1,872 research outputs found

    Gas-Filled Phospholipid Nanoparticles Conjugated with Gadolinium Play a Role as a Potential Theragnostics for MR-Guided HIFU Ablation

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    To develop a long-circulating theragnostics, meaning therapeutics and diagnostics for MR-guided HIFU ablation, we designed and prepared Gd-C5F12-phospholipid nanobubbles (PLNs) 30–100 nm in diameter. The biochemical and physical characterization of Gd-C5F12-PLNs were performed. Since Gd-C5F12-PLN-50 (Φ = 50 nm) and Gd-C5F12-PLN-100 (Φ = 100 nm) enhanced the hyperthermal effect of HIFU size- and concentration-dependently in a tissue-mimicking phantom, its circulation, distribution, tumor accumulation and tumor ablation were examined in tumor-bearing mice. The plasma-half life of Gd-C5F12-PLNs was longer than 1.5 hrs. Gd-C5F12-PLNs mainly accumulated in the liver and the spleen, suggesting that they are slowly secreted through the hepatobiliary pathway. Monitored by the T1 signal intensity of MR, Gd-C5F12-PLNs accumulated in tumor tissues for 8 hours in mice. HIFU with Gd-C5F12-PLN-100 showed the increased tumor ablation area as compared with HIFU alone. The results suggest that Gd-C5F12-PLNs exhibit a potential theragnostics for MR-guided HIFU ablation

    Alpha-tocopherol exerts protective function against the mucotoxicity of particulate matter in amphibian and human goblet cells

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    Exposure to particulate matter (PM) in ambient air is known to increase the risk of cardiovascular disorders and mortality. The cytotoxicity of PM is mainly due to the abnormal increase of reactive oxygen species (ROS), which damage cellular components such as DNA, RNA, and proteins. The correlation between PM exposure and human disorders, including mortality, is based on long-term exposure. In this study we have investigated acute responses of mucus-secreting goblet cells upon exposure to PM derived from a heavy diesel engine. To this end, we employed the mucociliary epithelium of amphibian embryos and human Calu-3 cells to examine PM mucotoxicity. Our data suggest that acute exposure to PM significantly impairs mucus secretion and results in the accumulation of mucus vesicles in the cytoplasm of goblet cells. RNA-seq analysis revealed that acute responses to PM exposure significantly altered gene expression patterns; however, known regulators of mucus production and the secretory pathway were not significantly altered. Interestingly, pretreatment with alpha-tocopherol nearly recovered the hyposecretion of mucus from both amphibian and human goblet cells. We believe this study demonstrates the mucotoxicity of PM and the protective function of alpha-tocopherol on mucotoxicity caused by acute PM exposure from heavy diesel engines

    Translational repression of mouse mu opioid receptor expression via leaky scanning

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    Mu opioid receptor (MOR) expression is under temporal and spatial controls, but expression levels of the MOR gene are relatively low in vivo. In addition to transcriptional regulations, upstream AUGs (uAUGs) and open reading frames (uORFs) profoundly affect the translation of the primary ORF and thus the protein levels in several genes. The 5′-untranslated region (UTR) of mouse MOR mRNA contains three uORFs preceding the MOR main initiation codon. In MOR-fused EGFP or MOR promoter/luciferase reporter constructs, mutating each uAUG individually or in combinations increased MOR transient heterologous expression in neuroblastoma NMB and HEK293 cells significantly. Translation of such constructs increased up to 3-fold without altering the mRNA levels if either the third uAUG or both the second and third AUGs were mutated. Additionally, these uAUG-mediated translational inhibitions were independent of their peptide as confirmed by internal mutation analyses in each uORF. Translational studies indicated that protein syntheses were initiated at these uAUG initiation sites, with the third uAUG initiating the highest translation level. These results support the hypothesis that uORFs in mouse MOR mRNA act as negative regulators through a ribosome leaky scanning mechanism. Such leaky scanning resulted in the suppression of mouse MOR under normal conditions

    Hepatitis C Virus NS5B Protein Is a Membrane-Associated Phosphoprotein with a Predominantly Perinuclear Localization

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    AbstractHepatitis C virus NS5B protein is an RNA-dependent RNA polymerase. To investigate the properties and function of this protein, we have expressed the NS5B protein in insect and mammalian cells. NS5B was found to be present as fine speckles in the cytoplasm, particularly concentrated in the perinuclear region, suggesting its association with the nuclear membrane, the endoplasmic reticulum, or the Golgi complex. This conclusion was supported by the biochemical demonstration that NS5B was associated with the membranes in the cells. Furthermore, it was shown that NS5B protein is a phosphoprotein. These properties may be related to its function as an RNA polymerase

    Ginseng Purified Dry Extract, BST204, Improved Cancer Chemotherapy-Related Fatigue and Toxicity in Mice

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    Cancer related fatigue (CRF) is one of the most common side effects of cancer and its treatments. A large proportion of cancer patients experience cancer-related physical and central fatigue so new strategies are needed for treatment and improved survival of these patients. BST204 was prepared by incubating crude ginseng extract with ginsenoside-β-glucosidase. The purpose of the present study was to examine the effects of BST204, mixture of ginsenosides on 5-fluorouracil (5-FU)-induced CRF, the glycogen synthesis, and biochemical parameters in mice. The mice were randomly divided into the following groups: the naïve normal (normal), the HT-29 cell inoculated (xenograft), xenograft and 5-FU treated (control), xenograft + 5-FU + BST204-treated (100 and 200 mg/kg) (BST204), and xenograft + 5-FU + modafinil (13 mg/kg) treated group (modafinil). Running wheel activity and forced swimming test were used for evaluation of CRF. Muscle glycogen, serum inflammatory cytokines, aspartic aminotransferase (AST), alanine aminotransferase (ALT), creatinine (CRE), white blood cell (WBC), neutrophil (NEUT), red blood cell (RBC), and hemoglobin (HGB) were measured. Treatment with BST204 significantly increased the running wheel activity and forced swimming time compared to the control group. Consistent with the behavioral data, BST204 markedly increased muscle glycogen activity and concentrations of WBC, NEUT, RBC, and HGB. Also, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), AST, ALT, and CRE levels in the serum were significantly reduced in the BST204-treated group compared to the control group. This result suggests that BST204 may improve chemotherapy-related fatigue and adverse toxic side effects

    Limits of Binaries That Can Be Characterized by Gravitational Microlensing

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    Due to the high efficiency of planet detections, current microlensing planet searches focus on high-magnification events. High-magnification events are sensitive to remote binary companions as well and thus a sample of wide-separation binaries are expected to be collected as a byproduct. In this paper, we show that characterizing binaries for a portion of this sample will be difficult due to the degeneracy of the binary-lensing parameters. This degeneracy arises because the perturbation induced by the binary companion is well approximated by the Chang-Refsdal lensing for binaries with separations greater than a certain limit. For binaries composed of equal mass lenses, we find that the lens binarity can be noticed up to the separations of 60\sim 60 times of the Einstein radius corresponding to the mass of each lens. Among these binaries, however, we find that the lensing parameters can be determined only for a portion of binaries with separations less than 20\sim 20 times of the Einstein radius.Comment: 5 pages, 3 figures, 1 tabl
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