The spinal column of a human body must support the weight of the upper half of the body including the head and the upper limbs, befitting to the bipedal upright posture. Vertebral bodies of the lower lumbar are larger than the upper one for this support. Since the ventral side of the spinal column has a thorax, cervical and lumbar lordoses are indispensable to bring the center of gravity close to a centroidal line. Therefore, the thickness of the inferior lumbar vertebrae are greater ventrally, and an intervertebral disk is thick, and wedge-shaped. Since the weight shifts forward and backward as to the standing and the sitting position, the angle of a pelvis must be changed, and a sacrum and lumbar vertebrae cannot be unified. The lumbar vertebrae at the time of a walk should take the rotational shear, between an upper-limb-thorax block and a lower-limb-pelvis block, since they can hardly rotate due to the dissociation of the center of the rotary axis and the actual center of the vertebral bodies. The situation results in propensity for disk herniation or compressive fractures.

 人工多能性幹 (induced Pluripotent Stem : iPS) 細胞は, 体細胞に少数の因子を導入し, 特定の環境下で培養することで得られる多能性幹細胞株である. iPS細胞は, ①生体を構成するさまざまな細胞に分化することができる能力 (分化多能性) と, ②①の性質を保ちながら無限に増殖することができる能力 (自己複製能) を有している. 加えて, ③iPS細胞はさまざまな患者あるいは健常者など, 個性が判明している個人からの樹立が可能であり, ④ある個体を構成するさまざまな特定の細胞から樹立することが可能である. これらのことから, iPS細胞は創薬や病態研究, そして, 細胞移植医療へ応用することが期待されている.

 iPS細胞の応用を推進するためには, 研究機関において行われる実験などのみならず, 予算措置や規制改革, 倫理的問題への対応, 強力なチームづくりなどが必要であるが, このすべてにわたってわが国では総合的施策がなされており, 着実な成果を挙げている. 実際, いくつもの有望なプロジェクトが具体的タイムテーブルの上で進行している. また, iPS細胞の真の実用化のためには産業化も必須の要素である. 現実的なビジネスモデルをいかに構築していくかが現時点での最重要課題の1つであり, それを解決するための適切な方策策定とその実行がなされなければならない.

1) 霊長類の赤核には, 局在する位置, 細胞構築, 連絡する回路構造など, その解剖学的特徴から明瞭な区分 (おもに大細胞性と小細胞性) が存在し, それぞれの機能には大きな差異がある.

2) 赤核の各区分における細胞群の発達の程度は, 哺乳類の中で大きなバリエーションがあり, 四足歩行動物では赤核脊髄路が, 高等霊長類では赤核オリーブ路が発達している. ヒトにおいてこの差異は極端であり, 前者の赤核脊髄路はほぼ退化し痕跡的となっている. このため, 齧歯類, ネコ, さらにはサルにおける実験結果から得られた知見を直接ヒトに外挿するには慎重を要する.

3) ヒトにおいて特異的に発達した小細胞性赤核の具体的, 詳細な機能についてはほとんどわかっていないが, その臨床病態の像や破壊損傷によって作出された実験動物の機能異常から, 小細胞性赤核は振戦への関わりがある.

  Purpose : To compare the efficacy of hydroxyapatite (HAP) spacers and beta-triphosphate calcium-HAP complex (HAP-TCP) spacers in spinous process-splitting open-door cervical laminoplasty.

  Methods : Among 299 patients who underwent laminoplasty between January 2006 and December 2012, 83 patients with cervical spondylotic myelopathy without ossification of the longitudinal ligament or history of trauma were included in the study. In all patients, spacers were inserted into each split spinous process (C3-6). The patients were divided into two groups : the HAP spacer group (n=32) and the HAP-TCP spacer group (n=51). Computed tomography scans were obtained at 7 days, 3 months, and 6 months post-surgery to assess the extent of bone-spacer bonding and ossifications at the laminar hinges (the gutter). Bone-spacer bonding was classified according to Ichikawa's classification A-E¹⁾ , whereby grades above C represent bone growth, and grades above D represent bone union. Bone changes at the gutter were classified into three grades : none, growth, and union. The chi-square test was used to evaluate frequencies. Statistical significance was defined as p<0.05.

  Results : Bone growth and union were observed in the spacer-bone interface in the HAP-TCP spacer group in 98.0% and 61.3% at 3 months and 97.6% and 53.4% at 6 months. The corresponding rates in the HAP spacer group were 96.3% and 7.8% at 3 months and 88.3% and 6.3% at 6 months, respectively. Bone growth and union rates at the bone-spacer were higher in the HAP-TCP spacer group than in the HAP spacer group, with a significant difference between the two groups at 3 months (χ²=93.42, df=2, p<0.01) and 6 months (χ²=80.52, df=4, p<0.01)]. The bone-spacer bonding rates decreased from 3 to 6 months post-surgery in both groups [HAP group : χ²=2.97, df=3, p>0.05, HAP-TCP group : χ²=8.40, df=4, p<0.05). The bone regrowth and union rates at the gutter at 6 months post-surgery were 93.4% and 63.1% in the HAP-TCP spacer group, and 98.8% and 80.3%. The differences were significant between the two groups (χ²=16.90, df=2, p<0.05).

  Conclusion : Compared to the HAP spacers, the HAP-TCP spacers demonstrated superior bone-spacer bonding but inferior bone union at the gutter. The effectiveness of both spacers was comparable in spinous process-splitting open-door cervical laminoplasty.

  Objective : To identify efficacy of lumbar fusion and fixation in restoration of total sagittal alignment in adult patients with degenerative disc disease of the lumbar spine and to determine the optimal angle of lumbar lordosis for lumbar fusion and fixation.

  Background : Total sagittal alignment is increasingly recognized as a critical parameter in adult lumbar degenerative deformity. Adult degenerative disc disease of the lumbar spine may be one of the major causes of adult spinal deformity if the spinal misalignment remains uncorrected. Therefore, restoration of the total sagittal alignment should be the goal of surgery for lumbar degenerative disc disease.

  Methods : We conducted a retrospective radiological assessment of patients who underwent lumbar fusion and fixation for lumbar lordosis. Analysis of the total sagittal plane was based on multiple parameters : cervical lordosis, thoracic kyphosis, lumbar lordosis, C7 plumb line/sagittal vertical axis (SVA), pelvic incidence, sacral slope, and lumbosacral angle. Furthermore, spinopelvic harmony was used to analyze the optimal fixation angle.

  Results : Following lumbar fusion and fixation, both lumbar lordosis and thoracic kyphosis increased significantly, and there was significant posterior shift of the C7 plumb line/SVA. As a result, total sagittal alignment was improved following lumbar fusion and fixation, particularly in patients who had received fixation according to spinopelvic harmony.

  Conclusions : We have concluded that lumbar fusion and fixation improves total sagittal alignment in adult patients with degenerative disc disease of the lumbar spine. Furthermore, the intraoperative fixation angle of lumbar lordosis has proven to be a key component in the regulation of total sagittal alignment. Our results support the therapeutic strategy of lumbar fixation according to spinopelvic harmony in adult degenerative disc disease of the lumbar spine.

  Solitary fibrous tumor (SFT) is a spindle cell tumor, derived from mesenchymal cells, that arises most commonly in the pleura. Cases of SFT in the central nervous system, both intracranial and intraspinal, have been reported. We report a case of an intramedullary primary SFT of the thoracic spinal cord. A 65-year-old man presented with a 5-year history of lower back and left leg pain and 5-month history of rapid progressive weakness of the left lower leg. Thoracic magnetic resonance imaging indicated an intradural tumor at the Th8level. Intraoperative findings revealed that the tumor arose from an intramedullary site and had no attachment with the arachnoid membrane and dura mater. Histological examination and immunohistochemical staining confirmed the diagnosis of SFT. Although intramedullary SFT is rare, SFT should be considered during the differential diagnosis of intramedullary tumor.