535 research outputs found

    NTIRE 2023 Quality Assessment of Video Enhancement Challenge

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    This paper reports on the NTIRE 2023 Quality Assessment of Video Enhancement Challenge, which will be held in conjunction with the New Trends in Image Restoration and Enhancement Workshop (NTIRE) at CVPR 2023. This challenge is to address a major challenge in the field of video processing, namely, video quality assessment (VQA) for enhanced videos. The challenge uses the VQA Dataset for Perceptual Video Enhancement (VDPVE), which has a total of 1211 enhanced videos, including 600 videos with color, brightness, and contrast enhancements, 310 videos with deblurring, and 301 deshaked videos. The challenge has a total of 167 registered participants. 61 participating teams submitted their prediction results during the development phase, with a total of 3168 submissions. A total of 176 submissions were submitted by 37 participating teams during the final testing phase. Finally, 19 participating teams submitted their models and fact sheets, and detailed the methods they used. Some methods have achieved better results than baseline methods, and the winning methods have demonstrated superior prediction performance

    MAPK-activated transcription factor PxJun suppresses PxABCB1 expression and confers resistance to Bacillus thuringiensis Cry1Ac toxin in Plutella xylostella (L.)

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    Deciphering the molecular mechanisms underlying insect resistance to Cry toxins produced by Bacillus thuringiensis (Bt) is pivotal for the sustainable utilization of Bt biopesticides and transgenic Bt crops. Previously, we identified that MAPK-mediated reduced expression of the PxABCB1 gene is associated with Bt Cry1Ac resistance in the diamondback moth, Plutella xylostella (L.). However, the underlying transcriptional regulation mechanism remains enigmatic. Herein, the PxABCB1 promoter in Cry1Ac-susceptible and Cry1Ac-resistant P. xylostella strains was cloned and analyzed and found to contain a putative Jun binding site (JBS). A dual-luciferase reporter assay and yeast one-hybrid assay (Y1H) demonstrated that the transcription factor PxJun repressed PxABCB1 expression by interacting with this JBS. The expression levels of PxJun were increased in the midguts of all resistant strains compared to the susceptible strain. Silencing of PxJun expression significantly elevated PxABCB1 expression and Cry1Ac susceptibility in the resistant NIL-R strain, and silencing of PxMAP4K4 expression decreased PxJun expression and also increased PxABCB1 expression. These results indicate that MAPK-activated PxJun suppresses PxABCB1 expression to confer Cry1Ac resistance in P. xylostella, deepening our understanding of the transcriptional regulation of midgut Cry receptor genes and the molecular basis of insect resistance to Bt Cry toxins.ImportanceThe transcriptional regulation mechanisms underlying reduced expression of Bt toxin receptor genes in Bt-resistant insects remain elusive. This study unveils that a transcription factor PxJun activated by the MAPK signaling pathway represses PxABCB1 expression and confers Cry1Ac resistance in P. xylostella Our results provide new insights into the transcriptional regulation mechanisms of midgut Cry receptor genes and deepen our understanding of the molecular basis of insect resistance to Bt Cry toxins. To our knowledge, this study identified the first transcription factor that can be involved in the transcriptional regulation mechanisms of midgut Cry receptor genes in Bt-resistant insects

    Synthesis of a Dual Functional Anti-MDR Tumor Agent PH II-7 with Elucidations of Anti-Tumor Effects and Mechanisms

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    Multidrug resistance mediated by P-glycoprotein in cancer cells has been a major issue that cripples the efficacy of chemotherapy agents. Aimed for improved efficacy against resistant cancer cells, we designed and synthesized 25 oxindole derivatives based on indirubin by structure-activity relationship analysis. The most potent one was named PH II-7, which was effective against 18 cancer cell lines and 5 resistant cell lines in MTT assay. It also significantly inhibited the resistant xenograft tumor growth in mouse model. In cell cycle assay and apoptosis assay conducted with flow cytometry, PH II-7 induced S phase cell cycle arrest and apoptosis even in resistant cells. Consistently revealed by real-time PCR, it modulates the expression of genes related to the cell cycle and apoptosis in these cells, which may contributes to its efficacy against them. By side-chain modification and FITC-labeling of PH II-7, we were able to show with confocal microscopy that not only it was not pumped by P-glycoprotein, it also attenuated the efflux of Adriamycin by P-glycoprotein in MDR tumor cells. Real-time PCR and western blot analysis showed that PH II-7 down-regulated MDR1 gene via protein kinase C alpha (PKCA) pathway, with c-FOS and c-JUN as possible mediators. Taken together, PH II-7 is a dual-functional compound that features both the cytotoxicity against cancer cells and the inhibitory effect on P-gp mediated drug efflux

    Overexpression of Cell Surface Cytokeratin 8 in Multidrug-Resistant MCF-7/MX Cells Enhances Cell Adhesion to the Extracellular Matrix1

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    Accumulating evidence suggests that multiple complex mechanisms may be involved, simultaneously or complementarily, in the emergence and development of multidrug resistance (MDR) in various cancers. Cell adhesion-mediated MDR is one such mechanism. In the present study, we initially observed increased cell adhesion to extracellular matrix proteins by the MDR human breast tumor cell line MCF-7/MX compared to its parental cells. We then used a strategy that combined antibody-based screening technique and mass spectrometry-based proteomics to identify membrane proteins that contribute to the enhanced adhesion of MCF-7/MX cells. Using MCF-7/MX cells as immunogen, we isolated a mouse monoclonal antibody, 9C6, that preferentially reacts with MCF-7/MX cells over the parental MCF-7 cells. The molecular target of 9C6 was identified as cytokeratin 8 (CK8), which was found to be overexpressed on the cell surface of MCF-7/MX cells. We further observed that down-regulation of cell surface levels of CK8 through siRNA transfection significantly inhibited MCF-7/MX cell adhesion to fibronectin and vitronectin. In addition, anti-CK8 siRNA partially reversed the MDR phenotype of MCF-7/MX cells. Taken together, our results suggest that alterations in the expression level and cellular localization of CK8 may play a significant role in enhancing the cellular adhesion of MDR MCF-7/MX cells

    Efficient Inhibition of Human B-cell Lymphoma in SCID Mice by Synergistic Antitumor Effect of Human 4-1BB Ligand/Anti-CD20 Fusion Proteins and Anti-CD3/Anti-CD20 Diabodies

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    Here we constructed and produced a recombinant human 4-1BB ligand (4-1BBL)/anti-CD20 fusion protein and examined its antitumor activity, alone and in combination with an anti-CD3/anti-CD20 bispecific diabody. The 4-1BBL/anti-CD20 fusion protein retained both the costimulatory activity of 4-1BBL on T cells and the tumor targeting ability of CD20 antibody on B cells. The fusion protein bound as efficiently to 4-1BB-and CD20-positive cells as its respective parental antibodies, and was capable of cross-linking human T lymphocytes and CD20-positive tumor cells. Combination treatment with 4-1BBL/anti-CD20 fusion protein and anti-CD3/anti-CD20 diabody led to significantly increased T-cell cytotoxicity to human B-lymphoma cells in vitro and drastically more potent tumor inhibitory activity in vivo in xenografted B-cell lymphoma in severe combined immunodeficiency disease mice. Mechanistic studies revealed that the combination treatment remarkably inhibited apoptosis of human peripheral blood lymphocytes, accompanied by upregulation of Bcl-X-L and Bf1-1, perforin and granzyme B mRNA, and increased interleukin-2 production. Taken together, these results suggest that targeted delivery of 4-1BBL to the tumor site, when combined with anti-CD3/anti-CD20 diabody, could strongly potentiate the antitumor activity of the diabody, thus may have significant clinical application in the treatment of human CD20-positive B-cell malignancies

    Separation and structural elucidation of a novel vardenafil analogue as an adulterant in a natural health care dietary supplement

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    A novel vardenafil analogue was identified in dietary supplement as an adulterant in herbal formulations. The structure of this analogue was elucidated using HRMS, NMR after extraction from the pulverized powder. It was named morphardenafil as a morpholine ring has replaced the N-ethyl piperazine ring in vardenafil. A tablet of this dietary supplement contained about 50Β mg of unspecified morphardenafil, which is 2.5 – 20-times the prescriptive dosage of Levetra, the commercial formulation of the vardenafil monohydrochloride salt in the market and probably places unwary consumers at risk for potentially serious adverse effects or drug-drug interaction (DDI)
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