Fusimotor reflexes to antagonistic muscles simultaneously assessed by multi-afferent recordings from muscle spindle afferents

Several single agonist/antagonist primary muscle spindle afferents were simultaneously recorded in chloralose anaesthetized cats. It was shown that their dynamic and static sensitivity to sinusoidal muscle stretches could be increased or decreased via the fusimotor system by extension and flexion of the contralateral hind limb as well as by stretch of ipsilateral muscles and stimulation of ipsilateral skin nerves. The results seem to support the hypothesis that the primary muscle spindle afferents convey complex multisensory messages to the central nervous system (CNS).     

Elemental composition and water content of myelinated axons and glial cells in rat central nervous system

The distribution of elements (e.g. Na, Cl, K) and water in CNS cells is unknown. Therefore, electron probe X-ray microanalysis (EPMA) was used to measure water content and concentrations (mmol/kg dry or wet weight) of Na, Mg, P, S, Cl, K and Ca in morphological compartments of myelinated axons and glial cells from rat optic nerve and cervical spinal cord white matter. Axons in both CNS regions exhibited similar water content ( 90%), and relatively high concentrations (wet and dry weight) of K with low Na and Ca levels. The K content of axons was related to diameter, i.e. small axons in spinal cord and optic nerve had significantly less (25–50%) K than larger diameter axons from the same CNS region. The elemental composition of spinal cord mitochondria was similar to corresponding axoplasm, whereas the water content (75%) of these organelles was substantially lower than that of axoplasm. In glial cell cytoplasm of both CNS areas, P and K (wet and dry weight) were the most abundant elements and water content was approximately 75%. CNS myelin had predominantly high P levels and the lowest water content (33–55%) of any compartment measured. The results of this study demonstrate that each morphological compartment of CNS axons and glia exhibits a characteristic elemental composition and water content which might be related to the structure and function of that neuronal region.     

Unusual course of an epidural rhabdomyosarcoma of the upper thoracic spine

Summary This report deals with a case of rhabdomyosarcoma in the upper thoracic spine. It is of particular interest, not only for the rarity of type and location of this tumour, but for its clinical course, which presented fluctuations of neurological status, included an acute demonstration of complete paraplegia followed by full recovery after conservative treatment, and gradual relapsing of neurological deficit, one year later.     

谷氨酸诱导体外培养的鸡胚脊髓神经细胞释放NO

用鸡胚脊髓神经细胞的原代培养,测定细胞中亚硝酸盐的含量,研究了谷氨酸(Glu)对原代培养神经细胞中NO的影响。结果表明,谷氨酸作用于原代培养的鸡胚脊髓神经细胞,在诱导神经细胞释放乳酸脱氢酶(LDH)的同时,还可诱导细胞释放一氧化氮(NO)。如先用NO合成酶抑制剂L-NOARG作用细胞,再加入Glu,则发现L-NOARG能降低Glu导致的培养液中LDH活性升高。提示NO可能参与介导Glu的神经毒性作用。     

涉及全椎骨之脊柱肿瘤的外科治疗

本文报告了4例涉及椎体及其后部结构的全椎骨肿瘤的外科治疗,介绍了全椎骨切除术的手术方法及手术注意事项。手术采用后路附件切除,上下椎体Steffee钢板内固定,前路椎体切除自体髂骨植骨融合,初步效果满意。本手术难度大、出血多、危险性高,术中采用控制性低血压,以减少出血。     

Serotonin and norepinephrine in the spinal cord of man

The content of serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA) and norepinephrine (NE) was analysed in 71 human spinal cords obtained post-mortem. The highest content of 5-HT, 5-HIAA and NE was found in the lumbar enlargement of the spinal cord. 5-HT and 5-HIAA content increased from fetal to adult spinal cord whereas the content of NE decreased. Characteristic segmental distribution of measured monoamines was present in adult spinal cord only. In two patients spinal cord lesion led to the reduction in spinal cord content of 5-HT, 5-HIAA and NE and loss of characteristic segmental distribution of these substances. These results are in general agreement with observations on spinal cord of different animal species.     

Imaging of thoracic and lumbar spinal extradural arachnoid cysts: report of two cases

Extradural arachnoid cysts are uncommon expanding lesions in the spinal canal which may communicate with the subarachnoid space. Usually in the lower thoracic spine, they may cause symptoms by compressing the spinal cord or nerve roots. We report cases of thoracic and lumbar arachnoid cysts studied by cystography, myelography, CT and MRI. These techniques showed extradural cystic lesions containing cerebrospinal fluid, with variable communication with the subarachnoid space, causing anterior displacement and flattening of the spinal cord. Received: 3 November 1995 Accepted: 16 April 1996     

脊髓损伤的MR表现

研究脊髓损伤的MR表现。采用GESigna0．5T超导型磁共振检查机，用脊柱表面线圈，对55例脊柱创伤病人做MR检查。所有病例做轮位和矢状位检查，用自旋回波序列和快速自旋回波序列。脊髓损伤表现为脊髓水肿23例次（41．8％），髓内出血10例次（18．1％），脊髓不完全性和完全性断裂7例次（12．7％），椎间盘值22例次（364％），脊柱韧带断裂30例次（545％）。脊髓损伤多见于爆裂型和骨折脱位型脊柱骨折。MR是脊髓损伤最有效的检查方法，MR对发现和评估脊髓损伤优于CT扫描。     

狗脊髓截除自体隐神经大网膜移植的初步观察

实验用6只狗于T13处切除脊髓8mm，局部用隐神经、大网膜移植。对照组6只狗单纯切除脊髓8mm。术后3个月、6个月实验组动物全部恢复到C／Ⅲ级功能，组织学切片见移植神经有不同程度存活，可记录到股四头肌、胫前肌电位。对照组动物仅达到0／0～A／I织功能，组织学切片见脊髓缺损处为结缔组织，诱电位波形消失。分析了影响脊髓神经功能恢复的原因。     

胸腰椎稳定性重建方法的改进

为了改进胸腰椎脱位的治疗方法，更好地重建脊柱稳定性，设计了一种新的脊柱固定器械，由滚花钉及连接板构成，并通过椎弓根进行的一种脊柱后路短节段固定方法，脊柱固定范围限制在两个椎体间。１９８９年～１９９５年，临床应用这种新器械矫正胸腰椎脱位１２例，经１～４年随访，畸形矫正满意，固定牢固。结果表明：该器械具有手术方法简单、固定牢固和手术创伤小等优点。认为，该项技术适用于胸腰椎稳定性的重建。