430 research outputs found

    Optimizing the Environmental and Economic Sustainability of Remote Community Infrastructure

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    Remote communities such as rural villages, post-disaster housing camps, and military forward operating bases are often located in remote and hostile areas with limited or no access to established infrastructure grids. Operating these communities with conventional assets requires constant resupply, which yields a significant logistical burden, creates negative environmental impacts, and increases costs. For example, a 2000-member isolated village in northern Canada relying on diesel generators required 8.6 million USD of fuel per year and emitted 8500 tons of carbon dioxide. Remote community planners can mitigate these negative impacts by selecting sustainable technologies that minimize resource consumption and emissions. However, the alternatives often come at a higher procurement cost and mobilization requirement. To assist planners with this challenging task, this paper presents the development of a novel infrastructure sustainability assessment model capable of generating optimal tradeoffs between minimizing environmental impacts and minimizing life-cycle costs over the community’s anticipated lifespan. Model performance was evaluated using a case study of a hypothetical 500-person remote military base with 864 feasible infrastructure portfolios and 48 procedural portfolios. The case study results demonstrated the model’s novel capability to assist planners in identifying optimal combinations of infrastructure alternatives that minimize negative sustainability impacts, leading to remote communities that are more self-sufficient with reduced emissions and costs

    Projected t-SNE for batch correction

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    Motivation: Low-dimensional representations of high-dimensional data are routinely employed in biomedical research to visualize, interpret and communicate results from different pipelines. In this article, we propose a novel procedure to directly estimate t-SNE embeddings that are not driven by batch effects. Without correction, interesting structure in the data can be obscured by batch effects. The proposed algorithm can therefore significantly aid visualization of high-dimensional data. Results: The proposed methods are based on linear algebra and constrained optimization, leading to efficient algorithms and fast computation in many high-dimensional settings. Results on artificial single-cell transcription profiling data show that the proposed procedure successfully removes multiple batch effects from t-SNE embeddings, while retaining fundamental information on cell types. When applied to single-cell gene expression data to investigate mouse medulloblastoma, the proposed method successfully removes batches related with mice identifiers and the date of the experiment, while preserving clusters of oligodendrocytes, astrocytes, and endothelial cells and microglia, which are expected to lie in the stroma within or adjacent to the tumours. Contact: [email protected]

    Local and systemic glucocorticoid metabolism in inflammatory arthritis

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    Background: Isolated, primary synovial fibroblasts generate active glucocorticoids through expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). This enzyme produces cortisol from inactive cortisone (and prednisolone from prednisone). Objective: To determine how intact synovial tissue metabolises glucocorticoids and to identify the local and systemic consequences of this activity by examination of glucocorticoid metabolism in patients with rheumatoid arthritis (RA). Methods: Synovial tissue was taken from patients with RA during joint replacement surgery. Glucocorticoid metabolism in explants was assessed by thin-layer chromatography and specific enzyme inhibitors. RT-PCR and immunohistochemistry were used to determine expression and distribution of 11β-HSD enzymes. Systemic glucocorticoid metabolism was examined in patients with RA using gas chromatography/mass spectrometry. Results: Synovial tissue synthesised cortisol from cortisone, confirming functional 11β-HSD1 expression. In patients with RA, enzyme activity correlated with donor erythrocyte sedimentation rate (ESR). Synovial tissues could also convert cortisol back to cortisone. Inhibitor studies and immunohistochemistry suggested this was owing to 11β-HSD2 expression in synovial macrophages, whereas 11β-HSD1 expression occurred primarily in fibroblasts. Synovial fluids exhibited lower cortisone levels than matched serum samples, indicating net local steroid activation. Urinary analyses indicated high 11β-HSD1 activity in untreated patients with RA compared with controls and a significant correlation between total body 11β-HSD1 activity and ESR. Conclusions: Synovial tissue metabolises glucocorticoids, the predominant effect being glucocorticoid activation, and this increases with inflammation. Endogenous glucocorticoid production in the joint is likely to have an impact on local inflammation and bone integrity

    Synergistic induction of local glucocorticoid generation by inflammatory cytokines and glucocorticoids: implications for inflammation associated bone loss

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    Objectives: Synovial fibroblasts and osteoblasts generate active glucocorticoids by means of the 11aβ-hydroxysteroid dehydrogenase type 1 (11aβ-HSD1) enzyme. This activity increases in response to proinflammatory cytokines or glucocorticoids. During inflammatory arthritis synovium and bone are exposed to both these factors. This study hypothesised that glucocorticoids magnify the effects of inflammatory cytokines on local glucocorticoid production in both synovium and bone. Methods: The effects of inflammatory cytokines (IL-1aβ/tumour necrosis factor alpha; TNFα) and glucocorticoids, alone or combined, were assessed on the expression and activity of 11β-HSD1 in primary synovial fibroblasts, primary human osteoblasts and MG-63 osteosarcoma cells. A range of other target genes and cell types were used to examine the specificity of effects. Functional consequences were assessed using IL-6 ELISA. Results: In synovial fibroblasts and osteoblasts, treatment with cytokines or glucocorticoids in isolation induced 11β-HSD1 expression and activity. However, in combination, 11β-HSD1 expression, activity and functional consequences were induced synergistically to a level not seen with isolated treatments. This effect was seen in normal skin fibroblasts but not foreskin fibroblasts or adipocytes and was only seen for the 11β-HSD1 gene. Synergistic induction had functional consequences on IL-6 production. Conclusions: Combined treatment with inflammatory cytokines and glucocorticoids synergistically induces 11aβ-HSD1 expression and activity in synovial fibroblasts and osteoblasts, providing a mechanism by which synovium and bone can interact to enhance anti-inflammatory responses by increasing localised glucocorticoid levels. However, the synergistic induction of 11β-HSD1 might also cause detrimental glucocorticoid accumulation in bone or surrounding tissues

    Treatment of inflammatory arthritis via targeting of tristetraprolin, a master regulator of pro-inflammatory gene expression

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    Objectives Tristetraprolin (TTP), a negative regulator of many pro-inflammatory genes, is strongly expressed in rheumatoid synovial cells. The mitogen-activated protein kinase (MAPK) p38 pathway mediates the inactivation of TTP via phosphorylation of two serine residues. We wished to test the hypothesis that these phosphorylations contribute to the development of inflammatory arthritis, and that, conversely, joint inflammation may be inhibited by promoting the dephosphorylation and activation of TTP. Methods The expression of TTP and its relationship with MAPK p38 activity were examined in non-inflamed and rheumatoid arthritis (RA) synovial tissue. Experimental arthritis was induced in a genetically modified mouse strain, in which endogenous TTP cannot be phosphorylated and inactivated. In vitro and in vivo experiments were performed to test anti-inflammatory effects of compounds that activate the protein phosphatase 2A (PP2A) and promote dephosphorylation of TTP. Results TTP expression was significantly higher in RA than non-inflamed synovium, detected in macrophages, vascular endothelial cells and some fibroblasts and co-localised with MAPK p38 activation. Substitution of TTP phosphorylation sites conferred dramatic protection against inflammatory arthritis in mice. Two distinct PP2A agonists also reduced inflammation and prevented bone erosion. In vitro anti-inflammatory effects of PP2A agonism were mediated by TTP activation. Conclusions The phosphorylation state of TTP is a critical determinant of inflammatory responses, and a tractable target for novel anti-inflammatory treatments

    Cytokines and Inflammatory Mediators [30-39]: 30. The LPS Stimulated Production of Interleukin-10 is not Associated with -819C/T and -592C/A Promoter Polymorphisms in Healthy Indian Subjects

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    Background: Interleukin-10 is a pivotal immunoregulatory cytokine with pleiotropic effects on the immune system. IL-10 promoter polymorphisms have been associated with disease susceptibility and the ability to secrete IL-10 in vitro. We suspected that the association of the widely studied -819C/T and -592C/A polymorphisms with the IL-10 production might vary between ethnic groups. Therefore, we examined the association of -819 C/T and -592 C/A promoter polymorphisms with in vitro LPS stimulated secretion of IL-10 in normal healthy Indian volunteers. Methods: Peripheral blood was collected from 103 healthy volunteers and diluted whole blood cultures were set up with 100 ng/ml of LPS as stimulant: supernatant was collected at 24 h and IL-10 levels were assayed by ELISA. Genotyping was done for -819C/T polymorphism in 101 individuals and -592C/A polymorphism in 68 individuals by polymerase chain reaction followed by RFLP. The differences in IL-10 production between the genotypes were analysed by ANOVA. Results: There were 30, 47 and 24 individuals with the CC, CT and TT genotypes with a minor allele (T) frequency of 47% for the -819C/T polymorphism. The CC and TT genotypes at position -819 were strongly associated with CC and AA genotypes at -592 position suggestive of strong linkage disequilibrium. There was no association between the -819 genotype and the in vitro LPS stimulated IL-10 levels. Conclusions: The -819C/T and the -592 C/A polymorphisms of the IL-10 promoter region are not significantly associated with LPS stimulated IL-10 production healthy Indian subjects. Disclosure statement: All authors have declared no conflicts of interes

    Cytokines and inflammatory mediators: 25. Certolizumab Pegol has a Different Profile from the other Anti-TNFS, Including Golimumab, in a Variety of in Vitro Assays

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    Background: Activities of the anti-TNFs, certolizumab pegol (CZP), etanercept (ETA), infliximab (IFX) and adalimumab (ADA), have been compared in a range of in vitro assays. CZP is the only licensed PEGylated Fab' anti-TNF; ETA is a fusion protein with an IgG1 Fc, and IFX and ADA are both antibodies with an IgG1 Fc. Golimumab (GLM) is a monoclonal IgG1 TNF inhibitor recently approved for a number of indications; it is thus of interest to assess the in vitro activity of GLM. In vitro assays previously used were neutralisation of TNF in the L929 bioassay, inhibition of LPS-driven cytokine production by monocytes, induction of apoptosis in activated lymphocytes and monocytes, and induction of neutrophil necrosis. Methods: Neutralisation of human TNF was assessed in the L929 bioassay using a range of concentrations of the anti-TNFs and a fixed concentration of TNF (100 pg/mL). Activity of the anti-TNFs at inhibiting LPS-driven IL-1β secretion by monocytes was assessed by incubating peripheral blood monocytes with various concentrations of the anti-TNF for 1 hour (hr) and then washing the cells. LPS was added for 4 hrs, the supernatants collected and the IL-1β level measured by ELISA. To assess induction of apoptosis, peripheral blood lymphocytes were activated for 2 days with 2 μg/mL CD3/CD28 and monocytes with 300 U/mL IL-4 and GMCSF for 3 days. The effect of the anti-TNFs on apoptosis was assessed by Annexin V staining using flow cytometry 24 hrs later. The effect of the anti-TNFs on neutrophil necrosis was determined by measuring myeloperoxidase release after 12 hrs. An isotype-matched control was used in all assays except the L929 bioassay. Results: IC90 neutralisation activity of the anti-TNFs in the L929 bioassay was 0.3 ng/mL for ETA, 4 ng/mL for GLM, 15 ng/mL for ADA, and 20 ng/mL for IFX, compared with 2.5 ng/mL for CZP. CZP was the most potent inhibitor of LPS-driven IL-1β secretion (IC50 ∼0.1 ng/mL), followed by GLM (20 ng/mL) and IFX (50 ng/mL). GLM, ADA, IFX and ETA induced apoptosis of monocytes and lymphocytes to a similar degree reaching a level of 23% and ∼40% at 100 μg/mL, respectively. CZP caused no increase in apoptosis above the levels seen with the isotype-matched control. In the neutrophil necrosis assay, ADA,IFX and GLM caused ∼70% necrosis at 100 μg/mL, and ETA 48%. CZP did not increase the level of necrosis above the level of the control. Conclusions: Bioactivity of the IgG1 molecules GLM, IFX and ADA in neutralising human TNF was inferior to that of CZP and ETA. CZP, the only PEGylated anti-TNF, had a different profile to the other anti-TNFs as it was the most potent at inhibiting LPS-driven IL-1β production by monocytes, did not induce apoptosis of activated monocytes and lymphocytes, and did not cause neutrophil necrosis. The clinical relevance of these in vitro effects is unknown. Nevertheless, these assays show interesting in vitro differences between the anti-TNFs. Disclosure statement: G.F. and A.N. are employees of UC
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