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Uppsala, Sweden

Gerontas S.,University College London | Asplund M.,Bio science AB | Hjorth R.,Bio science AB | Bracewell D.G.,University College London
Journal of Chromatography A | Year: 2010

Chromatography is an essential downstream processing step in the production of biopharmaceuticals. Here we present an approach to chromatography scale-up using scale-down experimentation integrated with general rate modelling. This type of modelling takes account all contributions to the mass transfer kinetics providing process understanding. The model is calibrated using a 2.5cm height, 1 ml column and used to predict chromatograms for 20cm height columns from 40 ml to 160 L volume. Simulations were found to be in good agreement with experimental results. The envisaged approach could potentially reduce the number of experiments, shorten development time and reduce costs. © 2010 Elsevier B.V.

Kask L.,Uppsala University | Jorsback A.,Bio science AB | Winkvist M.,Bio science AB | Alfredsson J.,Uppsala University | And 3 more authors.
Journal of Proteome Research | Year: 2014

Tissue factor (TF) is both an initiator of blood coagulation and a signaling receptor. Using a proteomic approach, we investigated the role of TF in cell signaling when stimulated by its ligand, activated factor VII (FVIIa). From a 2-D difference gel electrophoresis (DIGE) study we found forty one spots that were differentially regulated over time in FVIIa stimulated cells or in comparison to nonstimulated cells. Mass spectrometry identifies 23 out of these as 13 different proteins. One of them, elongation factor 2 (EF-2), was investigated in greater detail by Western blot, a protein synthesis assay and cell cycle analysis. When tissue factor was stimulated by FVIIa, the phosphorylation of EF-2 increased which inactivates this protein. Analyzing the effect using site inactivated FVIIa (FVIIai), as well as the protease activated receptor 2 (PAR-2) agonist SLIGKV, indicated that the inactivation was not PAR-2 dependent. A panel of tissue factor mutants was analyzed further to try to pinpoint what part of the cytoplasmic domain that is needed for this effect. Performing a protein synthesis assay in two different cell lines we could confirm that protein synthesis decreased upon stimulation by FVIIa. Cell cycle analysis showed that FVIIa also promotes a higher degree of cell proliferation. © 2013 American Chemical Society.

Stenholm A.,Bio science AB | Holmstrom S.,Cardinova AB | Hjarthag S.,Bio science AB | Lind O.,Bio science AB
Environmental Technology | Year: 2012

Trace-level analysis of alkylphenol polyethoxylates (APEOs) in wastewater containing sludge requires the prior removal of contaminants and preconcentration. In this study, the effects on optimal work-up procedures of the types of alkylphenols present, their degree of ethoxylation, the biofilm wastewater treatment and the sample matrix were investigated for these purposes. The sampling spot for APEO-containing specimens from an industrial wastewater treatment plant was optimized, including a box that surrounded the tubing outlet carrying the wastewater, to prevent sedimented sludge contaminating the collected samples. Following these changes, the sampling precision (in terms of dry matter content) at a point just under the tubing leading from the biofilm reactors was 0.7% RSD. The findings were applied to develop a work-up procedure for use prior to a high-performance liquid chromatography - fluorescence detection analysis method capable of quantifying nonylphenol polyethoxylates (NPEOs) and poorly investigated dinonylphenol polyethoxylates (DNPEOs) at low μg L -1concentrations in effluents from non-activated sludge biofilm reactors. The selected multi-step work-up procedure includes lyophilization and pressurized fluid extraction (PFE) followed by strong ion exchange solid phase extraction (SPE). The yields of the combined procedure, according to tests with NP10EO-spiked effluent from a wastewater treatment plant, were in the 62-78% range. © 2012 Taylor & Francis.

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