36 research outputs found

    Functionality of primary hepatic non-parenchymal cells in a 3D spheroid model and contribution to acetaminophen hepatotoxicity.

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    In addition to hepatocytes, the liver comprises a host of specialised non-parenchymal cells which are important to consider in the development of in vitro models which are both physiologically and toxicologically relevant. We have characterized a 3D co-culture system comprising primary human hepatocytes (PHH) and non-parenchymal cells (NPC) and applied it to the investigation of acetaminophen-induced toxicity. Firstly, we titrated ratios of PHH:NPC and confirmed the presence of functional NPCs via both immunohistochemistry and activation with both LPS and TGF-β. Based on these data we selected a ratio of 2:1 PHH:NPC for further studies. We observed that spheroids supplemented with NPCs were protected against acetaminophen (APAP) toxicity as determined by ATP (up to threefold difference in EC50 at day 14 compared to hepatocytes alone) and glutathione depletion, as well as miR-122 release. APAP metabolism was also altered in the presence of NPCs, with significantly lower levels of APAP-GSH detected. Expression of several CYP450 enzymes involved in the bioactivation of APAP was also lower in NPC-containing spheroids. Spheroids containing NPCs also expressed higher levels of miRNAs which have been implicated in APAP-induced hepatotoxicity, including miR-382 and miR-155 which have potential roles in liver regeneration and inflammation, respectively. These data indicate that the interaction between hepatocytes and NPCs can have significant metabolic and toxicological consequences important for the correct elucidation of hepatic safety mechanisms

    Rapid Identification of Bio-Molecules Applied for Detection of Biosecurity Agents Using Rolling Circle Amplification

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    Detection and identification of pathogens in environmental samples for biosecurity applications are challenging due to the strict requirements on specificity, sensitivity and time. We have developed a concept for quick, specific and sensitive pathogen identification in environmental samples. Target identification is realized by padlock- and proximity probing, and reacted probes are amplified by RCA (rolling-circle amplification). The individual RCA products are labeled by fluorescence and enumerated by an instrument, developed for sensitive and rapid digital analysis. The concept is demonstrated by identification of simili biowarfare agents for bacteria (Escherichia coli and Pantoea agglomerans) and spores (Bacillus atrophaeus) released in field

    Genome-wide meta-analysis uncovers novel loci influencing circulating leptin levels

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    Leptin is an adipocyte-secreted hormone, the circulating levels of which correlate closely with overall adiposity. Although rare mutations in the leptin (LEP) gene are well known to cause leptin deficiency and severe obesity, no common loci regulating circulating leptin levels have been uncovered. Therefore, we performed a genome-wide association study (GWAS) of circulating leptin levels from 32,161 individuals and followed up loci reaching P <10(-6) in 19,979 additional individuals. We identify five loci robustly associated (P <5 x 10(-8)) with leptin levels in/near LEP, SLC32A1, GCKR, CCNL1 and FTO. Although the association of the FTO obesity locus with leptin levels is abolished by adjustment for BMI, associations of the four other loci are independent of adiposity. The GCKR locus was found associated with multiple metabolic traits in previous GWAS and the CCNL1 locus with birth weight. Knockdown experiments in mouse adipose tissue explants show convincing evidence for adipogenin, a regulator of adipocyte differentiation, as the novel causal gene in the SLC32A1 locus influencing leptin levels. Our findings provide novel insights into the regulation of leptin production by adipose tissue and open new avenues for examining the influence of variation in leptin levels on adiposity and metabolic health.Peer reviewe

    Firm-level inefficiency and its determinants in the Swedish water and wastewater sector

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    The Swedish Water and Wastewater (WW) utilities are subject to a cost-of-service regulation with no regulatory incentives to reduce costs. An estimation of firm-level inefficiency using stochastic frontier models on a cross-sectional sample of 148 utilities from 2006 suggests that overall the sector has at least a 15% cost reduction potential. Utilities can increase efficiency by reducing network losses. The cost frontier shifts to a higher level when (1) two or more municipalities merge their WW operations and when (2) utilities receive tax subsidies.

    Public interest versus regulatory capture in the Swedish electricity market

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    This article tests the public interest and regulatory capture hypotheses, in the context of the Swedish electricity market, by studying the factors influencing the Swedish Energy Agency’s decision to replace decision-makers it employs to hear customer complaints against utilities. The study covers the period from the beginning of 1996, when a series of regulatory reforms were introduced to improve consumer protection, until the end of 2008. The study concludes that decision-makers who find in favor of customers have had a statistically lower probability of being removed, consistent with public interest theory. A transitory effect of favoring utilities can be observed for the period from 2 to 6 years following the reforms. In this period, government and public scrutiny of the regulator, which had been high in the immediate aftermath of the reforms, had waned and there were few precedents decided by the courts that the regulator was required to follow. This vacuum created an opportunity for the utilities to increase their influence over the regulator. Once the courts started establishing precedents in relatively large numbers, the supervisory role of the courts ensured that the actions of the regulator were scrutinized. This development has served a similar function to government and public scrutiny in the years immediately following the reforms in promoting the public interest.

    Regulatory behaviour under threat of court reversal

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    We investigate how public bureaucrats influence outcomes in regulated markets when they resolve price disputes. It has previously been demonstrated that regulators cause biased outcomes when they have short office terms, i.e. when they have relatively strong career concerns (Leaver, 2009). This paper extends previous studies to the situation when bureaucrats have life tenure and therefore have relatively weaker career concerns. We posit that potential career concerns are negatively related to experience in that experienced regulators develop stronger concerns for consumers. This suggests that the regulator's motivation matter for regulatory decisions but that motivation might change as regulators become more experienced. We also posit that regulators' behaviour is influenced by case complexity, which affects how much effort that have to put in towards a regulatory decision. Our theoretical model predicts that regulators set lower prices when cases are less complex and that those prices are confirmed when appealed to the court. For more complex cases, the court reduces the regulator's price when she is only concerned about her career and the court increases the regulator's price when she cares about both her career and consumer surplus. All these predictions are confirmed empirically when using data on 489 disputes from the Swedish electricity market

    Allelic imbalance on chromosomes 13 and 17 and mutation analysis of BRCA1 and BRCA2 genes in monozygotic twins concordant for breast cancer

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    To study genetic changes associated with the development of breast cancer and the extent of its hereditary predisposition, paraffin-embedded tissue samples were obtained from monozygotic twin pairs concordant for breast cancer through the linked Swedish Twin and Cancer Registries. DNA samples extracted from the matched tumour and normal tissues of nine twin pairs were analysed for allelic imbalance using a series of microsatellite markers on chromosomes 13 and 17, containing loci with known tumour suppressor genes. Multiple losses of constitutional heterozygosity (LOH), consistent with a loss of large genomic region, the whole chromosome or chromosome arm, was found in at least three pairs of twins. One double mitotic crossover was identified in one tumour sample in a pair concordant for LOH at multiple loci on both chromosomes. Recombination breakpoints were mapped to regions delineated by D13S218 and D13S263, and D13S155 and D13S279, respectively. In general, no genetic effect of losing the same allele within a twin pair was found. However, for one marker at chromosome 13 (D13S328, between the BRCA2 and the RB-1 loci) and two markers on chromosome 17 (D17S786, distal to the p53 locus, and D17S855, an intragenic BRCA1 marker) the proportion of twin pairs with the same LOH was significantly higher than expected. These regions may reflect hereditary genomic changes in our sample set. In addition, tumour DNA samples from a subset of 12 twin pairs were analysed for BRCA1 and BRCA2 mutations using exon-by-exon single-strand conformation polymorphism analysis. Two unclassified BRCA2 variants, with a putative pathogenic effect, were identified, but no pathogenic alterations were found in the BRCA1 gene

    Applying Numerical Weather Prediction Models to the Production of New European Wind Atlas: Sensitivity studies of the wind climate to the planetary boundary layer parametrization

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    Reliable and precise information about the wind speed climate is crucial for the development of wind energy. Meteorological processes in the mesoscale (2 - 200 km) can be represented using Numerical Weather Prediction (NWP) models such as the Weather Research and Forecast model (WRF), but before their application for creating wind energy atlases, their results and sensitivity to modelling parameters should be investigated. Here the WRF model wind speed results for the year 2015 for the Baltic Sea region are investigated, and the effect of the planetary boundary layer parametrization scheme is analyzed
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