Effect of extracorporeal liver support by MARS and Prometheus on serum cytokines in acute-on-chronic liver failure

INTRODUCTION: Cytokines are believed to play an important role in acute-on-chronic liver failure (ACLF). Extracorporeal liver support systems may exert beneficial effects in ACLF via removal of cytokines. At present, two systems are commercially available, the Molecular Adsorbent Recirculating System (MARS™) and Fractionated Plasma Separation, Adsorption and Dialysis (Prometheus™). The aim of this study was to compare the effects of MARS and Prometheus treatments on serum cytokine levels and their clearances. METHODS: Eight patients with ACLF underwent alternating treatments with either MARS or Prometheus in a randomized cross-over design. Thirty-four treatments (17 MARS, 17 Prometheus) were available for analysis. Serum cytokines were measured before and after each treatment, and cytokine clearance was calculated from paired arterial and venous samples and effective plasma flow one hour after the start of treatment. RESULTS: Baseline serum levels of interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-alpha (TNF-α), and soluble TNF-α receptor 1 were significantly elevated in patients with ACLF. Measurable plasma clearances were detected for all cytokines tested, but no significant changes in serum levels of any cytokine were found after treatments with MARS or Prometheus. In MARS treatments, IL-10 was cleared from plasma more efficiently than IL-6. Clearance of IL-10 was higher in Prometheus than in MARS treatments. CONCLUSION: Cytokines are cleared from plasma by both MARS and Prometheus, but neither system is able to change serum cytokine levels. This discrepancy is probably due to a high rate of cytokine production in patients with ACLF

Impact of the conceptual model\u27s representation format on identifying and understanding user stories

Context: Eliciting user stories is a major challenge for agile development approaches. Conceptual models are used to support the identification of user stories and increase their understanding. In many companies, existing model documentation stored as either use cases or BPMN models is available. However, these two types of business process models might not be equally effective for elicitation tasks due to their formats. Objective: We address the effectiveness of different elicitation tasks when supported either with visual or textual conceptual model. Since the agile literature shows little attention to reusing existing BPMN documentation, we propose several hypotheses to compare it to the use of textual use case models. Method: We conducted an experiment to compare the effectiveness of the two business process formats: textual use cases and visual BPMN models. We studied their effects on three elicitation tasks: identifying user stories and understanding their execution-order and integration dependencies. Results: The subjects better understood execution-order dependencies when visual input in the form of BPMN models was provided. The performance of the other two tasks showed no statistical differences. Conclusion: We addressed an important problem of user story elicitation: which informationally equivalent model (visual BPMN or textual use case) is more effective when identifying and understanding user stories

Volume regulation and renal function at high altitude across gender.

We investigated changes in volume regulating hormones and renal function at high altitudes and across gender.Included in this study were 28 subjects (n = 20 males; n = 8 females. ages: 19 - 65 yrs), who ascended to a height of 3440m (HA1), on the 3rd day and to 5050m (HA2), on the 14th day. Plasma and urinary creatinine and urinary osmolality as well as plasma levels of plasma renin activity (PRA), Aldosterone, antidiuretic hormone (ADH), and atrial natriuretic peptide (ANP) were measured. The plasma volume loss (PVL) was estimated from plasma density and hematocrit. Glomerular filtration rate (GFR) was measured based on nocturnal (9 hour) creatinine clearance; this was compared with various methods for estimation of GFR.The mean 24-hour urine production increased significantly in both sexes across the expedition. But PVL reached significance only in males. No changes in Na+ in plasma, urine or its fractional excretion were seen at both altitudes. Urinary osmolality decreased upon ascent to the higher altitudes. ADH and PRA decreased significantly at both altitudes in males but only at HA2 in females. However, no changes in aldosterone were seen across the sexes and at different altitudes. ANP increased significantly only in males during the expedition. GFR, derived from 9-h creatinine clearance (CreaCl), decreased in both sexes at HA1 but remained stable at HA2. Conventional Crea[p]-based GFR estimates (eGFR) showed only poor correlation to CreaCl.We report details of changes in hormonal patterns across high altitude sojourn. To our knowledge we are not aware of any study that has examined these hormones in same subjects and across gender during high altitude sojourn. Our results also suggest that depending on the estimation formula used, eGFR underestimated the observed decrease in renal function measured by CreaCl, thus opening the debate regarding the use of estimated glomerular filtration rates at high altitudes

EHR problem list clustering for improved topic-space navigation

Abstract Background The amount of patient-related information within clinical information systems accumulates over time, especially in cases where patients suffer from chronic diseases with many hospitalizations and consultations. The diagnosis or problem list is an important feature of the electronic health record, which provides a dynamic account of a patient’s current illness and past history. In the case of an Austrian hospital network, problem list entries are limited to fifty characters and are potentially linked to ICD-10. The requirement of producing ICD codes at each hospital stay, together with the length limitation of list items leads to highly redundant problem lists, which conflicts with the physicians’ need of getting a good overview of a patient in short time. This paper investigates a method, by which problem list items can be semantically grouped, in order to allow for fast navigation through patient-related topic spaces. Methods We applied a minimal language-dependent preprocessing strategy and mapped problem list entries as tf-idf weighted character 3-grams into a numerical vector space. Based on this representation we used the unweighted pair group method with arithmetic mean (UPGMA) clustering algorithm with cosine distances and inferred an optimal boundary in order to form semantically consistent topic spaces, taking into consideration different levels of dimensionality reduction via latent semantic analysis (LSA). Results With the proposed clustering approach, evaluated via an intra- and inter-patient scenario in combination with a natural language pipeline, we achieved an average compression rate of 80% of the initial list items forming consistent semantic topic spaces with an F-measure greater than 0.80 in both cases. The average number of identified topics in the intra-patient case (μ Intra  = 78.4) was slightly lower than in the inter-patient case (μ Inter  = 83.4). LSA-based feature space reduction had no significant positive performance impact in our investigations. Conclusions The investigation presented here is centered on a data-driven solution to the known problem of information overload, which causes ineffective human-computer interactions at clinicians’ work places. This problem is addressed by navigable disease topic spaces where related items are grouped and the topics can be more easily accessed

Comparing absolute 9-h-creatinine clearance (CreaCl) with estimated values of the GFR using formulae postulated by Cockcroft-Gault across gender.

<p>Comparing absolute 9-h-creatinine clearance (CreaCl) with estimated values of the GFR using formulae postulated by Cockcroft-Gault across gender.</p

Removal of bile acids by two different extracorporeal liver support systems in acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is accompanied by marked intrahepatic cholestasis leading to accumulation of cytotoxic bile acids. Extracorporeal liver support systems efficiently remove bile acids, but their effect on bile acid composition in ACLF is unknown. The aim of the present study was to compare elimination of individual plasma bile acids by albumin dialysis (Molecular Adsorbents Recirculating System, MARS) and fractionated plasma separation (Prometheus). Eight consecutive patients with ACLF underwent alternating 6-hour sessions with MARS or Prometheus in a randomized, cross-over design. Serum samples were obtained before, during, and after each treatment, and individual bile acids including cholic acid and chenodeoxycholic acid (CDCA) were measured by gas chromatography. MARS and Prometheus removed total bile acids to a similar extent (reduction ratio, 45% and 46%, respectively). Both devices cleared cholic acid more efficiently than did CDCA. The molar fraction of CDCA (fCDCA) was elevated at baseline and correlated with the degree of liver dysfunction. Prometheus but not MARS treatments further increased fCDCA. Although both devices eliminate total bile acids to a similar extent, clearance of individual bile acids is different, leading to a slight change of the bile acid profile toward hydrophobic bile acids during Prometheus treatment

Anthropometric measurements and resting hemodynamic variables at baseline, at HA1 and at HA2.

<p>Anthropometric measurements and resting hemodynamic variables at baseline, at HA1 and at HA2.</p

Urine parameters at different altitudes across gender.

<p>Urine parameters at different altitudes across gender.</p