871 research outputs found

    Tolfenamic Acid Induces Apoptosis and Growth Inhibition in Head and Neck Cancer: Involvement of NAG-1 Expression

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    Nonsteroidal anti-inflammatory drug-activated gene-1 (NAG-1) is induced by nonsteroidal anti-inflammatory drugs and possesses proapoptotic and antitumorigenic activities. Although tolfenamic acid (TA) induces apoptosis in head and neck cancer cells, the relationship between NAG-1 and TA has not been determined. This study investigated the induction of apoptosis in head and neck cancer cells treated by TA and the role of NAG-1 expression in this induction. TA reduced head and neck cancer cell viability in a dose-dependent manner and induced apoptosis. The induced apoptosis was coincident with the expression of NAG-1. Overexpression of NAG-1 enhanced the apoptotic effect of TA, whereas suppression of NAG-1 expression by small interfering RNA attenuated TA-induced apoptosis. TA significantly inhibited tumor formation as assessed by xenograft models, and this result accompanied the induction of apoptotic cells and NAG-1 expression in tumor tissue samples. Taken together, these results demonstrate that TA induces apoptosis via NAG-1 expression in head and neck squamous cell carcinoma, providing an additional mechanistic explanation for the apoptotic activity of TA

    INTERPARTICLE POTENTIAL OF 10 NANOMETER TITANIUM NANOPARTICLES IN LIQUID SODIUM: THEORETICAL APPROACH

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    A suspension of titanium nanoparticles (Ti NPs) in liquid sodium (Na) has been proposed as a method to mitigate the violent sodium-water reaction (SWR). The interparticle potential between Ti NPs in liquid Na may play a significant role in the agglomeration of NPs on the reaction surface and in the bulk liquid Na, since the potential contributes to a reduction in the long-term dispersion stability. For the effective control of the SWR with NPs, a physical understanding of the molecular dynamics of NPs in liquid Na is key. Therefore in this study, the nonretarded Van der Waals model and the solvation potential model are employed to analyze the interparticle potential. The ab initio calculation reveals that a strong repulsive force driven by the solvation potential exceeds the interparticle attraction and predicts the agglomeration energy required for two 10-nm Ti NPs to be 4 x 10(-17) J. The collision theory suggests that Ti NPs can be effective suppressors of the SWR due to the high energy barrier that prevents significant agglomeration of Ti NPs in quiescent liquid Na. Copyright (C) 2015, Published by Elsevier Korea LLC on behalf of Korean Nuclear Society.110Ysciescopu

    Microstructure-dependent DC set switching behaviors of Ge-Sb-Te-based phase-change random access memory devices accessed by in situ TEM

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    Phase-change random access memory (PCRAM) is one of the most promising nonvolatile memory devices. However, inability to secure consistent and reliable switching operations in nanometer-scale programing volumes limits its practical use for highdensity applications. Here, we report in situ transmission electron microscopy investigation of the DC set switching of Ge-Sb-Te (GST)-based vertical PCRAM cells. We demonstrate that the microstructure of GST, particularly the passive component surrounding the dome-shaped active switching volume, plays a critical role in determining the local temperature distribution and is therefore responsible for inconsistent cell-to-cell switching behaviors. As demonstrated by a PCRAM cell with a highly crystallized GST matrix, the excessive Joule heat can cause melting and evaporation of the switching volume, resulting in device failure. The failure occurred via two-step void formation due to accelerated phase separation in the molten GST by the polaritydependent atomic migration of constituent elements. The presented real-time observations contribute to the understanding of inconsistent switching and premature failure of GST-based PCRAM cells and can guide future design of reliable PCRAM.1176Ysciescopu

    A rapid, efficient, and facile solution for dental hypersensitivity: The tannin–iron complex

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    Dental hypersensitivity due to exposure of dentinal tubules under the enamel layer to saliva is a very popular and highly elusive technology priority in dentistry. Blocking water flow within exposed dentinal tubules is a key principle for curing dental hypersensitivity. Some salts used in "at home" solutions remineralize the tubules inside by concentrating saliva ingredients. An "in-office" option of applying dense resin sealants on the tubule entrance has only localized effects on well-defined sore spots. We report a self-assembled film that was formed by facile, rapid (4 min), and efficient (approximately 0.5 g/L concentration) dip-coating of teeth in an aqueous solution containing a tannic acid-iron(III) complex. It quickly and effectively occluded the dentinal tubules of human teeth. It withstood intense tooth brushing and induced hydroxyapatite remineralisation within the dentinal tubules. This strategy holds great promise for future applications as an effective and user-friendly desensitizer for managing dental hypersensitivity.111310Ysciescopu

    Assimilating Seizure Dynamics

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    Observability of a dynamical system requires an understanding of its state—the collective values of its variables. However, existing techniques are too limited to measure all but a small fraction of the physical variables and parameters of neuronal networks. We constructed models of the biophysical properties of neuronal membrane, synaptic, and microenvironment dynamics, and incorporated them into a model-based predictor-controller framework from modern control theory. We demonstrate that it is now possible to meaningfully estimate the dynamics of small neuronal networks using as few as a single measured variable. Specifically, we assimilate noisy membrane potential measurements from individual hippocampal neurons to reconstruct the dynamics of networks of these cells, their extracellular microenvironment, and the activities of different neuronal types during seizures. We use reconstruction to account for unmeasured parts of the neuronal system, relating micro-domain metabolic processes to cellular excitability, and validate the reconstruction of cellular dynamical interactions against actual measurements. Data assimilation, the fusing of measurement with computational models, has significant potential to improve the way we observe and understand brain dynamics

    Sphingosine 1-phosphate receptor 4 promotes nonalcoholic steatohepatitis by activating NLRP3 inflammasome

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    BACKGROUND & AIMS: Sphingosine 1-phosphate receptors (S1PRs) are a group of G-protein-coupled receptors that confer a broad range of functional effects in chronic inflammatory and metabolic diseases. S1PRs also may mediate the development of nonalcoholic steatohepatitis (NASH), but the specific subtypes involved and the mechanism of action are unclear. METHODS: We investigated which type of S1PR isoforms is activated in various murine models of NASH. The mechanism of action of S1PR4 was examined in hepatic macrophages isolated from high-fat, high-cholesterol diet (HFHCD)-fed mice. We developed a selective S1PR4 functional antagonist by screening the fingolimod (2-amino-2-[2-(4- n-octylphenyl)ethyl]-1,3-propanediol hydrochloride)-like sphingolipid-focused library. RESULTS: The livers of various mouse models of NASH as well as hepatic macrophages showed high expression of S1pr4. Moreover, in a cohort of NASH patients, expression of S1PR4 was 6-fold higher than those of healthy controls. S1pr4(++/-) mice were protected from HFHCD-induced NASH and hepatic fibrosis without changes in steatosis. S1pr4 depletion in hepatic macrophages inhibited lipopolysaccharide-mediated Ca++ release and deactivated the Nod-like receptor pyrin domaincontainning protein 3 (NLRP3) inflammasome. S1P increased the expression of S1pr4 in hepatic macrophages and activated NLRP3 inflammasome through inositol trisphosphate/inositol trisphosphate-receptor-dependent [Ca++] signaling. To further clarify the biological function of S1PR4, we developed SLB736, a novel selective functional antagonist of SIPR4. Similar to S1pr4(+/-) mice, administration of SLB736 to HFHCD-fed mice prevented the development of NASH and hepatic fibrosis, but not steatosis, by deactivating the NLRP3 inflammasome. CONCLUSIONS: S1PR4 may be a new therapeutic target for NASH that mediates the activation of NLRP3 inflammasome in hepatic macrophages

    Gene expression profile of the skin in the 'hairpoor' (HrHp) mice by microarray analysis

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    <p>Abstract</p> <p>Background</p> <p>The transcriptional cofactor, Hairless (HR), acts as one of the key regulators of hair follicle cycling; the loss of function mutations is the cause of the expression of the hairless phenotype in humans and mice. Recently, we reported a new <it>Hr </it>mutant mouse called 'Hairpoor' (<it>Hr<sup>Hp</sup></it>). These mutants harbor a gain of the function mutation, T403A, in the <it>Hr </it>gene. This confers the overexpression of HR and <it>Hr<sup>Hp </sup></it>is an animal model of Marie Unna hereditary hypotrichosis in humans. In the present study, the expression profile of <it>Hr<sup>Hp</sup>/Hr<sup>Hp </sup></it>skin was investigated using microarray analysis to identify genes whose expression was affected by the overexpression of HR.</p> <p>Results</p> <p>From 45,282 mouse probes, differential expressions in 43 (>2-fold), 306 (>1.5-fold), and 1861 genes (>1.2-fold) in skin from <it>Hr<sup>Hp</sup>/Hr<sup>Hp </sup></it>mice were discovered and compared with skin from wild-type mice. Among the 1861 genes with a > 1.2-fold increase in expression, further analysis showed that the expression of eight genes known to have a close relationship with hair follicle development, ascertained by conducting real-time PCR on skin RNA produced during hair follicle morphogenesis (P0-P14), indicated that four genes, <it>Wif1</it>, <it>Casp14</it>, <it>Krt71</it>, and <it>Sfrp1</it>, showed a consistent expression pattern with respect to HR overexpression in vivo.</p> <p>Conclusion</p> <p><it>Wif1 </it>and <it>Casp14 </it>were found to be upregulated, whereas <it>Krt71 </it>and <it>Sfrp1 </it>were downregulated in cells overexpressing HR in transient transfection experiments on keratinocytes, suggesting that HR may transcriptionally regulate these genes. Further studies are required to understand the mechanism of this regulation by the HR cofactor.</p

    Structured cost analysis of robotic TME resection for rectal cancer:a comparison between the da Vinci Si and Xi in a single surgeon's experience

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    Background: Robotic-assisted surgery by the da Vinci Si appears to benefit rectal cancer surgery in selected patients, but still has some limitations, one of which is its high costs. Preliminary studies have indicated that the use of the new da Vinci Xi provides some added advantages, but their impact on cost is unknown. The aim of the present study is to compare surgical outcomes and costs of rectal cancer resection by the two platforms, in a single surgeon’s experience. Methods: From April 2010 to April 2017, 90 robotic rectal resections were performed, with either the da Vinci Si (Si-RobTME) or the da Vinci Xi (Xi-RobTME). Based on CUSUM analysis, two comparable groups of 40 consecutive Si-RobTME and 40 consecutive Xi-RobTME were obtained from the prospectively collected database and used for the present retrospective comparative study. Data costs were analysed based on the level of experience on the proficiency–gain curve (p–g curve) by the surgeon with each platform. Results: In both groups, two homogeneous phases of the p–g curve were identified: Si1 and Xi1: cases 1–19, Si2 and Xi2: cases 20–40. A significantly higher number of full RAS operations were achieved in the Xi-RobTME group (p &lt; 0.001). A statistically significant reduction in operating time (OT) during Si2 and Xi2 phase was observed (p &lt; 0.001), accompanied by reduced overall variable costs (OVC), personnel costs (PC) and consumable costs (CC) (p &lt; 0.001). All costs were lower in the Xi2 phase compared to Si2 phase: OT 265 versus 290&nbsp;min (p = 0.052); OVC 7983 versus 10231.9 (p = 0.009); PC 1151.6 versus 1260.2 (p = 0.052), CC 3464.4 versus 3869.7 (p &lt; 0.001). Conclusions: Our experience confirms a significant reduction of costs with increasing surgeon’s experience with both platforms. However, the economic gain was higher with the Xi with shorter OT, reduced PC and CC, in addition to a significantly larger number of cases performed by the fully robotic approach
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