Publications by authors named "Shigeki Sakai"

Mammalian wounds leave visible scars, and there are no methods for complete regeneration. However, mouse fetuses regenerate their skin, including epidermal and dermal structures, up to embryonic day (E)13. This regeneration pattern requires the formation of actin cables in the wound margin epithelium; however, the molecular mechanisms are not fully understood.

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  • - This study focused on how different cells in fetal mouse skin interact in 3D during regeneration, particularly looking at cell relationships and the role of tunneling nanotubes (TNTs) on embryonic days 13 and 15.
  • - Researchers performed skin incisions on the embryos and used advanced imaging techniques to observe the wound healing process, finding that epidermal keratinocytes worked closely with fibroblasts and macrophages for skin regrowth, especially at E13.
  • - They discovered that TNTs were present at the wound sites and played a crucial role in regeneration, but inhibiting their formation with cytochalasin B negatively affected healing, highlighting the importance of these cellular interactions.
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Wounds that occur in adults form scars due to fibrosis, whereas those in embryos regenerate. If wound healing in embryos is mimicked in adults, scarring can be reduced. We found that mouse fetuses could regenerate tissues up to embryonic day (E) 13, but visible scars remained thereafter.

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Unlike adult mammalian wounds, early embryonic mouse skin wounds completely regenerate and heal without scars. Analysis of the underlying molecular mechanism will provide insights into scarless wound healing. Twist2 is an important regulator of hair follicle formation and biological patterning; however, it is unclear whether it plays a role in skin or skin appendage regeneration.

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  • - Eyelid cancer often requires complete surgical removal, followed by reconstruction of both the front and back layers using various tissue grafts, each with its pros and cons.
  • - The study involved three patients who had their lower eyelids reconstructed after basal cell carcinoma removal, using local skin flaps and auricular cartilage with its surrounding tissue.
  • - Results were positive, with no major complications like eyelid drooping or corneal irritation one year later, although two patients did experience some lower eyelid drooping that may require correction in future surgeries.
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Various flap monitoring techniques have been used in the early detection of anastomotic thrombus; however, the use of automatic and continuous monitoring methods is presently uncommon. The purpose of this study was to investigate trends in interstitial fluid glucose concentration (IFG) in flap monitoring by measuring IFG automatically and continuously. Nine patients underwent unilateral breast reconstruction using a transverse rectus abdominis myocutaneous flap with vascular anastomosis.

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This case series aimed to describe a new technique for correcting contractures and deformities that reliably addresses lacrimal punctum deviation and severe cicatricial lower eyelid ectropion. This was a technical description and a retrospective interventional case series. Eyelid ectropion and lacrimal punctum deviation were treated surgically by grafting the fascia lata and suturing the tarsus-Horner muscle.

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A physics-based model on polarization switching in ferroelectric polycrystalline films is proposed. The calculation results by the model agree well with experimental results regarding dynamic operations of ferroelectric-gate field-effect transistors (FeFETs). In the model, an angle for each grain in the ferroelectric polycrystal is defined, where is the angle between the spontaneous polarization and the film normal direction.

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Mammalian skin, including human and mouse skin, does not regenerate completely after injury; it is repaired, leaving a scar. However, it is known that skin wounds up to a certain stage of embryonic development can regenerate. The mechanism behind the transition from regeneration to scar formation is not fully understood.

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Unlike adults, early developing fetuses can completely regenerate tissue, and replicating this could lead to the development of treatments to reduce scarring. Mice epidermal structures, including wound healing patterns, are regenerated until embryonic day (E) 13, leaving visible scars thereafter. These patterns require actin cable formation at the epithelial wound margin through AMP-activated protein kinase (AMPK) activation.

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Deep inferior epigastric perforator flaps are commonly used for breast reconstruction using autologous tissue. For such free flaps, the internal mammary artery provides stable blood flow as the recipient for anastomosis. We report a novel dissection method of the internal mammary artery.

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Scar treatments include fractional laser treatment, cell transplantation, surgery, skin needling, and dermal fillers. Fractional laser treatments are used to reduce scarring and blurring. Cell transplantation is promising, with mature fibroblasts and adipose-derived stem cells being used clinically, while embryonic fibroblasts are used experimentally.

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Article Synopsis
  • Wounds on embryonic mouse fetuses can regenerate well until embryonic day (E) 13, after which they leave a permanent scar, suggesting a loss in regenerative capability.
  • The study investigated the role of sonic hedgehog (Shh), a protein important in embryonic development, in skin regeneration by examining its expression and effects in injured mouse embryos and adult mice.
  • Results indicated that while Shh expression remains stable at E13, it increases after E14 and negatively impacts skin texture regeneration, highlighting its crucial role in keratinocyte behavior during wound healing.
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Unlabelled: The dermal panniculus carnosus (PC) muscle is critical for wound contraction in lower mammals and is a useful model of muscle regeneration owing to its high cellular metabolic turnover. During wound healing in mice, skin structures, including PC, are completely regenerated up to embryonic day (E) 13, but PC is only partially regenerated in fetuses or adult animals after E14. Nevertheless, the mechanisms underlying wound repair for complete regeneration in PC have not been fully elucidated.

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Up to a certain developmental stage, a fetus can completely regenerate wounds in the skin. To clarify the mechanism of fetal skin regeneration, identifying when the skin switches from fetal-type wound regeneration to adult-type wound repair is necessary. We hypothesized that this switch occurs at several time points and that complete skin regeneration requires epidermal-dermal interactions and the formation of actin cables.

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  • Mice embryos have a unique ability to heal wounds without scars up to embryonic day 13 (E13), but this ability decreases after E17, leading to scar formation.
  • The protein Lhx2 plays a crucial role in managing hair follicle stem cells during this healing process, with its expression increasing after E13.
  • When Lhx2 was knocked down in embryos at E15, wound healing was significantly delayed and scars became more prominent, indicating its importance in both cell division related to healing and the development of scars.
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Wnt proteins secrete glycoproteins that are involved in various cellular processes to maintain homeostasis during development and adulthood. However, the expression and role of Wnt in wound healing have not been fully documented. Our previous studies have shown that, in an early-stage mouse fetus, no scarring occurred after cutaneous wounding, and complete regeneration was achieved.

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Adult mammalian wounds leave visible scars, whereas skin wounds in developing mouse fetuses are scarless until a certain point in development when complete regeneration occurs, including the structure of the dermis and skin appendages. Analysis of the molecular mechanisms at this transition will provide clues for achieving scarless wound healing. The fibroblast growth factor (FGF) family is a key regulator of inflammation and fibrosis during wound healing.

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Background: Fibrotic scars are common in both human and mouse skin wounds. However, wound-induced hair neogenesis in the murine wounding models often results in regenerative repair response. Herein, we aimed to uncover cellular functional heterogeneity in dermis between fibrotic and regenerative wound healing fates.

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Background: Variations in skin healing capacities are observed during different murine embryonic developmental stages. Through embryonic day 16 (E16), embryos are able to regenerate dermal architecture following flank skin wounding; however, after E17, wounds heal incompletely, inducing scar formation. The regenerative ability of the E16 fetal dermis depends on the migration of dermal mesenchymal cells.

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Cutaneous melanoma refers to a common skin tumor that is dangerous to health with a great risk of metastasis. Previous researches reported that autophagy is associated with the progression of cutaneous melanoma. Nevertheless, the role played by genes with a relation to autophagy (ARG) in the prediction of the course of metastatic cutaneous melanoma is still largely unknown.

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Background: In silicone breast implant (SBI)-based breast reconstructions, aesthetic outcomes are often low due to the visible upper edge of the SBI. To ameliorate this, grafting fat harvested from the SBI operative field has not been reported to date. Therefore, we aimed to develop a novel technique for fat onlay-grafting, harvested from the inframammary fold (IMF) of the reconstructed breast, and investigate its usefulness.

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Article Synopsis
  • - The study focuses on complications arising from breast augmentation using autologous fat grafting or hyaluronic acid, including issues like induration, cysts, calcification, and infections that necessitate surgical intervention.
  • - A total of 20 patients, aged 25 to 63, were examined from May 2007 to June 2018, with most complications linked to fat grafting; the surgical methods employed included a zigzag incision and mammary gland resection for silicone and paraffin cases.
  • - Results showed that the zigzag incision was effective in managing most complications related to fat and hyaluronic acid, leading to satisfactory outcomes with minimal visible scarring, but it was inadequate for removing silicone and paraffin.
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Acquired coagulation factor V (FV) inhibitors are rare disorders in which antibodies against FV develop under various conditions. We herein report the case of a 71-year-old woman with FV inhibitor during radiochemotherapy for pancreatic cancer. Multiple purpuras suddenly appeared on her bilateral upper limbs with prolonged coagulation data (APTT 97.

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