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Masashi Yamazaki, Takana Koshi, Chikato Mannoji, Akihiko Okawa, and Masao Koda

✓ The authors report the case of a 62-year-old woman who suffered an accidental fall and complained of severe neck pain and right C-7 radiculopathy. A right C6–7 facet fracture–subluxation was diagnosed. Bone fragments impinged on the right C-7 nerve root at the neural foramen. The bilateral vertebral arteries (VAs) ascended at the anterior aspect of C-6 and C-5 and entered the transverse foramen at the C-4 level.

Based on findings of anomalous VAs, the authors applied a pedicle screw (PS)/rod system to effect surgical correction of the deformity. Intraoperatively, they successfully performed reduction of the subluxation, decompression of the impinged nerve root, and minimum single-segment fusion involving the placement of a PS/rod system. After surgery, the patient's neurological deficit dramatically improved and spinal fusion was completed without any loss of deformity correction.

Prior to surgery for cervical injuries, the possible presence of an abnormal VA course should be considered. Preoperative detection of anomalous VAs will affect decisions on the appropriate corrective surgery option in cases of cervical spine injuries.

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Junko Kawabe, Masao Koda, Masayuki Hashimoto, Takayuki Fujiyoshi, Takeo Furuya, Tomonori Endo, Akihiko Okawa, and Masashi Yamazaki

Object

Granulocyte colony-stimulating factor (G-CSF) has neuroprotective effects on the CNS. The authors have previously demonstrated that G-CSF also exerts neuroprotective effects in experimental spinal cord injury (SCI) by enhancing migration of bone marrow–derived cells into the damaged spinal cord, increasing glial differentiation of bone marrow–derived cells, enhancing antiapoptotic effects on both neurons and oligodendrocytes, and by reducing demyelination and expression of inflammatory cytokines. Because the degree of angiogenesis in the subacute phase after SCI correlates with regenerative responses, it is possible that G-CSF's neuroprotective effects after SCI are due to enhancement of angiogenesis. The aim of this study was to assess the effects of G-CSF on the vascular system after SCI.

Methods

A contusive SCI rat model was used and the animals were randomly allocated to either a G-CSF–treated group or a control group. Integrity of the blood–spinal cord barrier was evaluated by measuring the degree of edema in the cord and the volume of extravasation. For histological evaluation, cryosections were immunostained with anti–von Willebrand factor and the number of vessels was counted to assess revascularization. Real-time reverse transcriptase polymerase chain reaction was performed to assess expression of angiogenic cytokines, and recovery of motor function was assessed with function tests.

Results

In the G-CSF–treated rats, the total number of vessels with a diameter > 20 μm was significantly larger and expression of angiogenic cytokines was significantly higher than those in the control group. The G-CSF–treated group showed significantly greater recovery of hindlimb function than the control group.

Conclusions

These results suggest that G-CSF exerts neuroprotective effects via promotion of angiogenesis after SCI.

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Koichi Hayashi, Masayuki Hashimoto, Masao Koda, Atsuhiko T. Naito, Atsushi Murata, Akihiko Okawa, Kazuhisa Takahashi, and Masashi Yamazaki

Object

Clinical use of autologous induced pluripotent stem cells (iPSCs) could circumvent immune rejection and bioethical issues associated with embryonic stem cells. Spinal cord injury (SCI) is a devastating trauma with long-lasting disability, and current therapeutic approaches are not satisfactory. In the present study, the authors used the neural stem sphere (NSS) method to differentiate iPSCs into astrocytes, which were evaluated after their transplantation into injured rat spinal cords.

Methods

Induced pluripotent stem cell–derived astrocytes were differentiated using the NSS method and injected 3 and 7 days after spinal contusion–based SCI. Control rats were injected with DMEM in the same manner. Locomotor recovery was assessed for 8 weeks, and sensory and locomotion tests were evaluated at 8 weeks. Immunohistological parameters were then assessed.

Results

Transplant recipients lived for 8 weeks without tumor formation. Transplanted cells stretched their processes along the longitudinal axis, but they did not merge with the processes of host GFAP-positive astrocytes. Locomotion was assessed in 3 ways, but none of the tests detected statistically significant improvements compared with DMEM-treated control rats after 8 weeks. Rather, iPSC transplantation caused even greater sensitivity to mechanical stimulus than DMEM treatment.

Conclusions

Astrocytes can be generated by serum treatment of NSS-generated cells derived from iPSCs. However, transplantation of such cells is poorly suited for repairing SCI.

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Morio Matsumoto, Yoshiaki Toyama, Hirotaka Chikuda, Katsushi Takeshita, Tsuyoshi Kato, Shigeo Shindo, Kuniyoshi Abumi, Masahiko Takahata, Yutaka Nohara, Hiroshi Taneichi, Katsuro Tomita, Norio Kawahara, Shiro Imagama, Yukihiro Matsuyama, Masashi Yamazaki, and Akihiko Okawa

Object

The aim of this study was to evaluate the outcomes of fusion surgery in patients with ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL) and to identify factors significantly related to surgical outcomes.

Methods

The study included 76 patients (34 men and 42 women with a mean age of 56.3 years) who underwent fusion surgery for T-OPLL at 7 spine centers during the 5-year period from 2003 to 2007. The authors evaluated the patient demographic data, underlying disease, preoperative comorbidities, history of spinal surgery, radiological findings, surgical methods, surgical outcomes, and complications. Surgical outcomes were assessed using the Japanese Orthopaedic Association (JOA) scale score for thoracic myelopathy (11 points) and the recovery rate.

Results

The mean JOA scale score was 4.6 ± 2.1 points preoperatively and 7.7 ± 2.5 points at the time of the final follow-up examination, yielding a mean recovery rate of 45.4% ± 39.1%. The recovery rates by surgical method were 38.5% ± 37.8% for posterior decompression and fusion, 65.0% ± 35.6% for anterior decompression and fusion via an anterior approach, 28.8% ± 41.2% for anterior decompression via a posterior approach, and 57.5% ± 41.1% for circumferential decompression and fusion. The recovery rate was significantly higher in patients without diabetes mellitus (DM) than in those with DM. One or more complications were experienced by 31 patients (40.8%), including 20 patients with postoperative neurological deterioration, 7 with dural tears, 5 with epidural hematomas, 4 with respiratory complications, and 10 with other complications.

Conclusions

The outcomes of fusion surgery for T-OPLL were favorable. The absence of DM correlated with better outcomes. However, a high rate of complications was associated with the fusion surgery.

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Yutaka Nishio, Masao Koda, Takahito Kamada, Yukio Someya, Katsunori Yoshinaga, Seiji Okada, Hideki Harada, Akihiko Okawa, Hideshige Moriya, and Masashi Yamazaki

Object

The use of human umbilical cord blood (HUCB) cells has been reported to improve functional recovery in cases of central nervous system injuries such as stroke, traumatic brain injury, and spinal cord injury (SCI). The authors investigated the effects of hemopoietic stem cells that were derived from HUCB and transplanted into the injured spinal cords of rats.

Methods

One week after injury, an HUCB fraction enriched in CD34-positive cells was transplanted into the experimental group. In control animals, vehicle (Matrigel) was transplanted. Recovery of motor functions was assessed using the Basso, Beattie, and Bresnahan Locomotor Scale, and immunohistochemical examinations were performed.

Cells from HUCB that were CD34 positive improved functional recovery, reduced the area of the cystic cavity at the site of injury, increased the volume of residual white matter, and promoted the regeneration or sparing of axons in the injured spinal cord. Immunohistochemical examination revealed that transplanted CD34-positive cells survived in the host spinal cord for at least 3 weeks after transplantation but had disappeared by 5 weeks. The transplanted cells were not positive for neural markers, but they were positive for hemopoietic markers. There was no evidence of an immune reaction at the site of injury in either group.

Conclusions

These results suggest that transplantation of a CD34-positive fraction from HUCB may have therapeutic effects for SCI. The results of this study provide important preclinical data regarding HUCB stem cell–based therapy for SCI.

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Yukio Someya, Masao Koda, Mari Dezawa, Tomoko Kadota, Masayuki Hashimoto, Takahito Kamada, Yutaka Nishio, Ryo Kadota, Chikato Mannoji, Tomohiro Miyashita, Akihiko Okawa, Katsunori Yoshinaga, and 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.