419 research outputs found

    Value of imaging detected joint inflammation in explaining fatigue in RA at diagnosis and during the disease course: a large MRI study

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    Objective Fatigue in rheumatoid arthritis (RA) is hypothesised to be caused by inflammation. Still similar to 50% of the variance of fatigue in RA cannot be explained by the Disease Activity Score (DAS), nor by background or psychological factors. Since MRI can detect joint inflammation more sensitively than the clinical joint counts as incorporated in the DAS, we hypothesised that inflammation detected by MRI could aid in explaining fatigue in RA at diagnosis and during the follow-up.Methods 526 consecutive patients with RA were followed longitudinally. Fatigue was assessed yearly on a Numerical Rating Scale. Hand and foot MRIs were performed at inclusion, after 12 and 24 months in 199 patients and were scored for inflammation (synovitis, tenosynovitis and osteitis combined). We studied whether patients with RA with more MRI-inflammation were more fatigued at diagnosis (linear regression), whether the 2-year course of MRI-inflammation associated with the course of fatigue (linear mixed models) and whether decrease in MRI-inflammation in year 1 associated with subsequent improvement in fatigue in year 2 (cross-lagged models). Similar analyses were done with DAS as inflammation measure.Results At diagnosis, higher DAS scores were associated with more severe fatigue (p<0.001). However, patients with more MRI-inflammation were not more fatigued (p=0.94). During 2-year follow-up, DAS decrease associated with improvement in fatigue (p<0.001), but MRI-inflammation decrease did not (p=0.96). DAS decrease in year 1 associated with fatigue improvement in year 2 (p=0.012), as did MRI-inflammation decrease (p=0.039), with similar effect strength.Conclusion Sensitive measurements of joint inflammation did not explain fatigue in RA at diagnosis and follow-up. This supports the concept that fatigue in RA is partly uncoupled from inflammation.Pathophysiology and treatment of rheumatic disease

    Correlation of carotid artery reactivity with cardiovascular risk factors and coronary artery vasodilator responses in asymptomatic, healthy volunteers.

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    OBJECTIVES: Carotid artery reactivity (CAR%), involving carotid artery diameter responses to a cold pressor test (CPT), is a noninvasive measure of conduit artery function in humans. This study examined the impact of age and cardiovascular risk factors on the CAR% and the relationship between CAR% and coronary artery vasodilator responses to the CPT. METHODS: Ultrasound was used to measure resting and peak carotid artery diameters during the CPT, with CAR% being calculated as the relative change from baseline (%). We compared CAR% between young (n = 50, 24 ± 3 years) and older participants (n = 44, 61 ± 8 years), and subsequently assessed relationships between CAR% and traditional cardiovascular risk factors in 50 participants (44 ± 21 years). Subsequently, we compared left anterior descending (LAD) artery velocity (using transthoracic Doppler) with carotid artery diameter (i.e. CAR%) during the CPT (n = 33, 37 ± 17 years). RESULTS: A significantly larger CAR% was found in young versus older healthy participants (4.1 ± 3.7 versus 1.8 ± 2.6, P < 0.001). Participants without cardiovascular risk factors demonstrated a higher CAR% than those with at least two risk factors (2.9 ± 2.9 versus 0.5 ± 2.9, P = 0.019). Carotid artery diameter and LAD velocity increased during CPT (P < 0.001). Carotid diameter and change in velocity correlated with LAD velocity (r = 0.486 and 0.402, P < 0.004 and 0.02, respectively). CONCLUSION: Older age and cardiovascular risk factors are related to lower CAR%, while CAR% shows good correlation with coronary artery responses to the CPT. Therefore, CAR% may represent a valuable technique to assess cardiovascular risk, while CAR% seems to reflect coronary artery vasodilator function

    The socio-technical organisation of community pharmacies as a factor in the Electronic Prescription Service Release Two implementation: a qualitative study

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    Background The introduction of a new method of transmitting prescriptions from general practices to community pharmacies in England (Electronic Prescription Service Release 2 (EPS2)) has generated debate on how it will change work practice. As EPS2 will be a key technical element in dispensing, we reviewed the literature to find that there were no studies on how social and technical elements come together to form work practice in community pharmacies. This means the debate has little point of reference. Our aim therefore was to study the ways social and technical elements of a community pharmacy are used to achieve dispensing through the development of a conceptual model on pharmacy work practice, and to consider how a core technical element such the EPS2 could change work practice. Method We used ethnographic methods inclusive of case-study observations and interviews to collect qualitative data from 15 community pharmacies that were in the process of adopting or were soon to adopt EPS2. We analysed the case studies thematically and used rigorous multi-dimensional and multi-disciplinary interpretive validation techniques to cross analyse findings. Results In practice, dispensing procedures were not designed to take into account variations in human and technical integration, and assumed that repetitive and collective use of socio-technical elements were at a constant. Variables such as availability of social and technical resources, and technical know-how of staff were not taken into account in formalised procedures. Yet community pharmacies were found to adapt their dispensing in relation to the balance of social and technical elements available, and how much of the social and technical elements they were willing to integrate into dispensing. While some integrated as few technical elements as possible, some depended entirely on technical artefacts. This pattern also applied to the social elements of dispensing. Through the conceptual model development process, we identified three approaches community pharmacies used to appropriate procedures in practice. These were ‘technically oriented’, ‘improvising’ or ‘socially oriented’. Conclusion We offer a model of different work approaches community pharmacies use to dispense, which suggests that when adopting a core technical element such as the EPS2 system of dispensing there could be variations in its successful adoption. Technically oriented pharmacies might find it easiest to integrate a similar artefact into work practice although needs EPS2 to synchronise effectively with existing technologies. Pharmacies adopting an improvising-approach have the potential to improve how they organise dispensing through EPS2 although they will need to improve how they apply their operating procedures. Socially oriented pharmacies will need to dramatically adapt their approach to dispensing since they usually rely on few technical tools

    Genetics of rheumatoid arthritis: what have we learned?

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    Rheumatoid arthritis (RA) is a chronic autoimmune disease affecting 0.5–1% of the population worldwide. The disease has a heterogeneous character, including clinical subsets of anti-citrullinated protein antibody (ACPA)-positive and APCA-negative disease. Although the pathogenesis of RA is poorly understood, progress has been made in identifying genetic factors that contribute to the disease. The most important genetic risk factor for RA is found in the human leukocyte antigen (HLA) locus. In particular, the HLA molecules carrying the amino acid sequence QKRAA, QRRAA, or RRRAA at positions 70–74 of the DRÎČ1 chain are associated with the disease. The HLA molecules carrying these “shared epitope” sequences only predispose for ACPA-positive disease. More than two decades after the discovery of HLA-DRB1 as a genetic risk factor, the second genetic risk factor for RA was identified in 2003. The introduction of new techniques, such as methods to perform genome-wide association has led to the identification of more than 20 additional genetic risk factors within the last 4 years, with most of these factors being located near genes implicated in immunological pathways. These findings underscore the role of the immune system in RA pathogenesis and may provide valuable insight into the specific pathways that cause RA

    Tailored preconceptional dietary and lifestyle counselling in a tertiary outpatient clinic in the Netherlands

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    Background Adverse reproductive performance has been linked to unhealthy dietary intake and lifestyles. Our objectives were to investigate the prevalence of unhealthy dietary intake and lifestyles before conception and to evaluate whether tailored preconception counselling modifies these behaviours. Methods Between October 2007 and April 2009, 419 couples received tailored preconception dietary and lifestyle counselling at the outpatient clinic of Obstetrics and Gynaecology of the Erasmus University Medical Center Rotterdam, the Netherlands. A subgroup (n = 110 couples) was counselled twice with a fixed time interval of 3 months. Self-administered questionnaires were used for tailored dietary and lifestyle counselling. A cumulative score based on six Dutch dietary guidelines was displayed in the personal Preconception Dietary Risk score (PDR score). In a similar manner, the Rotterdam Reproduction Risk score (R3 score) was calculated from lifestyle factors (women: 13 items, men: 10 items). Univariate and paired tests were used. Results Most couples (93.8) were subfertile. At the second counselling, the percentage consuming the recommended intake of fruit had increased from 65 to 80 in women and from 49 to 68 in men and the percentage of women getting the recommended intake of fish increased from 39 to 52. As a consequence, the median PDR score was decreased [women: 2.6 (95 CI 2.4-2.9) to 2.4 (95 CI 2.1-2.6), men: 2.5 (95 CI 2.3-2.7) to 2.2 (95 CI 1.9-2.4), both P < 0.05]. The median R3 scores were also lower [women: 4.7 (95 CI 4.3-5.0) to 3.1 (95 CI 2.8-3.4), men: 3.0 (95 CI 2.8-3.3) to 2.0 (95 CI 1.7-2.3), both P < 0.01] due to less alcohol use (-14.6), more physical exercise and folic acid use in women, and less alcohol use in men (-19.4) (all P < 0.01). The R3 scores in women and men were decreased in all ethnicity, educational level, neighbourhood and BMI categories. However, low educated women appeared to show a larger reduction than better educated women and men with a normal BMI to show a larger decrease than overweight men. The reduction in the PDR score of women was similar in both ethnic groups. More than 85 women and men found the counselling useful and around 70 would recommend it to others. Conclusions Tailored preconception counselling about unhealthy dietary and lifestyle behaviours of subfertile couples in an outpatient tertiary clinic is feasible and seems to decrease the prevalence of harmful behaviours in the short term. These Results with subfertile couples are promising and illustrate their opportunities to contribute to reproductive performance and pregnancy outcome

    Measurement of the Atmospheric Muon Spectrum from 20 to 3000 GeV

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    The absolute muon flux between 20 GeV and 3000 GeV is measured with the L3 magnetic muon spectrometer for zenith angles ranging from 0 degree to 58 degree. Due to the large exposure of about 150 m2 sr d, and the excellent momentum resolution of the L3 muon chambers, a precision of 2.3 % at 150 GeV in the vertical direction is achieved. The ratio of positive to negative muons is studied between 20 GeV and 500 GeV, and the average vertical muon charge ratio is found to be 1.285 +- 0.003 (stat.) +- 0.019 (syst.).Comment: Total 32 pages, 9Figure

    Scientific merits and analytical challenges of tree-ring densitometry

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    R.W. was supported by NERC grant NE/K003097/1.X-ray microdensitometry on annually-resolved tree-ring samples has gained an exceptional position in last-millennium paleoclimatology through the maximum latewood density parameter (MXD), but also increasingly through other density parameters. For fifty years, X-ray based measurement techniques have been the de facto standard. However, studies report offsets in the mean levels for MXD measurements derived from different laboratories, indicating challenges of accuracy and precision. Moreover, reflected visible light-based techniques are becoming increasingly popular and wood anatomical techniques are emerging as a potentially powerful pathway to extract density information at the highest resolution. Here we review the current understanding and merits of wood density for tree-ring research, associated microdensitometric techniques, and analytical measurement challenges. The review is further complemented with a careful comparison of new measurements derived at 17 laboratories, using several different techniques. The new experiment allowed us to corroborate and refresh ?long-standing wisdom?, but also provide new insights. Key outcomes include; i) a demonstration of the need for mass/volume based re-calibration to accurately estimate average ring density; ii) a substantiation of systematic differences in MXD measurements that cautions for great care when combining density datasets for climate reconstructions; and iii) insights into the relevance of analytical measurement resolution in signals derived from tree-ring density data. Finally, we provide recommendations expected to facilitate future inter-comparability and interpretations for global change research.Publisher PDFPeer reviewe
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