257 research outputs found
Genetic Profiling Reveals Cross-Contamination and Misidentification of 6 Adenoid Cystic Carcinoma Cell Lines: ACC2, ACC3, ACCM, ACCNS, ACCS and CAC2
Adenoid cystic carcinoma (ACC) is the second most common malignant neoplasm of the salivary glands. Most patients survive more than 5 years after surgery and postoperative radiation therapy. The 10 year survival rate, however, drops to 40%, due to locoregional recurrences and distant metastases. Improving long-term survival in ACC requires the development of more effective systemic therapies based on a better understanding of the biologic behavior of ACC. Much preclinical research in this field involves the use of cultured cells and, to date, several ACC cell lines have been established. Authentication of these cell lines, however, has not been reported. We performed DNA fingerprint analysis on six ACC cell lines using short tandem repeat (STR) examinations and found that all six cell lines had been contaminated with other cells. ACC2, ACC3, and ACCM were determined to be cervical cancer cells (HeLa cells), whereas the ACCS cell line was composed of T24 urinary bladder cancer cells. ACCNS and CAC2 cells were contaminated with cells derived from non-human mammalian species: the cells labeled ACCNS were mouse cells and the CAC2 cells were rat cells. These observations suggest that future studies using ACC cell lines should include cell line authentication to avoid the use of contaminated or non-human cells
An unexplored role of the CrOx shell in an elaborated Rh/CrOx core–shell cocatalyst for photocatalytic water splitting: a selective electron transport pathway from semiconductors to core metals, boosting charge separation and H₂ evolution
A core–shell structured Rh/CrOx cocatalyst has endowed various semiconductors with high efficiency in water-splitting photocatalysis, where thin CrOx layers on Rh have been assumed to be physical blockers of O₂ to the metal surface to suppress unfavorable reverse reactions (e.g., catalytic H₂O formation from H₂ and O₂). Herein, we propose another unexplored but favorable function of CrOx layers: a selective electron transport pathway from photocatalysts to the Rh core boosting charge separation and H₂ production. The subsequent loading of CrOx layers onto Rh increased the rate of visible light H₂ evolution of a Bi₄NbO₈Cl photocatalyst, even in a half reaction with a hole scavenger where O₂ does not evolve. Transient absorption spectroscopy revealed that the CrOx layer increases the electron path from Bi₄NbO₈Cl to Rh. Importantly, the highest H₂-evolution activity was obtained by simultaneous photodeposition using CrIII and RhIII precursors, which had not yet been examined. In this sample, Rh nanoparticles were enclosed by an amorphous CrOx shell, where Rh particles were less directly attached to the semiconductor. Therein, CrOx inserted between Bi₄NbO₈Cl and Rh effectively suppresses undesirable hole transfer from Bi₄NbO₈Cl to Rh, while such hole transfer partially occurs when they are in direct contact. These results indicated that CrOx functions as a selective electron transport pathway and improves the H₂ evolution activity. Although the development strategy of cocatalysts has so far focused on surface redox reactions, this study offers a new approach for the design of highly efficient cocatalysts based on the carrier transfer process, especially at semiconductor–cocatalyst interfaces
Heat Shock Protein 70 Negatively Regulates TGF-β-Stimulated VEGF Synthesis via p38 MAP Kinase in Osteoblasts
Resveratrol promotes expression of SIRT1 and StAR in rat ovarian granulosa cells: an implicative role of SIRT1 in the ovary
<p>Abstract</p> <p>Background</p> <p>Resveratrol is a natural polyphenolic compound known for its beneficial effects on energy homeostasis, and it also has multiple properties, including anti-oxidant, anti-inflammatory, and anti-tumor activities. Recently, silent information regulator genes (Sirtuins) have been identified as targets of resveratrol. Sirtuin 1 (SIRT1), originally found as an NAD<sup>+</sup>-dependent histone deacetylase, is a principal modulator of pathways downstream of calorie restriction, and the activation of SIRT1 ameliorates glucose homeostasis and insulin sensitivity. To date, the presence and physiological role of SIRT1 in the ovary are not known. Here we found that SIRT1 was localized in granulosa cells of the human ovary.</p> <p>Methods</p> <p>The physiological roles of resveratrol and SIRT1 in the ovary were analyzed. Immunohistochemistry was performed to localize the SIRT1 expression. SIRT1 protein expression of cultured cells and luteinized human granulosa cells was investigated by Western blot. Rat granulosa cells were obtained from diethylstilbestrol treated rats. The cells were treated with increasing doses of resveratrol, and subsequently harvested to determine mRNA levels and protein levels. Cell viability was tested by MTS assay. Cellular apoptosis was analyzed by caspase 3/7 activity test and Hoechst 33342 staining.</p> <p>Results</p> <p>SIRT1 protein was expressed in the human ovarian tissues and human luteinized granulosa cells. We demonstrated that resveratrol exhibited a potent concentration-dependent inhibition of rat granulosa cells viability. However, resveratrol-induced inhibition of rat granulosa cells viability is independent of apoptosis signal. Resveratrol increased mRNA levels of SIRT1, LH receptor, StAR, and P450 aromatase, while mRNA levels of FSH receptor remained unchanged. Western blot analysis was consistent with the results of quantitative real-time RT-PCR assay. In addition, progesterone secretion was induced by the treatment of resveratrol.</p> <p>Conclusions</p> <p>These results suggest a novel mechanism that resveratrol could enhance progesterone secretion and expression of luteinization-related genes in the ovary, and thus provide important implications to understand the mechanism of luteal phase deficiency.</p
大型核融合試験施設におけるメガワットミリ波ジャイロトロン発振器周辺の電磁環境調査
将来のエネルギー源として開発が進められている磁場閉じ込め方式の核融合研究では,高温プラズマの生成や制御,プラズマ加熱及び計測のために大電力高周波発振機器が利用されている.本論文では,核融合科学研究所の大型ヘリカル装置で使用されているメガワットミリ波ジャイロトロン発振器(周波数: 77 GHz,最大出力: 1~1.5 MW/2秒)を対象とし,作業従事者の安全管理を目的に,ホーンアンテナを用いて機器周辺での電磁環境を定点調査した.その結果,77 GHz発振器からおよそ30 m離れた場所で観測された漏洩電界の周波数は,77 GHzが最も強く,そこから数GHz離れた両側の周波数領域にも微弱なスプリアススペクトルが確認された.また,同じ場所で,数十秒から数百秒の発振運転に伴う漏洩電界(最大実効値: 数V/m)が観測された.電界の漏洩箇所は,ジャイロトロン発振器を構成する接地電位の電子ビームコレクターと,その他の部位とを電気的に絶縁するために具備された窒化ケイ素製絶縁部と推定された.本研究により,大型核融合試験施設におけるメガワットジャイロトロン発振器周辺のミリ波帯での漏洩電界の実態を初めて明らかにした
The fastest-actin-based motor protein from the green algae, Chara, and its distinct mode of interaction with actin
AbstractThe endoplasmic streaming in Characean cells is an actin-dependent movement. The motor protein responsible for the streaming was partially purified and characterized. It was soluble at low ionic strength, an ATPase of a molecular mass of 225 kDa and activated more than 100 times by muscle F-actin. Surprisingly, in an in vitro motility assay, the motor protein moved muscle F-actin at 60 μm/s, which is similar to the velocity of streaming in a living cell and 10 times faster than muscle myosin. Proteolytic cleavage of actin impaired movement crucially on muscle myosin, but did not affect movement at all on the Chara motor protein, suggesting that the Chara motor protein would interact with actin via a set of sites different from those of muscle myosin
Partial purification and biological activities and properties of chick growth factors.
Cellular stimulating factors on cell proliferation in the supernatants of chick embryo carcases and adult muscles were studied. There were plural stimulating factors in embryonic and adult muscular supernatants that promoted cell proliferation without any supplement of sera and other materials. Salting-out methods with ammonium sulfate, ethanol fractionation, and isoelectric precipitation were used to isolate the stimulating factors, and these three methods proved the presence of plural stimulants on cell proliferation in the supernatants of chick embryo and adult muscles. The stimulants had altered physico-chemical properties and biological activities due to embryological development. The embryonic stimulants enhanced the synthesis of DNA and protein remarkably, and RNA synthesis in whole cell systems slightly. The muscular stimulants enhanced protein synthesis without any stimulation of DNA and RNA synthesis. Partial purification of the stimulants from the ethanol fractions was performed by DEAE-cellulose chromatography and Sephadex gel chromatography.</p
Efficacy of 23-valent pneumococcal vaccine in preventing pneumonia and improving survival in nursing home residents: double blind, randomised and placebo controlled trial
Objective To determine the efficacy of a 23-valent pneumococcal polysaccharide vaccine in people at high risk of pneumococcal pneumonia
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