Publications by authors named "Yamaga K"

Conventionally, the size, shape, and biomechanics of cartilages are determined by their voluminous extracellular matrix. By contrast, we found that multiple murine cartilages consist of lipid-filled cells called lipochondrocytes. Despite resembling adipocytes, lipochondrocytes were molecularly distinct and produced lipids exclusively through de novo lipogenesis.

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  • Juvenile xanthogranuloma (JXG) is a rare benign condition primarily affecting neonates and young children, often presenting as skin lesions, but intramuscular JXG is much less common, accounting for only 0.6% of cases.
  • A case involving a 5-month-old girl showed a slow-growing lump in her left thigh, which was diagnosed as deep JXG after imaging, biopsy, and surgical resection.
  • Histological findings revealed characteristics typical of JXG, and despite initial concerns about tumor margins, the patient has shown no signs of recurrence over 48 months post-surgery, highlighting the importance of proper diagnosis and monitoring.
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The cryopreservation of rat embryos is useful for efficiently archiving rat resources in bioresource repositories. The cryopreserved fertilized oocytes can be quickly reanimated to rats with homozygous mutations using embryo transfer. In addition, cryopreserved rat fertilized oocytes are easier to transport than live animals.

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Cold transport of the cauda epididymides is a useful technique for shipping laboratory rat sperm. Cold transport of rat sperm avoids potential risks of microbiological infection, animal escape or death, and animal welfare issues. Previously, we reported that a cold-storage solution containing dimethyl sulfoxide and quercetin maintained the fertility of cold-stored rat sperm.

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Genetically modified rats are valuable models in human disease research. We recently developed an improved system for rat sperm cryopreservation and in vitro fertilization (IVF) that facilitates the efficient production and preservation of genetically modified rats. In the IVF procedure performed using frozen-thawed rat sperm, the IVF schedule is fixed to ensure timely hormone administration and oocyte collection.

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Niche signals maintain stem cells in a prolonged quiescence or transiently activate them for proper regeneration. Altering balanced niche signalling can lead to regenerative disorders. Melanocytic skin nevi in human often display excessive hair growth, suggesting hair stem cell hyperactivity.

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Hair follicles (HFs) undergo cyclic phases of growth, regression, and rest in association with hair shafts to maintain the hair coat. Nonsense mutations in the tight junction protein claudin (CLDN)-1 cause hair loss in humans. Therefore, we evaluated the roles of CLDNs in hair retention.

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Previous studies have observed the fertilization process in rats using whole-mount preparation at different time-points after insemination. However, very few reports have described the various events during the fertilization process using an inverted microscope without whole-mount. Moreover, to the best of our knowledge, no reports have described the observation of changes in sperm motility associated with sperm penetration into oocytes.

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Laboratory rats have been used in biomedical research for over 170 years. Recently, genome editing technology has facilitated the generation of genetically modified rats worldwide. This development has increased the demand for efficient preservation and production of rat resources.

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Shipment of laboratory rats between animal facilities is frequently performed using special containers. However, the shipment of live animals is associated with potential risks of infectious diseases, escape and death during shipment and animal welfare issues. The transport of cold-stored sperm avoids such risks; however, there have been no reports on cold storage of rat sperm.

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Article Synopsis
  • Macrophages, which are immune cells, interact with the extracellular matrix but the effects of matrix properties on their function are not well understood.
  • Research shows that when macrophages adhere to softer materials, they exhibit less inflammation due to decreased activity of the transcriptional coactivator YAP.
  • In vivo studies confirm that macrophages in soft environments have lower inflammatory markers and YAP levels compared to those on stiff materials, suggesting YAP plays a critical role in regulating inflammation and sensing material stiffness.
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We report a case of GCTB in an 84-year-old Japanese man who had a tumor in his left iliac bone and was treated safely with denosumab. The patient noticed a painful mass, with gradual enlargement, in his left low back next to the iliac region. Magnetic resonance imaging revealed that the tumor measured 94 × 66 × 90 mm and was located in the left iliac bone.

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Reconstruction of bone and soft-tissue defects in the forearm is a surgery that often proves unsuccessful. Free fibular osteocutaneous flaps are a useful material for reconstruction that enable simultaneous reconstruction of bone, skin, and soft tissues. However, in free fibular osteocutaneous flaps, the fibula, skin, and vascular pedicle are tightly bound together by the posterior intermuscular septum and the perforators that pass through the septum, giving the disadvantage of a low degree of freedom when setting these structures in place.

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Hematidrosis is a rare disorder involving spontaneous excretion of sweat contaminated by blood cells. We report the case of a 6-year-old girl with hematidrosis from her palms with no underlying disease or psychotic disorder. Before the onset of this symptom, the patient was given an indoor horizontal exercise bar with which she had been frequently playing.

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Sweating plays an important role in maintaining temperature homeostasis in humans. However, under certain circumstances, sweat can cause itching. For example, when excessive sweat accumulates on the skin surface for a long period, miliaria can develop and cause itching.

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  • During skin wound healing in adult mice, hair follicles and adipocytes regenerate, with adipocytes coming from specialized contractile fibroblasts called myofibroblasts.
  • Researchers utilized single-cell RNA-sequencing to identify twelve different clusters of wound fibroblasts, revealing various stages of differentiation and distinct lineages.
  • The study found that some fibroblasts originate from hematopoietic (blood-related) cells, which contribute to myofibroblast and adipocyte regeneration, highlighting the diverse nature of fibroblasts during wound healing.
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Sweat is a transparent hypotonic body fluid made from eccrine sweat glands. Various ingredients contained in sweat are involved in a broad sense in skin homeostasis including temperature regulation, skin moisture, and immune functions. Thus, sweat plays a major role in maintaining skin homeostasis.

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The transfer of sweat to the skin surface without leakage is important for the homeostatic regulation of skin and is impaired in atopic dermatitis. Although the precise composition of the leakage barrier remains obscure, there is a large contribution from claudins, the major components of tight junctions. In humans, claudin-1, -3, and -15 are expressed on sweat ducts, and claudin-3 and -10 are expressed on secretory coils.

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Superficial cluster of differentiation (CD)34-positive fibroblastic tumor (SCPFT) is a rare mesenchymal neoplasm of borderline malignancy. It is characterized by a superficial location, marked cellular pleomorphism, an extremely low incidence of mitotic figures, and strong CD34 immunohistochemical positivity. As SCPFT is a recently described neoplasm, its characteristics are yet to be fully elucidated.

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Objectives: Sleep disturbances are related to somatic and mental disorders, industrial accidents, absenteeism, and retirement because of disability. We aimed to identify health-related behaviors associated with subjective sleep insufficiency in Japanese workers.

Methods: This cross-sectional study included 5,297 employees (mean age: 43.

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This article is a report of the fourth meeting of the Harmonising Outcome Measures for Eczema (HOME) initiative held in Malmö, Sweden on 23-24 April 2015 (HOME IV). The aim of the meeting was to achieve consensus over the preferred outcome instruments for measuring patient-reported symptoms and quality of life for the HOME core outcome set for atopic eczema (AE). Following presentations, which included data from systematic reviews, consensus discussions were held in a mixture of whole group and small group discussions.

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