Science News | January 25(2), 2008

# 今日は多いな

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Biotechnology Japan | 心筋梗塞修復の関連たんぱく質、東工大グループが機能を解明

Periostin is essential for cardiac healing after acute myocardial infarction.
Masashi Shimazaki, Kazuto Nakamura, Isao Kii, Takeshi Kashima, Norio Amizuka, Minqi Li, Mitsuru Saito, Keiichi Fukuda, Takashi Nishiyama, Satoshi Kitajima, Yumiko Saga, Masashi Fukayama, Masataka Sata, Akira Kudo.
The Journal of Experimental Medicine, Latest Articles | doi:10.1084/jem.20071297

Acute myocardial infarction (AMI) is a common and lethal heart disease, and the recruitment of fibroblastic cells to the infarct region is essential for the cardiac healing process. Although stiffness of the extracellular matrix in the infarct myocardium is associated with cardiac healing, the molecular mechanism of cardiac healing is not fully understood. We show that periostin, which is a matricellular protein, is important for the cardiac healing process after AMI. The expression of periostin protein was abundant in the infarct border of human and mouse hearts with AMI. We generated periostin^–/– mice and found no morphologically abnormal cardiomyocyte phenotypes; however, after AMI, cardiac healing was impaired in these mice, resulting in cardiac rupture as a consequence of reduced myocardial stiffness caused by a reduced number of α smooth muscle actin–positive cells, impaired collagen fibril formation, and decreased phosphorylation of FAK. These phenotypes were rescued by gene transfer of a spliced form of periostin. Moreover, the inhibition of FAK or αv-integrin, which blocked the periostin-promoted cell migration, revealed that αv-integrin, FAK, and Akt are involved in periostin signaling. Our novel findings show the effects of periostin on recruitment of activated fibroblasts through FAK-integrin signaling and on their collagen fibril formation specific to healing after AMI.

　# 急性心筋梗塞後の心筋回復に必須なタンパク質が見つかったそうです

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Biotechnology Japan | MIT、理研の利根川教授ら、海馬の神経回路を遮断した「物覚えが悪い」マウスを作製

その名は「ＤＩＣＥ―Ｋ」…利根川教授が遺伝子操作技術開発 : 科学 : YOMIURI ONLINE（読売新聞）

脳神経回路：遮断し復元…記憶や学習探る　利根川教授ら - 毎日ｊｐ(毎日新聞)

asahi.com： 利根川教授ら「ダイスケ」開発　神経回路をオン・オフ - サイエンス

神経回路を遮断し回復する技術を世界で始めて開発 | 独立行政法人 理化学研究所 研究成果

Transgenic Inhibition of Synaptic Transmission Reveals Role of CA3 Output in Hippocampal Learning.
Toshiaki Nakashiba, Jennie Z. Young, Thomas J. McHugh, Derek L. Buhl, Susumu Tonegawa.
Science, Science Express | DOI: 10.1126/science.1151120

The hippocampus is an area of the brain involved in learning and memory. It contains parallel excitatory pathways referred to as the trisynaptic pathway (which carries information from the entorhinal cortex → dentate gyrus → CA3 → CA1 →entorhinal cortex) and the monosynaptic pathway (which connects entorhinal cortex → CA1 → entorhinal cortex). We developed a generally applicable tetanus toxin-based method for transgenic mice that permits inducible and reversible inhibition of synaptic transmission and applied it to the trisynaptic pathway while preserving transmission in the monosynaptic pathway. We found that synaptic output from CA3 in the trisynaptic pathway is dispensable and the short monosynaptic pathway is sufficient for incremental spatial learning. In contrast, the full trisynaptic pathway containing CA3 is required for rapid, one-trial contextual learning, for pattern completionbased memory recall and for spatial tuning of CA1 cells.

　# 「doxycycline-inhibited circuit exocytosis-knock down」＝「DICE-K」だそうです

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ゲノム：ＤＮＡを人工的に完全合成　米チームが成功 - 毎日ｊｐ(毎日新聞)

asahi.com： 細菌ゲノム、完全合成　米チーム「人工生命」に前進 - サイエンス

細菌のゲノム合成に成功：2008年中に合成生命も？ | WIRED VISION

人工生命の創造近づく？細菌ゲノムの合成に成功、米研究チーム 国際ニュース : AFPBB News

Complete Chemical Synthesis, Assembly, and Cloning of a Mycoplasma genitalium Genome.
Daniel G. Gibson, Gwynedd A. Benders, Cynthia Andrews-Pfannkoch, Evgeniya A. Denisova, Holly Baden-Tillson, Jayshree Zaveri, Timothy B. Stockwell, Anushka Brownley, David W. Thomas, Mikkel A. Algire, Chuck Merryman, Lei Young, Vladimir N. Noskov, John I. Glass, J. Craig Venter, Clyde A. Hutchison III, Hamilton O. Smith.
Science, Science Express | DOI: 10.1126/science.1151721

We have synthesized a 582,970 bp Mycoplasma genitalium genome. This synthetic genome, named M. genitalium JCVI-1.0, contains all the genes of wild-type M. genitalium G37 except MG408, which was disrupted by an antibiotic marker to block pathogenicity and to allow for selection. To identify the genome as synthetic, we inserted "watermarks" at intergenic sites known to tolerate transposon insertions. Overlapping "cassettes" of 5 to 7 kb, assembled from chemically synthesized oligonucleotides, were joined by in vitro recombination to produce intermediate assemblies of approximately 24 kb, 72 kb ("1/8 genome"), and 144 kb ("1/4 genome"), which were all cloned as bacterial artificial chromosomes (BACs) in Escherichia coli. Most of these intermediate clones were sequenced, and clones of all four 1/4 genomes with the correct sequence were identified. The complete synthetic genome was assembled by transformation-associated recombination (TAR) cloning in the yeast Saccharomyces cerevisiae, then isolated and sequenced. A clone with the correct sequence was identified. The methods described here will be generally useful for constructing large DNA molecules from chemically synthesized pieces and also from combinations of natural and synthetic DNA segments.

　# 不覚にもこんな記事が昨年の10月に出ていたのを見落としていたようです
　# ていうか、何か見覚えがあるのに何で取り上げなかったんだろう…

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世界初、肝臓移植後に血液型変わる 国際ニュース : AFPBB News

Chimerism and Tolerance in a Recipient of a Deceased-Donor Liver Transplant.
Stephen I. Alexander, Neil Smith, Min Hu, Deborah Verran, Albert Shun, Stuart Dorney, Arabella Smith, Boyd Webster, Peter John Shaw, Ahti Lammi, Michael O. Stormon.
NEJM 358, 369-374 (2008) | doi:

Complete hematopoietic chimerism and tolerance of a liver allograft from a deceased male donor developed in a 9-year-old girl, with no evidence of graft-versus-host disease 17 months after transplantation. The tolerance was preceded by a period of severe hemolysis, reflecting partial chimerism that was refractory to standard therapies. The hemolysis resolved after the gradual withdrawal of all immunosuppressive therapy.

　# 何が凄いって、肝臓を移植したら、ついでに血液型から免疫系までまるっと移植されちゃって、拒否反応も出なかったという…

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中日新聞:がん防ぐ酵素を特定　ＤＮＡの傷すぐ察知:社会(CHUNICHI Web)

Chk1 Is a Histone H3 Threonine 11 Kinase that Regulates DNA Damage-Induced Transcriptional Repression.
Midori Shimada, Hiroyuki Niida, Doaa H. Zineldeen, Hideaki Tagami, Masafumi Tanaka, Hiroyuki Saito, Makoto Nakanishi.
Cell 132, 221-232 (2008) | DOI 10.1016/j.cell.2007.12.013

DNA damage results in activation or suppression of transcription of a large number of genes. Transcriptional activation has been well characterized in the context of sequence-specific DNA-bound activators, whereas mechanisms of transcriptional suppression are largely unexplored. We show here that DNA damage rapidly reduces histone H3 Threonine 11 (T11) phosphorylation. This correlates with repression of genes, including cyclin B1 and cdk1. H3-T11 phosphorylation occurs throughout the cell cycle and is Chk1 dependent in vivo. Following DNA damage, Chk1 undergoes rapid chromatin dissociation, concomitant with reduced H3-T11 phosphorylation. Furthermore, we find that loss of H3-T11 phosphorylation correlates with reduced binding of the histone acetyltransferase GCN5 at cyclin B1 and cdk1 promoters and reduced H3-K9 acetylation. We propose a mechanism for Chk1 as a histone kinase, responsible for DNA-damage-induced transcriptional repression by loss of histone acetylation.

　# Chk1がHistone H3のThreonineキナーゼで、そのリン酸化の有無がヒストンアセチル化の損失による損傷誘導転写を抑制しているそうな

Science News | January 25(1), 2008

The Biodesign Institute: Nanotechnology innovation may revolutionize gene detection in a single cell

Self-Assembled Water-Soluble Nucleic Acid Probe Tiles for Label-Free RNA Hybridization Assays.
Yonggang Ke, Stuart Lindsay, Yung Chang, Yan Liu, Hao Yan.
Science 319, 180-183 (2008) | DOI: 10.1126/science.1150082

The DNA origami method, in which long, single-stranded DNA segments are folded into shapes by short staple segments, was used to create nucleic acid probe tiles that are molecular analogs of macroscopic DNA chips. One hundred trillion probe tiles were fabricated in one step and bear pairs of 20-nucleotide-long single-stranded DNA segments that act as probe sequences. These tiles can hybridize to their targets in solution and, after adsorption onto mica surfaces, can be examined by atomic force microscopy in order to quantify binding events, because the probe segments greatly increase in stiffness upon hybridization. The nucleic acid probe tiles have been used to study position-dependent hybridization on the nanoscale and have also been used for label-free detection of RNA.

　# プレスリリースのページはどこだ？
　# KU君、サンキュー
　# 文字制限の関係でこちらより移動しました…論文を教えてもらったので…

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耳の“電池”が音を増幅　大阪大など発表 - MSN産経ニュース

The endocochlear potential depends upon two K+ diffusion potentials and an electrical barrier in the stria vascularis of the inner ear.
Fumiaki Nin, Hiroshi Hibino, Katsumi Doi, Toshihiro Suzuki, Yasuo Hisa, Yoshihisa Kurachi.
Proc. Natl. Acad. Sci. USA, Early Edition | doi:10.1073/pnas.0711463105

An endocochlear potential (EP) of +80 mV is essential for audition. Although the regulation of K⁺ concentration ([K⁺]) in various compartments of the cochlear stria vascularis seems crucial for the formation of the EP, the mechanism remains uncertain. We have used multibarreled electrodes to measure the potential, [K⁺], and input resistance in each compartment of the stria vascularis. The stria faces two fluids, perilymph and endolymph, and contains an extracelluar compartment, the intrastrial space (IS), surrounded by two epithelial layers, the marginal cell (MC) layer and that composed of intermediate and basal cells. Fluid in the IS exhibits a low [K⁺] and a positive potential, called the intrastrial potential (ISP). We found that the input resistance of the IS was high, indicating this space is electrically isolated from the neighboring extracellular fluids. This arrangement is indispensable for maintaining positive ISP. Inhibiting the K⁺ transporters of the stria by anoxia, ouabain, or bumetanide caused the [K⁺] of the IS to increase and the intracellular [K⁺] of MCs to decrease, reducing both the ISP and the EP. Calculations indicate that the ISP represents the K⁺ diffusion potential across the apical membranes of intermediate cells through Ba²⁺-sensitive K⁺ channels. The K⁺ diffusion potential across the apical membranes of MCs also contributes to the EP. Because the EP depends on two K⁺ diffusion potentials and an electrical barrier in the stria vascularis, interference with any of these elements can interrupt hearing.

　# 産経、先走りすぎ…
　# 年末に亡くなった祖母ちゃんも難聴もこれが原因かしら？

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妊婦のカフェイン摂取は流産リスク高める、米研究 国際ニュース : AFPBB News

Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study.
Weng X, Odouli R, and Li D-K.
Am J Obstet Gynecol 2008;xx:xx-xx.

OBJECTIVE: The objective of the study was to examine whether the risk of miscarriage is associated with caffeine consumption during pregnancy after controlling for pregnancy-related symptoms.

STUDY DESIGN: This was a population-based prospective cohort study.

RESULTS: An increasing dose of daily caffeine intake during pregnancy was associated with an increased risk of miscarriage, compared with no caffeine intake, with an adjusted hazard ratio (aHR) of 1.42 (95% confidence interval 0.93 to 2.15) for caffeine intake of less than 200 mg/day, and aHR of 2.23 (1.34 to 3.69) for intake of 200 or more mg/day, respectively. Nausea or vomiting during pregnancy did not materially affect this observed association, nor did the change in intake pattern of caffeine during pregnancy. In addition, the magnitude of the association appeared to be stronger among women without a history of miscarriage (aHR 2.33, 1.48 to 3.67) than that among women with such a history (aHR 0.81, 0.34 to 1.94).

CONCLUSION: Our results demonstrated that high doses of caffeine intake during pregnancy increase the risk of miscarriage, independent of pregnancy-related symptoms.

　# まだpdfしか公開されていません
　# 妊娠したらコーヒーだけじゃなくお茶や紅茶も控えましょう

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二酸化炭素：化石燃料発生の３０％は海吸収、１４％は森林 - 毎日ｊｐ(毎日新聞)

記者発表2008年1月23日大気中酸素濃度の減少量から二酸化炭素の陸域生物圏吸収量の推定に成功-放出された化石燃料起源の二酸化炭素の30％が海洋に、14％が陸域生物圏に吸収- | 国立環境研究所

Atmospheric O₂/N₂ measurements at two Japanese sites: estimation of global oceanic and land biotic carbon sinks and analysis of the variations in atmospheric potential oxygen (APO).
Yasunori Tohjima, Hitoshi Mukai, Yukihiro Nojiri, Hiroaki Yamagishi, Toshinobu Machida.
Tellus B, OnlineEarly Articles | doi:10.1111/j.1600-0889.2007.00334.x

We present measurements of atmospheric O₂/N₂ and CO₂ mixing ratios taken at Hateruma Island (HAT) and Cape Ochi-Ishi (COI) in Japan. Global carbon sinks are estimated from the tracer atmospheric potential oxygen (APO) calculated as the weighted sums of the observed O₂/N₂ and CO₂, and the global CO₂ data from the NOAA/ESRL GMD flask sampling network. The oceanic and land biotic sinks are 2.4 ± 0.7 and 0.5 ± 0.9 Pg C yr^－1, respectively, for the 7-yr period (July 1998–July 2005) and 2.1 ± 0.7 and 1.0 ± 0.9 Pg C yr^－1, respectively, for the 6-yr period (July 1999–July 2005). The former 7-yr estimates are based on the data from HAT only, while the latter 6-yr estimates are obtained using data from both HAT and COI. These estimations include an ocean outgassing correction of 0.48 Pg C yr^－1. The instantaneous rates of change in the APO trends show large interannual variability with peak-to-peak amplitudes of about 30 per meg yr^－1. The winter anomalies in the APO trend are the major contributor to the interannual variability, and the oceanic O₂ influx associated with winter ventilation may be a significant cause of the variability in APO.

　# 気候変動は海や森林の二酸化炭素吸収能力にも影響してくるだろうから、この値がずっと続くとは考えにくいだろうな

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ネット上で話題、NASAの公開画像に写っていた「宇宙人」 - Technobahn
　# まぁ、そう見ようと思えば見えるわな

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世界各地で人気を集める「サイエンスカフェ」 | WIRED VISION
　# もしかして、求めているものはこれかもしれない…

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乗客を乗せて飛ぶ初の民間宇宙船『SpaceShipTwo』、詳細を公開 | WIRED VISION
　# 昨日の記事の詳報です

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肺炎病原菌の新検査方法、山口大教授ら考案 : 山口 : 地域 : YOMIURI ONLINE（読売新聞）
　# 肝心の核酸増幅のところがさっぱり分からん

気になるニュース(1/25)

・朝鮮戦争時、韓国人25万人が同胞による虐殺の犠牲に、調査進む 国際ニュース : AFPBB News
　# 間近にあったkilling field…

・ロンドンの日本大使館で10代少女が反捕鯨活動 国際ニュース : AFPBB News
　# なぜクジラは素晴らしくて権利や愛が与えられるのに、牛などの家畜はそうではないのかを合理的に説明して欲しい

・ ミクシィ、mixi運営事務局を騙るメールや類似サイトに注意喚起
　# もの凄い勢いでブログアカウントの方に来ています

・Nokia、「打ったふり」を認識する仮想キーボード特許を出願 - Engadget Japanese
　# こりゃまたおもろいこと考えるなぁ

・Vista SP1は2月15日リリース？ - Engadget Japanese
　# 出ていると思っていたのはRCでした…

・450グラムの重りで飼い猫をジャンプさせない「訓練装置」 | WIRED VISION
　# 「この道具に残酷な点など一切ありません」云々…詭弁が現実を支配する妙な社会…

・時事ドットコム：「事件多い大阪の大学と違う」＝准教授、高校にファクス－京都府立大
　# まぁ、そういうことをいわれてしまう大府大・大市大にも問題がないとはいわないが…

・『トイ・ストーリー』シリーズ、デジタル3-Dで全作リメイク決定 | エンタテインメント | マイコミジャーナル
　# まぁ、一度は見てみたい

・『DEATH NOTE』のディレクターズカット完全決着版、遂にDVD化が決定! | ホビー | マイコミジャーナル
　# 最後の方だけ見れなかったんだよね、あのとき

・フリーなMac OS X用ウイルスチェッカー「ClamXav 1.1.0」 | パソコン | マイコミジャーナル
　# SymantecがLeopardに対応したCEを出す気配がないので助かります

・asahi.com：４人家族で最大１８００ドルの現金支給　米景気対策合意 - ビジネス
　# 米国の景気対策って、現金ばらまいたりするんだ

・医療ミス：「慰謝料は通常交通事故より高額」確定　最高裁 - 毎日ｊｐ(毎日新聞)
　# 7,200万円？2,700万円？どっち？

・「アンネの木」残った…アムステルダム市が伐採計画撤回 : 国際 : YOMIURI ONLINE（読売新聞）
　# 日本から樹医さんを派遣して差し上げたら如何ですか？

・仏の大手銀行、トレーダーの不正取引で巨額損失 : 国際 : YOMIURI ONLINE（読売新聞）
　# な、7,600億円の損失？その価値を生産するのにどれほどの労力が掛かると思っているんだ？

・かわいらしい？歴代首相の似顔絵タオル、参議院売店に登場 : 社会 : YOMIURI ONLINE（読売新聞）
　# これ欲しいな

・asahi.com：たまげた？直立ワニが人気　広島・宮島水族館 - 社会
　# なぜに立ち上がる？

・「ログインできない」「メールがない」――「エキサイトメール」リニューアルで不具合 - ITmedia News
　# エキサイトメールをメインに使ってなくてよかったぁ

・映画業界団体の違法コピー調査に誤り - ITmedia News
　# ま、日本みたいに想像で既得権を死守しようとするよりはマシかと

・asahi.com：ウイルス亜種１００種作成　多重感染型も　大学院生供述 - 社会
　# こいつ、相当鬱屈しているな

・asahi.com：運転の男、基準の９倍のアルコール　江戸川の交通事故 - 社会
　# げ…2.7 mg/mlも血中アルコール濃度があったってこと？よく運転できたな

超内輪ネタ

共同研究先の先生がネタで送ってきてくれた写真。

もうね、内輪の中でも極一部の人にしかウケないという、超特異ネタ。大半の方には何のことか分からない内容で大変申し訳ありません。

# しかし、TM先生ってお茶目だな

別意味気楽

某リーダーなるものにならなかったということは、今まで背負ってきた余分な仕事や悩み事、SVMとか人事考課とか中間管理職仕事から解放されるという意味だと考えればある意味気楽…

# 某リーダーの皆様、後は任せた…頑張ってね
# そうか、今度は下から文句を言う側に戻れるのか