Dynamic organization of cortical actin filaments during the ooplasmic segregation of ascidian Ciona eggs

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ishii, H., & Tani, T. Dynamic organization of cortical actin filaments during the ooplasmic segregation of ascidian Ciona eggs. Molecular Biology of the Cell, 32(3), (2021): 274-288, https://doi.org/10.1091/mbc.E20-01-0083.Spatial reorganization of cytoplasm in zygotic cells is critically important for establishing the body plans of many animal species. In ascidian zygotes, maternal determinants (mRNAs) are first transported to the vegetal pole a few minutes after fertilization and then to the future posterior side of the zygotes in a later phase of cytoplasmic reorganization, before the first cell division. Here, by using a novel fluorescence polarization microscope that reports the position and the orientation of fluorescently labeled proteins in living cells, we mapped the local alignments and the time-dependent changes of cortical actin networks in Ciona eggs. The initial cytoplasmic reorganization started with the contraction of vegetal hemisphere approximately 20 s after the fertilization-induced [Ca2+] increase. Timing of the vegetal contraction was consistent with the emergence of highly aligned actin filaments at the cell cortex of the vegetal hemisphere, which ran perpendicular to the animal–vegetal axis. We propose that the cytoplasmic reorganization is initiated by the local contraction of laterally aligned cortical actomyosin in the vegetal hemisphere, which in turn generates the directional movement of cytoplasm within the whole egg.We deeply thank Shalin Mehta for use of his MATLAB codes for our fluorescence polarization analyses and Mark Terasaki for reading our manuscript and giving us helpful feedback. We thank William Jeffery for sharing information about local C. intestinalis around the Marine Biological Laboratory. We also thank Takahito Nishikata and Takehiro G. Kusakabe for their generous support and kind suggestions for our experiments. Our research was supported by National Institutes of Health grant R01 GM100160, Japan Society for the Promotion of Science KAKENHI grant JP18K19962 to T.T., institutional funds of the Marine Biological Laboratory to T.T. and H.I., and a TOYOBO Biotechnology Foundation long-term fellowship to H.I

Analysis of Chinese Graded Readers: Regarding Appropriateness of Extensive Reading

本論文は中国語学習者のために制作された初級段階別読み物（GR）が多読活動を行う上で日本人学習者に適しているのか、また適した読み物はどのような特徴があるのか探ったものである。本研究では現在出版されている中国語GRの中でも初級者用の比較的多読活動に適していると思われるGRを取り上げ、これらのGRに用いられている語彙や文法項目が初級学習者のレベルに適切か考察し、されあに１年間の中国語学習を終えた学生を被験者と死、これらのGRの理解度を図った。分析の結果、中国語GRには多くの未習語彙が用いられているが、これらが学習者の理解度には影響を与えないということが分かった。また理解度が高いGRは学習者がイラストを手掛かりに未習語彙の意味を理解しているということが分かった

Spatially resolved metabolic distribution for unraveling the physiological change and responses in tomato fruit using matrix-assisted laser desorption/ionization–mass spectrometry imaging (MALDI–MSI)

Information on spatiotemporal metabolic behavior is indispensable for a precise understanding of physiological changes and responses, including those of ripening processes and wounding stress, in fruit, but such information is still limited. Here, we visualized the spatial distribution of metabolites within tissue sections of tomato (Solanum lycopersicum L.) fruit using a matrix-assisted laser desorption/ionization–mass spectrometry imaging (MALDI–MSI) technique combined with a matrix sublimation/recrystallization method. This technique elucidated the unique distribution patterns of more than 30 metabolite-derived ions, including primary and secondary metabolites, simultaneously. To investigate spatiotemporal metabolic alterations during physiological changes at the whole-tissue level, MALDI–MSI was performed using the different ripening phenotypes of mature green and mature red tomato fruits. Although apparent alterations in the localization and intensity of many detected metabolites were not observed between the two tomatoes, the amounts of glutamate and adenosine monophosphate, umami compounds, increased in both mesocarp and locule regions during the ripening process. In contrast, malate, a sour compound, decreased in both regions. MALDI–MSI was also applied to evaluate more local metabolic responses to wounding stress. Accumulations of a glycoalkaloid, tomatine, and a low level of its glycosylated metabolite, esculeoside A, were found in the wound region where cell death had been induced. Their inverse levels were observed in non-wounded regions. Furthermore, the amounts of both compounds differed in the developmental stages. Thus, our MALDI–MSI technique increased the understanding of the physiological changes and responses of tomato fruit through the determination of spatiotemporally resolved metabolic alterations

Open MRI Operating Room with Automatic Electronic Recording of Medical Equipment Provided by Wireless LAN - Anesthesia Care Experience of ２５ Cases in Hiroshima University Hospital

オープンMRI設置手術室で25例の麻酔を経験した。MRI設置手術室では術中にMRI画像を判断材料として手術をすすめるため，MRI画像へのノイズ混入対策が必要である。また，MRI磁場の影響で術中にモニター機器や麻酔器が誤動作を起こす可能性があるため，MRI非対応機器からの画像ノイズの遮断対策として，電子機器から発生するノイズの軽減には特殊シールドボックスやイキソルメッシュを使用し，手術室外からのノイズには手術室全体にシールド工事を行った。MRIが発生させる磁場による電子機器の誤動作・故障対策は，オープンMRIの磁場が5ガウス以下となる範囲に電子機器や手術器具を置くことで対応した。問題の克服に加えて，医療機器からのデータの無線通信により，ケーブル類をなくすことでMRI撮影時の患者移動の簡素化をはかり，安全性を高めることができた。We provided anesthesia care for 25 patients in an open MRI operating room and summarized here our experience. When surgeons use MRI during surgery, the presence of noise in the images caused by other electronic equipment in the area often hinders accurate diagnosis.　In addition, malfunction of monitoring and anesthesia equipment during surgery due to the MRI magnetic field created during an MR examination can occur. In order to prevent imaging interference affecting equipment not compatible with MRI, we utilized 2 specially prepared shield boxes and wrapped the personal computer used for coordinating the data with a mesh-like cloth made by Ixol-mesh.　In addition, we prepared a shielded operating room in order to block noise from the outside. To prevent malfunction of the surgical and electronic instruments, we kept them outside the magnetic field of 5 Gauss or lower to minimize the magnetic effect generated with MRI.　Furthermore, patient safety during MRI imaging was improved by establishing a wireless communication system to feed data from medical devices, which allowed elimination of cabling

Human A-myb gene encodes a transcriptional activator containing the negative regulatory domains

AbstractThe myb gene family has three members, c-myb, A-myb, and B-myb. A-myb mRNA is mainly expressed in testis and peripheral blood leukocytes. A-Myb can activate transcription from the promoter containing Myb-binding sites in all cells examined. In addition to the two domains (a DNA-binding domain and a transcriptional activation domain), two negative regulatory domains have been identified in A-Myb. These results indicate that A-Myb functions as a transcriptional activator mainly in testis and peripheral blood cells, and the regulatory mechanism of A-Myb activity is similar to that of c-Myb

Oligomerization of Hepatitis C Virus Core Protein is Crucial for Interaction with the Cytoplasmic Domain of E1 Envelope Protein

Hepatitis C virus (HCV) contains two membrane-associated envelope glycoproteins, E1 and E2, which assemble as a heterodimer in the endoplasmic reticulum (ER). In this study, predictive algorithms and genetic analyses of deletion mutants and glycosylation site variants of the E1 glycoprotein were used to suggest that the glycoprotein can adopt two topologies in the ER membrane: the conventional type I membrane topology and a polytopic topology in which the protein spans the ER membrane twice with an intervening cytoplasmic loop (amino acid residues 288 to 360). We also demonstrate that the E1 glycoprotein is able to associate with the HCV core protein, but only upon oligomerization of the core protein in the presence of tRNA to form capsid-like structures. Yeast two-hybrid and immunoprecipitation analyses reveal that oligomerization of the core protein is promoted by amino acid residues 72 to 91 in the core. Furthermore, the association between the E1 glycoprotein and the assembled core can be recapitulated using a fusion protein containing the putative cytoplasmic loop of the E1 glycoprotein. This fusion protein is also able to compete with the intact E1 glycoprotein for binding to the core. Mutagenesis of the cytoplasmic loop of E1 was used to define a region of four amino acids (residues 312 to 315) that is important for interaction with the assembled HCV core. Taken together, our studies suggest that interaction between the self-oligomerized HCV core and the E1 glycoprotein is mediated through the cytoplasmic loop present in a polytopic form of the E1 glycoprotein

Coronary Artery Disease/Effects of Ablation on Cardiac Reserve

The effects of catheter ablation on exercise tolerance and quality of life in patients with atrial fibrillation (AF) have been reported. We assessed cardiac function in more detail using the leg positive pressure (LPP) technique and found that contractile reserve is particularly important in relation to exercise tolerance and prognosis. In this study, we used the LPP technique to examine changes in contractile reserve immediately after ablation and 6 months later. We prospectively enrolled patients who underwent catheter ablation for AF at 2 institutes. We performed LPP stress echocardiography 2 to 3 days after (FU-1) and 6 months after (FU-2) ablation to examine changes in cardiac function indexes. The primary end point was improvement in contractile reserve. Ultimately, 109 patients (mean age 67.4 ± 9.6 years; 70% men) underwent 2 sessions of LPP stress echocardiography. The median CHA2DS2-VASC score was 2 (interquartile range 13). From FU-1 to FU-2, the change in the stroke volume index after the LPP maneuver increased in patients with paroxysmal and persistent AF with low CHA2DS2-VASC scores (both p <0.05). Regardless of AF subtype, contractile reserve at FU-2 improved in patients with low CHA2DS2-VASC scores compared with that at FU-1. In contrast, patients with high CHA2DS2-VASC scores had no change. In conclusion, patients with AF with a low CHA2DS2-VASC score had improved contractile reserve after ablation, whereas patients with high scores did not show any improvement. Aggressive interventions in patients with high scores may lead to better management after catheter ablation