136 resultados para Mental fatigue
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Introduction: Human experience takes place in the line of mental-time (MT) created through imagination of oneself in different time-points in past or future (self-projection in time). Here we manipulated self-projection in MT not only with respect to one's life-events but also with respect to one's faces from different past and future time-points. Methods: We here compared MTT with respect to one's facial images from different time points in past and future (study 1: MT-faces) as well as with respect to different past and future life events (study 2: MT-events). Participants were asked to make judgments about past and future face images and past and future events from three different time-points: the present (Now), eight years earlier (Past) or eight years later (Future). In addition, as a control task participants were asked to make recognition judgments with respect to faces and memory-related judgments with respect to events without changing their habitual self-location in time. Behavioral measures and functional magnetic resonance imaging (fMRI) activity after subtraction of recognition and memory related activities show both absolute MT and relative MT effects for faces and events, signifying a fundamental brain mechanism of MT, disentangled from episodic memory functions. Results: Behavioural and event-related fMRI activity showed three independent effects characterized by (1) similarity between past recollection and future imagination, (2) facilitation of judgments related to the future as compared to the past, and (3) facilitation of judgments related to time-points distant from the present. These effects were found with respect to faces and events suggesting that the brain mechanisms of MT are independent of whether actual life episodes have to be re-/pre-experienced and recruited a common cerebral network including the medial-temporal, precuneus, inferior-frontal, temporo-parietal, and insular cortices. Conclusions: These behavioural and neural data suggest that self-projection in time is a crucial aspect of MT, relying on neural structures encoding memory, mental imagery, and self. Furthermore our results emphasize the idea that mental temporal processing is more strongly directed to future prediction than to past recollection.
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The haemodynamic effects of the sympathetic nervous system (SNS) activations elicited by hypoglycaemia, acute alcohol administration, or insulin can be prevented by a pretreatment with dexamethasone in humans. This suggests a possible role of central corticotropin releasing hormone (GRIT) release. Mental stress activates the SNS, and decreases systemic vascular resistances though a beta-adrenergic-mediated vasodilation thought to involve vascular nitric oxide release. It also increases insulin-mediated glucose disposal, an effect presumably related to vasodilation. In order to evaluate whether activation of SNS by mental stress is glucocorticoid-sensitive, we monitored the haemodynamic and metabolic effects of mental stress during hyperinsulinaemia in healthy humans with and without a 2-day treatment with 8 mg day(-1) dexamethasone. Mental stress decreased systemic vascular resistances by 21.9% and increased insulin-mediated glucose disposal by 2 8.4% without dexamethasone pretreatment. After 2 days of dexamethasone treatment, whole body insulin-mediated glucose disposal was decreased by 40.8%. The haemodynainic effects of mental stress were however, not affected. Mental stress acutely increased insulin-mediated glucose disposal by 28.0%. This indicates that mental stress elicits a stimulation of SNS through dexamethasone-insensitive pathway, distinct of those activated by insulin, alcohol, or hyperglycaemia.
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BACKGROUND: Fragile X-associated tremor/ataxia syndrome (FXTAS) is an inherited late-onset neurodegenerative disorder, characterized both by neurological and cognitive deficits. It is caused by the expansion of CGG repeats (55 to 200 repeats) in the noncoding region of the fragile X mental retardation 1 (FMR1) gene. Abnormal immunological patterns are often associated with neurodegenerative disorders and implicated in their etiology. We therefore investigated the immune status of FXTAS patients, which had not been assessed prior to this study. METHOD: Peripheral blood mononuclear cells (PBMCs) were collected from 15 asymptomatic FMR1 premutation carriers and 20 age-matched controls. Concentrations of three cytokines (IL-6, IL-8, IL-10) were measured in PBMC supernatants using ELISA assays. RESULTS: We found a significant increase in the concentration of the major anti-inflammatory cytokine IL-10 in supernatants of PBMCs derived from premutation carriers, when compared with controls (P = 0.019). This increase correlated significantly with the number of CGG repeats (P = 0.002). CONCLUSIONS: Elevated IL-10 levels were observed in all premutation carriers, before appearance of the classical neurological symptoms; therefore, IL-10 may be one of the early biomarkers of FXTAS.
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The burden of disease linked to mental disorders represents more than one-fifth of years lived with disability in the world. Less than half of people suffering from mental disorders are adequately treated. Three quarter of those who receive treatment are followed by primary care. Collaborative care aims to increase the efficiency of direct general practitioner's treatment. Main components are sustainable and individualized consultation-liaison relationship (1/2 day of psychiatrist by 15 days for 10-15 general practitioners), and support of a clinical case manager for complex situations. Collaboration is bidirectional: early or crisis access to specialist care and long-term followup by general practitioner. This model is a challenge for the doctor-patient dual relationship and requires incentives in a public health perspective.
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Post-stroke objective or subjective fatigue occurs in around 50% of patients and is frequent (30%) even after minor strokes. It can last more than one year after the event, and is characterised by a different quality from usual fatigue and good response to rest. Associated risk factors include age, single patients, female, disability, depression, attentional impairment and sometimes posterior strokes, but also inactivity, overweight, alcohol and sleep apnoea syndrome. There are few therapy studies, but treatment may include low-intensity training, cognitive therapy, treatment of associated depression, wakefulness-promoting agents like modafinil, correction of risk factors and adaptation of activities.
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Oculofaciocardiodental (OFCD) and Lenz microphthalmia syndromes form part of a spectrum of X-linked microphthalmia disorders characterized by ocular, dental, cardiac and skeletal anomalies and mental retardation. The two syndromes are allelic, caused by mutations in the BCL-6 corepressor gene (BCOR). To extend the series of phenotypes associated with pathogenic mutations in BCOR, we sequenced the BCOR gene in patients with (1) OFCD syndrome, (2) putative X-linked ('Lenz') microphthalmia syndrome, (3) isolated ocular defects and (4) laterality phenotypes. We present a new cohort of females with OFCD syndrome and null mutations in BCOR, supporting the hypothesis that BCOR is the sole molecular cause of this syndrome. We identify for the first time mosaic BCOR mutations in two females with OFCD syndrome and one apparently asymptomatic female. We present a female diagnosed with isolated ocular defects and identify minor features of OFCD syndrome, suggesting that OFCD syndrome may be mild and underdiagnosed. We have sequenced a cohort of males diagnosed with putative X-linked microphthalmia and found a mutation, p.P85L, in a single case, suggesting that BCOR mutations are not a major cause of X-linked microphthalmia in males. The absence of BCOR mutations in a panel of patients with non-specific laterality defects suggests that mutations in BCOR are not a major cause of isolated heart and laterality defects. Phenotypic analysis of OFCD and Lenz microphthalmia syndromes shows that in addition to the standard diagnostic criteria of congenital cataract, microphthalmia and radiculomegaly, patients should be examined for skeletal defects, particularly radioulnar synostosis, and cardiac/laterality defects.
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PURPOSE: This longitudinal study aimed at comparing heart rate variability (HRV) in elite athletes identified either in 'fatigue' or in 'no-fatigue' state in 'real life' conditions. METHODS: 57 elite Nordic-skiers were surveyed over 4 years. R-R intervals were recorded supine (SU) and standing (ST). A fatigue state was quoted with a validated questionnaire. A multilevel linear regression model was used to analyze relationships between heart rate (HR) and HRV descriptors [total spectral power (TP), power in low (LF) and high frequency (HF) ranges expressed in ms(2) and normalized units (nu)] and the status without and with fatigue. The variables not distributed normally were transformed by taking their common logarithm (log10). RESULTS: 172 trials were identified as in a 'fatigue' and 891 as in 'no-fatigue' state. All supine HR and HRV parameters (Beta+/-SE) were significantly different (P<0.0001) between 'fatigue' and 'no-fatigue': HRSU (+6.27+/-0.61 bpm), logTPSU (-0.36+/-0.04), logLFSU (-0.27+/-0.04), logHFSU (-0.46+/-0.05), logLF/HFSU (+0.19+/-0.03), HFSU(nu) (-9.55+/-1.33). Differences were also significant (P<0.0001) in standing: HRST (+8.83+/-0.89), logTPST (-0.28+/-0.03), logLFST (-0.29+/-0.03), logHFST (-0.32+/-0.04). Also, intra-individual variance of HRV parameters was larger (P<0.05) in the 'fatigue' state (logTPSU: 0.26 vs. 0.07, logLFSU: 0.28 vs. 0.11, logHFSU: 0.32 vs. 0.08, logTPST: 0.13 vs. 0.07, logLFST: 0.16 vs. 0.07, logHFST: 0.25 vs. 0.14). CONCLUSION: HRV was significantly lower in 'fatigue' vs. 'no-fatigue' but accompanied with larger intra-individual variance of HRV parameters in 'fatigue'. The broader intra-individual variance of HRV parameters might encompass different changes from no-fatigue state, possibly reflecting different fatigue-induced alterations of HRV pattern.
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BACKGROUND: We aimed to determine the smallest changes in health-related quality of life (HRQoL) scores in the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire core 30 and the Brain Cancer Module (QLQ-BN20), which could be considered as clinically meaningful in brain cancer patients. Materials and methods: World Health Organisation performance status (PS) and mini-mental state examination (MMSE) were used as clinical anchors appropriate to related subscales to determine the minimal clinically important differences (MCIDs) in HRQoL change scores (range 0-100) in the QLQ-C30 and QLQ-BN20. A threshold of 0.2 standard deviation (SD) (small effect) was used to exclude anchor-based MCID estimates considered too small to inform interpretation. RESULTS: Based on PS, our findings support the following integer estimates of the MCID for improvement and deterioration, respectively: physical (6, 9), role (14, 12), and cognitive functioning (8, 8); global health status (7, 4*), fatigue (12, 9), and motor dysfunction (4*, 5). Anchoring with MMSE, cognitive functioning MCID estimates for improvement and deterioration were (11, 2*) and for communication deficit were (9, 7). Estimates with asterisks were <0.2 SD and were excluded from our MCID range of 5-14. CONCLUSION: These estimates can help clinicians evaluate changes in HRQoL over time, assess the value of a health care intervention and can be useful in determining sample sizes in designing future clinical trials.
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BACKGROUND: Mental disorders, common in primary care, are often associated with physical complaints. While exposure to psychosocial stressors and development or presence of principal mental disorders (i.e. depression, anxiety and somatoform disorders defined as multisomatoforme disorders) is commonly correlated, temporal association remains unproven. The study explores the onset of such disorders after exposure to psychosocial stressors in a cohort of primary care patients with at least one physical symptom. METHOD: The cohort study SODA (SOmatization, Depression and Anxiety) was conducted by 21 private-practice GPs and three fellow physicians in a Swiss academic primary care centre. GPs included patients via randomized daily identifiers. Depression, anxiety or somatoform disorders were identified by the full Patient Health Questionnaire (PHQ), a validated procedure to identify mental disorders based on DSM-IV criteria. The PHQ was also used to investigate exposure to psychosocial stressors (before the index consultation and during follow up) and the onset of principal mental disorders after one year of follow up. RESULTS: From November 2004 to July 2005, 1020 patients were screened for inclusion. 627 were eligible and 482 completed the PHQ one year later and were included in the analysis (77%). At one year, prevalence of principal mental disorders was 30/153 (19.6% CI95% 13.6; 26.8) for those initially exposed to a major psychosocial stressor and 26/329 (7.9% CI95% 5.2; 11.4) for those not. Stronger association exists between psychosocial stressors and depression (RR = 2.4) or anxiety (RR = 3.5) than multisomatoforme disorders (RR = 1.8). Patients who are "bothered a lot" (subjective distress) by a stressor are therefore 2.5 times (CI95% 1.5; 4.0) more likely to experience a mental disorder at one year. A history of psychiatric comorbidities or psychological treatment was not a confounding factor for developing a principal mental disorder after exposure to psychosocial stressors. CONCLUSION: This primary care study shows that patients with physical complaints exposed to psychosocial stressors had a higher risk for developing mental disorders one year later. This temporal association opens the field for further research in preventive care for mental diseases in primary care patients.
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RESUME Depuis les années 1980, les stéroïdes androgéniques anabolisants (SAA) sont restés les produits dopants les plus utilisés par les sportifs. Les propriétés principales attribuées à ces substances sont une augmentation de la masse et de la force musculaire ainsi qu'une agressivité supérieure pouvant s'avérer bénéfique lors des entraînements ou des compétitions. En plus de cette "tradition" liée à la consommation des SAA, une autre problématique est apparue dans le monde antidopage suite à la fulgurante expansion de l'utilisation des compléments alimentaires par les athlètes professionnels et amateurs. Dès la fin des années 1990, une recrudescence de cas positifs de dopage aux SAA a été attribuée à la contamination des compléments alimentaires par des composés anabolisants tels que la testostérone ou la nandrolone ou par des prohormones se situant en amont dans le métabolisme de certains SAA et conduisant à la présence, dans les urines, de traces de substances interdites par l'Agence Mondiale Antidopage (AMA). Afin de mettre en garde les autorités antidopage ainsi que les athlètes quant aux problèmes liés aux compléments alimentaires, le Laboratoire Suisse d'Analyse du Dopage (LAD) a décidé d'étudier de manière plus précise la composition d'une centaine de produits accessibles en Suisse par l'intermédiaire d'internet. Cette étude a permis de mettre en évidence un taux de non conformité des produits avoisinant les 20%, avec une contamination plus importante des produits contenant des hormones ou des prohormones. La consommation de doses journalières recommandées des produits contaminés a mené à la détection dans les urines de la présence de substances interdites par l'AMA. Ces résultats confirment ainsi que l'usage de compléments alimentaires peut s'avérer dangereuse dans le cadre de contrôles antidopage et que les effets sur l'état physique et mental des athlètes peuvent dépasser les effets désirés et être dramatiques pour la poursuite d'une carrière sportive. D'autre part, cela démontre que l'alimentation peut mener à la présence urinaire de substances proscrites telles que les métabolites de la nandrolone, la 19-norandrostéreone (19-NA) et la 19-norétiocholanolone (19-NE). Afin de démontrer un effet potentiel de l'exercice physique sur l'excrétion urinaire des métabolites de la nandrolone, une première étude clinique a été réalisée avec 34 volontaires. Deux doses orales de nandrolone marquée avec deux atomes de C13 ont été administrées aux sujets. Les urines ont été récoltées durant les 5 jours suivant les prises orales (études d'excrétion) ainsi qu'avant et après les 8 séances d'entraînements du protocole. Les analyses des études d'excrétion ont permis d'établir une variabilité intra- et inter-individuelle du métabolisme et de la pharmacocinétique de la 19-NA et de la 19-NE. En dépit de la rapide élimination urinaire des métabolites de la nandrolone C13, les analyses des échantillons prélevés avant et après les différents efforts n'ont pas révélé une influence nette de l'exercice physique sur les concentrations urinaires de la 19-NA et 19-NE. Une seconde étude clinique a été effectuée, avec la participation de 30 volontaires. Il s'agissait de déterminer si la consommation de multiples doses orales d'un décanoate de testostérone, de 19-norandrostenedione (un précurseur de la nandrolone) ou de placebo durant un mois, pouvait avoir des effets bénéfiques sur la récupération et la performance physique. En parallèle, les sujets étaient soumis à un entrainement d'endurance intense et individualisé. Divers paramètres physiologiques ont été étudiés dans le sérum et les urines afin de mettre en évidence une meilleure récupération de l'organisme. Aucun de ses paramètres n'a permis de conclure que la consommation orale de SAA est favorable pour optimaliser les capacités de récupération des athlètes. De plus, les performances physiques ont été évaluées avant et après l'entraînement et le traitement. Aucune différence significative n'a été démontrée entre les trois groupes de volontaires. L'état psychologique des volontaires a été évalué à l'aide de questionnaires (short Profile of Mood State, sPOMS) remplis à trois reprises au cours du protocole. De manière générale, l'évolution observée est une augmentation de la fatigue avec une diminution de la vigueur. Des analyses statistiques ont révélé que des prises orales de testostérone, et dans une moindre mesure de 19-norandrostenedione, ont une légère influence sur cette évolution générale en diminuant les effets de l'entrainement sur le profil psychologique. Les urines récoltées durant le protocole ont été analysées par GC/C/IRMS et GCMS afin de détecter les variations des concentrations des hormones liées au métabolisme de la testostérone. Les résultats ont démontré une variabilité interindividuelle du métabolisme de la testostérone qui implique que les critères de positivité imposés par l'AMA ne sont pas forcément valables pour tous les individus. La détection de la 19-NA et de la 19-NE, issus du métabolisme in vivo de la 19norandrostenedione, a confirmé les résultats obtenus sur la pharmacocinétique et le métabolisme de la nandrolone C13 obtenus lors de la première étude clinique. Ce travail a permis de clarifier certains points en lien avec l'abus de la nandrolone dans le sport et notamment par rapport à la consommation de compléments alimentaires. Les deux études cliniques n'ont pas véritablement apporté les réponses souhaitées aux hypothèses de départ. Cependant certains aspects intéressants en relation avec le métabolisme des SAA ont été découverts et pourront peut-être permettre à la lutte antidopage d'évoluer vers une meilleure efficacité. SUMMARY Since 1980's, anabolic androgenic steroids (AAS) are still the most used doping agents in sports. The main properties attributed to these substances are an increase of muscle mass and strength and also a higher aggressiveness that could be beneficial during trainings and competitions. In addition to this "tradition" linked to the AAS intake, another problematics has raised in the antidoping field. Indeed, nutritional supplements have been more and more used by professional and amateur athletes. Since the end of the 1990's, an outburst of positive doping cases with AAS has been attributed to nutritional supplements contaminations with anabolic compounds like testosterone or nandrolone or with prohormones located above in the metabolism of some AAS and prompting urinary traces of forbidden compounds by the World Antidoping Agency (WADA). In order to inform the antidoping authorities and the athletes about the problems linked to the nutritional supplements, the Swiss Laboratory for Doping Analyses (LAD) decided to investigate more precisely the composition of about hundred products accessible in Switzerland through different web sites. This study showed that about 20% of the products were not conformed to the composition announced by the manufacturers. The oral intake of daily recommended doses of the contaminated products revealed the presence in urines of forbidden substances by the WADA. Hence, these results confirm that the use of nutritional supplements can lead to adverse analytical findings in antidoping controls and that the effects on athletes' physical and mental state could be different from the ones desired and could be dramatic for the continuation of an athlete's career. Moreover, this demonstrates that the diet can lead to the presence in urines of proscribed substances like nandrolone metabolites, i.e. 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE). To put forward a potential effect of physical exercise on urinary nandrolone metabolites excretion rate, a first clinical study was done with 34 volunteers. Two oral doses of nandrolone labelled with two C13 atoms were administered to the subjects. The urines were collected during the 5 days following the treatment (excretion studies) and before and after the 8 exercise sessions of the protocol. The analyses of excretion studies revealed an intra- and inter-individual variability of the metabolism and the pharmacokinetics of 19-NA and 19-NE. In spite of the rapid urinary elimination of the nandrolone C13 metabolites, the analyses of the urine samples gathered before and after efforts did not show a clear influence of physical exercise on the urinary 19-NA and 19-NE concentrations. A second clinical study was done with the participation of 30 volunteers. The main aim was to determine if multiple oral doses of testosterone undecanoate, 19-norandrostenedione (a nandrolone precursor) or placebo during one month, could have beneficial effects on recovery and physical performance. Meanwhile, the individuals had to follow an intense and personalized endurance training program. Several physiological parameters were investigated in serum and urines in order to demonstrate a better organism's recovery. None of these parameters lead to the conclusion that oral intake of AAS is useful to optimise the recovery capacities of athletes. In addition, physical performances were evaluated before and after the training and treatment month. No significant difference was shown between the three volunteers groups. The psychological state of the volunteers was assessed through questionnaires (short Profile of Mood State, sP4MS) filled three times during the protocol. The global evolution is an increase of fatigue with an decrease of vigour. Statistical analyses revealed that the oral intake of testosterone, and to a lesser extent of 19= norandrostenedione, have a small influence on this general evolution in decreasing the effect of training on the psychological profile. The urines collected during the protocol were analysed by GC/C/IRMS and GCMS to detect concentrations variations of hormones related to the testosterone metabolism. The results revealed an interindividual variability of testosterone metabolism which implies that the guidance concerning endogenous steroids prescribed by the WADA are not uniformly valid for all individuals. Detection of 19-NA and 19-NE, coming from the in vivo metabolism of 19norandrostenedione, confirmed the results previously obtained on the pharamcokinetics and metabolism of the nandrolone C13 in the first clinical study. This work allowed to clarify some aspects linked to nandrolone abuse in sports and noteworthy related to nutritional supplements intake. The two clinical studies did not really bring plain answers to the basal hypotheses but some interesting aspects in relation with AAS metabolism were put forth and would perhaps allow an evolution of a more effective fight against doping.
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PURPOSE: The present study was designed to determine the stimulation intensity necessary for an adequate assessment of central and peripheral components of neuromuscular fatigue of the knee extensors. METHODS: Three different stimulation intensities (100, 120 and 150 % of the lowest intensity evoking a plateau in M-waves and twitch amplitudes, optimal stimulation intensity, OSI) were used to assess voluntary activation level (VAL) as well as M-wave, twitch and doublet amplitudes before, during and after an incremental isometric exercise performed by 14 (8 men) healthy and physically active volunteers. A visual analog scale was used to evaluate the associated discomfort. RESULTS: There was no difference (p > 0.05) in VAL between the three intensities before and after exercise. However, we found that stimulating at 100 % OSI may overestimate the extent of peripheral fatigue during exercise, whereas 150 % OSI stimulations led to greater discomfort associated with doublet stimulations as well as to an increased antagonist co-activation compared to 100 % OSI. CONCLUSION: We recommend using 120 % OSI, as it constitutes a good trade-off between discomfort and reliable measurements.
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AIM: This study assessed the mental health of parents of children with inflammatory bowel disease (IBD), compared their mental health with age-matched and gender-matched references and examined parental and child predictors for mental health problems. METHODS: A total of 125 mothers and 106 fathers of 125 children with active and inactive IBD from the Swiss IBD multicentre cohort study were included. Parental mental health was assessed by the Symptom Checklist 27 and child behaviour problems by the Strengths and Difficulties Questionnaire. Child medical data were extracted from hospital records. RESULTS: While the mothers reported lower mental health, the fathers' mental health was similar, or even better, than in age-matched and gender-matched community controls. In both parents, shorter time since the child's diagnosis was associated with poorer mental health. In addition, the presence of their own IBD diagnosis and child behaviour problems predicted maternal mental health problems. CONCLUSIONS: Parents of children with IBD may need professional support when their child is diagnosed, to mitigate distress. This, in turn, may help the child to adjust better to IBD. Particular attention should be paid to mothers who have their own IBD diagnosis and whose children display behaviour problems.