91 research outputs found

    Percent error of ultrasound examination to estimate fetal weight at term in different categories of birth weight with focus on maternal diabetes and obesity

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    Background: Sonography based estimate of fetal weight is a considerable issue for delivery planning. The study evaluated the influence of diabetes, obesity, excess weight gain, fetal and neonatal anthropometrics on accuracy of estimated fetal weight with respect to the extent of the percent error of estimated fetal weight to birth weight for different categories. Methods: Multicenter retrospective analysis from 11,049 term deliveries and fetal ultrasound biometry performed within 14 days to delivery. Estimated fetal weight was calculated by Hadlock IV. Percent error from birth weight was determined for categories in 250 g increments between 2500 g and 4500 g. Estimated fetal weight accuracy was categorized as accurate +/- 10% - +/- 20% and > 20%. Results: Diabetes was diagnosed in 12.5%, obesity in 12.6% and weight gain exceeding IOM recommendation in 49.1% of the women. The percentage of accurate estimated fetal weight was not significantly different in the presence of maternal diabetes (70.0% vs. 71.8%, p = 0.17), obesity (69.6% vs. 71.9%, p = 0.08) or excess weight gain (71.2% vs. 72%, p = 0.352) but of preexisting diabetes (61.1% vs. 71.7%; p = 0.007) that was associated with the highest macrosomia rate (26.9%). Mean percent error of estimated fetal weight from birth weight was 2.39% +/- 9.13%. The extent of percent error varied with birth weight with the lowest numbers for 3000 g-3249 g and increasing with the extent of birth weight variation: 5% +/- 11% overestimation in the lowest and 12% +/- 8% underestimation in the highest ranges. Conclusion: Diabetes, obesity and excess weight gain are not necessarily confounders of estimated fetal weight accuracy. Percent error of estimated fetal weight is closely related to birth weight with clinically relevant over- and underestimation at both extremes. This work provides detailed data regarding the extent of percent error for different birth weight categories and may therefore improve delivery planning

    Discovery and quantitative spectral analysis of an Ofpe/WN9 (WN11) star in the Sculptor spiral galaxy NGC 300

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    We have discovered an Ofpe/WN9 (WN11 following Smith et al.) star in the Sculptor spiral galaxy NGC 300, the first object of this class found outside the Local Group, during a recent spectroscopic survey of blue supergiant stars obtained at the ESO VLT. The light curve over a five-month period in late 1999 displays a variability at the 0.1 mag level. The intermediate resolution spectra (3800-7200 A) show a very close resemblance to the Galactic LBV AG Car during minimum. We have performed a detailed non-LTE analysis of the stellar spectrum, and have derived a chemical abundance pattern which includes H, He, C, N, O, Al, Si and Fe, in addition to the stellar and wind parameters. The derived stellar properties and the He and N surface enrichments are consistent with those of other Local Group WN11 stars in the literature, suggesting a similar quiescent or post-LBV evolutionary status.Comment: 9 pages, 4 figures, 2 tables. Accepted for publication in the Astrophysical Journal Letter

    Extragalactic chemical abundances: do HII regions and young stars tell the same story? The case of the spiral galaxy NGC 300

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    (Abridged) We have obtained new spectrophotometric data for 28 HII regions in the spiral galaxy NGC 300, a member of the nearby Sculptor Group. The detection of auroral lines, including [OIII]4363, [SIII]6312 and [NII]5755, has allowed us to measure electron temperatures and direct chemical abundances for the whole sample. We determine for the first time in this galaxy a radial gas-phase oxygen abundance gradient based solely on auroral lines, and obtain the following least-square solution: 12+log(O/H)=8.57-0.41 R/R25, where the galactocentric distance is expressed in terms of the isophotal radius R25. The gradient corresponds to -0.077 dex/kpc, and agrees very well with the galactocentric trend in metallicity obtained for 29 B and A supergiants in the same galaxy. The intercept of the regression for the nebular data virtually coincides with the intercept obtained from the stellar data. This allows little room for depletion of nebular oxygen onto dust grains, although in this kind of comparison we are somewhat limited by systematic uncertainties, such as those related to the atomic parameters used to derive the chemical compositions. We discuss the implications of our result with regard to strong-line abundance indicators commonly used to estimate the chemical compositions of star-forming galaxies, such as R23. By applying a few popular calibrations of these indices based on grids of photoionization models on the NGC 300 HII region fluxes we find metallicities that are higher by 0.3 dex (a factor of two) or more relative to our nebular (Te-based) and stellar ones. We confirm a metallicity dependence of the `softness' parameter eta=(O+/O++)/(S+/S++), in the sense that softer stellar continua are found at high metallicity.Comment: Accepted for publication in The Astrophysical Journa

    Neisseria gonorrhoeae O-linked pilin glycosylation: functional analyses define both the biosynthetic pathway and glycan structure

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    Neisseria gonorrhoeae expresses an O-linked protein glycosylation pathway that targets PilE, the major pilin subunit protein of the Type IV pilus colonization factor. Efforts to define glycan structure and thus the functions of pilin glycosylation (Pgl) components at the molecular level have been hindered by the lack of sensitive methodologies. Here, we utilized a ‘top-down’ mass spectrometric approach to characterize glycan status using intact pilin protein from isogenic mutants. These structural data enabled us to directly infer the function of six components required for pilin glycosylation and to define the glycan repertoire of strain N400. Additionally, we found that the N. gonorrhoeae pilin glycan is O-acetylated, and identified an enzyme essential for this unique modification. We also identified the N. gonorrhoeae pilin oligosaccharyltransferase using bioinformatics and confirmed its role in pilin glycosylation by directed mutagenesis. Finally, we examined the effects of expressing the PglA glycosyltransferase from the Campylobacter jejuni N-linked glycosylation system that adds N-acetylgalactosamine onto undecaprenylpyrophosphate-linked bacillosamine. The results indicate that the C. jejuni and N. gonorrhoeae pathways can interact in the synthesis of O-linked di- and trisaccharides, and therefore provide the first experimental evidence that biosynthesis of the N. gonorrhoeae pilin glycan involves a lipid-linked oligosaccharide precursor. Together, these findings underpin more detailed studies of pilin glycosylation biology in both N. gonorrhoeae and N. meningitidis, and demonstrate how components of bacterial O- and N-linked pathways can be combined in novel glycoengineering strategies

    Nicotinic acid adenine dinucleotide phosphate-mediated calcium signalling in effector T cells regulates autoimmunity of the central nervous system

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    Nicotinic acid adenine dinucleotide phosphate represents a newly identified second messenger in T cells involved in antigen receptor-mediated calcium signalling. Its function in vivo is, however, unknown due to the lack of biocompatible inhibitors. Using a recently developed inhibitor, we explored the role of nicotinic acid adenine dinucleotide phosphate in autoreactive effector T cells during experimental autoimmune encephalomyelitis, the animal model for multiple sclerosis. We provide in vitro and in vivo evidence that calcium signalling controlled by nicotinic acid adenine dinucleotide phosphate is relevant for the pathogenic potential of autoimmune effector T cells. Live two photon imaging and molecular analyses revealed that nicotinic acid adenine dinucleotide phosphate signalling regulates T cell motility and re-activation upon arrival in the nervous tissues. Treatment with the nicotinic acid adenine dinucleotide phosphate inhibitor significantly reduced both the number of stable arrests of effector T cells and their invasive capacity. The levels of pro-inflammatory cytokines interferon-gamma and interleukin-17 were strongly diminished. Consecutively, the clinical symptoms of experimental autoimmune encephalomyelitis were ameliorated. In vitro, antigen-triggered T cell proliferation and cytokine production were evenly suppressed. These inhibitory effects were reversible: after wash-out of the nicotinic acid adenine dinucleotide phosphate antagonist, the effector T cells fully regained their functions. The nicotinic acid derivative BZ194 induced this transient state of non-responsiveness specifically in post-activated effector T cells. Naïve and long-lived memory T cells, which express lower levels of the putative nicotinic acid adenine dinucleotide phosphate receptor, type 1 ryanodine receptor, were not targeted. T cell priming and recall responses in vivo were not reduced. These data indicate that the nicotinic acid adenine dinucleotide phosphate/calcium signalling pathway is essential for the recruitment and the activation of autoaggressive effector T cells within their target organ. Interference with this signalling pathway suppresses the formation of autoimmune inflammatory lesions and thus might qualify as a novel strategy for the treatment of T cell mediated autoimmune diseases
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