Publications by authors named "Katrin Sommer"

Comprehensive data on the occurrence of sterols in plant oils is currently hardly available since only a few sterols are obtainable as standard compounds. Accordingly, many peaks are rarely labeled in gas chromatograms due to missing or outdated information. This lack of information hampers the progress in sterol research.

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Monocytes, as well as downstream macrophages and dendritic cells, are essential players in the immune system, fulfilling key roles in homeostasis as well as in inflammatory conditions. Conventionally, driven by studies on reporter models, mouse monocytes are categorized into a classical and a non-classical subset based on their inversely correlated surface expression of Ly6C/CCR2 and CX3CR1. Here, we aimed to challenge this concept by antibody staining and reporter mouse models.

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Background: Closing mucosal defects to reach mucosal healing is an important goal of therapy in inflammatory bowel disease (IBD). Among other cells, monocyte-derived macrophages are centrally involved in such intestinal wound healing. We had previously demonstrated that the anti-α4β7 integrin antibody vedolizumab blocks the recruitment of non-classical monocytes as biased progenitors of wound healing macrophages to the gut and delays wound healing.

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Introduction: Macrophages play an important role in intestinal wound healing. However, the trajectories from circulating monocytes to gut macrophages are incompletely understood.

Methods: Taking advantage of mice depleted for non-classical monocytes due to deficiency for the transcription factor Nr4a1, we addressed the relevance of non-classical monocytes for large intestinal wound healing using flow cytometry, in vivo wound healing assays and immunofluorescence.

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The intestinal epithelial barrier is carrying out two major functions: restricting the entry of potentially harmful substances while on the other hand allowing the selective passage of nutrients. Thus, an intact epithelial barrier is vital to preserve the integrity of the host and to prevent development of disease. Vice versa, an impaired intestinal epithelial barrier function is a hallmark in the development and perpetuation of inflammatory bowel disease (IBD).

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Tissue-resident memory T cells (T cells) have crucial functions in host defense in mucosal tissues. They provide local adaptive immune surveillance and allow the fast initiation of targeted adaptive immune responses in case of antigen re-exposure. Recently, an aberrant activation in the case of immunologically mediated diseases has been increasingly acknowledged.

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The increasing demand of valuable truffles ( sp.) has prompted new areas of naturally growing truffles entering the market. Hence, the identification of valueless species is an important task to prevent food fraud.

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Retinal vessels are at least in part involved in clearing of Fc terminus-containing proteins from the vitreous. In vitro, the Fc fusion protein aflibercept is transported through a monolayer of unchallenged immortalized bovine retinal endothelial cells (iBREC), mediated by the neonatal Fc receptor (FcRn), but part of the Fc fusion protein is also degraded. Aflibercept's target VEGF-A not only enhances the permeability of REC by destabilization of tight junctions (TJs) thereby allowing for paracellular flow, it may also lower the intracellular stability of the Fc fusion protein by changing its binding properties to the FcRn.

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Lipid compounds (fatty acids, tocochromanols, phytosterols) are difficult to separate by countercurrent chromatography (CCC) due to the existence of many similar structures and the limited availability of suitable biphasic solvent systems. Here we show that for these compound classes the success of a CCC separation can be directly derived from the chemical structures without the necessity of experimental determinations of K values. In most cases, lipid compounds differ in the total carbon number and the number of double bonds.

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Species of the genus are traditionally used as human food in some of the Asian countries. Therefore, all 11 species of this genus, identified by molecular barcoding, were investigated for ingredients relevant to human nutrition. The total protein content varied between 20 and 30% of the freeze-dry weight, the starch content between 10 and 20%, the fat content between 1 and 5%, and the fiber content was ~25%.

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