1,720,975 research outputs found
Peridialytic Serum Cytokine Levels and Their Relationship with Postdialysis Fatigue and Recovery in Patients on Chronic Hemodialysis
No full textBackground: The etiology of postdialysis fatigue (PDF), an intermittent but debilitating fatigue occurring in 40-80% of chronic hemodialysis (HD) patients after HD treatment, is still unclear. In other illnesses, such as inflammatory diseases, mounting evidence points toward the involvement of the immune system in the development of fatigue symptoms. Altered serum levels of inflammatory cytokines have also been shown in chronic HD patients and positive associations between interleukin-6 (IL-6) and fatigue symptoms in general in this patient population have been recently reported. Therefore, we investigated whether fatigue specifically occurring after HD (PDF) or the time needed to recover from HD treatment (TIRD) were related to pre- and postdialysis serum levels of pro- and anti-inflammatory cytokines (i.e. IL-1β, IL-6, TNF-α and IL-10) or their intradialytic changes (if any).
Methods: Serum levels of IL-1β, IL-6, TNF-α and IL-10 were measured immediately before and after HD in 45 chronic HD patients using commercially available kits on an ELLATM automated immunoassay system. The presence and severity of PDF as well as TIRD duration were assessed by self-report measures.
Results: Thirty-three patients (74%) reported PDF, with a median PDF severity index of 3.30 [IQR: 3.00-4.30] on a scale from 1 to 5. Median TIRD was 120 min [IQR: 60-480]. PDF severity correlated strongly with TIRD, rs=0.85, p<0.001. Only predialysis IL-10 serum levels significantly and positively correlated with PDF severity (rs=0.43, p=0.003). Postdialysis cytokine levels and their intradialytic changes were not significantly related to PDF or TIRD.
Conclusions: The present study does not support the hypothesis that the immune system may be involved in the development of PDF or TIRD. The positive, but counterintuitive relation between predialysis anti-inflammatory IL-10 levels and PDF severity warrants further research. However, the present findings do not necessarily undermine the previously found positive relationship between IL-6 levels and chronically fatigue experience in HD patients, as fatigue as response to treatment may have other determinants than a more chronically fatigue
Daily physical activity in patients on chronic haemodialysis and its relation with fatigue and depressive symptoms
No full textObjective: Fatigue and depressed mood are considered main impediments to physical activity in haemodialysis (HD) patients. A better understanding of their interrelationships is crucial to develop effective therapies. Moreover, measurement of daily physical activity (DPA) in HD patients is tricky, as it is usually assessed by subjective self-report questionnaires. Therefore, we aimed to objectively measure sponteanous DPA with motion sensors and to explore its relation with fatigue and depressive symptoms. Methods: DPA was assessed for seven consecutive days in 37 HD patients based on their daily step count measured with the SenseWear™ Armband. The Fatigue Severity Scale (FSS) and Beck Depression Inventory-II (BDI-II) were administered to evaluate fatigue and depressed mood. Results: Median DPA was 2424 steps/day, (IQR:892–4545). In 81% of subjects, DPA felt within a sedentary lifestyle classification, as they made < 5.000 steps/day. DPA did not correlate with fatigue (rs = 0.04, p = 0.832), and did not significantly differ between patients categorized as clinically fatigued (n = 23, FSS ≥ 4) or not (n = 14, FSS < 4) (p = 0.654, d = 0.20). Although low-depressed subjects (n = 19, BDI-II ≤ 13) made on average 1.7 times more steps/day than high-depressed subjects (n = 18, BDI-II > 13) (p = 0.111, d = 0.60), depressive mood did also not correlate significantly with DPA (rs = − 0.23, p = 0.175). Conclusion: Objective assessment of DPA with motion sensors is feasible in HD patients and allows identifying a sedentary lifestyle. Our results suggest that spontanous DPA is determined by age rather than by fatigue or mood
mHealth-based experience sampling method to identify fatigue in the context of daily life in haemodialysis patients
No full textBackground: Fatigue in haemodialysis (HD) patients is a prevalent but complex symptom impacted by biological, behavioural, psychological and social variables. Conventional retrospective fatigue questionnaires cannot provide detailed insights into symptom variability in daily life and related factors. The experience sampling methodology (ESM) overcomes these limitations through repeated momentary assessments in patients' natural environments using digital questionnaires. This study aimed to gain in-depth understanding of HD patients' diurnal fatigue patterns and related variables using a mobile Health (mHealth) ESM application and sought to better understand the nature of their interrelationships.Methods: Forty HD patients used the mHealth ESM application for 7days to assess momentary fatigue and potentially related variables, including daily activities, self-reported physical activity, social company, location and mood.Results: Multilevel regression analyses of momentary observations (n=1777) revealed that fatigue varied between and within individuals. Fatigue was significantly related to HD treatment days, type of daily activity, mood and sleep quality. Time-lagged analyses showed that HD predicted higher fatigue scores at a later time point (beta =0.22, P=0.013). Interestingly, higher momentary fatigue also significantly predicted more depressed feelings at a later time point (beta =0.05, P=0.019) but not the other way around.Conclusions: ESM offers novel insights into fatigue in chronic HD patients by capturing informative symptom variability in the flow of daily life. Electronic ESM as a clinical application may help us better understand fatigue in HD patients by providing personalized information about its course and relationship with other variables in daily life, paving the way towards personalized interventions
Hemodynamic Monitoring During Hemodialysis Using Bioimpedance:A Comparison of Changes in Resistance Between Different Body Segments
No full textIntroduction: Prevention of hemodynamic complications during hemodialysis remains challenging. Although whole body bioimpedance is well established in fluid status assessment, its use for dynamic or continuous recordings is limited. A segmental approach may serve this purpose better. This study investigates which body segment is best targeted to measure bioimpedance for hemodynamic monitoring. Methods: In this observational study, serial bioimpedance measurements were conducted on the whole body, lower leg, upper arm, and thorax of 15 patients during two hemodialysis sessions. The resistance component of bioimpedance was used to investigate the relationship with changes in volume and systolic blood pressure (SBP). Findings: Predialysis to postdialysis changes in relative resistance between the two sessions revealed the lowest intraclass correlation coefficient for upper arm (0.023) and the highest for thoracic resistance (0.728). Correlation between ultrafiltration volume and relative resistance was comparable between upper arm and thoracic segment (0.538 [0.447–0.618] and 0.537 [0.446–0.617], both p < 0.001, respectively) and the highest for whole-body and lower leg (0.697 [0.63–0.754] and 0.670 [0.598–0.731], both p < 0.001, respectively). In contrast, the correlation between changes in SBP and relative resistance was the highest in the thoracic segment (−0.33 [−0.432 to −0.219], p < 0.001) and the lowest for whole body measurements (−0.154 [−0.269 to −0.036], p = 0.01). In addition, multiple regression analysis indicated thoracic resistance as the best predictor for changes in SBP (β = −0.261 [−0.353 to −0.126], p < 0.001). Discussion: These findings suggest that the thorax is the most suitable region for segmental bioimpedance measurements to assess hemodynamic parameters. Thoracic bioimpedance may innovate the hemodynamic monitoring of hemodialysis patients.</p
Serum interleukin-6 and endotoxin levels and their relationship with fatigue and depressive symptoms in patients on chronic haemodialysis
No full textBackground: Little is known about the underlying aetiology of fatigue in haemodialysis (HD) patients apart from a significant association and overlapping symptomatology with depressive symptoms. Growing evidence exists for the involvement of the immune system, by pro-inflammatory cytokines, in the development of fatigue in other inflammatory diseases. In HD patients, increased exposure to bacterial endotoxins may contribute to an inflammatory response and may potentially lead to fatigue. We therefore aimed (i) to assess the interrelationship between serum endotoxin (EA) levels, interleukin-6 (IL-6) levels and fatigue in HD patients; (ii) to evaluate whether there is a relationship between depressive symptoms and inflammation as well and (iii) to what extent depressive symptoms and fatigue are related to each other.Methods: Fatigue and depressive symptoms in daily life were assessed in 59 individuals using the SF-36 vitality subscale and the Geriatric Depression Scale. Blood samples were collected on a mid-week dialysis session to determine EA levels, through the Endotoxin Activity Assay (EAA™), and IL-6 concentrations, through the commercially available Abcam ELISA (Enzyme-Linked Immunosorbent Assay) kit.Results: EA, IL-6 levels and depressive symptoms were significantly correlated with fatigue. EA levels and depressive symptoms were significant predictors of fatigue, explaining 31% of its variance. However, EA and IL-6 were not significantly associated with depression.Conclusions: Fatigue in HD patients may be related to endotoxemia and inflammation through IL-6. Furthermore, fatigue is significantly associated with depressive symptoms. Future research into the causal interrelationship of inflammation, fatigue and depression in HD patients might lead to potential targets for therapeutic strategies
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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