145 research outputs found

    Sox14 is essential for initiation of interneuron differentiation in the chick spinal cord

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    The neural tube comprises several different types of progenitors and postmitotic neurons that coordinately act with each other to play integrated functions. Its development consists of two phases: proliferation of progenitor cells and differentiation into postmitotic neurons. How progenitor cells differentiate into each corresponding neuron is an important question for understanding the mechanisms of neuronal development. Here we introduce one of the Sox transcription factors, Sox14, which plays an essential role in the promotion of neuronal differentiation. Sox14 belongs to the SoxB subclass and its expression starts in the progenitor regions before neuronal differentiation is initiated at the trunk level of the neural tube. After neuronal differentiation is initiated, Sox14 expression gradually becomes confined to the V2a region of the neural tube, where Chx10 is co-expressed. Overexpression of Sox14 restricts progenitor cell proliferation. Conversely, the blockade of Sox14 expression by the RNAi strategy inhibits V2a neuron differentiation and causes expansion of the progenitor domain. We further found that Sox14 acted as a transcriptional activator. Taken together, Sox14 acts as a modulator of cell proliferation and an initiator protein for neuronal differentiation in the intermediate region of the neural tube

    Vestigial-like 2 contributes to normal muscle fiber type distribution in mice

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    Honda, M., Hidaka, K., Fukada, Si. et al. Vestigial-like 2 contributes to normal muscle fiber type distribution in mice. Sci Rep 7, 7168 (2017). https://doi.org/10.1038/s41598-017-07149-

    Light-dependent induction of Edn2 expression and attenuation of retinal pathology by endothelin receptor antagonists in Prominin-1- deficient mice

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    Retinitis pigmentosa (RP) and macular dystrophy (MD) are prevalent retinal degenerative diseases associated with gradual photoreceptor death. These diseases are often caused by genetic mutations that result in degeneration of the retina postnatally after it has fully developed. The Prominin-1 gene (Prom1) is a causative gene for RP and MD, and Prom1- knockout (KO) mice recapitulate key features of these diseases including light-dependent retinal degeneration and stenosis of retinal blood vessels. The mechanisms underlying progression of such degeneration have remained unknown, however. We here analysed early events associated with retinal degeneration in Prom1-KO mice. We found that photoreceptor cell death and glial cell activation occur between 2 and 3 weeks after birth. High-throughput analysis revealed that expression of the endothelin-2 gene (Edn2) was markedly up-regulated in the Prom1-deficient retina during this period. Expression of Edn2 was also induced by light stimulation in Prom1-KO mice that had been reared in the dark. Finally, treatment with endothelin receptor antagonists attenuated photoreceptor cell death, gliosis, and retinal vessel stenosis in Prom1-KO mice. Our findings suggest that inhibitors of endothelin signalling may delay the progression of RP and MD and therefore warrant further study as potential therapeutic agents for these diseases

    Genome-wide Analysis of Chlamydophila pneumoniae Gene Expression at the Late Stage of Infection

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    Chlamydophila pneumoniae, an obligate intracellular eubacterium, changes its form from a vegetative reticulate body into an infectious elementary body during the late stage of its infection cycle. Comprehension of the molecular events in the morphological change is important to understand the switching mechanism between acute and chronic infection, which is deemed to relate to the pathogenesis of atherosclerosis. Herein, we have attempted to screen genes expressed in the late stage with a genome-wide DNA microarray, resulting in nomination of 17 genes as the late-stage genes. Fourteen of the 17 genes and six other genes predicted as late-stage genes were confirmed to be up-regulated in the late stage with a quantitative reverse transcriptase–polymerase chain reaction. These 20 late-stage genes were classified into two groups by clustering analysis: ‘drastically induced’ and ‘moderately induced’ genes. Out of eight drastically induced genes, four contain σ28 promoter-like sequences and the other four contain an upstream common sequence. It suggests that besides σ28, there are certain up-regulatory mechanisms at the late stage, which may be involved in the chlamydial morphological change and thus pathogenesis

    Effects of Perioperative Management Training Program on the Awareness of Team Medicine among Trainee Dentists

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     質が高く、安心・安全な医療を実現していくために、チーム医療の促進は重要な課題であり、チーム医療を担う医療人の育成が必要とされている。岡山大学病院歯科医師臨床研修では、平成23年度から周術期管理センターを研修の場とする「チーム医療研修プログラム」を開始した。本報告では、研修歯科医のプログラムに対する関心とチーム医療に関する理解に与えた効果をアンケート調査によって検討することを目的とした。対象は平成23年度本学病院研修歯科医44名とし、医師、看護師、薬剤師、理学療法士、管理栄養士など多職種によって行われる周術期管理チーム医療を体験させた。受講前には本プログラムに対する期待度を、受講後には満足度、有意義度について質問し、研修歯科医のプログラムに対する関心度を評価した。また、プログラム受講前後に周術期チーム医療に関する用語や職種について質問し、チーム医療に関する理解度を評価した。90.9%の研修歯科医がプログラムに対して期待し、受講後は88.6%が満足だった、84.1%が有意義だったと回答した。さらに、周術期管理に関する用語について主観的理解度が向上し、チーム医療にかかわる職種についての理解が深まった。歯科医師臨床研修におけるチーム医療教育の方法として、周術期管理チーム医療の現場に実際に関与させるプログラムは、研修歯科医の関心が高く、研修歯科医の周術期管理チーム医療に対する理解を深めることが示唆された

    Observing and modeling the sequential pairwise reactions that drive solid-state ceramic synthesis

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    Solid-state synthesis from powder precursors is the primary processing route to advanced multicomponent ceramic materials. Designing ceramic synthesis routes is usually a laborious, trial-and-error process, as heterogeneous mixtures of powder precursors often evolve through a complicated series of reaction intermediates. Here, we show that phase evolution from multiple precursors can be modeled as a sequence of pairwise interfacial reactions, with thermodynamic driving forces that can be efficiently calculated using ab initio methods. Using the synthesis of the classic high-temperature superconductor YBa2_2Cu3_3O6+x_{6+x} (YBCO) as a representative system, we rationalize how replacing the common BaCO3_3 precursor with BaO2_2 redirects phase evolution through a kinetically-facile pathway. Our model is validated from in situ X-ray diffraction and in situ microscopy observations, which show rapid YBCO formation from BaO2_2 in only 30 minutes. By combining thermodynamic modeling with in situ characterization, we introduce a new computable framework to interpret and ultimately design synthesis pathways to complex ceramic materials

    X-Ray Magnetic Circular Dichroism at the K edge of Mn3GaC

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    We theoretically investigate the origin of the x-ray magnetic circular dichroism (XMCD) spectra at the K edges of Mn and Ga in the ferromagnetic phase of Mn3GaC on the basis of an ab initio calculation. Taking account of the spin-orbit interaction in the LDA scheme, we obtain the XMCD spectra in excellent agreement with the recent experiment. We have analyzed the origin of each structure, and thus elucidated the mechanism of inducing the orbital polarization in the p symmetric states. We also discuss a simple sum rule connecting the XMCD spectra with the orbital moment in the p symmetric states.Comment: 5 pages, 5 figures, accepted for publication in Physical Review

    Heliocentric Distance Dependence of Zodiacal Light Observed by Hayabusa2#

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    Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as n(r)rαn(r) \sim r^{-\alpha}, and the exponent α1.3\alpha \sim 1.3 was obtained by previous observations from interplanetary space by Helios 1/2 and Pioneer 10/11 in the 1970s and 1980s. However, no direct measurements of α\alpha based on ZL observations from interplanetary space outside Earth's orbit have been performed since then. Here, we introduce initial results for the radial profile of the ZL at optical wavelengths observed over the range 0.76-1.06 au by ONC-T aboard the Hayabusa2# mission in 2021-2022. The ZL brightness we obtained is well reproduced by a model brightness, although there is a small excess of the observed ZL brightness over the model brightness at around 0.9 au. The radial power-law index we obtained is α=1.30±0.08\alpha = 1.30 \pm 0.08, which is consistent with previous results based on ZL observations. The dominant source of uncertainty arises from the uncertainty in estimating the diffuse Galactic light (DGL).Comment: 22 pages, 19 figures, 4 tables, accepted for publication by Earth, Planets and Spac
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