966 research outputs found

    Controlled release of human growth hormone fused with a human hybrid Fc fragment through a nanoporous polymer membrane

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    Nanotechnology has been applied to the development of more effective and compatible drug delivery systems for therapeutic proteins. Human growth hormone (hGH) was fused with a hybrid Fc fragment containing partial Fc domains of human IgD and IgG(4) to produce a long-acting fusion protein. The fusion protein, hGH-hyFc, resulted in the increase of the hydrodynamic diameter (ca. 11 nm) compared with the diameter (ca. 5 nm) of the recombinant hGH. A diblock copolymer membrane with nanopores (average diameter of 14.3 nm) exhibited a constant release rate of hGH-hyFc. The hGH-hyFc protein released in a controlled manner for one month was found to trigger the phosphorylation of Janus kinase 2 (JAK2) in human B lymphocyte and to exhibit an almost identical circular dichroism spectrum to that of the original hGH-hyFc, suggesting that the released fusion protein should maintain the functional and structural integrity of hGH. Thus, the nanoporous release device could be a potential delivery system for the long-term controlled release of therapeutic proteins fused with the hybrid Fc fragment.X111313sciescopu

    Stemness and chemoresistance in epithelial ovarian carcinoma cells under shear stress

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    One of greatest challenges to the successful treatment of cancer is drug resistance. An exciting approach is the eradication of cancer stem cells (CSCs). However, little is known about key signals regulating the formation and expansion of CSCs. Moreover, lack of a reliable predictive preclinical model has been a major obstacle to discover new cancer drugs and predict their clinical activity. Here, in ovarian cancer, a highly chemoresistant tumor that is rapidly fatal, we provide the first evidence demonstrating the causal involvement of mechanical stimulus in the CSC phenotype using a customizable microfluidic platform and three-dimensional spheroids, which most closely mimic tumor behavior. We found that ovarian cancer cells significantly acquired the expression of epithelial-to-mesenchymal transition and CSC markers and a remarkable chemoresistance to clinically relevant doses of frontline chemotherapeutic drugs cisplatin and paclitaxel when grown under fluid shear stress, which corroborates with the physiological attainable levels in the malignant ascites, but not under static condition. Furthermore, we uncovered a new link of microRNA-199a-3p, phosphatidylinositol 3-kinase/Akt, and multidrug transporter activation in shear stress-induced CSC enrichment. Our findings shed new light on the significance of hydrodynamics in cancer progression, emphasizing the need of a flow-informed framework in the development of therapeutics

    The Kinematics of Quasar Broad Emission Line Regions Using a Disk-Wind Model

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    The structure and kinematics of the broad line region in quasars are still unknown. One popular model is the disk-wind model that offers a geometric unification of a quasar based on the viewing angle. We construct a simple kinematical disk-wind model with a narrow outflowing wind angle. The model is combined with radiative transfer in the Sobolev, or high velocity, limit. We examine how angle of viewing affects the observed characteristics of the emission line. The line profiles were found to exhibit distinct properties depending on the orientation, wind opening angle, and region of the wind where the emission arises. At low inclination angle (close to face-on), we find that the shape of the emission line is asymmetric, narrow, and significantly blueshifted. As the inclination angle increases (close to edge-on), the line profile becomes more symmetric, broader, and less blueshifted. Additionally, lines that arise close to the base of the disk wind, near the accretion disk, tend to be broad and symmetric. Single-peaked line profiles are recovered for the intermediate and equatorial wind. The model is also able to reproduce a faster response in either the red or blue sides of the line profile, consistent with reverberation mapping studies.NFB thanks the STFC for support under Ernest Rutherford Grant ST/M003914/1

    Genomic and Resistome Analyses of <em>Elizabethkingia anophelis</em> Strain B2D isolated from Dental Plaque of Patient

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    \ua9 2024, HH Publisher. All rights reserved.In this study, strain B2D isolated from a dental plaque sample of a human patient was studied for its general characteristics, taxonomic identification, genome features, and resistome profile. The bacterium exhibited antibiotic resistance to all beta-lactam antibiotics, nitrofuran, and sulfonamides, with high minimum inhibitory concentrations. It was only sensitive to the fluoroquinolone ciprofloxacin and intermediately susceptible to aminoglycoside tobramycin. A preliminary identification through 16S rRNA gene sequences revealed that it shared the highest sequence identity with Elizabethkingia anophelis subsp. endophytica JM-87T (100%) and Elizabethkingia anophelis subsp. anophelis R26T (99.31%). The draft genome of strain B2D was approximately 3.9 Mbp with 50 contigs and 35.5% GC content. A 16S rRNA gene and core genes-based phylogenetic analyses revealed a close phylogenetic relationship between strain B2D and the other Elizabethkingia type strains. An above species level threshold average nucleotide identity value confirmed its taxonomic identity as Elizabethkingia anophelis. Furthermore, we conducted a resistome analysis of strain B2D and Elizabethkingia type strains, revealing the presence of widespread antibiotic resistance genes, including beta-lactamases and genes associated with cationic antiseptic resistance and glycopeptide resistance. Overall, the multidrug resistant profile of strain B2D as elucidated and confirmed through whole genome analysis indicated its potential as a reservoir of beta-lactamase genes. Moreover, its presence within dental plaque in the human oral cavity prompts speculation regarding its role as an opportunistic pathogen capable of causing infections, particularly in immunocompromised individuals

    The patatin-containing phospholipase A pPLAIIα modulates oxylipin formation and water loss in Arabidopsis thaliana

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    The patatin-related phospholipase A (pPLA) hydrolyzes membrane glycerolipids to produce monoacyl compounds and free fatty acids. Phospholipids are cleaved by pPLAIIα at the sn-1 and sn-2 positions, and galactolipids, including those containing oxophytodienoic acids, can also serve as substrates. Ablation of pPLAIIα decreased lysophosphatidylcholine and lysophosphatidylethanolamine levels, but increased free linolenic acid. pPLAIIα-deficient plants displayed a higher level of jasmonic acid and methyl jasmonate, as well as the oxylipin-biosynthetic intermediates 13-hydroperoxylinolenic acid and 12-oxophytodienoic acid than wild-type plants. The expression of genes involved in oxylipin production was also higher in the pPLAIIα-deficient mutant than in wild-type plants. The mutant plants lost water faster than wild type plants did. The stomata of wild type and mutant plants responded similarly to abscisic acid. In response to desiccation, the mutant and wild type leaves produced abscisic acid at the same rate, but after 4 h of desiccation, the jasmonic acid level was much higher in mutant than wild-type leaves. These results indicate that pPLAIIα negatively regulates oxylipin production and suggest a role in the removal of oxidatively modified fatty acids from membranes

    The Combination of RAD001 and NVP-BEZ235 Exerts Synergistic Anticancer Activity against Non-Small Cell Lung Cancer In Vitro and In Vivo

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    The phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) signaling axis has emerged as a novel target for cancer therapy. Agents that inhibit PI3K, mTOR or both are currently under development. The mTOR allosteric inhibitor, RAD001, and the PI3K/mTOR dual kinase inhibitor, BEZ235, are examples of these agents. We were interested in developing strategies to enhance mTOR-targeted caner therapy. In this study, we found that BEZ235 alone effectively inhibited the growth of rapamycin-resistant cancer cells. Interestingly, the combination of sub-optimal concentrations of RAD001 and BEZ235 exerted synergistic inhibition of the growth of human lung cancer cells along with induction of apoptosis and G1 arrest. Furthermore, the combination was also more effective than either agent alone in inhibiting the growth of lung cancer xenografts in mice. The combination showed enhanced effects on inhibiting mTOR signaling and reducing the expression of c-Myc and cyclin D1. Taken together, our results suggest that the combination of RAD001 and BEZ235 is a novel strategy for cancer therapy

    Deep learning enables spatial mapping of the mosaic microenvironment of myeloma bone marrow trephine biopsies

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    Bone marrow trephine biopsy is crucial for the diagnosis of multiple myeloma. However, the complexity of bone marrow cellular, morphological, and spatial architecture preserved in trephine samples hinders comprehensive evaluation. To dissect the diverse cellular communities and mosaic tissue habitats, we developed a superpixel-inspired deep learning method (MoSaicNet) that adapts to complex tissue architectures and a cell imbalance aware deep learning pipeline (AwareNet) to enable accurate detection and classification of rare cell types in multiplex immunohistochemistry images. MoSaicNet and AwareNet achieved an area under the curve of &amp;gt;0.98 for tissue and cellular classification on separate test datasets. Application of MoSaicNet and AwareNet enabled investigation of bone heterogeneity and thickness as well as spatial histology analysis of bone marrow trephine samples from monoclonal gammopathies of undetermined significance (MGUS) and from paired newly diagnosed and post-treatment multiple myeloma. The most significant difference between MGUS and newly diagnosed multiple myeloma (NDMM) samples was not related to cell density but to spatial heterogeneity, with reduced spatial proximity of BLIMP1+ tumor cells to CD8+ cells in MGUS compared with NDMM samples. Following treatment of multiple myeloma patients, there was a reduction in the density of BLIMP1+ tumor cells, effector CD8+ T cells, and T regulatory cells, indicative of an altered immune microenvironment. Finally, bone heterogeneity decreased following treatment of MM patients. In summary, deep-learning based spatial mapping of bone marrow trephine biopsies can provide insights into the cellular topography of the myeloma marrow microenvironment and complement aspirate-based techniques
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