医学部 形成外科学講座

須永 中

スナガ アタル  (Ataru Sunaga)

基本情報

所属
自治医科大学 とちぎ子ども医療センター 小児形成外科 講師

研究者番号
00406117
J-GLOBAL ID
202301003224485449
researchmap会員ID
R000058567

論文

 41
  • Yoshihiro Sowa, Seiji Sawai, Kenta Yamamoto, Ataru Sunaga, Natsumi Saito, Takako Shirado, Yoshihiro Toyohara, Li Bolun, Kotaro Yoshimura, Osam Mazda
    Tissue & cell 89 102457-102457 2024年8月  
    INTRODUCTION: A specialized device equipped with a sharp blade filter has been developed to enable more efficient purification of a micronized cellular adipose matrix (MCAM) containing stem cells. The aim of this study is to compare the characteristics and functions of the population of stromal cells (mSVF) and cultured cells (mASCs) purified using this device with those of cSVF and cASCs obtained through conventional enzymatic purification. METHODS: Cell viability, proliferation capacity and yield were assessed. Characterization of stem cell potency was performed by analyzing cell surface markers including CD34, a marker of activated adipose-derived stem cells. The trilineage differentiation potential was evaluated using RT-PCR and histology. RESULTS: The yield rate of mSVF obtained from MCAM was significantly higher than that with the conventional method, although use of the device resulted in a slight decrease in cell viability. After culture, mASCs exhibited a remarkable clonogenic potential and significantly higher cell proliferation potential than cASCs. The mASCs also displayed a distinct pattern of ASC cell surface markers, increased expression of genes related to CD34, high pluripotency, and a high trilineage differentiation ability. CONCLUSION: The specialized device enhanced the yield of SVF and produced cells with high proliferation rates and characteristics that include expression of stem cell markers.
  • Rintaro Asahi, Ataru Sunaga, Takako Shirado, Natsumi Saito, Masanori Mori, Yoshihiro Yamamoto, Yunyan Wu, Kotaro Yoshimura
    Plastic and reconstructive surgery 2023年9月6日  
    BACKGROUND: Radiation therapies are often associated with permanent devitalization in the surrounding tissue. We hypothesized that stem cells are damaged depending on each irradiation dose and frequency of fractionated radiotherapies, which results in impaired tissue function including wound healing capacity. METHODS: To test the hypothesis, susceptibility of human adipose-derived stem cells (ASCs) to a single irradiation (0-10 Gy) was assessed in vitro. In vivo chronic radiation effects were also assessed on the mouse dorsal skin (N=4-5) for 6 months after a total of 40 Gy irradiation (0 Gy as control) using one of three fractionated protocols (2 Gy daily for 20 days, 10 Gy weekly for 4 weeks, or 10 Gy monthly for 4 months). Oxygen partial pressure, oxygen saturation of hemoglobin, and dorsal skin viscoelasticity were periodically measured, and wound healing and tissue immunohistology were compared at 6 months. RESULTS: A single irradiation of cultured human ASCs resulted in a dose-dependent increase in cell death up to 2 Gy but with no further increases between 2 and 10 Gy. Most of the apoptotic ASCs were in the proliferation phase. Among the three in vivo irradiation protocols, the 2 Gy×20 group had the most severe chronic tissue damage (i.e., skin dysfunction, subcutaneous atrophy, and depletion of CD34+ stem cells) 6 months after the irradiation. Wound healing was also impaired most significantly in the 2 Gy×20 group. CONCLUSIONS: These results have important clinical implications for surgeons and radiotherapists such as the timing of surgical interventions and the optimization of fractionation protocols.Clinical Relevance Statement: Irradiation damages stem cells depending on the radiation dose and frequency. Using the ultimately optimized protocol, we can minimize the long-term functional deficits of radiated tissue without losing anti-cancer efficacy of radiation therapy.
  • Akira Gomi, Ataru Sunaga
    No shinkei geka. Neurological surgery 50(6) 1247-1255 2022年11月  
    In this article we explain in detail the Multidirectional Cranial Distraction Osteogenesis(MCDO)procedure for treating craniosynostosis, in which the multiple cranial bone flaps are pulled up in different directions by the external distractor with the helmet-type frame. MCDO has several advantages over conventional procedures such as unilateral cranial distraction osteogenesis(UCDO). First, the design of the osteotomy in MCDO is flexible depending on the deformities. Each bone flap can be moved to the desired direction in MCDO, while being moved only in one direction along the axis of the distractor in UCDO. This enables remodeling of the deformed cranium to the desired shape. Second, compared with UCDO, the distance between each bone flap after distraction is narrower in MCDO, allowing earlier bone formation and fusion, and thus a shorter consolidation period. Third, the expansion efficacy of MCDO is greater than that of UCDO. The maximum defects of MCDO were the large amount of osteotomy and the resulting heavy bleeding. Therefore, we have recently attempted to improve the design and procedure of osteotomy. The MCDO method allows all phenotypes of skull deformity to be reshaped by distraction osteogenesis.
  • Yoshihiro Toyohara, Nanako Mito, Shiho Nakagawa, Kotaro Yoshimura, Ataru Sunaga
    Plastic and reconstructive surgery. Global open 10(9) e4544 2022年9月  
    Bradycardia and asystole due to oculocardiac reflex (OCR) are potential intraoperative complications of periocular surgery. We report a case of asystole due to OCR that occurred during surgical repair performed 40 hours after an orbital blowout fracture. The patient had vomiting, bradycardia, and ocular motility disorder before the operation. During the operation, asystole occurred when the entrapped tissue was grasped with forceps. After administration of anticholinergic drugs, the heart promptly resumed beating, and no sequelae due to asystole were observed after surgery. Before and during periocular surgery, it is important for the surgeon to maintain a protective surgical procedure and communicate appropriately with the anesthesiologist, including discussion of risks and emergency measures. In addition, prolonged entrapment of the extraocular muscles is likely to cause irreversible damage, so it is important to make a diagnosis and perform surgery as soon as possible.
  • Yuya Morishita, Ataru Sunaga, Akira Gomi, Alice Hatade, Yuhei Morita, Kotaro Yoshimura
    Plastic and reconstructive surgery. Global open 9(4) e3551 2021年4月  
    Frontometaphyseal dysplasia (FMD), also known as Gorlin-Cohen syndrome, is a rare genetic syndrome. This syndrome affects the skeletal system and connective tissue, and causes a wide spectrum of manifestations of the skull, tubular bones, cardiovascular system, urinary system, and/or gastrointestinal system. Craniofacial findings of FMD are characterized by protruding supraorbital ridge, broad nasal bridge, hypertelorism, down-slanting palpebral fissures, and/or micrognathia. We describe a case of a 2-year-old girl diagnosed with sagittal synostosis accompanied with FMD. She presents anterior sagittal synostosis cranial form, compressed cerebrospinal fluid space (which suggested increased intracranial pressure), and the supraorbital hyperostosis. She underwent multi-directional cranial distraction osteogenesis in the calvaria and shaving of the supraorbital ridges. Despite concerns about bone fragility associated with FMD, the surgery was accomplished as usual. The patient had no intra- and postoperative complications. After 6 months of follow-up, the cranial shape has improved and the cerebrospinal fluid space has widened, but the supraorbital ridge has protruded again. Re-protrusion of the supraorbital ridge appears to be due to age-appropriate vigorous osteogenesis. The multi-directional cranial distraction osteogenesis procedure has been useful for treating sagittal synostosis even concomitant with FMD.

共同研究・競争的資金等の研究課題

 12