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- Surowiec, Izabella, et al.
(author)
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Quantification of run order effect on chromatography : mass spectrometry profiling data
- 2018
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In: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1568, s. 229-234
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Journal article (peer-reviewed)abstract
- Chromatographic systems coupled with mass spectrometry detection are widely used in biological studies investigating how levels of biomolecules respond to different internal and external stimuli. Such changes are normally expected to be of low magnitude and therefore all experimental factors that can influence the analysis need to be understood and minimized. Run order effect is commonly observed and constitutes a major challenge in chromatography-mass spectrometry based profiling studies that needs to be addressed before the biological evaluation of measured data is made. So far there is no established consensus, metric or method that quickly estimates the size of this effect. In this paper we demonstrate how orthogonal projections to latent structures (OPLS®) can be used for objective quantification of the run order effect in profiling studies. The quantification metric is expressed as the amount of variation in the experimental data that is correlated to the run order. One of the primary advantages with this approach is that it provides a fast way of quantifying run-order effect for all detected features, not only internal standards. Results obtained from quantification of run order effect as provided by the OPLS can be used in the evaluation of data normalization, support the optimization of analytical protocols and identification of compounds highly influenced by instrumental drift. The application of OPLS for quantification of run order is demonstrated on experimental data from plasma profiling performed on three analytical platforms: GCMS metabolomics, LCMS metabolomics and LCMS lipidomics.
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| 2. |
- Bergström, Sven, et al.
(author)
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Microbiological features distinguishing Lyme disease and relapsing fever spirochetes
- 2018
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In: Wiener Klinische Wochenschrift. - : Springer. - 0043-5325 .- 1613-7671. ; 130:15-16, s. 484-490
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Journal article (peer-reviewed)abstract
- The recent proposal of splitting the genus Borrelia into two genera in the newly formed family of Borreliaceae, i.aEuroe. Borrelia and Borreliella has motivated us to reflect upon how these organisms has been characterized and differentiated. This article therefore aims to take a closer look on the biology and virulence attributes of the two suggested genera, i.aEuroe. those causing Lyme borreliosis and relapsing fever borreliosis. Both genera have much in common with similar infection biological features. They are both characterized as bacterial zoonoses, transmitted by hematophagous arthropods with almost identical microbiological appearance. Nevertheless, a closer look at the genotypic and phenotypic characteristics clearly reveals several differences that might motivate the suggested split. On the other hand, a change of this well-established classification within the genus Borrelia might impose an economical burden as well as a great confusion in society, including medical and scientific societies as well as the general population.
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| 3. |
- Normark, Daniel, 1974, et al.
(author)
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Mundane intermodality: a comparative analysis of bike-renting practices
- 2018
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In: Mobilities. - : Informa UK Limited. - 1745-0101 .- 1745-011X. ; 13:6, s. 791-807
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Journal article (peer-reviewed)abstract
- Bike rental systems have been introduced as a sustainable urban mobility alternative. This paper analyses the social practices that emerge as part of these systems. We specifically focus on the interactions and street-level performances at a bike rental station. We argue that the bike-sharing service is a pivotal device that enables its users to transform (to re-configure from pedestrians to cyclists and vice versa), hence creating intermodality. The bike rental system ensures the technical standardization of behaviour while simultaneously revealing differences between those familiar with the system and those who are not. Thus, competences and meanings of the station are not subordinate to materials – they are interdependent, entwined and enacted in and through the practice itself.
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| 5. |
- Reuterswärd, Philippa, et al.
(author)
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Levels of human proteins in plasma associated with acute paediatric malaria
- 2018
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In: Malaria Journal. - : BMC. - 1475-2875. ; 17
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Journal article (peer-reviewed)abstract
- Background: The intimate interaction between the pathophysiology of the human host and the biology of the Plasmodium falciparum parasite results in a wide spectrum of disease outcomes in malaria. Development of severe disease is associated with a progressively augmented imbalance in pro- and anti-inflammatory responses to high parasite loads and sequestration of parasitized erythrocytes. Although these phenomena collectively constitute common denominators for the wide variety of discrete severe malaria manifestations, the mechanistic rationales behind discrepancies in outcome are poorly understood. Exploration of the human pathophysiological response by variations in protein profiles in plasma presents an excellent opportunity to increase the understanding. This is ultimately required for better prediction, prevention and treatment of malaria, which is essential for ongoing elimination and eradication efforts. Results: An affinity proteomics approach was used to analyse 541 paediatric plasma samples collected from community controls and patients with mild or severe malaria in Rwanda. Protein profiles were generated with an antibody-based suspension bead array containing 255 antibodies targetting 115 human proteins. Here, 57 proteins were identified with significantly altered levels (adjusted p-values<0.001) in patients with malaria compared to controls. From these, the 27 most significant proteins (adjusted p-values<10(-14)) were selected for a stringent analysis approach. Here, 24 proteins showed elevated levels in malaria patients and included proteins involved in acute inflammatory response as well as cell adhesion. The remaining three proteins, also implicated in immune regulation and cellular adhesivity, displayed lower abundance in malaria patients. In addition, 37 proteins (adjusted p-values<0.05) were identified with increased levels in patients with severe compared to mild malaria. This set includes, proteins involved in tissue remodelling and erythrocyte membrane proteins. Collectively, this approach has been successfully used to identify proteins both with known and unknown association with different stages of malaria. Conclusion: In this study, a high-throughput affinity proteomics approach was used to find protein profiles in plasma linked to P. falciparum infection and malaria disease progression. The proteins presented herein are mainly involved in inflammatory response, cellular adhesion and as constituents of erythrocyte membrane. These findings have a great potential to provide increased conceptual understanding of host-parasite interaction and malaria pathogenesis.
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