54 research outputs found

    Antioxidant Activity and Oxidation Products of 1,2,3,4- Tetrahydroquinoxalines in Peroxyl Radical Scavenging Reactions, Part I

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    This paper studies the antioxidant activity of 1,2,3,4-tetrahydroquinolines, 3,4-dihydro-2H-benzo[1,4]thiazines and 1,2,3,4-tetrahydroquinoxalines in the inhibition of the peroxidation of tetralin induced by an azo initiator. Neither 1,2,3,4- tetrahydroquinoline nor 3,4-dihydro-2H-benzo[1,4]thiazine alone acted as an antioxidant, but when they have an electron-donating group at the para position to the NH group, they act as potent antioxidants. On the other hand, 1,2,3,4- tetrahydroquinoxaline on its own showed good antioxidant activity. However, 1,2,3,4-tetrahydroquinoxalines with methyl and methoxy groups in the phenyl ring have reactivities similar to or less than that of unsubstituted 1,2,3,4-tetrahydroquinoxaline. The induction periods of 1,2,3,4-tetrahydroquinoxalines with an alkyl group or phenyl group at the 2-position were all longer than the value for the unsubstituted 1,2,3,4-tetrahydroquinoxaline, except for a compound with a t-butyl group. The oxidation of 1,2,3,4-tetrahydroquinoxalines by peroxyl radicals generated from an azo initiator in tetralin or benzene yields quinoxalines and a dimer product of quinoxalines, 6-(1,2,3,4-tetrahydroquinoxalin-1-yl)-quinoxaline

    Mg2Ge/Si Composite Electrodes Prepared by Gas-Deposition as Anodes for Lithium Rechargeable Battery

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    Mg2Ge/Si composite electrodes were prepared by a gas-deposition (GD) method and evaluated their electrochemical properties of anodes for Li rechargeable battery. The discharge capacity of the Mg2Ge/Si composite electrodes increased in comparison with that of Mg2Ge GD-film electrode. Among them, the Mg2Ge/Si composite electrode with 30 wt% Si content exhibited good cycle stability, which is 603 mAh g-1 after 200 cycles. At this composition of composite, each Si particle was surrounded with Mg2Ge layer, and the Mg2Ge layer appears to be easy to release the stress generated in the Si particle at Li insertion-extraction because Mg2Ge is more ductile than Si. Thus, we succeeded to develop the electrode which can take advantage of both high capacity of Si and good cyclability of Mg2Ge

    Anode Properties of LaSi2/Si Composite Thick-Film Electrodes for Lithium Secondary Batteries

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    LaSi2 and LaSi2/Si composite as active materials for the negative electrode of lithium-ion battery were synthesized by mechanical alloying. Furthermore, thick-film electrodes prepared with a gas-deposition method by using these material powders, and their electrode performances were investigated. The LaSi2 GD-film electrode exhibited superb cycle stability, where more than 70 % of the initial capacity was maintained for a period of 1000 cycles, though the initial capacity was only about 40 mA h g-1. As for the LaSi2/Si composite electrodes, the original high discharge capacity of Si was retained even after several hundred cycles. The capacity after 300 cycles was 500 mA h g-1, which is larger than the theoretical capacity of graphite electrode practically used. Thus, we succeeded in developing the new composite electrode with both high discharge capacity of Si and good cyclability of LaSi2

    Endoscopic features of oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type differ between patients with and without Helicobacter pylori infection: a retrospective observational study

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    Background The endoscopic features of oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type have not been fully investigated in relation to Helicobacter pylori infection status. We compared the morphology, color, and location of these lesions between patients with and without H. pylori infection. Methods We retrospectively enrolled 165 patients (180 lesions) from 10 institutions. We divided the patients into the (i) Hp group (patients with current H. pylori infection [active gastritis, n = 13] and those with past infection [inactive gastritis, n = 76]) and (ii) uninfected group (H. pylori-uninfected patients, n = 52). We compared the clinical and endoscopic features of the two groups. We also performed an analysis between (i) lesions with atrophy of the surrounding gastric mucosa (atrophy group) and (ii) lesions without atrophy of the surrounding gastric mucosa (non-atrophy group). Results The average age was older in the Hp group than in the uninfected group (68.1 +/- 8.1 vs. 63.4 +/- 8.7 years, p < 0.01). Although the difference was not statistically significant (p = 0.09), multiple lesions were observed in 9 of 89 patients (10.1%) in the Hp group and in only 1 of 52 patients (1.9%) in the uninfected group. Meanwhile, significant differences were observed in the prevalence of lesions located in the gastric fornix or cardia (uninfected group: 67.3% vs. Hp group: 38.0%, p < 0.01), with an elevated morphology (80.0% vs. 56.0%, p < 0.01), with a subepithelial-like appearance (78.2% vs. 42.0%, p < 0.01), and with a color similar to that of the peripheral mucosa (43.6% vs. 25.0%, p = 0.02). The male-to-female ratio, lesion size, and presence or absence of vascular dilatation or black pigmentation on the surface were not different between the two groups. In the analysis comparing lesions with and without mucosal atrophy, the prevalence of multiple lesions was significantly higher (p = 0.02) in the atrophy group (5/25 patients, 20.0%) than in the non-atrophy group (7/141 patients, 5.0%). Conclusions The endoscopic features of oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type differ between patients with and without H. pylori infection

    Lesion size, elevated morphology, and non or closed-type atrophy are predictive factors for gastric adenocarcinoma of the fundic gland type rather than oxyntic gland adenoma

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    Background: An oxyntic gland neoplasm confined to the mucosal layer (T1a) is classified as an oxyntic gland adenoma, whereas that with submucosal invasion (T1b) is defined as gastric adenocarcinoma of the fundic gland type (GA-FG). Methods: To reveal the differences in clinical features between them, we retrospectively investigated 136 patients with 150 oxyntic gland adenoma and GA-FG lesions. Results: The univariate analysis revealed that the mean size (GA-FG vs. oxyntic gland adenoma, 7.7±5.4 vs. 5.5±3.1 mm), the prevalence of elevated morphology (79.1% vs. 51.8%), black pigmentation within the lesion (23.9% vs. 9.6%), and non or closed-type atrophy (81.2% vs. 65.1%) were different between the two groups. A multivariate logistic regression analysis revealed that ≥5 mm lesion size (odds ratio, 2.96; 95% confidence interval: 1.21–7.23), elevated morphology (odds ratio, 2.40; 95% confidence interval: 1.06–5.45), and no or closed-type atrophy (odds ratio, 2.49; 95% confidence interval: 1.07–5.80) were factors in distinguishing GA-FG from oxyntic gland adenoma. When oxyntic gland neoplasms with no or one feature were judged as oxyntic gland adenomas and those with two or three features were judged as GA-FG, the sensitivity and specificity were 85.1% and 43.4% for GA-FG, respectively. Conclusions: We identified three possible distinctive features of GA-FG compared to oxyntic gland adenoma: lesion size ≥5 mm, elevated morphology, and no or closed-type atrophy

    NMII Forms a Contractile Transcellular Sarcomeric Network to Regulate Apical Cell Junctions and Tissue Geometry

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    SummaryNonmuscle myosin II (NMII) is thought to be the master integrator of force within epithelial apical junctions, mediating epithelial tissue morphogenesis and tensional homeostasis [1–3]. Mutations in NMII are associated with a number of diseases due to failures in cell-cell adhesion [4–8]. However, the organization and the precise mechanism by which NMII generates and responds to tension along the intercellular junctional line are still not known. We discovered that periodic assemblies of bipolar NMII filaments interlace with perijunctional actin and α-actinin to form a continuous belt of muscle-like sarcomeric units (∼400–600 nm) around each epithelial cell. Remarkably, the sarcomeres of adjacent cells are precisely paired across the junctional line, forming an integrated, transcellular contractile network. The contraction/relaxation of paired sarcomeres concomitantly impacts changes in apical cell shape and tissue geometry. We show differential distribution of NMII isoforms across heterotypic junctions and evidence for compensation between isoforms. Our results provide a model for how NMII force generation is effected along the junctional perimeter of each cell and communicated across neighboring cells in the epithelial organization. The sarcomeric network also provides a well-defined target to investigate the multiple roles of NMII in junctional homeostasis as well as in development and disease

    A Novel iRFP-Incorporated in vivo Murine Atherosclerosis Imaging System

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    By using near-infrared fluorescent protein (iRFP)-expressing hematopoietic cells, we established a novel, quantitative, in vivo, noninvasive atherosclerosis imaging system. This murine atherosclerosis imaging approach targets macrophages expressing iRFP in plaques. Low-density lipoprotein receptor-deficient (LDLR−/−) mice transplanted with beta-actin promoter-derived iRFP transgenic (TG) mouse bone marrow (BM) cells (iRFP → LDLR−/−) were used. Atherosclerosis was induced by a nonfluorescent 1.25% cholesterol diet (HCD). Atherosclerosis was compared among the three differently induced mouse groups. iRFP → LDLR−/− mice fed a normal diet (ND) and LDLR−/− mice transplanted with wild-type (WT) BM cells were used as controls. The in vivo imaging system (IVIS) detected an enhanced iRFP signal in the thoracic aorta of HCD-fed iRFP → LDLR−/− mice, whereas iRFP signals were not observed in the control mice. Time-course imaging showed a gradual increase in the signal area, which was correlated with atherosclerotic plaque progression. Oil red O (ORO) staining of aortas and histological analysis of plaques confirmed that the detected signal was strictly emitted from plaque-positive areas of the aorta. Our new murine atherosclerosis imaging system can noninvasively image atherosclerotic plaques in the aorta and generate longitudinal data, validating the ability of the system to monitor lesion progression

    Conserved Charged Amino Acids within Sendai Virus C Protein Play Multiple Roles in the Evasion of Innate Immune Responses

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    One of the accessory proteins of Sendai virus (SeV), C, translated from an alternate reading frame of P/V mRNA has been shown to function at multiple stages of infection in cell cultures as well as in mice. C protein has been reported to counteract signal transduction by interferon (IFN), inhibit apoptosis induced by the infection, enhance the efficiency of budding of viral particles, and regulate the polarity of viral genome-length RNA synthesis to maximize production of infectious particles. In this study, we have generated a series of SeV recombinants containing substitutions of highly conserved, charged residues within the C protein, and characterized them together with previously-reported C′/C(−), 4C(−), and F170S recombinant viruses in infected cell cultures in terms of viral replication, cytopathogenicity, and antagonizing effects on host innate immunity. Unexpectedly, the amino acid substitutions had no or minimal effect on viral growth and viral RNA synthesis. However, all the substitutions of charged amino acids resulted in the loss of a counteracting effect against the establishment of an IFN-α-mediated anti-viral state. Infection by the virus (Cm2′) containing mutations at K77 and D80 induced significant IFN-β production, severe cytopathic effects, and detectable amounts of viral dsRNA production. In addition to the Cm2′ virus, the virus containing mutations at E114 and E115 did not inhibit the poly(I:C)-triggered translocation of cellular IRF-3 to the nucleus. These results suggest that the C protein play important roles in viral escape from induction of IFN-β and cell death triggered by infection by means of counteracting the pathway leading to activation of IRF-3 as well as of minimizing viral dsRNA production
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