Browsing by Author "Denk, B."

Objectives: Performance evaluation of Elecsys sFlt-1 and PIGF assays. Design and methods: Within-, between-run, total imprecision, functional sensitivity, inter-laboratory comparison, method comparison and lot-to-lot reproducibility were evaluated. Results: Within- and between-run CVs were below 4% for sFlt-1 >60 and PIGF >20 pg/mL Total imprecision CVs were below 4.3%. Functional sensitivity was <5 pg/mL. Inter-laboratory CVs were <5%. Elecsys correlated well with Quantikine VEGF-R1 (r = 0.960) and PIGF (r = 0.968). Lot-to-lot comparisons yielded highly correlated results (r>0.999). In healthy pregnancies, the median levels of sFlt-1 remained constant in first (1107 pg/mL) and second trimesters (1437 pg/mL) but increased in the third trimester (2395 pg/mL), while median PIGF levels increased in the first (30 pg/mL) and second trimesters (279 pg/mL) and peaked at 29 to 32 weeks (626 pg/mL) and decreased thereafter (340 pg/mL). The sFlt-1/PIGF ratio is highest in the first trimester (median: 28) but remained constant in the second (median: 4.7) and third trimesters (median: 5.1). In PE/HELPP samples matched for gestational age the sFlt-1 levels were significantly higher (6894-34,624 pg/mL), whereas PlGF levels were lower (9.2-80 pg/mL) and the median sFlt-1/PIGF ratio is much higher (461; range: 121-2614) than in apparently healthy pregnancies (3.6; range: 0.3-105). Conclusion: The new Roche Elecsys sFlt-1 and PIGF immunoassay showed excellent precision and reliability. There was a clear difference in the Elecsys sFlt-1/PIGF ratio between samples obtained from women with apparently normal pregnancy at the time of blood collection and those diagnosed with PE/HELLP at the same age of gestation. (C) 2010 The Canadian Society of Clinical Chemists. Published by Elsevier inc. All rights reserved.

We report new mid-eclipse times of the two close binaries NSVS14256825 and HS0705+6700, harboring an sdB primary and a low-mass main-sequence secondary. Both objects display clear variations in their measured orbital period, which can be explained by the action of a third object orbiting the binary. If this interpretation is correct, the third object in NSVS14256825 is a giant planet with a mass of roughly 12 M-Jup. For HS0705+6700, we provide evidence that strengthens the case for the suggested periodic nature of the eclipse time variation and reduces the uncertainties in the parameters of the brown dwarf implied by that model. The derived period is 8.4 yr and the mass is 31 M-Jup, if the orbit is coplanar with the binary. This research is part of the PlanetFinders project, an ongoing collaboration between professional astronomers and student groups at high schools.