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Dive into the research topics where Yukio Someya is active.

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Featured researches published by Yukio Someya.


Brain Research | 2007

Granulocyte colony-stimulating factor (G-CSF) mobilizes bone marrow-derived cells into injured spinal cord and promotes functional recovery after compression-induced spinal cord injury in mice

Masao Koda; Yutaka Nishio; Takahito Kamada; Yukio Someya; Akihiko Okawa; Chisato Mori; Katsunori Yoshinaga; Seiji Okada; Hideshige Moriya; Masashi Yamazaki

The aim of the present study was to elucidate the effects of granulocyte colony-stimulating factor (G-CSF)-mediated mobilization of bone marrow-derived stem cells on the injured spinal cord. Bone marrow cells of green fluorescent protein (GFP) transgenic mice were transplanted into lethally irradiated C57BL/6 mice. Four weeks after bone marrow transplantation, spinal cord injury was produced by a static load (20 g, 5 min) at T8 level. G-CSF (200 microg/kg/day) was injected subcutaneously for 5 days. Immunohistochemistry for GFP and cell lineage markers was performed to evaluate G-CSF-mediated mobilization of bone marrow-derived cells into injured spinal cord. Hind limb locomotor recovery was assessed for 6 weeks. Immunohistochemistry revealed that G-CSF increased the number of GFP-positive cells in injured spinal cord, indicating that bone marrow-derived cells were mobilized and migrated into injured spinal cord. The numbers of double positive cells for GFP and glial markers were larger in the G-CSF treated mice than in the control mice. Luxol Fast Blue staining revealed that G-CSF promoted white matter sparing. G-CSF treated mice showed significant recovery of hind limb function compared to that of the control mice. In conclusion, G-CSF showed efficacy for spinal cord injury treatment through mobilization of bone marrow-derived cells.


Journal of Neuropathology and Experimental Neurology | 2007

Granulocyte colony-stimulating factor attenuates neuronal death and promotes functional recovery after spinal cord injury in mice

Yutaka Nishio; Masao Koda; Takahito Kamada; Yukio Someya; Ryo Kadota; Chikato Mannoji; Tomohiro Miyashita; Seiji Okada; Akihiko Okawa; Hideshige Moriya; Masashi Yamazaki

Granulocyte colony-stimulating factor (G-CSF) is a protein that stimulates differentiation, proliferation, and survival of granulocytic lineage cells. Recently, a neuroprotective effect of G-CSF was reported in a model of cerebral infarction. The aim of the present study was to elucidate the potential therapeutic effect of G-CSF for spinal cord injury (SCI) in mice. We found that G-CSF is neuroprotective against glutamate-induced cell death of cerebellar granule neurons in vitro. Moreover, we used a mouse model of compressive SCI to examine the neuroprotective potential of G-CSF in vivo. Histologic assessment with cresyl violet staining revealed that the number of surviving neurons in the injured spinal cord was significantly increased in G-CSF-treated mice. Immunohistochemistry for neuronal apoptosis revealed that G-CSF suppressed neuronal apoptosis after SCI. Moreover, administration of G-CSF promoted hindlimb functional recovery. Examination of signaling pathways downstream of the G-CSF receptor suggests that G-CSF might promote functional recovery by inhibiting neuronal apoptosis after SCI. G-CSF is currently used in the clinic for hematopoietic stimulation, and its ongoing clinical trial for brain infarction makes it an appealing molecule that could be rapidly placed into trials for patients with acute SCI.


Journal of Neurosurgery | 2008

Reduction of cystic cavity, promotion of axonal regeneration and sparing, and functional recovery with transplanted bone marrow stromal cell–derived Schwann cells after contusion injury to the adult rat spinal cord

Yukio Someya; Masao Koda; Mari Dezawa; Tomoko Kadota; Masayuki Hashimoto; Takahito Kamada; Yutaka Nishio; Ryo Kadota; Chikato Mannoji; Tomohiro Miyashita; Akihiko Okawa; Katsunori Yoshinaga; Masashi Yamazaki

OBJECT The authors previously reported that Schwann cells (SCs) could be derived from bone marrow stromal cells (BMSCs) in vitro and that they promoted axonal regeneration of completely transected rat spinal cords in vivo. The aim of the present study is to evaluate the efficacy of transplanted BMSC-derived SCs (BMSC-SCs) in a rat model of spinal cord contusion, which is relevant to clinical spinal cord injury. METHODS Bone marrow stromal cells were cultured as plastic-adherent cells from the bone marrow of GFPtransgenic rats. The BMSC-SCs were derived from BMSCs in vitro with sequential treatment using beta-mercaptoethanol, all-trans-retinoic acid, forskolin, basic fibroblast growth factor, platelet derived-growth factor, and heregulin. Schwann cells were cultured from the sciatic nerve of neonatal, GFP-transgenic rats. Immunocytochemical analysis and the reverse transcriptase-polymerase chain reaction were performed to characterize the BMSC-SCs. For transplantation, contusions with the New York University impactor were delivered at T-9 in 10- to 11-week-old male Wistar rats. Four groups of rats received injections at the injury site 7 days postinjury: the first received BMSCSCs and matrigel, a second received peripheral SCs and matrigel, a third group received BMSCs and matrigel, and a fourth group received matrigel alone. Histological and immunohistochemical studies, electron microscopy, and functional assessments were performed to evaluate the therapeutic effects of BMSC-SC transplantation. RESULTS Immunohistochemical analysis and reverse transcriptase-polymerase chain reaction revealed that BMSC-SCs have characteristics similar to SCs not only in their morphological characteristics but also in their immunocytochemical phenotype and genotype. Histological examination revealed that the area of the cystic cavity was significantly reduced in the BMSC-SC and SC groups compared with the control rats. Immunohistochemical analysis showed that transplanted BMSCs, BMSC-SCs, and SCs all maintained their original phenotypes. The BMSC-SC and SC groups had a larger number of tyrosine hydroxilase-positive fibers than the control group, and the BMSC-SC group had more serotonin-positive fibers than the BMSC or control group. The BMSC-SC group showed significantly better hindlimb functional recovery than in the BMSC and control group. Electron microscopy revealed that transplanted BMSC-SCs existed in association with the host axons. CONCLUSIONS Based on their findings, the authors concluded that BMSC-SC transplantation reduces the size of the cystic cavity, promotes axonal regeneration and sparing, results in hindlimb functional recovery, and can be a useful tool for spinal cord injury as a substitute for SCs.


Neuroradiology | 2008

Abnormal course of the vertebral artery at the craniovertebral junction in patients with Down syndrome visualized by three-dimensional CT angiography

Masashi Yamazaki; Akihiko Okawa; Mitsuhiro Hashimoto; Atsuomi Aiba; Yukio Someya; Masao Koda

IntroductionWe determined the incidence of vertebral artery (VA) anomalies at the craniovertebral junction (CVJ) in patients with Down syndrome, and characterized the VA anomalies.MethodsThe course of the VA in 46 consecutive patients who were due to undergo posterior arthrodesis surgery at the CVJ were evaluated by three-dimensional CT angiography (3DCTA). Included were five patients with Down syndrome who suffered from myelopathy due to atlantoaxial subluxation. All five patients with Down syndrome also had a simultaneous congenital skeletal anomaly, either os odontoideum or ossiculum terminale.ResultsOf the five patients with Down syndrome, three had VA anomalies at the CVJ, two had fenestration and one had a persistent first intersegmental artery. Of the other 41 patients without Down syndrome, five had VA anomalies at the CVJ. The incidence of VA anomalies at the CVJ was much higher in patients with Down syndrome than in those without Down syndrome.ConclusionIn planning surgery in patients with Down syndrome with symptomatic atlantoaxial subluxation and a congenital skeletal anomaly at the CVJ, we should consider the possible presence of VA anomalies. Preoperative 3DCTA allows us to precisely identify an anomalous VA and evaluate the possible risk of intraoperative VA injury in advance.


Spine | 2014

Multicenter Prospective Nonrandomized Controlled Clinical Trial to Prove Neurotherapeutic Effects of Granulocyte Colony-stimulating Factor for Acute Spinal Cord Injury: Analyses of Follow-up Cases After at Least 1 Year

Taigo Inada; Hiroshi Takahashi; Masashi Yamazaki; Akihiko Okawa; Tsuyoshi Sakuma; Kei Kato; Mitsuhiro Hashimoto; Koichi Hayashi; Takeo Furuya; Takayuki Fujiyoshi; Junko Kawabe; Chikato Mannoji; Tomohiro Miyashita; Ryo Kadota; Yukio Someya; Osamu Ikeda; Masayuki Hashimoto; Kota Suda; Tomomichi Kajino; Haruki Ueda; Yasuo Ito; Takayoshi Ueta; Hideki Hanaoka; Kazuhisa Takahashi; Masao Koda

Study Design. An open-labeled multicenter prospective nonrandomized controlled clinical trial. Objective. To confirm the feasibility of using granulocyte colony-stimulating factor (G-CSF) for treatment of acute spinal cord injury (SCI). Summary of Background Data. We previously reported that G-CSF promotes functional recovery after compression-induced SCI in mice. On the basis of these findings, we conducted a multicenter prospective controlled clinical trial to assess the feasibility of G-CSF therapy for patients with acute SCI. Methods. The trial ran from August 2009 to March 2011, and included 41 patients with SCI treated within 48 hours of onset. Informed consent was obtained from all patients. After providing consent, patients were divided into 2 groups. In the G-CSF group (17 patients), G-CSF (10 &mgr;g/kg/d) was intravenously administered for 5 consecutive days, and in the control group (24 patients), patients were similarly treated except for the G-CSF administration. We evaluated motor and sensory functions using the American Spinal Cord Injury Association score and American Spinal Cord Injury Association impairment scale at 1 week, 3 months, 6 months, and 1 year after onset. Results. Only 2 patients did not experience American Spinal Cord Injury Association impairment scale improvement in the G-CSF group. In contrast, 15 patients in the control group did not experience American Spinal Cord Injury Association impairment scale improvement. In the analysis of increased American Spinal Cord Injury Association motor score, a significant increase in G-CSF group was detected from 1 week after the administration compared with the control group. After that, some spontaneous increase of motor score was detected in control group, but the significant increase in G-CSF group was maintained until 1 year of follow-up. Conclusion. Despite the limitation that patient selection was not randomized, the present results suggest the possibility that G-CSF administration has beneficial effects on neurological recovery in patients with acute SCI. Level of Evidence: 3


Neuroscience Letters | 2008

Brain-derived neurotrophic factor suppresses anoikis-induced death of Schwann cells

Masao Koda; Yukio Someya; Yutaka Nishio; Ryo Kadota; Chikato Mannoji; Tomohiro Miyashita; Akihiko Okawa; Atsushi Murata; Masashi Yamazaki

Anoikis is a type of apoptosis due to the detachment from the extracellular matrix and neighboring cells. In case of cell transplantation therapy for spinal cord injury, preparation of graft cells includes dissociation of cultured cells, which may cause anoikis-induced cell death. Thus suppression of anoikis may increase survival of grafted cells. Here we tested the effect of brain-derived neurotrophic factor (BDNF) on anoikis-induced cell death of cultured Schwann cells. Schwann cells were collected and cultured from sciatic nerves of neonatal Wistar rats. Schwann cells were plated upon a non-adherent polyhydroxyethyl methacrylate substrate to induce anoikis. BDNF was added into the culture medium at various concentrations. Twenty-four hours after non-adherent culture, approximately 40% of Schwann cells died and BDNF significantly decreased the number of dead cells in that culture condition. Next, Schwann cells were transplanted with or without BDNF treatment into contused rat spinal cord 1 week after injury. Five weeks after transplantation, immunohistochemistry revealed that the number of transplanted cells was significantly larger in the BDNF-treated group than that of the non-treated group. Suppression of anoikis may increase survival of grafted cells in case of cell therapy for spinal cord injury.


Spine | 2012

Neuroprotective Therapy Using Granulocyte Colony-Stimulating Factor for Patients With Worsening Symptoms of Thoracic Myelopathy A Multicenter Prospective Controlled Trial

Tsuyoshi Sakuma; Masashi Yamazaki; Akihiko Okawa; Hiroshi Takahashi; Kei Kato; Mitsuhiro Hashimoto; Koichi Hayashi; Takeo Furuya; Takayuki Fujiyoshi; Junko Kawabe; Chikato Mannoji; Tomohiro Miyashita; Ryo Kadota; Yukio Someya; Osamu Ikeda; Tomonori Yamauchi; Masayuki Hashimoto; Toshimi Aizawa; Atsushi Ono; Shiro Imagama; Tokumi Kanemura; Hideki Hanaoka; Kazuhisa Takahashi; Masao Koda

Study Design. An open-labeled multicenter prospective controlled clinical trial. Objective. To confirm the feasibility of granulocyte colony–stimulating factor (G-CSF) administration for patients with thoracic myelopathy. Summary of Background Data. Although G-CSF is best known as an important cytokine commonly used to treat neutropenia, it also has nonhematopoietic functions. Previous experimental studies have shown that G-CSF can enhance tissue regeneration of several organs, such as the heart and the brain. We previously reported that G-CSF promotes functional recovery after spinal cord injury in rodents. On the basis of those findings, we started a clinical trial of neuroprotective therapy, using G-CSF for patients with worsening symptoms of thoracic myelopathy. Methods. Patients whose Japanese Orthopaedic Association (JOA) score for thoracic myelopathy had decreased 2 points or more during a recent 1-month period were eligible for entry. After giving informed consent, patients were assigned to G-CSF and control groups. The G-CSF group (n = 10) received G-CSF 10 &mgr;g/kg per day intravenously for 5 consecutive days. The control group (n = 14) received similar treatments as the G-CSF group except for G-CSF administration. The primary outcome was JOA recovery rate at 1 month after G-CSF administration or initial treatment. Results. There was greater improvement in neurological functioning between baseline and 1-month follow-up in the G-CSF group (JOA recovery rate: 29.1 ± 20.5%) than in the control group (JOA recovery rate: 1.1 ± 4.2%) (P < 0.01). No serious adverse events occurred during or after the G-CSF administration. Conclusion. The results provide evidence that G-CSF administration caused neurological recovery in patients with worsening symptoms of thoracic compression myelopathy.


Spine | 2008

Infection-related atlantoaxial subluxation (Grisel syndrome) in an adult with Down syndrome.

Masashi Yamazaki; Yukio Someya; Masaaki Aramomi; Yutaka Masaki; Akihiko Okawa; Masao Koda

Study Design. Case report. Objective. To report an adult case with Down syndrome, in whom infection-related atlantoaxial subluxation (Grisel syndrome) developed. Summary of Background Data. Atlantoaxial instability is a common complication in Down syndrome patients; however, there have been limited reports of adult-onset atlantoaxial subluxation with myelopathy. Grisel syndrome has been characterized as a nontraumatic atlantoaxial subluxation associated with pharyngeal infection. It usually affects children, and the subluxation can be successfully reduced by conservative treatments in most cases. Methods. A 26-year-old man with Down syndrome suffered from retropharyngeal infection, after which his atlantoaxial subluxation was aggravated and myelopathy developed. He was treated with administration of antibiotics and application of a halo-vest. Results. The conservative treatments failed to reduce the atlantoaxial subluxation. We performed a C1 laminectomy and posterior occipitocervical fusion, which successfully relieved his symptoms. Conclusion. This experience suggests that when Down syndrome patients have retropharyngeal infection, we should consider the possible aggravation of atlantoaxial instability and development of myelopathy, even if the patient is an adult.


Journal of Spinal Cord Medicine | 2011

Postmortem findings in a woman with history of laminoplasty for severe cervical spondylotic myelopathy

Yukio Someya; Masao Koda; Masayuki Hashimoto; Akihiko Okawa; Yutaka Masaki; Masashi Yamazaki

Abstract Context We report the autopsy of a 65-year-old woman who underwent a C3–C7 laminoplasty 4 years after the diagnosis of cervical spondylotic myelopathy (CSM). Her sensory disturbance, spasticity, and vesicorectal disturbance, which corresponded to long tract sign, had improved after surgery. Findings Cross sections at the C4–C5 level showed a triangular shape because of atrophied ventral gray matter. Moreover, despite the scarce glial scar formation around the cystic cavity, regeneration of gray matter had not occurred. In the white matter, the posterior and lateral funiculi were shrunken including three to four segments. Conclusion Pathological change of white matter did not coincide with relief of clinical symptoms in this case. These findings indicate that it may be better to operate earlier in cases of CSM, because delay may lead to irreversible histological change.


Neuroreport | 2005

Hematopoietic stem cell and marrow stromal cell for spinal cord injury in mice.

Masao Koda; Seiji Okada; Toshinori Nakayama; Shuhei Koshizuka; Takahito Kamada; Yutaka Nishio; Yukio Someya; Katsunori Yoshinaga; Akihiko Okawa; Hideshige Moriya; Masashi Yamazaki

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