "Amazonki." The response rate was 28.3% of whom 31.70% reported arm lymphedema. The WHO-DAS II survey showed that patients with arm lymphedema had a higher overall disability score (45.04 versus 38.80 in group without arm lymphedema; p=0.01) and higher mean values in the scales of understanding and communicating, getting around, life activities at home, getting along with people, participating in society. The EORTC QLQ-C30 survey showed that patients with lymphedema had lower mean values in physical (0.55 versus 0.65; p=0.001), emotional (0.47 versus 0.57; p=0.01), social (0.59 versus 0. 73; p=0.002), cognitive and role functioning, increased fatigue, pain, insomnia, dyspnea, nausealvomiting and financial problems. The EORTC QLQ-BR23 data demonstrated worse future perspectives and an increase in breast and arm symptoms, and the GHQ-30 survey produced higher psychological distress (scores 15.18 versus 11.24; p=0.004). In conclusion, breast cancer survivors with arm lymphedema were more disabled, experienced a poorer quality of life and had increased psychological distress in comparison to survivors without this condition.
 ...
PMID:Disability, psychological distress and quality of life in breast cancer survivors with arm lymphedema. 1731 31

The absence of GLUT4 severely impairs basal glucose uptake in vivo, but does not alter glucose homeostasis or circulating insulin. Glucose uptake in isolated contracting skeletal muscle (MGU) is also impaired by the absence of GLUT4, and onset of muscle fatigue is hastened. Whether the body can compensate and preserve glucose homeostasis during exercise, as it does in the basal state, is unknown. One aim was to test the effectiveness of glucoregulatory compensation for the absence of GLUT4 in vivo. The absence of GLUT4 was also used to further define the role of hexokinase (HK) II, which catalyses glucose phosphorylation after it is transported in the cell. HK II increases MGU during exercise, as well as exercise endurance. In the absence of GLUT4, HK II expression will not affect MGU. A second aim was to test whether, in the absence of GLUT4, HK II retains its ability to increase exercise endurance. Wild-type (WT), GLUT4 null (GLUT4(-/-)), and GLUT4 null overexpressing HK II (GLUT4(-/-)HK(Tg)) mice were studied using a catheterized mouse model that allows blood sampling and isotope infusions during treadmill exercise. The impaired capacity of working muscle to take up glucose in GLUT4(-/-) is partially offset by an exaggerated increase in the glucagon: insulin ratio, increased liver glucose production, hyperglycaemia, and a greater capillary density in order to increase the delivery of glucose to the exercising muscle of GLUT4(-/-). Hearts of GLUT4(-/-) also exhibited a compensatory increase in HK II expression and a paradoxical increase in glucose uptake. Exercise tolerance was reduced in GLUT4(-/-) compared to WT. As expected, MGU in GLUT4(-/-)HK(Tg) was the same as in GLUT4(-/-). However, HK II overexpression retained its ability to increase exercise endurance. In conclusion, unlike the basal state where glucose homeostasis is preserved, hyperglycaemia results during exercise in GLUT4(-/-) due to a robust stimulation of liver glucose release in the face of severe impairments in MGU. Finally, studies in GLUT4(-/-)HK(Tg) show that HK II improves exercise tolerance, independent of its effects on MGU.
 ...
PMID:Glucose kinetics and exercise tolerance in mice lacking the GLUT4 glucose transporter. 1749 42

This follow-up study explored parents' (N=452) intimate relationships when their firstborn child was 6 months old and then 4 years later. The measurement used was a modified version of the Dyadic Adjustment Scale, DAS. The present results show that most parents responding were content sensually at 6 months postpartum in 2002 and 4 years later, in 2006. More parents had changed from being sensually content in 2002 to discontent in 2006, than the contrary, however, and the sexual contentment remained low. The average sexual frequency was low both at 6 months and at 4 years for both parents with and without additional children. Experiencing tiredness as a hindrance to having sex was perceived as a greater problem among those parents without additional children. Prospective regression analyses indicated that sexuality was significantly related to both sensual and sexual contentment 4 years later. Sexuality was also one of the most significant covariates in the cross-sectional regression analysis for sensual contentment. Since sexuality plays a central role in partner well-being, it may be an important target for helping parents with small children.
 ...
PMID:Sensual and sexual marital contentment in parents of small children--a follow-up study when the first child is four years old. 1868 58

In the neonatal heart the transition from using carbohydrates to using fatty acids has not fully matured and oxidative metabolism/ATP generation may be limiting contractile function after ischemia. This study tested the hypothesis that increasing fatty acid availability increases recovery of left ventricular (LV) work by increasing palmitate oxidation, tricarboxylic acid (TCA) cycle activity, and ATP generation. Isolated working hearts from 7-day-old rabbits were perfused with Krebs solution containing low (0.4 mM) or high (2.4 mM) palmitate and 5.5 mM glucose. Hearts were subjected to 35-min global ischemia before 40-min reperfusion, and rates of glycolysis, glucose oxidation, and palmitate oxidation were assessed. LV work was similar before ischemia but was greater during reperfusion in hearts perfused with 2.4 mM palmitate compared with hearts perfused with 0.4 mM palmitate [6.98 +/- 0.14 (n = 15) vs. 3.01 +/- 0.23 (n = 16) mJ.beat(-1).g dry wt(-1); P < 0.05]. This was accompanied by increased LV energy expenditure during reperfusion [35.98 +/- 0.16 (n = 8) vs. 19.92 +/- 0.18 (n = 6) mJ.beat(-1).g dry wt(-1); P < 0.05]. During reperfusion the rates of palmitate oxidation [237.5 +/- 28.10 (n = 7) vs. 86.0 +/- 9.7 (n = 6) nmol.g dry wt(-1).min(-1); P < 0.05], total TCA cycle activity [2.65 +/- 0.39 (n = 7) vs. 1.36 +/- 0.14 (n = 6) micromol acetyl-CoA.g dry wt(-1).min(-1); P < 0.05], and ATP generation attributable to palmitate oxidation [26.6 +/- 3.1 (n = 7) vs. 12.6 +/- 1.7 (n = 6) micromol.g dry wt(-1).min(-1); P < 0.05] were greater in hearts perfused with 2.4 mM palmitate. These data indicate that the neonatal heart has decreased energy reserve, and, in contrast to the mature heart, increasing availability of fatty acid substrate increases energy production and improves recovery of function after ischemia.
 ...
PMID:High levels of fatty acids increase contractile function of neonatal rabbit hearts during reperfusion following ischemia. 2015 56


1 2 Next >>