1,071 research outputs found

    Evaluation of renal Kt/V as a marker of renal function in predialysis patients

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    Evaluation of renal Kt/V as a marker of renal function in predialysis patients.BackgroundThe use of renal Kt/V (r-Kt/V) as an indicator for the need of dialysis initiation has been recommended in the NKF-DOQI guidelines. In analogy to clinical practice in peritoneal dialysis, a fall of r-Kt/V below a threshold of 2.0 per week may indicate inadequate renal toxin elimination. However, there are no studies linking r-Kt/V with other parameters of glomerular filtration rate (GFR) in predialysis patients, and the validity of r-Kt/V as parameter for timing of dialysis initiation is unknown.MethodsRenal function was assessed repeatedly in 125 patients (N = 465 measurements). In predialysis patients (r-Kt/V <2.5 per week) r-Kt/V was compared with creatinine [CCr], urea [CUr], averaged creatinine/urea clearance [CCr/Ur], Cockcroft-Gault formula [CCG], and MDRD prediction equation 6 (MDRD6-GFR). The diagnostic performance of r-Kt/V as a parameter for timing the initiation of dialysis was evaluated.ResultsRenal Kt/V <2.5 was prevalent in 24.9% of cases (N = 116, mean 1.92 ± 0.34). In this group mean CCr was 13.8 ± 4.9, mean CUr 6.7 ± 1.3, and CCr/Ur 10.2 ± 2.9mL/min/1.73m2. There was no correlation of r-Kt/V with serum creatinine and MDRD6-GFR, but a significantly positive correlation with CCr/Ur (r2 = 0.3382, P < 0.001). Sensitivity of r-Kt/V to detect CCr/Ur < 10.5mL/min/1.73m2, defined as the threshold for dialysis initiation, was 73.6% with a specificity of 91.9%.ConclusionsThese results suggest that r-Kt/V is a parameter of acceptable specificity but poor sensitivity for the timing of dialysis initiation. Additional measures of renal function, such as the average of measured creatinine and urea clearance, also should be taken into consideration when deciding on the timing of dialysis initiation prior to the development of clinical signs of uremia and malnutrition

    Hepatotoxic substance(s) removed by high-flux membranes enhances the positive acute phase response

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    Hepatotoxic substance(s) removed by high-flux membranes enhances the positive acute phase response.BackgroundAcute phase proteins (APPs) are enhanced in end-stage renal disease patients (ESRD) requiring dialysis treatment. They are involved in a variety of pathologic processes like muscle proteolysis, cachexia, regulation of appetite, and atherosclerosis. They are predictive for mortality. APPs are not only makers but also active substances. They are mainly produced in liver cells and are primarily, but not exclusively, regulated by proinflammatory cytokines. To what extent hepatic APPs are influenced by uremic toxins is still unclear. Therefore, we investigated the effects of different ultrafiltrates (UFs) on the synthesis of α1-acid glycoprotein (AGP) in HepG2 cells.MethodsA cross-sectional as well as a crossover study with high-/low-flux membranes was conducted to investigate the impact of UFs on bioactivity of liver cell cultures. Metabolic activity (MTT test), cytotoxicity (lactate dehydrogenase release), and the positive APP AGP were measured in HepG2 cells.ResultsCultured hepatocytes treated with UFs from high-flux membranes exhibited a higher cytotoxicity (18.6 ± 0.3% high-flux vs. 13.9 ± 0.2% low-flux, P < 0.001) and a lower metabolic activity (29.3% high-flux vs. 50.3% low-flux, P < 0.001) in comparison with low-flux UFs. In addition, enhanced APP secretion could be observed under costimulatory conditions (high-flux 5.0 ± 0.7 vs. low-flux 3.1 ± 0.6 ng/μg protein, P < 0.05). The effects of high- and low-flux UFs were strongly expressed at the beginning and were still significantly different after 120 minutes of hemodialysis (HD) treatment. The cross-over experiments confirmed that UFs collected during high-flux HD had a higher capacity to stimulate AGP synthesis in liver cells.ConclusionThe effects of UFs from dialysis patients demonstrate that hepatotoxic substances can be removed by dialysis. Stimulating the acute phase response UF collected during high-flux HD had a higher impact on liver cells in comparison with low-flux UF. These substances are putative cofactors involved in cytokine regulation

    The function of tcf3 in medaka embryos: efficient knockdown with pePNAs

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    Background: The application of antisense molecules, such as morpholino oligonucleotides, is an efficient method of gene inactivation in vivo. We recently introduced phosphonic ester modified peptide nucleic acids (PNA) for in vivo loss-of-function experiments in medaka embryos. Here we tested novel modifications of the PNA backbone to knockdown the medaka tcf3 gene. Results: A single tcf3 gene exists in the medaka genome and its inactivation strongly affected eye development of the embryos, leading to size reduction and anophthalmia in severe cases. The function of Tcf3 strongly depends on co-repressor interactions. We found interactions with Groucho/Tle proteins to be most important for eye development. Using a dominant negative approach for combined inactivation of all groucho/tle genes also resulted in eye phenotypes, as did interference with three individual tle genes. Conclusions: Our results show that side chain modified PNAs come close to the knockdown efficiency of morpholino oligonucleotides in vivo. A single medaka tcf3 gene combines the function of the two zebrafish paralogs hdl and tcf3b. In combination with Groucho/Tle corepressor proteins Tcf3 acts in anterior development and is critical for eye formation

    Automatisiertes Off-Line-Rüsten von Ummantelungsanlagen

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    Ummanteln ist eine Fertigungstechnologie, deren Bedeutung noch immer w~chst. Mit ihr werden Holzwerkstoffprofile und Kaschierungen mit Schmelzklebstoffen gefügt Zu deutlich geringeren Kosten werden Profjlelemente erzeugt, die heute ihren Vorbildern aus Massivholz oder Metallen in Optik und Haptik gleichkommen oder einen eigenständigen Charme aufweisen. Allerdings müssen beim Ummantelungsprozess eine Vielzahl an Andruckrollen und ggf. Heißluftdüsen entlang des durchlaufenden Profils angeordnet werden, um die meist nur eingeschränkt formbare, mit heißem Schmelzkleber beschichtete Kaschierung mit dem Profilkern zu fügen. Da die Maschinen im Stillstand manuell gerüstet werden, reduziert die dafür benötigte Rüstzeit deutlich die Produktivität der Ummantelungsanlagen. Daher muss das Rüsten off-line, parallel zu den Fertigungsaufträgen. an einem separaten ROststand erfolgen und sich somit die Belegungszeit der Anlage auf das Einwechseln der Rollensätze beschränken. Basierend auf einer umfangreichen Prozessbetrachtung wurde ein Prozessmodell entwickelt, welches mittels Geometriedaten, Rüstregeln sowie Informationen über Material, Werkzeug und Ummantelungsmaschine ein virtuelles Bild der Rollenpositionierung erzeugt Die daraus gewonnenen Positionen und Anstellwinkel der einzelnen Rollen werden dann Ober einen Postprozessor an einen roboterunterstutzten Rüstplatz weitergegeben, welcher die benötigten Rollenhalter automatisiert rüstet

    First Experimental Characterization of Microwave Emission from Cosmic Ray Air Showers

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    We report the first direct measurement of the overall characteristics of microwave radio emission from extensive air showers. Using a trigger provided by the KASCADE-Grande air shower array, the signals of the microwave antennas of the CROME (Cosmic-Ray Observation via Microwave Emission) experiment have been read out and searched for signatures of radio emission by high-energy air showers in the GHz frequency range. Microwave signals have been detected for more than 30 showers with energies above 3*10^16 eV. The observations presented in this Letter are consistent with a mainly forward-directed and polarised emission process in the GHz frequency range. The measurements show that microwave radiation offers a new means of studying air showers at energies above 10^17 eV.Comment: Accepted for publication in PR

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
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