76 research outputs found

    Inactivation of HeLa cells on nanoporous gold

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    Nanoporous metals strongly affect organic matter; however, there is a poor understanding of their effects on cells. The present work shows that HeLa cells on nanoporous gold (NPG) were less active than those on flat gold (FG) with no nanoporous structure. Initially, HeLa cells adhered to the NPG over a period of more than 10 h, then the adhered cells subsequently exhibited apoptosis that was not related to anoikis. ELISA analyses showed that the conformational change of fibronectin was more greatly induced by NPG than FG. First-principles calculations and molecular dynamics simulations were performed to investigate the conformational change in the RGD sequence and the integrin signaling. The simulations suggested that the extended form of integrin, with an open headpiece, was not generated owing to the conformational change of RGD, and the outside-in signals could not be intracellularly transmitted via the integrin binding to the fibronectin on NPG, resulting in cell death

    Involvement of the leaf-specific multidrug and toxic compound extrusion (MATE) transporter Nt-JAT2 in vacuolar sequestration of nicotine in Nicotiana tabacum

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    Alkaloids play a key role in higher plant defense against pathogens and herbivores. Following its biosynthesis in root tissues, nicotine, the major alkaloid of Nicotiana species, is translocated via xylem transport toward the accumulation sites, leaf vacuoles. Our transcriptome analysis of methyl jasmonate-treated tobacco BY-2 cells identified several multidrug and toxic compound extrusion (MATE) transporter genes. In this study, we characterized a MATE gene, Nicotiana tabacum jasmonate-inducible alkaloid transporter 2 (Nt-JAT2), which encodes a protein that has 32% amino acid identity with Nt-JAT1. Nt-JAT2 mRNA is expressed at a very low steady state level in whole plants, but is rapidly upregulated by methyl jasmonate treatment in a leaf-specific manner. To characterize the function of Nt-JAT2, yeast cells were used as the host organism in a cellular transport assay. Nt-JAT2 was localized at the plasma membrane in yeast cells. When incubated in nicotine-containing medium, the nicotine content in Nt-JAT2-expressing cells was significantly lower than in control yeast. Nt-JAT2-expressing cells also showed lower content of other alkaloids like anabasine and anatabine, but not of flavonoids, suggesting that Nt-JAT2 transports various alkaloids including nicotine. Fluorescence assays in BY-2 cells showed that Nt-JAT2-GFP was localized to the tonoplast. These findings indicate that Nt-JAT2 is involved in nicotine sequestration in leaf vacuoles following the translocation of nicotine from root tissues

    A questionnaire-based comparative study of postoperative quality of life between laryngotracheal separation and tracheoesophageal diversion

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    Purpose: Whether tracheoesophageal diversion (TED) is preferable to laryngotracheal separation (LTS) is unclear. This study examined the need for tracheoesophageal anastomosis by reviewing complications after TED and LTS and administering a questionnaire on postoperative quality of life.Patients and methods: Medical records of TED/LTS cases performed at a single institution from 2003 to 2015 were retrospectively reviewed and a questionnaire was administered to parents of patients at an outpatient visit.Results: A total of 40 TED and 18 LTS cases were included. Complications occurred in six TED cases and one LTS case, with no significant differences between groups (P=0.42). A total of 22 parents of patients (TED 16 cases; LTS six cases) completed the questionnaire. Voice production was reported in three TED cases and two LTS cases. Patients indicated that suctions were ‘decreased’ in 13 and ‘unchanged’ in two TED cases, but ‘decreased’ in one and ‘unchanged’ in five LTS cases (P=0.0055). Readmissions were ‘increased’ in one and ‘decreased’ in 14 TED cases, but ‘decreased’ in three and ‘unchanged’ in three LTS cases (P=0.015).Conclusion: Postoperative complication rate was equivalent between groups, and the numbers of suctions and readmissions were decreased in the TED group. Therefore, tracheoesophageal anastomosis should be performed more commonly.Keywords: complication, laryngotracheal separation, quality of life questionnaire, tracheoesophageal diversio

    Algal protein kinase, Triacylglycerol Accumulation Regulator 1, modulates cell viability and gametogenesis in carbon/nitrogen imbalanced conditions

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    Nutrient-deprived microalgae accumulate triacylglycerol (TAG) in lipid droplets. A dual-specificity tyrosine phosphorylation-regulated kinase, TAG accumulation regulator 1 (TAR1) has been shown to be required for acetate-dependent TAG accumulation and the degradation of chlorophyll and photosynthesis-related proteins in photomixotrophic nitrogen (N)-deficient conditions (Kajikawa et al. 2015). However, this previous report only examined particular condition. Here, we report that in photoautotrophic N-deficient conditions, tar1-1 cells, with a mutation in the TAR1 gene, maintained higher levels of cell viability and lower levels of hydrogen peroxide generation and accumulated higher levels of TAG and starch compared with those of wild-type (WT) cells with bubbling of air containing 5% carbon dioxide. Transcriptomic analyses suggested that genes involved in the scavenging of reactive oxygen species are not repressed in tar1-1 cells. In contrast, the mating efficiency and mRNA levels of key regulatory genes for gametogenesis, MID, MTD, and FUS, were suppressed in tar1-1 cells. Among the TAR1-dependent phosphopeptides deduced by phosphoproteomic analysis, protein kinases and enzymes related to N assimilation and carbon (C) metabolism are of particular interest. Characterization of these putative downstream factors may elucidate the molecular pathway whereby TAR1 mediates cellular propagation and C and N metabolism in C/N-imbalanced stress conditions

    Investigation into the Effect of Breast Volume on Irradiation Dose Distribution in Asian Women with Breast Cancer

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    Reports on irradiation dose distribution in breast cancer radiotherapy with sufficient sample size are limited in Asian patients. Elucidating dose distribution in Asian patients is particularly important as their breast volume differs compared to patients in Europe and North America. Here, we examined dose distribution in the irradiation field relative to breast volume for three irradiation methods historically used in our facility. We investigated the influence of breast volume on each irradiation method for Asian women. A total of 573 women with early-stage breast cancer were treated with breast-conserving surgery and adjuvant radiotherapy. Three methods were compared: wedge (W), field-in-field (FIF), and wedge-field-in-field (W-FIF). In patients with small breast volume, FIF decreased low- and high-dose areas within the planning target volume, and increased optimal dose area more than W. In patients with medium and large breast volumes, FIF decreased high-dose area more than W. The absolute values of correlation coefficients of breast volume to low-, optimal-, and high-dose areas and mean dose were significantly lower in FIF than in W. The correlation coefficients of V107% were 0.00 and 0.28 for FIF and W, respectively. FIF is an excellent irradiation method that is less affected by breast volume than W in Asian breast cancer patients

    Limits on Neutrino Mass from Cosmic Structure Formation

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    We consider the effect of three species of neutrinos with nearly degenerate mass on the cosmic structure formation in a low matter-density universe within a hierarchical clustering scenario with a flat initial perturbation spectrum. The matching condition for fluctuation powers at the COBE scale and at the cluster scale leads to a strong upper limit on neutrino mass. For a flat universe with matter density parameter Omega=0.3, we obtain m_nu<0.6eV for the Hubble constant H_0<80km/s/Mpc. Allowing for the more generous parameter space limited by Omega11.5Gyr, the limit is 0.9eV.Comment: 4 pages with 2 figure

    Non-clinical studies for oncology drug development

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    Non-clinical studies are necessary at each stage of the development of oncology drugs. Many experimental cancer models have been developed to investigate carcinogenesis, cancer progression, metastasis, and other aspects in cancer biology and these models turned out to be useful in the efficacy evaluation and the safety prediction of oncology drugs. While the diversity and the degree of engagement in genetic changes in the initiation of cancer cell growth and progression are widely accepted, it has become increasingly clear that the roles of host cells, tissue microenvironment, and the immune system also play important roles in cancer. Therefore, the methods used to develop oncology drugs should continuously be revised based on the advances in our understanding of cancer. In this review, we extensively summarize the effective use of those models, their advantages and disadvantages, ranges to be evaluated and limitations of the models currently used for the development and for the evaluation of oncology drugs

    Reflectivity of Venus's Dayside Disk During the 2020 Observation Campaign: Outcomes and Future Perspectives

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    We performed a unique Venus observation campaign to measure the disk brightness of Venus over a broad range of wavelengths in 2020 August and September. The primary goal of the campaign was to investigate the absorption properties of the unknown absorber in the clouds. The secondary goal was to extract a disk mean SO2 gas abundance, whose absorption spectral feature is entangled with that of the unknown absorber at ultraviolet wavelengths. A total of three spacecraft and six ground-based telescopes participated in this campaign, covering the 52-1700 nm wavelength range. After careful evaluation of the observational data, we focused on the data sets acquired by four facilities. We accomplished our primary goal by analyzing the reflectivity spectrum of the Venus disk over the 283-800 nm wavelengths. Considerable absorption is present in the 350-450 nm range, for which we retrieved the corresponding optical depth of the unknown absorber. The result shows the consistent wavelength dependence of the relative optical depth with that at low latitudes, during the Venus flyby by MESSENGER in 2007, which was expected because the overall disk reflectivity is dominated by low latitudes. Last, we summarize the experience that we obtained during this first campaign, which should enable us to accomplish our second goal in future campaigns

    DIE FORSCHUNG UEBER DIE VERZUNDERUNG DES EISENS

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