62 research outputs found

    Changes in the levels of lipoperoxide and antioxidant factors in human placenta during gestation.

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    The concentration of lipoperoxides in maternal blood increases as gestation progresses. The concentration in pregnant women at 40 weeks gestation is 1.6 times higher than in nonpregnant women. The concentration in the cord blood, however, is 70% lower than that in maternal blood. To study the role of placental tissue in the difference in the lipoperoxide concentration between the cord blood and maternal blood, we investigated the lipoperoxide concentration, antioxidant activities and in vitro lipoperoxide formation in placental tissue during pregnancy. The lipoperoxide concentration was 50% lower in placental tissue of 40 weeks gestation than in tissue of 5-11 weeks gestation. Catalase and superoxide dismutase activities in placental tissues increased as gestation progressed, while glutathione peroxidase activity and alpha-tocopherol concentration did not change significantly during the gestational period. The in vitro formation of lipoperoxides in placental tissue decreased as gestation progressed. These results show that placental tissue suppresses lipoperoxide formation in the late gestational age, lowers the concentration of lipoperoxides in the blood and protects the fetus against oxygen toxicity.</p

    Effects of antioxidants on V79 Chinese hamster cells treated with ferric nitrilotriacetate.

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    The cytotoxic effects of ferric nitrilotriacetate (Fe-NTA) have been considered to be caused by free radicals produced by the drug. The present study was carried out to determine whether or not cytotoxic effects of Fe-NTA on cell growth and lipoperoxide formation of Chinese hamster cells were reduced by antioxidants. Using a spin trapping technique, we found that hydroxyl radical formation in the cells increased in the presence of Fe-NTA. Antioxidants, with the exception of superoxide dismutase, slightly inhibited production of the hydroxyl radical. Mannitol significantly reduced lipoperoxide formation, but other antioxidants did not. However, the growth inhibitory effects of Fe-NTA were not attenuated by these antioxidants. These results indicated that the cytotoxic effects of Fe-NTA may be mostly due to unknown factors other than oxygen free radicals.</p

    Fluorescence and electron microscopic study of intracellular F-actin in concanavalin A-treated and cytochalasin B-treated Ehrlich ascites tumor cells.

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    To investigate the involvement of actin filaments in concanavalin A (Con A)-induced cap formation and cytochalasin B (CB)-induced zeiotic knob migration, the distribution of F-actin was studied in Con A-treated and CB-treated Ehrlich ascites tumor cells (EATC) by fluorescence microscopy using heavy meromyosin conjugated with a fluorescent dye, N-(7-dimethylamino-4-methylcoumarinyl) maleimide, (DACM-HMM). In non-treated cells, the diffuse fluorescence of DACM-HMM was observed in the cytoplasm, particularly intensely under the plasma membrane and around the nucleus. In Con A- and CB-treated cells, the fluorescence was seen at Con A-induced-capped and CB-induced-knob-accumulated regions. This fluorescence was more intense in CB-treated cells. To study the actin filaments in these fluorescent regions more clearly, the soluble components of the cells were eliminated by treatment with Triton X-100 or saponin solution containing a low concentration of glutaraldehyde, and the detergent-treated and saponin-treated cells were observed under a transmission electron microscope. Concentrated actin filaments were observed directly beneath the Con A-induced capping area and CB-induced zeiotic knob-accumulation area. The area of concentrated actin filaments appeared to correspond to the electron dense area observed in the identical region in the cells fixed without detergent treatment. More actin filaments were observed in CB-treated cells than in Con A-treated ones.</p

    Factors affecting prognosis of idiopathic interstitial pneumonia.

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    &#60;P&#62;Idiopathic interstitial pneumonia (IIP) is a progressive and often fatal pulmonary disorder, and evaluating the prognosis of patients with IIP has never been sufficient. Accordingly, factors including clinical features, laboratory data, cellular components in bronchoalveolar lavage (BAL) fluid and response to corticosteroid therapy were analyzed in 35 patients with IIP whose median age of respiratory onset was 60 years (range; 37-77 years). Nineteen patients (54.3%) were in the active stage of IIP and 16 of them were treated with corticosteroids. Significant prognostic factors were the neutrophil percentage in BAL fluid, interstitial shadows on chest radiograph, pulmonary function, blood oxygen level, grade of dyspnea, and disease activity at the initial examination. Patients in the active stage showed higher proportions of neutrophils and eosinophils in BAL fluid than those in the non-active stage. Despite corticosteroid therapy, the survival of patients in the active stage was significantly shorter than those in the non-active stage. Fifty percent of the patients treated with corticosteroids were regarded as responders at 1 month after the initiation of therapy; however, there was no significant difference between responders and non-responders in terms of survival time. In conclusion, disease activity and neutrophils in BAL fluid may be important predictors of the prognosis of IIP.&#60;/P&#62;</p

    The apelin‑apelin receptor signaling pathway in fibroblasts is involved in tumor growth via p53 expression of cancer cells

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    Cancer-associated fibroblasts (CAFs) are pivotal in tumor progression. TP53-deficiency in cancer cells is associated with robust stromal activation. The apelin-apelin receptor (APJ) system has been implicated in suppressing fibroblast-to-myofibroblast transition in non-neoplastic organ fibrosis. The present study aimed to elucidate the oncogenic role of the apelin-APJ system in tumor fibroblasts. APJ expression and the effect of APJ suppression in fibroblasts were investigated for p53 status in cancer cells using human cell lines (TP53-wild colon cancer, HCT116, and Caco-2; TP53-mutant colon cancer, SW480, and DLD-1; and colon fibroblasts, CCD-18Co), resected human tissue samples of colorectal cancers, and immune-deficient nude mouse xenograft models. The role of exosomes collected by ultracentrifugation were also analyzed as mediators of p53 expression in cancer cells and APJ expression in fibroblasts. APJ expression in fibroblasts co-cultured with p53-suppressed colon cancer cells (HCT116sh p53 cells) was significantly lower than in control colon cancer cells (HCT116sh control cells). APJ-suppressed fibroblasts treated with an antagonist or small interfering RNA showed myofibroblast-like properties, including increased proliferation and migratory abilities, via accelerated phosphorylation of Sma- and Mad-related protein 2/3 (Smad2/3). In addition, xenografts of HCT116 cells with APJ-suppressed fibroblasts showed accelerated tumor growth. By contrast, apelin suppressed the upregulation of phosphorylated Smad2/3 in fibroblasts. MicroRNA 5703 enriched in exosomes derived from HCT116sh p53 cells inhibited APJ expression, and inhibition of miR-5703 diminished APJ suppression in fibroblasts caused by cancer cells. APJ suppression from a specific microRNA in cancer cell-derived exosomes induced CAF-like properties in fibroblasts. Thus, the APJ system in fibroblasts in the tumor microenvironment may be a promising therapeutic target.Saiki H., Hayashi Y., Yoshii S., et al. The apelin‑apelin receptor signaling pathway in fibroblasts is involved in tumor growth via p53 expression of cancer cells. International Journal of Oncology 63, 139 (2023); https://doi.org/10.3892/ijo.2023.5587

    Space demostration of bare electrodynamic tape-tether technology on the sounding rocket S520-25

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    A spaceflight validation of bare electro dynamic tape tether technology was conducted. A S520-25 sounding rocket was launched successfully at 05:00am on 31 August 2010 and successfully deployed 132.6m of tape tether over 120 seconds in a ballistic flight. The electrodynamic performance of the bare tape tether employed as an atmospheric probe was measured. Flight results are introduced through the present progressive report of the demonstration and the results of flight experiment are examined as the premier report of the international cooperation between Japan, Europe, USA and Australia. Future plans for maturing space tether technology, which will play an important role for future space activities, are also discussed

    T-REX: Bare electro-dynamic tape-tether technology experimetn on sounding rocket S520

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    The project to verify the performance of space tether technology was successfully demonstrated by the launch of the sounding rocket S520 the 25tu. The project is the space demonstration of science and engineering technologies of a bare tape electrodynamic tether (EDT) in the international campaign between Japan, USA, Europe and Australia. Method of "Inverse ORIGAMI (Tape tether folding)" was employed in order to deploy the bare tape EDT in a short period time of the suborbital flight. The deployment of tape tether was tested in a various experimental schemes on ground to show high reliability of tape tether deployment. The rocket was launched on the summer of 2010 and deployed a bare electro-dynamic tape tether with length 132.6 m, which is the world record of the length deployment of tape tether. The verification of tether technology has found a variety kind of science and technology results as the first in the humankind and will lead a large number of applications of space tether technologie
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