Differential production of prostaglandins and prostacyclins by liver and head kidney cells from Atlantic salmon challenged with arachidonic and eicosapentaenoic acids

Polyunsaturated fatty acids such as arachidonic and eicosapentaenoic acids are the precursors of eicosanoid metabolites (e.g prostaglandins and prostacyclins) which regulate inflammatory and immune response processes in fish organs. The present research studies the differential production of PGI2, PGI3, PGE2 and PGE3 by primary liver and head kidney cells isolated from salmon and challenged with single or combined ARA and/or EPA. There was a significant increase in the production of PGE2 and PGI3 in both types of cells after exposure to single and combined fatty acids. Increased production of PGE3 was only detected in liver cells after exposure to ARA+EPA. The levels of PGI2 in liver cells were significantly increased after exposure to all the tested fatty acid systems, while the production levels in head kidney cells were only significant after exposure to ARA or ARA+EPA, but not to EPA, where the production was non-significantly decreased compared to the control cells. In general, liver cells synthetized higher prostaglandin levels than prostacyclins, and the opposite was observed in head kidney cells, which synthetized highly remarkable amounts of prostacyclin compared to liver cells. The overall production for both types of cells and various fatty acid systems were characterized by a high proportion of the omega-3 fatty acid metabolites (PGE3+PGI3) compared to the omega-6 counterpart (PGE2+PGI2). Some potential production mechanisms are proposed and comprehensively discussed. The results of the present research are the first to deliver the differential production of prostacyclins and prostaglandins by liver and head kidney cells from salmon, thereby paving the way for understanding the significance of these prostanoids in fish physiology and disease.publishedVersio

Thermal noise limitations to force measurements with torsion pendulums: Applications to the measurement of the Casimir force and its thermal correction

A general analysis of thermal noise in torsion pendulums is presented. The specific case where the torsion angle is kept fixed by electronic feedback is analyzed. This analysis is applied to a recent experiment that employed a torsion pendulum to measure the Casimir force. The ultimate limit to the distance at which the Casimir force can be measured to high accuracy is discussed, and in particular the prospects for measuring the thermal correction are elaborated upon.Comment: one figure, five pages, to be submitted to Phys Rev

Practitioner-informed improvements to early childhood intervention performance checklists and practice guides

Results from four early childhood practitioner field tests of performance checklists and early intervention practice guides are reported. Findings from the first field test were used to make changes and improvements in the checklists and practice guides evaluated in the second and third field tests, and findings from the latter two field tests were used to improve the checklist and practice guide evaluated in the fourth field test. Results indicated that changes made in response to practitioners’ suggestions and feedback were associated with (1) progressive increases in the practitioners’ social validity judgments of the checklists, practice guides, and checklist-practice guide correspondence, and (2) progressive decreases in the number of practitioner suggestions and feedback for improving the early intervention materials. The field-test research demonstrates the importance of practitioner input, suggestions, and feedback for improving the usefulness of early childhood intervention practices

Dietary electrolyte balance of Atlantic salmon (Salmo salar) freshwater feeds: Impact on osmoregulation, mineral metabolism and performance in seawater

Dietary electrolyte balance is the equilibrium of monovalent cations and anions that influence the acid-base balance of the feed (dEB = Na + K − Cl, mEq kg−1). Dietary electrolytes/minerals can influence the physiological changes during smoltification in Atlantic salmon. In this context, we aimed to study if the dEB of the freshwater feeds can be used to pre-adapt the hypoosmotic functionality and the associated effects on mineral metabolism. The dEB of commercial freshwater Atlantic salmon feeds in Norway varied from −9 to 400 mEq kg−1 feed. Three experimental feeds were formulated to study incremental levels of dEB reflecting the low (L-dEB, −50 to 0), median (M-dEB, 200–250) and high (H-dEB, 350–400). Triplicate groups of Atlantic salmon parr (36 g) were fed one of the three feeds for 8 weeks in freshwater at 12 °C. The fish were transferred to full strength seawater in indoor tanks and fed a commercial diet for 6 weeks. Growth was not differentially affected by dEB levels, neither in the freshwater phase nor in the seawater. Plasma electrolytes (Na+ and Cl−) and gill mRNA expression of sodium potassium ATPase (NKA a1b, seawater isoform) were significantly lower in L-dEB fed fish. In the intestine, carbonate precipitates 24 h after seawater transfer was higher in fish fed both L-dEB and H-dEB feeds compared to the M-dEB fed fish. Whole body and plasma mineral levels were significantly affected by dEB levels in freshwater feeds. Interestingly, the carryover effect of dEB in freshwater feeds was significant after 6 weeks in seawater for plasma and whole-body Zn status, with the H-dEB fed fish showing significantly increased body Zn status compared to L-dEB and M-dEB fed fish. The study revealed that mineral metabolism and intestinal response to seawater transfer can be pre-adapted by modulating the electrolyte and/or mineral balance in freshwater feeds in Atlantic salmon. Further, dEB did not affect long term development of cataract or vertebral deformities.publishedVersio

Vitamin D deficiency is associated with sudden cardiac death, combined cardiovascular events, and mortality in haemodialysis patients

Dialysis patients experience an excess mortality, predominantly of sudden cardiac death (SCD). Accumulating evidence suggests a role of vitamin D for myocardial and overall health. This study investigated the impact of vitamin D status on cardiovascular outcomes and fatal infections in haemodialysis patients. 25-hydroxyvitamin D [25(OH)D] was measured in 1108 diabetic haemodialysis patients who participated in the German Diabetes and Dialysis Study and were followed up for a median of 4 years. By Cox regression analyses, we determined hazard ratios (HR) for pre-specified, adjudicated endpoints according to baseline 25(OH)D levels: SCD (n = 146), myocardial infarction (MI, n = 174), stroke (n = 89), cardiovascular events (CVE, n = 414), death due to heart failure (n = 37), fatal infection (n = 111), and all-cause mortality (n = 545). Patients had a mean age of 66 +/- 8 years (54% male) and median 25(OH)D of 39 nmol/L (interquartile range: 28-55). Patients with severe vitamin D deficiency [25(OH)D of 75 nmol/L [HR: 2.99, 95% confidence interval (CI): 1.39-6.40]. Furthermore, CVE and all-cause mortality were strongly increased (HR: 1.78, 95% CI: 1.18-2.69, and HR: 1.74, 95% CI: 1.22-2.47, respectively), all persisting in multivariate models. There were borderline non-significant associations with stroke and fatal infection while MI and deaths due to heart failure were not meaningfully affected. Severe vitamin D deficiency was strongly associated with SCD, CVE, and mortality, and there were borderline associations with stroke and fatal infection. Whether vitamin D supplementation decreases adverse outcomes requires further evaluation.Clinical epidemiolog

Elevated Serum Levels of Interferon-Regulated Chemokines Are Biomarkers for Active Human Systemic Lupus Erythematosus

BACKGROUND: Systemic lupus erythematosus (SLE) is a serious systemic autoimmune disorder that affects multiple organ systems and is characterized by unpredictable flares of disease. Recent evidence indicates a role for type I interferon (IFN) in SLE pathogenesis; however, the downstream effects of IFN pathway activation are not well understood. Here we test the hypothesis that type I IFN-regulated proteins are present in the serum of SLE patients and correlate with disease activity. METHODS AND FINDINGS: We performed a comprehensive survey of the serologic proteome in human SLE and identified dysregulated levels of 30 cytokines, chemokines, growth factors, and soluble receptors. Particularly striking was the highly coordinated up-regulation of 12 inflammatory and/or homeostatic chemokines, molecules that direct the movement of leukocytes in the body. Most of the identified chemokines were inducible by type I IFN, and their levels correlated strongly with clinical and laboratory measures of disease activity. CONCLUSIONS: These data suggest that severely disrupted chemokine gradients may contribute to the systemic autoimmunity observed in human SLE. Furthermore, the levels of serum chemokines may serve as convenient biomarkers for disease activity in lupus