1,094 research outputs found

    Increased plasma concentration of vascular endothelial growth factor in patients with atopic dermatitis and its relation to disease severity and platelet activation

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    BACKGROUND: Overproduction of vascular endothelial growth factor (VEGF) in atopic dermatitis (AD) lesions has previously been observed. It is also known that platelet is an important source of VEGF and platelet factor 4 (PF-4), a potential marker of AD severity. AIM: To evaluate concentrations of VEGF and its soluble receptors (sVEGF-R1 and sVEGF-R2) in the plasma of AD patients and to examine its possible correlation with disease severity and plasma concentrations of PF-4, a platelet activation marker. METHODS: Plasma concentrations of VEGF and its receptors and levels of PF-4 were measured by an immunoenzymatic assay in 51 AD patients and in 35 healthy non-atopic controls. The severity of the disease was evaluated using the eczema area and severity index. RESULTS: AD patients showed significantly increased VEGF and PF-4 plasma concentrations as compared with the controls. Plasma concentrations of sVEGF-R1 and sVEGF-R2 did not differ between the groups. There were no remarkable correlations between plasma VEGF concentration and disease severity or between VEGF and PF-4 concentration. CONCLUSIONS: This study shows that plasma concentration of VEGF may be increased in patients suffering from AD. It seems that plasma VEGF concentration is not a useful marker of disease severity and, apart from platelets, other cells might also release the cytokine

    MiKlip - a National Research Project on Decadal Climate Prediction

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    A German national project coordinates research on improving a global decadal climate prediction system for future operational use. MiKlip, an eight-year German national research project on decadal climate prediction, is organized around a global prediction system comprising the climate model MPI-ESM together with an initialization procedure and a model evaluation system. This paper summarizes the lessons learned from MiKlip so far; some are purely scientific, others concern strategies and structures of research that targets future operational use. Three prediction-system generations have been constructed, characterized by alternative initialization strategies; the later generations show a marked improvement in hindcast skill for surface temperature. Hindcast skill is also identified for multi-year-mean European summer surface temperatures, extra-tropical cyclone tracks, the Quasi-Biennial Oscillation, and ocean carbon uptake, among others. Regionalization maintains or slightly enhances the skill in European surface temperature inherited from the global model and also displays hindcast skill for wind-energy output. A new volcano code package permits rapid modification of the predictions in response to a future eruption. MiKlip has demonstrated the efficacy of subjecting a single global prediction system to a major research effort. The benefits of this strategy include the rapid cycling through the prediction-system generations, the development of a sophisticated evaluation package usable by all MiKlip researchers, and regional applications of the global predictions. Open research questions include the optimal balance between model resolution and ensemble size, the appropriate method for constructing a prediction ensemble, and the decision between full-field and anomaly initialization. Operational use of the MiKlip system is targeted for the end of the current decade, with a recommended generational cycle of two to three years

    Directed evolution of hydrocarbon-producing enzymes

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    Enzymes capable of catalysing the production of hydrocarbons hold promise for sustainable fuel synthesis. However, the native activities of these enzymes are often insufficient for their exploitation in industrial bioprocesses. Enzyme engineering approaches including directed evolution (DE) can be used to improve the properties of enzymes to meet desirable standards for their industrial application. In this review, we summarise DE methods for engineering hydrocarbon-producing enzymes, including both screening- and selection procedures. The efficacy of DE depends on several factors, including sensitive and accurate detection of enzyme activity, the throughput of screening or selection steps, and the scale of diversity generation. Although DE is a well-established approach, its application in engineering hydrocarbon-producing enzymes has not been widely demonstrated. This can be attributed to the physiochemical properties of the target molecules, such as aliphatic hydrocarbons, which can be insoluble, gaseous, and chemically inert. Detection of these molecules in vivo presents several unique challenges, as does dynamically coupling their abundance to cell fitness. We conclude with a discussion on future directions and potential advancements in this field

    Construction and characterization of MoClo-compatible vectors for modular protein expression in E. coli

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    Cloning methods are fundamental to synthetic biology research. The capability to generate custom DNA constructs exhibiting predictable protein expression levels is crucial to the engineering of biology. Golden Gate cloning, a modular cloning (MoClo) technique, enables rapid and reliable one-pot assembly of genetic parts. In this study, we expand on the existing MoClo toolkits by constructing and characterizing compatible low- (p15A) and medium-copy (pBR322) destination vectors. Together with existing high-copy vectors, these backbones enable a protein expression range covering a 500-fold difference in normalized fluorescence output. We further characterize the expression- and burden profiles of each vector and demonstrate their use for the optimization of growth-coupled enzyme expression. The optimal expression of adhE (encoding alcohol dehydrogenase) for ethanol-dependent growth of Escherichia coli is determined using randomized Golden Gate Assembly, creating a diverse library of constructs with varying expression strengths and plasmid copy numbers. Through selective growth experiments, we show that relatively low expression levels of adhE facilitated optimal growth using ethanol as the sole carbon source, demonstrating the importance of adding low-copy vectors to the MoClo vector repertoire. This study emphasizes the importance of varying vector copy numbers in selection experiments to balance expression levels and burden, ensuring accurate identification of optimal conditions for growth. The vectors developed in this work are publicly available via Addgene (catalog #217582–217609)

    TP53 mutated glioblastoma stem-like cell cultures are sensitive to dual mTORC1/2 inhibition while resistance in TP53 wild type cultures can be overcome by combined inhibition of mTORC1/2 and Bcl-2

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    Background: Glioblastoma is the most malignant tumor of the central nervous system and still lacks effective treatment. This study explores mutational biomarkers of 11 drugs targeting either the RTK/Ras/PI3K, the p53 or the Rb pathway using 25 patient-derived glioblastoma stem-like cell cultures (GSCs). Results: We found that TP53 mutated GSCs were approximately 3.5 fold more sensitive to dual inhibition of mammalian target of rapamycin complex 1 and 2 (mTORC1/2) compared to wild type GSCs. We identified that Bcl-2(Thr56/Ser70) phosphorylation contributed to the resistance of TP53 wild type GSCs against dual mTORC1/2 inhibition. The Bcl-2 inhibitor ABT-263 (navitoclax) increased sensitivity to the mTORC1/2 inhibitor AZD8055 in TP53 wild type GSCs, while sensitivity to AZD8055 in TP53 mutated GSCs remained unchanged. Conclusion: Our data suggest that Bcl-2 confers resistance to mTORC1/2 inhibitors in TP53 wild type GSCs and that combined inhibition of both mTORC1/2 and Bcl-2 is worthwhile to explore further in TP53 wild type glioblastomas, whereas in TP53 mutated glioblastomas dual mTORC1/2 inhibitors should be explored
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