Peroxisome proliferator-activated receptor δ as a molecular target to regulate lung cancer cell growth

AbstractIt has been assumed that prostaglandin (PG)I2 signaling contributes to the negative growth control of lung cancer cells; however, the mechanism remains unresolved. PGI2 functions through a cell surface G protein-coupled receptor (prostaglandin I2-binding receptor, IP) and also exerts an effect by interacting with a nuclear hormone receptor, peroxisome proliferator-activated receptor δ (PPARδ). We found that PPARδ was a key molecule of PGI2 signaling to give negative growth control of lung cancer cells (A549), using carbarprostacyclin, a PGI2 agonist for IP and PPARδ, and L-165041, a PPARδ agonist. Furthermore, PPARδ-induced cell growth control was reinforced by the inhibition of cyclooxygenase. These results suggest that PPARδ activation under the suppression of PG synthesis is important to regulate lung cancer cell growth

Anisotropy in broad component of Hα\alpha line in the magnetospheric device RT-1

Temperature anisotropy in broad component of H$\alpha$ line was found in the ring trap 1 (RT-1) device by Doppler spectroscopy. Since hot hydrogen neutrals emitting a broad component are mainly produced by charge exchange between neutrals and protons, the anisotropy in the broad component is the evidence of proton temperature anisotropy generated by betatron acceleration

Protein phosphatase 4 catalytic subunit regulates Cdk1 activity and microtubule organization via NDEL1 dephosphorylation

Protein phosphatase 4 catalytic subunit (PP4c) is a PP2A-related protein serine/threonine phosphatase with important functions in a variety of cellular processes, including microtubule (MT) growth/organization, apoptosis, and tumor necrosis factor signaling. In this study, we report that NDEL1 is a substrate of PP4c, and PP4c selectively dephosphorylates NDEL1 at Cdk1 sites. We also demonstrate that PP4c negatively regulates Cdk1 activity at the centrosome. Targeted disruption of PP4c reveals disorganization of MTs and disorganized MT array. Loss of PP4c leads to an unscheduled activation of Cdk1 in interphase, which results in the abnormal phosphorylation of NDEL1. In addition, abnormal NDEL1 phosphorylation facilitates excessive recruitment of katanin p60 to the centrosome, suggesting that MT defects may be attributed to katanin p60 in excess. Inhibition of Cdk1, NDEL1, or katanin p60 rescues the defective MT organization caused by PP4 inhibition. Our work uncovers a unique regulatory mechanism of MT organization by PP4c through its targets Cdk1 and NDEL1 via regulation of katanin p60 distribution

Slow dynamics near glass transitions in thin polymer films

The $\alpha$-process (segmental motion) of thin polystyrene films supported on glass substrate has been investigated in a wider frequency range from 10$^{-3}$ Hz to 10$^4$ Hz using dielectric relaxation spectroscopy and thermal expansion spectroscopy. The relaxation rate of the $\alpha$-process increases with decreasing film thickness at a given temperature above the glass transition. This increase in the relaxation rate with decreasing film thickness is much more enhanced near the glass transition temperature. The glass transition temperature determined as the temperature at which the relaxation time of the $\alpha$-process becomes a macroscopic time scale shows a distinct molecular weight dependence. It is also found that the Vogel temperature has the thickness dependence, i.e., the Vogel temperature decreases with decreasing film thickness. The expansion coefficient of the free volume $\alpha_f$ is extracted from the temperature dependence of the relaxation time within the free volume theory. The fragility index $m$ is also evaluated as a function of thickness. Both $\alpha_f$ and $m$ are found to decrease with decreasing film thickness.Comment: 9 pages, 7 figures, and 2 table

Citation Estimation Method Using Abstracts of Research Data Articles : Using Abstracts of Scientific Data Articles as An Example

オープンサイエンス時代の到来により，研究データの公開，利活用に向けた取り組みが盛んに行われている．公開もしくは共有された研究データの分野融合型研究への利活用を考慮した，異分野研究の研究者にも伝わりやすい抄録の記述方法の開発も今後期待される．これまで学術論文の論文誌のように抄録，本文，参照文献という形式をとる，研究データに特化した論文誌が登場してきている．本研究では研究データに特化した論文誌である「Scientific Data」の抄録に着目し，抄録を構成する英文の品詞の出現数，単語数，キーワード数と研究データ論文の被引用数を重回帰分析することで，各品詞等が研究データの利活用に及ぼす影響を考察した．また，それらの結果をもとに，説明変数を名詞，動詞，その他品詞，単語数，キーワード数に設定し，目的変数を被引用数として機械学習を行い，被引用数を予測する分類器を開発した．これにより，今後の研究データ利活用に向けた，研究データ公開の際の抄録記述の留意点についての議論に繋がることを期待する．With the trend of open science, efforts have been made to open and utilize research data. Considering the use of published or shared research data for interdisciplinary research, it is expected to develop a method of writing abstracts that can be easily understood by researchers in different research fields. Journals specializing in research data that have a format of abstract, text, and references like academic journals have emerged. In this study, we focus on the abstract of "Scientific Data", a journal specialized in research data, and examine the influence of each part of speech on the utilization of research data through multiple regression analysis of the number of occurrences of the part of speech, the number of words and the number of keywords in the abstract, and the number of citations to the research data article. Based on these results, we set the explanatory variables as the number of occurrences of nouns, verbs, the other parts of speech, the number of words, and the number of keywords in the abstract, and developed a classifier to estimate the number of citations by machine learning with the number of citations as the objective variable. We hope that this will lead to a discussion of the issues that need to be considered when writing abstracts for publication of research data for future use of research data

OAZ-t/OAZ3 Is Essential for Rigid Connection of Sperm Tails to Heads in Mouse

Polyamines are known to play important roles in the proliferation and differentiation of many types of cells. Although considerable amounts of polyamines are synthesized and stored in the testes, their roles remain unknown. Ornithine decarboxylase antizymes (OAZs) control the intracellular concentration of polyamines in a feedback manner. OAZ1 and OAZ2 are expressed ubiquitously, whereas OAZ-t/OAZ3 is expressed specifically in germline cells during spermiogenesis. OAZ-t reportedly binds to ornithine decarboxylase (ODC) and inactivates ODC activity. In a prior study, polyamines were capable of inducing a frameshift at the frameshift sequence of OAZ-t mRNA, resulting in the translation of OAZ-t. To investigate the physiological role of OAZ-t, we generated OAZ-t–disrupted mutant mice. Homozygous OAZ-t mutant males were infertile, although the polyamine concentrations of epididymides and testes were normal in these mice, and females were fertile. Sperm were successfully recovered from the epididymides of the mutant mice, but the heads and tails of the sperm cells were easily separated in culture medium during incubation. Results indicated that OAZ-t is essential for the formation of a rigid junction between the head and tail during spermatogenesis. The detached tails and heads were alive, and most of the headless tails showed straight forward movement. Although the tailless sperm failed to acrosome-react, the heads were capable of fertilizing eggs via intracytoplasmic sperm injection. OAZ-t likely plays a key role in haploid germ cell differentiation via the local concentration of polyamines

Establishment and Clinical Applications of a Portable System for Capturing Influenza Viruses Released through Coughing

Coughing plays an important role in influenza transmission; however, there is insufficient information regarding the viral load in cough because of the lack of convenient and reliable collection methods. We developed a portable airborne particlecollection system to measure the viral load; it is equipped with an air sampler to draw air and pass it through a gelatin membrane filter connected to a cone-shaped, megaphone-like device to guide the cough airflow to the membrane. The membrane was dissolved in a medium, and the viral load was measured using quantitative real-time reverse transcriptasepolymerase chain reaction and a plaque assay. The approximate viral recovery rate of this system was 10% in simulation experiments to collect and quantify the viral particles aerosolized by a nebulizer. Using this system, cough samples were collected from 56 influenza A patients. The total viral detection rate was 41% (23/56), and the viral loads varied significantly (from <10, less than the detection limit, to 2240 viral gene copies/cough). Viable viruses were detected from 3 samples with ?18 plaque forming units per cough sample. The virus detection rates were similar among different groups of patients infected with different viral subtypes and during different influenza seasons. Among patients who did not receive antiviral treatment, viruses were detected in one of six cases in the vaccinated group and four of six cases in the unvaccinated group. We found cases with high viral titers in throat swabs or oral secretions but very low or undetectable in coughs and vice versa suggesting other possible anatomical sites where the viruses might be mixed into the cough. Our system is easy to operate, appropriate for bedside use, and is useful for comparing the viral load in cough samples from influenza patients under various conditions and settings. However, further large-scale studies are warranted to validate our results

Experimental Analysis of the Magnetic Field Structure on the High-Beta Plasmas in the Magnetospheric Plasma Device

報告番号: 甲26310 ; 学位授与年月日: 2010-06-28 ; 学位の種別: 課程博士 ; 学位の種類: 博士(科学) ; 学位記番号: 博創域第612号 ; 研究科・専攻: 新領域創成科学研究科基盤科学研究系先端エネルギー工学専