Zobrazení zdroje stránky Hildebrandtbruhn1610

The respiratory tract is tasked with responding to a constant and vast influx of foreign agents. It acts as an important first line of defense in the innate immune system and as such plays a crucial role in preventing the entry of invading pathogens. While physical barriers like the mucociliary escalator exert their effects through the clearance of these pathogens, diverse and dynamic cellular mechanisms exist for the activation of the innate immune response through the recognition of pathogen-associated molecular patterns (PAMPs). These PAMPs are recognized by pattern recognition receptors (PRRs) that are expressed on a number of myeloid cells such as dendritic cells, macrophages, and neutrophils found in the respiratory tract. C-type lectin receptors (CLRs) are PRRs that play a pivotal role in the innate immune response and its regulation to a variety of respiratory pathogens such as viruses, bacteria, and fungi. This chapter will describe the function of both activating and inhibiting myeloid CLRs in the recognition of a number of important respiratory pathogens as well as the signaling events initiated by these receptors.C-type lectin receptors (CLRs) are a family of transmembrane proteins having at least one C-type lectin-like domain (CTLD) on the cell surface and either a short intracellular signaling tail or a transmembrane domain that facilitates interaction with a second protein, often the Fc receptor common gamma chain (FcRγ), that mediates signaling. Many CLRs directly recognize microbial cell walls and influence innate immunity by activating inflammatory and antimicrobial responses in phagocytes. In this review, we examine the contributions of certain CLRs to activation and regulation of phagocytosis in cells such as macrophages, dendritic cells and neutrophils.PURPOSE The WHO classification for IDH-mutant grade II and grade III astrocytoma may not be as prognostically meaningful as expected. We aimed to develop a novel classification system based on the DNA damage response signature. METHODS We developed the gene signature of DNA damage response with 115 samples from The Cancer Genome Atlas (TCGA) database. [https://www.selleckchem.com/products/hdm201.html find more] The dataset from Chinese Glioma Genome Atlas (CGGA) database with 41 samples was used as the validation set. Lasso Cox regression model was applied for selection of the best signature. Gene set enrichment analysis (GSEA) and gene ontology (GO) analysis were implemented to reveal its biological phenotype. RESULTS A two-gene DNA damage response signature (RAD18, MSH2) was developed using the lasso Cox regression model based on the TCGA dataset. Its prognostic efficiency was validated in the CGGA cohort. The result of Cox regression analysis showed that the signature has a better predictive accuracy than the WHO grade. The risk score was an independent prognostic factor for the overall survival of the IDH-mutant grade II and grade III astrocytoma. GSEA and GO analysis confirmed enhanced processes related to DNA damage response in high-risk group. CONCLUSION We developed a two-gene signature which can effectively predict the prognosis of patients with IDH-mutant grade II and grade III astrocytoma. It suggests a novel classification of astrocytoma with better prognostic accuracy based on the expression of DNA damage response genes.A new bilayer chiral stationary phase for use in open tubular capillary electrochromatography (OT-CEC) system is described. Gold nanoparticles were modified with L-cysteine, with a tetramethylammonium lactobionate ionic liquid that acts as the chiral selector. The gold nanoparticle-coated column provides good enantioseparation and favorable reproducibility. Compared with an uncoated separation system, the column developed displays improved separation of the racemic β-blockers propranolol, esmolol, bisoprolol and sotalol (resolutions of enotiomers are 6.29, 6.11, 6.12 and 6.02, respectively). The materials and coatings were characterized by scanning electron microscopy and transmission electron microscopy. The main driving forces (CEC and electro-osmotic flow) were studied to evaluate the variation of the immobilized columns. The effects of buffer pH value, concentration of chiral selector, type of organic modifier and applied voltage were optimized. Satisfactory relative standard deviations were achieved in run-to-run, day-to-day and column-to-column experiments. Graphical abstractSchematic preparation of a capillary column with bilayer chiral selectors coated gold nanoparticles. This novel OT-CEC system was applied for separation of four basic racemic β-blockers.In this work, novel silver sulphide quantum dots (Ag2S QD) are electrochemically quantified for the first time. The method is based on the electrochemical reduction of Ag+ to Ag0 at -0.3&nbsp;V on screen-printed carbon electrodes (SPCEs), followed by anodic stripping voltammetric oxidation that gives a peak of currents at +0.06&nbsp;V which represents the analytical signal. The optimized methodology allows the quantification of water-stabilized Ag2S QD in the range of approximately 2 × 109-2 × 1012 QD·mL-1 with a good reproducibility (RSD 5%). Moreover, as proof-of-concept of relevant biosensing application, Ag2S QD are evaluated as tags for Escherichia coli (E. coli) bacteria determination. Bacteria tagged with QD are separated by centrifugation from the sample solution and placed on the SPCE surface for quantitative analysis. The effect of two different Ag2S QD surface coating/stabilizing agents on both the voltammetric response and the bacteria sensing is also evaluated. 3-mercaptopropionic acid (3-MPA) is studied as model of short length coating ligand with no affinity for the bacteria, while boronic acid (BA) is evaluated as longer length ligand with chemical affinity for the polysaccharides present in the peptidoglycan layer on the bacteria cells surface. The biosensing system allows to detect bacteria in the range 10-1-103 bacteria·mL-1 with a limit of detection as low as 1 bacteria·mL-1.&nbsp;This methodology is a promising proof-of-concept alternative to traditional laboratory-based tests, with good sensitivity and short time and low cost of analysis. Graphical abstractNovel silver sulphide quantum dots (Ag2S QD) are electrochemically quantified for the first time. Moreover, Ag2S QD are evaluated as tags for Escherichia coli bacteria determination. The effect of two different QD surface coating ligands is also evaluated.