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磁場と抗がん剤の併用療法に関する基礎的研究
Get PDF抗がん剤は、投与後、全身へ広がり、正常細胞にもダメージを与え、強い副作用をもつことから適量設定は難しく、また腫瘍細胞は抗ガン剤投与中に多剤耐性になるという問題点もある。近年、多剤耐性となった細胞でも磁場曝露により薬剤が効くようになったとの報告がある。そこで磁場を非接触で標的部位に作用させることで、局所的に薬の効果を高めることができれば、薬の投与量や副作用を減らすことが可能となると考えられるとこから、本研究では、磁場と抗がん剤の併用療法の可能性を基礎的に検討することを目的としている。
これまでに感度の良いウイルスを用いて測定を行い、磁場はマイトマイシンCのDNA損傷作用を2倍高めることが判明している。さらに当該年度では、マイトマイシンC以外の抗ガン剤シスプラチンやブレオマイシンの作用における磁場曝露影響を測定した。シスプラチンはDNAに架橋し、DNA合成阻害により細胞増殖阻害する作用をもち、ブレオマシンはFe^イオンを介して、DNA鎖切断により細胞増殖阻害、抗腫瘍作用を示す。シスプラチンと60Hz,50mT磁場との併用曝露の結果、細胞のコロニー数は減少し、磁場はシスプラチンの細胞増殖阻害作用を高めることが明らかとなった。またブレオマイシンと磁場曝露結果では、ブレオマイシンのDNA鎖切断作用が強められ、コロニー形成能も低下し、磁場がブレオマイシンの作用を高めることも示唆された。
今後は磁場強度および周波数の検討や薬効への磁場影響メカニズムの解明を進める予定である。研究課題/領域番号:18700437, 研究期間(年度):2006 – 2007出典：「磁場と抗がん剤の併用療法に関する基礎的研究」研究成果報告書 課題番号18700437
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-18700437/)を加工して作成金沢大学環日本海域環境研究センターresearch repor
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Research of the combined effect of magnetic fields and anticancer drugs
Get PDF抗がん剤と磁場の併用曝露法の有効性を明らかにするため,基礎研究として交流磁場曝露による数種類の抗がん剤作用増強を測定した結果,検討した全ての薬剤で磁場による作用増強が見られ、作用増強率に影響する要因は薬剤の作用機序や半数阻害濃度ではなく分子量であることが示唆された。また,マイトマイシンCとシスプラチンの薬剤2種について,細菌細胞への作用時の交流磁場曝露による作用増強メカニズムを薬剤の細胞膜透過性の点から検討した結果,交流磁場曝露により薬剤の細胞膜の透過性が高まることで各薬剤作用は増強されることが示唆された。Our results indicated that each potency of cisplatin, mitoxantrone, daunorubicin, actinomycin D, bleomycin, and zinostatin, was enhanced by exposure to 60 Hz, 50 mT magnetic fields. The analysis of the potency of supernatant remaining drugs in the culture medium indicated that the intracellular drug potency was increased and extracellular drug potency was decreased by exposure to magnetic fields. The values of drug potency revealed a significant inverse correlation between intracellular and extracellular cells. The results suggested that magnetic fields(60 Hz, 50 mT) change the permeability of cell membrane and influence the drug intake.出典：研究課題「交流磁場と抗がん剤の併用療法の開発」課題番号22700508
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-22700508/22700508seika/）を加工して作成research repor
Effect of magnetic field on anticancer drugs in human cancer cells
Get PDFWe previously reported that 60 Hz magnetic field (MF) enhances the potency of some anticancer drugs on human cells. The mechanism of this enhancement on drug potency has not yet been clarified. We focused on the cell membrane in this study. The membrane potentials of cancer cell lines, A549, MES-SA, and MES-SA/Dx5, were increased by exposure to MF. When exposed to MF and an anticancer drug, changes in the membrane potentials were detected in A549 and MES-SA cells, but not in the multi drug-resistant cells, MES-SA/Dx5. We examined whether MF has an influence on the membrane proteins extracted from 549 cells, using a fluorescence dye. The increase in fluorescence observed following MF exposure indicated that the structure of the hydrophobic site on the membrane proteins changed. These results indicated that 60 Hz MF causes changes in the membrane potential of cancer cells and the conformation of membrane proteins extracted from cancer cells.ヒト肺がん細胞株A549、ヒト子宮肉腫細胞株MES-SAおよびMES-SA由来の多剤耐性細胞株MES-SA/Dx5を用いて、細胞膜電位への磁場影響を測定した結果、磁場のみ曝露の場合はどの細胞の膜電位も2.5～3 mV 増加、抗がん剤＋磁場の併用の場合にはA549 とMES-SA細胞では膜電位の増加が見られたのに対し、MES-SA/Dx5細胞では変化が見られなかった。さらにA549細胞から非変性的に抽出した膜タンパク質の立体構造は、磁場曝露により変化することを示す結果が得られた。これらの本研究結果より、磁場は細胞膜電位と一部の膜タンパク質の構造を変化させ、その変化は可逆的であることが示唆された。研究課題/領域番号:19K12819, 研究期間(年度):2019-04-01 - 2022-03-31出典：研究課題「抗がん剤作用への磁場影響メカニズムの解明」課題番号19K12819
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/ja/report/KAKENHI-PROJECT-19K12819/19K12819seika/）を加工して作成金沢大学理工研究域生命理工学系research repor
Development of targeted techniques of anticancer drug using magnetic fields
Get PDF大腸菌の実験系では、交流磁場曝露により薬剤作用が増強される結果が得られており、本研究ではヒトがん細胞における交流磁場曝露の薬剤作用への効果を検討するため、まずCO2インキュベータ内に設置できる磁場曝露システムを製作した。その装置を用いてヒト肺がん細胞株A549におけるシスプラチン作用への交流磁場影響を測定したところ、磁場曝露群（60 Hz, 50 mT, 24時間)は非曝露群に比べ生細胞数が減少し、磁場による薬剤作用の増強が認められた。Our results in previous study indicated that magnetic fields (60 Hz, 50 mT) enhance the potency of drugs in bacterial cells and suggested that magnetic fields change the permeability of cell membrane and increase drug uptake. If magnetic fields enable us to enhance the potency of anticancer drug on target region only, the dosage can be reduced and thus side effects can be suppressed in clinical cancer chemotherapy. In present study, we made a magnetic fields exposure system for cultured human cells and measured the effect of magnetic fields on a potency of anticancer drug, cisplatin to human lung cancer cell line. The viabilities of A549 cells treated with cisplatin only and cisplatin under magnetic fields exposure (60 Hz, 50 mT for 24 hours) were measured by colony assay. The result suggested that magnetic fields (60 Hz, 50 mT for 24 hours) enhance the potency of cisplatin on human cancer cells.研究課題/領域番号:24500541, 研究期間(年度):2012-04-01 – 2015-03-31出典：研究課題「交流磁場を用いた抗がん剤の標的治療技術の開発」課題番号24500541
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-24500541/24500541seika/)を加工して作成金沢大学環日本海域環境研究センターresearch repor
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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