Publications by authors named "Chizuka Obara"

Real-time visualisation of chick embryo development occurring inside an opaque eggshell is a major goal of developmental biology. This goal was partially achieved when 3-day-old embryos recovered from fertilised shelled eggs, preincubated in a conventional incubator, hatched after the egg contents had been transferred into shell-less embryo culture systems constructed of transparent plastic film placed in a plastic cup. However, the hatchable shell-less embryo culture systems described thus far cannot be used to visualise the dynamic morphological changes associated with the emergence of major organ systems during the first 3 days of embryo development, as the blastoderm area needs to be covered with an opaque membrane.

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Article Synopsis
  • * Researchers found that iPSC generation can occur without reduction even when exposed to ionizing radiation, indicating a unique radio-resistance during early genome reprogramming stages.
  • * A transient deficiency in the G1/S cell cycle checkpoint is noted during this process, suggesting similarities in mechanisms between iPSC creation and tumor development, supported by the discovery of specific cancer mutational signatures in these cells.
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The p300 and CBP histone acetyltransferases are recruited to DNA double-strand break (DSB) sites where they induce histone acetylation, thereby influencing the chromatin structure and DNA repair process. Whether p300/CBP at DSB sites also acetylate non-histone proteins, and how their acetylation affects DSB repair, remain unknown. Here we show that p300/CBP acetylate RAD52, a human homologous recombination (HR) DNA repair protein, at DSB sites.

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Plasminogen activator inhibitor-1 (PAI-1) is induced by radiation resulting in endothelial cell impairment, potentially leading to multiple organ failure. Vitronectin (VN) is a 75-kDa glycoprotein (VN) cleaved into two forms (VN or VN) by furin, which is regulated by intracellular PAI-1. VN protects against radiation-induced endothelial cell death, but the mechanisms involved in VN processing and its interactions with intra- and extracellular PAI-1 remain unclear.

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The generation of induced-pluripotential stem cells- (iPSCs-) derived mesenchymal stem cells (iMSCs) is an attractive and promising approach for preparing large, uniform batches of applicable MSCs that can serve as an alternative cell source of primary MSCs. Appropriate culture surfaces may influence their growth and differentiation potentials during iMSC derivation. The present study compared molecular properties and differentiation potential of derived mouse iPS-MSCs by deriving on gelatin or collagen-coated surfaces.

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  • Three-dimensional (3-D) aggregate culturing of mesenchymal stem/stromal cells (MSCs) helps retain their functional properties without the need for prior 2-D monolayer culturing, which can alter these properties.
  • Using nanoimprinted nanoculture plates, mouse bone marrow MSCs were found to self-assemble into aggregates that proliferated at a similar rate compared to 2-D cultured cells and released higher levels of key pro-angiogenic factors.
  • 3-D cultured MSCs maintained their differentiation ability and exhibited unique gene expression patterns, suggesting they can better mimic the natural characteristics of bone marrow MSCs, which has implications for tissue engineering and regenerative medicine.
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Measles among healthcare workers (HCWs) is associated with a significant risk of nosocomial transmission to susceptible patients. When a measles case occurs in the healthcare setting, most guidelines recommend exhaustive measures. To evaluate the effects of measures against measles transmission in the healthcare setting precisely, it is essential to determine whether secondary transmission generally occurs.

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Exosomes mediate intercellular communication, and mesenchymal stem cells (MSC) or their secreted exosomes affect a number of pathophysiologic states. Clinical applications of MSC and exosomes are increasingly anticipated. Radiation therapy is the main therapeutic tool for a number of various conditions.

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