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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This article describes the first phase of a study that was designed to gain an understanding of hazardous waste workers' attitudes and beliefs about the use of respiratory protective equipment. Exploratory, open-ended interviews were conducted among 28 respirator users at a US Department of Energy facility. Subjects were asked to describe their knowledge, attitudes, and beliefs about their risks to hazards at their worksites and to discuss their use of respiratory protective equipment. A detailed content analysis of the interviews resulted in the generation of a taxonomy of issues and concerns which fell into three general categories: 1) Knowledge, Beliefs, and Attitudes, 2) Physical and Psychological Effects, and 3) External Influences. Knowledge, Beliefs, and Attitudes included Training, Fit Testing, Medical Clearance, Work Exposures, Respirator Use, and Vulnerability to Disease. Physical and Psychological Effects included Somatic/Health Effects, Personal Comfort, Visual Effects, Fatigue, Communication, and Anxiety. External Influences included Structural Environment, Quality and Availability of Equipment, Other PPEs, Co-Worker Influence, Supervisor Influence, and Organizational Culture. The findings from this study have important implications to training and education programs. Effective respiratory protection programs depend on a knowledge of the factors that affect workers' use of equipment. This study suggests that efforts to assure equipment comfort and fit, to assist workers who see and hear less well as a result of their equipment, and to develop strategies to allay worker anxiety when wearing equipment should all be components of a program. An organizational culture that supports and abets the appropriate use of equipment is also a critical element in a successful program.
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PMID:A description of factors affecting hazardous waste workers' use of respiratory protective equipment. 1046 3

A major issue associated with functional electrical stimulation (FES) of a paralyzed limb is the decay with time of the muscle force as a result of fatigue. A possible means to reduce fatigue during FES is by using interrupted stimulation, in which fatigue and recovery occur in sequence. In this study, we present a model which enables us to evaluate the temporal force generation capacity within the electrically activated muscle during first stimulation fatigue, i.e., when the muscle is activated from unfatigued initial conditions, and during postrest stimulation, i.e., after different given rest durations. The force history of the muscle is determined by the activation as derived from actually measured electromyogram (EMG) data, and by the metabolic fatigue function expressing the temporal changes of muscle metabolites, from existing data acquired by in vivo 31P MR spectroscopy in terms of the inorganic phosphorus variables, Pi or H2PO4-, and by the intracellular pH. The model was solved for supra-maximal stimulation in isometric contractions separated by rest periods, and compared to experimentally obtained measurements. EMG data were fundamental for prediction of the ascending force during its posttetanic response. On the other hand, prediction of the decaying phase of the force was possible only by means of the metabolite-based fatigue function. The prediction capability of the model was assessed by means of the error between predicted and measured force profiles. The predicted force obtained from the model in first stimulation fatigue fits well with the experimental one. In postrest stimulation fatigue, the different metabolites provided different prediction capabilities of the force, depending on the duration of the rest period. Following rest duration of 1 min, Pi provided the best prediction of force; H2PO4- extended the prediction capacity of the model to up to 6 min and pH provided a reliable prediction for rest durations longer than 12 min. The results presented shed light on the roles of EMG and of metabolites in prediction of the force history of a paralyzed muscle under conditions where fatigue and recovery occur in sequence.
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PMID:EMG and metabolite-based prediction of force in paralyzed quadriceps muscle under interrupted stimulation. 1049 76

Increased symptom reporting has been found in American Gulf War Veterans. The symptoms comprise headache, fatigue, impaired short-term memory, sleep disturbances, agitation, respiratory symptoms, muscle and joint pain, diseases of the skin, and intermittent fever. This cross-sectional study was performed to clarify whether a corresponding pattern existed among Danes having served in the Persian Gulf during and mainly after the Gulf War. The investigation took place during the period January 1997 to January 1998 and included 821 subjects who had been deployed in the Persian Gulf within the period August 2, 1990 until December 31, 1997. Of 686 (83.6%) subjects who participated in the study, 95% had been engaged in peace keeping operations after the war. A group consisting of randomly selected age- and gender matched controls, comprised 231 of 400 potential participants (57.7%). All participants underwent clinical and paraclinical examinations, and had an interview based on a previously completed questionnaire. Unspecific symptoms such as repeated fits of headache, fatigue, memory and concentration difficulties, sleep disturbances, agitation, dyspneoa, diseases of the skin, and intermittent fever, were significantly more frequent among Danish Gulf War Veterans (p < 0.05) than among controls; no association was found with respect to muscle and joint pain. The higher symptom prevalence among Gulf War Veterans was observed for conditions which had made their first appearance during or after the Gulf War. The prevalence of diseases and symptoms which had made their first appearance before August 2, 1990 was similar for both groups. This study demonstrated a pattern of diseases and symptoms among Danish Gulf War Veterans consistent with the findings among American Gulf War Veterans. Considering that American Gulf War Veterans were predominantly deployed during the armament phase and the brief war phase, and that Danish Gulf War Veterans were predominantly deployed after the war restoring peace, the results indicate the existence of some common risk factors independent of war action.
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PMID:[Health status after serving in the Gulf war area. The Danish Gulf War Study]. 1055 55

A nationwide search of patients with classical 21-hydroxylase deficiency (21-OHD) was performed in Finland to determine the long-term outcome of the disease. In total, 108 patients were found. Fifty-four patients (50%, 31F, 23M) had deficiency of a salt-wasting form and another 54 (50%, 29F, 25M) had a simple virilizing form of 21-OHD. A significant number of severe complications suggestive of glucocorticoid deficiency was found. There were five deaths (4.6% of all) possibly connected with cortisol deficiency. Ten additional patients (9.3% of all) had been acutely admitted 14 times in all due to symptoms of glucocorticoid deficiency. These symptoms included sudden loss of consciousness, convulsions and severe fatigue. Afterwards, permanent neurological defects were detected in two of these patients. Finally, a cross-sectional study was carried out to establish an estimate of the long-term outcome of the disease. Thirty-two (55%) of the 58 patients aged 16 y or more participated in this study. The patient group did not differ from the general Finnish population in terms of education. Three of the patients (5%) had retired prematurely. Surprisingly, the patients felt that their health-related quality of life, as reported in the RAND-36 questionnaire, was better than that of the general Finnish population (p = 0.023). However, as a significant number of all patients did not participate in this study, the quality of life evaluation results must be interpreted with caution. In conclusion, a significant number of complications was found among patients treated for classical 21-OHD. Nevertheless, the disease has a favourable outcome in terms of quality of life.
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PMID:Long-term outcome of classical 21-hydroxylase deficiency: diagnosis, complications and quality of life. 1070 88

This study investigates the hypothesis that long lasting mental work demands are reflected in after-effects on attention demanding post-test probe tasks. Sixteen subjects were engaged in 2 simulated workdays consisting of mentally demanding tasks. On the difficult day the afternoon consisted of highly demanding information processing tasks; on the easy day the demands during the afternoon were low. The mornings of both days were equally demanding. At the start (pre-test) and the end (post-test) of both days, after 5 min (immediate post-test) as well as after approximately 2 h of recuperation (delayed post-test), a probe task was carried out. A memory-search task (varied mapping) is used as probe task. After-effects were expected in terms of a shift in the ratio between performance and effort on the post-test probe tasks compared with the pre-test probe task. Performance measures were reaction time and errors; effort was indicated by heart rate variability in the 0.07-0. 14 Hz band, referred to as 0.1 Hz component. Dayload manipulation appeared to be effective because of the load-related differences between the urinary excretion rates of adrenaline during both afternoons. Compared with the pre-test, only the number of errors was significantly increased in the post-test, carried out immediately at the end of the difficult afternoon. However, compared with the easy day, in the delayed post-test probe task after the difficult day, subjects tended to shorten reaction times, made significantly more errors, and invested significantly less effort. Moreover, at that time they felt more fatigued and deactivated as indicated by the results of the 'Scale of Experienced Load' (SEB) (fatigue) and 'Groninger Adjective Checklist' (GACL) (mood) questionnaires. The observed shift towards low-effort, more 'risky' task strategies in the post-tests fits well with Hockey's (1993) fatigue after-effects degradation pattern expected after periods of high workload. The repeated measurement of the relation of performance, effort and feelings reveals the dynamics of the pattern of fatigue after-effects over the (recovery) time.
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PMID:Immediate and delayed after-effects of long lasting mentally demanding work. 1087 64

Abacavir (formerly 1592U89) is a carbocyclic nucleoside analog with potent anti-human immunodeficiency virus (anti-HIV) activity when administered alone or in combination with other antiretroviral agents. The population pharmacokinetics and pharmacodynamics of abacavir were investigated in 41 HIV type 1 (HIV-1)-infected, antiretroviral naive adults with baseline CD4(+) cell counts of >/=100/mm(3) and plasma HIV-1 RNA levels of >30,000 copies/ml. Data for analysis were obtained from patients who received randomized, blinded monotherapy with abacavir at 100, 300, or 600 mg twice-daily (BID) for up to 12 weeks. Plasma abacavir concentrations from sparse sampling were analyzed by standard population pharmacokinetic methods, and the effects of dose, combination therapy, gender, weight, and age on parameter estimates were investigated. Bayesian pharmacokinetic parameter estimates were calculated to determine the peak concentration of abacavir in plasma (C(max)) and the area under the concentration-time curve from time zero to infinity (AUC(0-infinity)) for individual subjects. The pharmacokinetics of abacavir were dose proportional over the 100- to 600-mg dose range and were unaffected by any covariates. No significant correlations were observed between the incidence of the five most common adverse events (headache, nausea, diarrhea, vomiting, and malaise or fatigue) and AUC(0-infinity). A significant correlation was observed between C(max) and nausea by categorical analysis (P = 0.019), but this was of borderline significance by logistic regression (odds ratio, 1.45; 95% confidence interval, 0.95 to 2.32). The log(10) time-averaged AUC(0-infinity) minus baseline (AAUCMB) values for HIV-1 RNA and CD4(+) cell count correlated significantly with C(max) and AUC(0-infinity), but with better model fits for AUC(0-infinity). The increase in AAUCMB values for CD4(+) cell count plateaued early for drug exposures that were associated with little change in AAUCMB values for plasma HIV-1 RNA. There was less than a 0.4 log(10) difference over 12 weeks in the HIV-1 RNA levels with the doubling of the abacavir AUC(0-infinity) from 300 to 600 mg BID dosing. In conclusion, pharmacodynamic modeling supports the selection of abacavir 300 mg twice-daily dosing.
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PMID:Population pharmacokinetics and pharmacodynamic modeling of abacavir (1592U89) from a dose-ranging, double-blind, randomized monotherapy trial with human immunodeficiency virus-infected subjects. 1089 75

We present a case of villous adenoma of the rectum, associated with severe fluid imbalance in a 69 year-old, previously healthy woman. Severe dehydration with hyponatraemia, hypokalaemia, acidosis/alkalosis and watery diarrhoea is typical. Clinical presentation may include fatigue, confusion, convulsions or coma. Intensive rehydration is the primary intervention, and causal treatment is always surgery. Normally full recovery is achieved.
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PMID:[Villous adenoma of the rectum with electrolyte imbalance. McKittrick-Wheelock syndrome]. 1096 48

The clinical, pathophysiological and genetic features of some of the familial (idiopathic) paroxysmal movement disorders are reviewed. The paroxysmal dyskinesias share features and therefore may have the same pathophysiological mechanisms as other episodic neurological disorders which are known to be channelopathies. Paroxysmal kinesigenic choreoathetosis/dyskinesias (PKC/PKD) is a condition in which brief and frequent dyskinetic attacks are provoked by sudden movement. Antiepileptics particularly carbamazepine are very helpful for this condition. PKC has similarities to episodic ataxia type 1 which is caused by mutations of the KCNA1 gene. PKC and a related disorder in which infantile convulsions are associated (ICCA syndrome) have recently been linked to the pericentromic region of chromososme 16 in the vicinity of some ion channel genes. Paroxysmal exercise-induced dystonia (PED) is a rare disorder manifesting as episodes of dystonia mostly affecting the feet induced by continuous exercise like walking or running. The pathophysiology of PED is unknown and antiepileptic drugs are generally unhelpful. In paroxysmal dystonic choreoathetosis/nonkinesigenic dyskinesias (PDC/PNKD) the attacks are of long duration and induced by a variety of factors including coffee, tea, alcohol and fatigue but not by sudden movement. The gene for familial PDC has been linked to chromosome 2q close to a cluster of ion channel genes. Paroxysmal nocturnal dyskinesia is now known to be a form of frontal lobe epilepsy in some cases which may be familial with an autosomal dominant inheritance and has been given the eponym ADNFLE. ADNFLE is a genetically heterogenous condition. Mutations of the neuronal nicotinic acetylcholine receptor gene that have chromosome 20q have been reported in some families with ADNFLE. However, another family with ADNFLE has been linked to chromosome 15 in the area of another nicotinic acetylcholine receptor gene. Thus the familial paroxysmal dyskinesias appear to be clinically and genetically heterogeneous.
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PMID:Familial (idiopathic) paroxysmal dyskinesias: an update. 1134 27

Hypomagnesaemia as a primary cause of a generalized seizure is uncommon. A 60-year-old woman with Crohn's disease, who had had recent small bowel surgery and a total colectomy 10 years previously, was admitted complaining of severe nausea, vomiting, fatigue and thirst. Despite oral magnesium therapy she had a generalized seizure due to severe hypomagnesaemia of 0.09 mmol/l (normal range 0.65 to 1.05 mmol/l). Her serum calcium was 1.91 mmol/l (2.03 to 2.63 mmol/l). Hypomagnesaemia can cause generalized convulsions but is usually associated with hypocalcaemia. This patient had an almost normal serum calcium level, and therefore hypomagnesaemia would seem to have been the direct cause of her seizure. Long-term intravenous magnesium was necessary to prevent further seizures.
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PMID:Severe convulsant hypomagnesaemia and short bowel syndrome. 1143 1

Four cases of asthma (one adult, three children) developing acute adrenal crisis after introduction of high-dose inhaled fluticasone proprionate are presented. The three children, aged 7-9 yrs, had been prescribed inhaled fluticasone, dosage 500-2,000 microg x day(-1) and duration 5 months-5 yrs. All presented with convulsions due to hypoglycaemia (blood glucose 1.3-1.8 mM). The fourth case was a male of 33 yrs with difficult-to-control asthma and had been taking fluticasone propionate 1,000-2,000 microg x day(-1) for 3 yrs. He presented with fatigue, lethargy, nausea and postural hypotension. Acute adrenal crisis in each case was confirmed by investigations which included measurement of acute phase cortisol levels, short and long Synacthen stimulation tests and glucagon stimulation tests. Other cases of hypthoalamic-pituitary-adrenal axis suppression were excluded.
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PMID:Acute adrenal crisis in asthmatics treated with high-dose fluticasone propionate. 1210 82


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