[Circulating citrulline levels: a biomarker for intestinal functionality assessment].

International audienceCirculating citrulline is emerging as an innovating biomarker candidate for assessment of intestinal function. Amino acid synthesized by enterocytes of intestinal mucosal, citrulline is not included in proteins or nutrition products and is a precursor for production of arginine by the kidney. Plasma citrulline is, in clinical situation, an established biomarker of enterocyte functional metabolic mass (trophicity) in children and in adult patients due to its high relation to active functional small bowel remnant length in intestinal diseases (short bowel, extensive enteropathies, intestinal toxicity of chemotherapy and radiotherapy. Plasma citrulline concentration (30-50 μmol/L), independent of nutritional status, if less than 10 μmol/L can give an objective threshold for nutrition parenteral use in case of intestinal failure due to enterocyte abnormalities or lack. Its regular dosage allows the monitoring of intestinal function except in case of significant renal failure

Plasma L-citrulline concentrations and its relationship with inflammation at the onset of septic shock: A pilot study.: citrulline in septic shock

International audiencePURPOSE: Hypocitrullinemia has been suggested to be a prognostic factor for patients in intensive care. The aim of this ancillary study of the Corticosteroids and Intensive Insulin Therapy for Septic Shock prospective study was to investigate plasma l-citrulline concentrations and its relationship with inflammation and digestive bacterial translocation in patients with septic shock multiorgan failure and without primary intestinal disease or chronic renal failure. METHODS: Sixteen adult patients were selected. They were studied on day (D) 0 at hours (H) 0, 6, 12, 18, and 24 and on D4 (H96). Selected plasma amino acids and proteins, proinflammatory (tumor necrosis factor α [TNF-α]) and anti-inflammatory (interleukin [IL] 10) cytokine concentrations, and bacterial translocation were measured. RESULTS: Eight D14 survivors and 8 D14 nonsurvivors patients were studied. Citrulline was decreased on D0 (H0: 29 ± 10 vs nadir: 18 ± 6 μmol/L; P < .05). The citrulline nadir was lower (P < .01) in patients with digestive bacterial translocation than that in those without. Mean citrulline concentrations at H0 to H96 were not significantly different between survivors and nonsurvivors. In both groups, citrulline was significantly inversely correlated with C-reactive protein (r(2) = 0.10, P < .01) on D0. No significant correlations were found between citrulline and albumin, transthyretin, TNF-α, IL-10, or TNF-α/IL-10 ratio. CONCLUSIONS: At the onset of septic shock, plasma citrulline decreases and varies inversely with C-reactive protein and is lower when digestive bacterial translocation occurs. This finding could reflect an early acute intestinal dysfunction, but measurement of citrulline concentration does not appear to be able to predict the patients' mortality

Optical algorithms at satellite wavelengths for total suspended matter in tropical coastal waters,” Sensors 8

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Optical algorithms at satellite wavelengths for Total Suspended Matter in tropical coastal waters

Is it possible to derive accurately Total Suspended Matter concentration or its proxy, turbidity, from remote sensing data in tropical coastal lagoon waters? To investigate this question, hyperspectral remote sensing reflectance, turbidity and chlorophyll pigment concentration were measured in three coral reef lagoons. The three sites enabled us to get data over very diverse environments: oligotrophic and sediment-poor waters in the southwest lagoon of New Caledonia, eutrophic waters in the Cienfuegos Bay (Cuba), and sediment-rich waters in the Laucala Bay (Fiji). In this paper, optical algorithms for turbidity are presented per site based on 113 stations in New Caledonia, 24 stations in Cuba and 56 stations in Fiji. Empirical algorithms are tested at satellite wavebands useful to coastal applications. Global algorithms are also derived for the merged data set (193 stations). The performances of global and local regression algorithms are compared. The best one-band algorithms on all the measurements are obtained at 681 nm using either a polynomial or a power model. The best two-band algorithms are obtained with R412/R620, R443/R670 and R510/R681. Two three-band algorithms based on Rrs620. Rrs681/Rrs412 and Rrs620. Rrs681/Rrs510 also give fair regression statistics. Finally, we propose a global algorithm based on one or three bands: turbidity is first calculated from Rrs681 and then, if < 1 FTU, it is recalculated using an algorithm based on Rrs620. Rrs681/Rrs412. On our data set, this algorithm is suitable for the 0.2-25 FTU turbidity range and for the three sites sampled (mean bias: 3.6 %, rms: 35%, mean quadratic error: 1.4 FTU). This shows that defining global empirical turbidity algorithms in tropical coastal waters is at reach