62 research outputs found

    Liposome-based liquid handling platform featuring addition, mixing, and aliquoting of femtoliter volumes

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    This paper describes the utilization of giant unilamellar vesicles (GUVs) as a platform for handling chemical and biochemical reagents. GUVs with diameters of 5 to 10 µm and containing chemical/biochemical reagents together with inert polymers were fused with electric pulses (electrofusion). After reagent mixing, the fused GUVs spontaneously deformed to a budding shape, separating the mixed solution into sub-volumes. We utilized a microfluidic channel and optical tweezers to select GUVs of interest, bring them into contact, and fuse them together to mix and aliquot the reaction product. We also show that, by lowering the ambient temperature close to the phase transition temperature Tm of the lipid used, daughter GUVs completely detached (fission). This process performs all the liquid-handing features used in bench-top biochemistry using the GUV, which could be advantageous for the membrane-related biochemical assays

    Ventricular pacing inhibition by oversensing due to diaphragmatic myopotential during deep inspiration

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    AbstractAn 80-year-old man, who had dilated cardiomyopathy with right ventricular (RV) dilatation, underwent implantable cardioverter defibrillator (ICD) implantation for advanced atrioventricular block and primary prevention of sudden cardiac death. Tined and screw-in leads were placed on the right atrial appendage and RV apex, respectively. Ventricular pacing inhibition was detected after surgery due to oversensing by diaphragmatic myopotential occurring only during deep inspiration. We performed re-surgery and switched the screw-in lead for a tined lead. The diaphragmatic myopotential decreased, thereby improving oversensing by diaphragmatic myopotential and ventricular pacing inhibition. It might be beneficial to use a tined lead when placing the ventricular lead at the RV apex for implantation of a pacemaker or ICD if oversensing of diaphragmatic myopotential is observed using a screw-in lead.<Learning objective: Oversensing due to diaphragmatic myopotential is rarely observed. However if it occurs, it becomes a critical problem, which causes pacemaker inhibition or inappropriate ICD shock. However, the method of preventing this problem is unknown. In this case, we demonstrated that a tined-lead may be useful for the prevention of oversensing by diaphragmatic myopotential.

    TNF-α–Converting Enzyme/A Disintegrin and Metalloprotease−17 Mediates Mechanotransduction in Murine Tracheal Epithelial Cells

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    Bronchoconstriction applies compressive stress to airway epithelial cells. We show that the application of compressive stress to cultured murine tracheal epithelial cells elicits the increased phosphorylation of extracellular signal–regulated kinase (ERK) and Akt through an epidermal growth factor receptor (EGFR)–dependent process, consistent with previous observations of the bronchoconstriction-induced activation of EGFR in both human and murine airways. Mechanotransduction requires metalloprotease activity, indicating a pivotal role for proteolytic EGF-family ligand shedding. However, cells derived from mice with targeted deletions of the EGFR ligands Tgfα and Hb-egf showed only modest decreases in responses, even when combined with neutralizing antibodies to the EGFR ligands epiregulin and amphiregulin, suggesting redundant or compensatory roles for individual EGF family members in mechanotransduction. In contrast, cells harvested from mice with a conditional deletion of the gene encoding the TNF-α–converting enzyme (TACE/ADAM17), a sheddase for multiple EGF-family proligands, displayed a near-complete attenuation of ERK and Akt phosphorylation responses and compressive stress–induced gene regulation. Our data provide strong evidence that TACE plays a critical central role in the transduction of compressive stress

    構造研究に基づく南海トラフ(西部)地震発生帯のプレート形状および速度構造の3次元モデル

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    Great interplate earthquakes have repeatedly occurred in pairs along the Nankai Trough. In order to reduce a great deal of damage to coastal area from both strong ground motion and tsunami generation, it is necessary to understand rupture synchronization and segmentation of the Nankai megathrust earthquake. For a precise estimate of the rupture zone of the Nankai megathrust event based on the knowledge of realistic earthquake cycles and variations of magnitude, it is important to know the geometry and property of the plate boundary of the subduction seismogenic zone. To improve a physical model of the Nankai Trough seismogenic zone, the large-scale high-resolution wide-angle and reflection (MCS) seismic studies, and long-term observation have been conducted since 2008. Marine active source seismic data have been acquired along grid two-dimensional profiles having the total length of ~800km per year. A three-dimensional seismic tomography using active and passive seismic data observed both land and ocean bottom stations have been also performed. This study is part of 'Research concerning Interaction Between the Tokai, Tonankai and Nankai Earthquakes' funded by Ministry of Education, Culture, Sports, Science and Technology, Japan. The seismic survey was conducted off the Tokai area including the onshore survey across the eastern Kii Peninsula in 2012, the final year of this project. Compiling those studies provides a three-dimensional plate geometry and velocity structure models of the western Nankai Trough at the moment. Although their reliability and resolution should be evaluated, these models can be applied to a numerical simulation to examine if the observed rupture zone of the historical event can be reproduced. We will also try to construct more fine-scale model for the entire Nankai Trough area.SSS31-P15ポスター要旨 / 日本地球惑星科学連合2013年大会(2013年5月19日~5月24日, 幕張メッセ国際会議場) / 日本惑星科学連合の許諾に基づき本文ファイルを掲載http://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr10-11/ehttp://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr11-09/

    Structural variation from off Shikoku to the Kii Peninsula related to various earhthquake phenomena

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    南海トラフで繰り返し発生する巨大地震の中には、東海・東南海・南海地震が連動して発生する超巨大地震のケースがあることが指摘されている。このような超巨大地震について、どのような場合に連動し、あるいは非連動性巨大地震となるのかを明らかにすることが必要である。連動型地震の滑り域の範囲がどこまで広がるかを見積もることが重要な課題であり、そのためには南海トラフから沈み込むフィリピン海プレートの形状およびプレート境界周辺の構造、地震活動に関する詳細かつ高精度な情報が必要である。また、南海地震単独で発生した場合についても、深部および浅部低周波地震発生域まで含めた正確な破壊の広がりの把握、複雑な破壊分布の原因を明らかにするために南海地震破壊域とその縁辺での地殻構造や地震活動は重要な情報となる。平成20年度は日向灘、平成21年度は四国沖で調査を実施し、平成22年度は調査海域を東方の紀伊半島沖まで拡大し、沈み込み帯の地殻構造、巨大地震の発生、地震活動の相互関係の解明を目的として、南海・地震破壊域における沈み込みに関する詳細な構造のイメージングおよび地震のアスペリティに関する構造を明らかにするためのデータの取得、および西南日本の付加体先端部付近で発生している低周波地震や微動を含む自然地震観測を実施した。  本講演では、四国沖?紀伊半島沖の平成21~22年度の調査結果について述べる。平成21年10月、および平成22年10~11月、(独)海洋研究開発機構の海洋調査船「かいれい」によって短周期海底地震計各々180台と大容量チューンドエアガン(7800cu. in.)を用いた屈折法・広角反射法探査を実施した(図1)。海底地震計設置期間中に自然地震観測も実施した。四国沖では21観測点、紀伊半島沖では20観測点による約9ヶ月間の長期地震観測も実施した(一部実施中)。なお、本調査は文部科学省からの受託研究「東海・東南海・南海地震の連動性評価のための 調査観測・研究」の個別研究テーマ「南海トラフ域海域地震探査・地震観測」(平成20年度から受託)の一環として実施した。  一部の調査測線の解析の結果、足摺岬沖から日向灘に向かって約6km/sの古い付加体を示す岩体の分布が海側に張り出していること、また、SK05の構造モデルによると、SK03とSK02の中間付近からSK01付近までの付加堆積物が極端に薄いことなど、トラフ平行方向に構造変化があることがわかり、破壊様式の違いに関係する構造ではないかと考えられる。また、測線延長上のHi-net陸上観測点のデータを加えた海陸統合解析を実施しており、これにより深部低周波地震現象と構造との関連性が明らかになると期待されるC11-10発表要旨, 日本地震学会2011年度秋季大会(2011年10月12日~15日, 静岡県静岡市

    The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

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    「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    Prominent reflector beneath around the segmentation boundary between Tonankai-Nankai earthquake area

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    In the Nankai Trough subduction seismogenic zone, the Nankai and Tonankai earthquakes had often occurred simultaneously, and caused a great event. In most cases, first break of such large events of Nankai Trough usually begins from southwest off the Kii Peninsula so far. The idea of split Philippine Sea plate between the Kii Peninsula and the Shikoku Island, which explains seismicity, tectonic background, receiver function image and historical plate motion, was previously suggested. Moreover, between the Kii Peninsula and the Shikoku Island, there is a gap of deep low-frequency events observed in the belt-like zone along the strike of the subducting Philippine Sea plate. In 2010 and 2011, we conducted the large-scale high-resolution wide-angle and reflection (MCS) seismic study, and long-term observation from off Shikoku and Kii Peninsula. Marine active source seismic data have been acquired along grid two-dimensional profiles having the total length of ~800km/year. A three-dimensional seismic tomography using active and passive seismic data observed both land and ocean bottom stations have been also performed. From those data, we found a possible prominent reflector imaged in the offshore side in the Kii channel at the depth of ~18km. The velocity just beneath the reflector cannot be determined due to the lack of ray paths. Based of the amplitude information, we interpret the reflector as the forearc Moho based on the velocity gap (from ~6.4km/s to ~7.4km/s). However, the reflector is shallower than the forearc Moho of other area along the Nankai Trough. Similar reflectors are recognized along other seismic profiles around the Kii channel. In this presentation, we will show the result of structure analysis to understand the peculiar structure including the prominent reflector around the Kii channel. Relation between the structure and the existence of the segmentation of the Nankai megathrust earthquake or seismic gap of the deep low-frequency events will be also discussed. This study is part of 'Research concerning Interaction Between the Tokai, Tonankai and Nankai Earthquakes' funded by Ministry of Education, Culture, Sports, Science and Technology, Japan.Poster abstract T43C-2670 presented at 2013 Fall Meeting, AGU, San Francisco, Calif., 9-13 Dec
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