1,720 research outputs found

    15-Keto prostaglandin E2 induces heme oxygenase-1 expression through activation of Nrf2 in human colon epithelial CCD 841 CoN cells

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    Prostaglandin E-2 (PGE(2)) plays a key role in inflammation-associated carcinogenesis. NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes the oxidation of the 15(S)-hydroxyl group of PGE(2) to generate 15-keto PGE(2). 15-PGDH has been known as a tumor suppressor in various malignancies including colon cancer. However, the molecular mechanisms underlying the tumor-suppressive function of 15-PGDH remain largely unresolved. In this study, we found that 15-keto PGE(2) upregulated the expression of heme oxygenase-1 (HO-1), a representative antioxidative and anti-inflammatory enzyme, at both transcriptional and translational levels, in human colon epithelial CCD 841 CoN cells. A redox-sensitive transcription factor, NF-E2-related factor (Nrf2) plays a critical role in the regulation of HO-1 and other cytoprotective proteins. 15-Keto PGE(2) induced translocation of Nrf2 into the nucleus and antioxidant response element-driven luciferase activity. Furthermore, the silencing of the Nrf2 gene abolished 15-keto PGE(2)-induced HO-1 expression in CCD 841 CoN cells. 15-Keto PGE(2) activated AKT signaling, and the pharmacological AKT inhibitor, LY294002 suppressed the 15-keto PGE(2)-induced HO-1 expression. 15-Keto PGE(2) generates the reactive oxygen species which is suppressed by the general antioxidant N-acetyl-L-cysteine. N-acetyl-L-cysteine treatment attenuated the 15-keto PGE(2)-induced phosphorylation of GSK3 beta, transcriptional activity of Nrf2, and subsequently HO-1 expression. However, 13,14-dihydro-15-keto PGE(2) lacking the alpha,beta-unsaturated carbonyl moiety failed to induce intracellular production of reactive oxygen species, HO-1 expression and nuclear translocation of Nrf2. In conclusion, 15-keto PGE(2) induces HO-1 expression through Nrf2 activation in human colon epithelial cells.

    Moment-Fourier approach to ion parallel fluid closures and transport for a toroidally confined plasma

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    A general method of solving the drift kinetic equation is developed for an axisymmetric magnetic field. Expanding a distribution function in general moments a set of ordinary differential equations are obtained. Successively expanding the moments and magnetic-field involved quantities in Fourier series, a set of linear algebraic equations is obtained. The set of full (Maxwellian and non-Maxwellian) moment equations is solved to express the density, temperature, and flow velocity perturbations in terms of radial gradients of equilibrium pressure and temperature. Closure relations that connect parallel heat flux density and viscosity to the radial gradients and parallel gradients of temperature and flow velocity, are also obtained by solving the non-Maxwellian moment equations. The closure relations combined with the linearized fluid equations reproduce the same solution obtained directly from the full moment equations. The method can be generalized to derive closures and transport for an electron-ion plasma and a multi-ion plasma in a general magnetic field.Comment: 25 pages, 9 figure

    Electron Parallel Closures for Various Ion Charge Numbers

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    Electron parallel closures for the ion charge number Z = 1 [J.-Y. Ji and E. D. Held, Phys. Plasmas 21, 122116 (2014)] are extended for 1 ≤ Z ≤ 10. Parameters are computed for various Z with the same form of the Z = 1 kernels adopted. The parameters are smoothly varying in Z and hence can be used to interpolate parameters and closures for noninteger, effective ion charge numbers

    Electron Parallel Transport for Arbitrary Collisionality

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    Integral (nonlocal) closures [J.-Y. Ji and E. D. Held, Phys. Plasmas 21, 122116 (2014)] are combined with the momentum balance equation to derive electron parallel transport relations. For a single harmonic fluctuation, the relations take the same form as the classical Spitzer theory (with possible additional terms): the electric current and heat flux densities are connected to the modified electric field and temperature gradient by transport coefficients. In contrast to the classical theory, the dimensionless coefficients depend on the collisionality quantified by a Knudsen number, the ratio of the collision length to the angular wavelength. The key difference comes from the proper treatment of the viscosity and friction terms in the momentum balance equation, accurately reflecting the free streaming and collision terms in the kinetic equation. For an arbitrary fluctuation, the transport relations may be expressed by a Fourier series or transform. For low collisionality, the electric resistivity can be significantly larger than that of classical theory and may predict the correct timescale for fast magnetic reconnection

    Hanja alexia with agraphia after left posterior inferior temporal lobe infarction: a case study.

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    Korean written language is composed of ideogram (Hanja) and phonogram (Hangul), as Japanese consists of Kanji (ideogram) and Kana (phonogram). Dissociation between ideogram and phonogram impairment after brain injury has been reported in Japanese, but few in Korean. We report a 64-yr-old right-handed man who showed alexia with agraphia in Hanja but preserved Hangul reading and writing after a left posterior inferior temporal lobe infarction. Interestingly, the patient was an expert in Hanja; he had been a Hanja calligrapher over 40 yr. However, when presented with 65 basic Chinese letters that are taught in elementary school, his responses were slow both in reading (6.3 sec/letter) and writing (8.8 sec/letter). The rate of correct response was 81.5% (53 out of 65 letters) both in reading and writing. The patient's performances were beyond mean-2SD of those of six age-, sex-, and education-matched controls who correctly read 64.7 out of 65 and wrote 62.5 out of 65 letters with a much shorter reaction time (1.3 sec/letter for reading and 4.0 sec/letter for writing). These findings support the notion that ideogram and phonogram can be mediated in different brain regions and Hanja alexia with agraphia in Korean patients can be associated with a left posterior inferior temporal lesion

    Deep, noninvasive imaging and surgical guidance of submillimeter tumors using targeted M13-stabilized single-walled carbon nanotubes

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    Highly sensitive detection of small, deep tumors for early diagnosis and surgical interventions remains a challenge for conventional imaging modalities. Second-window near-infrared light (NIR2, 950–1,400 nm) is promising for in vivo fluorescence imaging due to deep tissue penetration and low tissue autofluorescence. With their intrinsic fluorescence in the NIR2 regime and lack of photobleaching, single-walled carbon nanotubes (SWNTs) are potentially attractive contrast agents to detect tumors. Here, targeted M13 virus-stabilized SWNTs are used to visualize deep, disseminated tumors in vivo. This targeted nanoprobe, which uses M13 to stably display both tumor-targeting peptides and an SWNT imaging probe, demonstrates excellent tumor-to-background uptake and exhibits higher signal-to-noise performance compared with visible and near-infrared (NIR1) dyes for delineating tumor nodules. Detection and excision of tumors by a gynecological surgeon improved with SWNT image guidance and led to the identification of submillimeter tumors. Collectively, these findings demonstrate the promise of targeted SWNT nanoprobes for noninvasive disease monitoring and guided surgery.National Institutes of Health (U.S.). Center for Nanotechnology Excellence (Grant U54-CA119349-04)National Institutes of Health (U.S.). Center for Nanotechnology Excellence (Grant U54-CA151884)David H. Koch Institute for Integrative Cancer Research at MIT. Frontier Research Program (Kathy and Curt Marble Cancer Research Fund)National Institute of Environmental Health Sciences (Grant P30-ES002109)Marie D. & Pierre Casimir-Lambert FundAmar G. Bose Research Gran

    Curcumin induces expression of 15-hydroxyprostaglandin dehydrogenase in gastric mucosal cells and mouse stomach in vivo: AP-1 as a potential target

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    15-Hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes the conversion of oncogenic prostaglandin E-2 to non-tumerigenic 15-keto prostaglandin E-2. In the present study, we found that curcumin, a yellow coloring agent present in the rhizome of Curcuma Tonga Linn (Zingiberaceae), induced expression of 15-PGDH at the both transcriptional and translational levels in normal rat gastric mucosal cells. By using deletion constructs of 15-PGDH promoter, we were able to demonstrate that activator protein-1 (AP-1) is the principal transcription factor responsible for regulating curcumin-induced 15-PGDH expression. Curcumin enhanced the expression of c-jun and cFos that are functional subunits of AP-1, in the nuclear fraction of cells. Silencing of c-jun suppressed curcumin-induced expression of 15-PGDH. Moreover, the chromatin immunoprecipitation assay revealed curcumin-induced binding of c-Jun to the AP-1 consensus sequence present in the 15-PGDH promoter. Curaimin increased phosphorylation of ERK1/2 and JNK. and pharmacologic inhibition of these kinases abrogated the curcumin-induced phosphorylation of clun and 15-PGDH expression. In contrast, tetrahydrocurcumin which lacks the alpha,beta-unsaturated carbonyl group failed to induce 15-PGDH expression, suggesting that the electrophilic carbonyl group of curcumin is essential for its induction of 15-PGDH expression. Curcumin restored the expression of 15-PGDH which is down-regulated by Helicobater pylori through suppression of DNA methyltransferase 1. In addition, oral administration of curcumin increased the expression of 15-PGDH and its regulators such as p-ERK1/2, p-JNK and c-Jun in the mouse stomach. Taken together, these findings suggest that curcumin-induced upregulation of 15-PGDH may contribute to chemopreventive effects of this phytochemical on inflammation-associated gastric carcinogenesis. (C) 2020 Elsevier Inc. All rights reserved.

    Eccrine Angiomatous Hamartoma Mimicking a Traumatic Hemorrhage

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    Eccrine angiomatous hamartoma (EAH) is a rare benign disease that is characterized by an abnormal proliferation of eccrine glands and vascular elements. It is generally congenital, but it can appear before puberty. It usually presents as a single plaque or nodule, but multiple patch-like lesions are also possible. EAH is mostly asymptomatic, but it is sometimes associated with pain or hyperhidrosis. It generally does not require aggressive treatment, but the lesion can be excised due to pain, enlargement and cosmetic reasons. A 3-week-old Korean female presented with a hemorrhagic skin lesion on the right foot since birth. There was no specific birth history. The lesion first appeared on the third toe of the right foot and quickly spread to almost half of the right foot. Histopathology examination revealed acanthosis in the epidermis and a proliferation of eccrine ducts, glands and capillaries. The eccrine glands were immunohistochemically-positive for carcinoembryonic antigen
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