Radiculopathy, commonly induced by intervertebral disk bulging or protrusion, is presently diag-nosed in accordance with clinical symptoms because there is no objective quantitative diagnostic criterion. Diffusion tensor magnetic resonance imaging and diffusion tensor tractography revealed the characterization of anisotropic diffusion and displayed the anatomic form of nerve root fibers. This study included 18 cases with intervertebral disc degeneration-induced unilateral radiculopathy. Magnetic resonance diffusion tensor imaging was creatively used to reveal the scanning pattern of fiber tracking of the spinal nerve root. A scoring system of nerve root morphology was used to quantitatively assess nerve root morphology and functional alteration after intervertebral disc de-generation. Results showed that after fiber tracking, compared with unaffected nerve root, fiber bundles gathered together and interrupted at the affected side. No significant alteration was de-tected in the number of fiber bundles, but the cross-sectional area of nerve root fibers was reduced. These results suggest that diffusion tensor magnetic resonance imaging-based tractography can be used to quantitatively evaluate nerve root function according to the area and morphology of fiber bundles of nerve roots.

作者： 刊期： 2013年第33期

It remains unclear whether spinal cord ischemia-reperfusion injury caused by ischemia and other non-mechanical factors can be monitored by somatosensory evoked potentials. Therefore, we monitored spinal cord ischemia-reperfusion injury in rabbits using somatosensory evoked potential detection technology. The results showed that the somatosensory evoked potential latency was significantly prolonged and the amplitude significantly reduced until it disappeared during the period of spinal cord ischemia. After reperfusion for 30-180 minutes, the amplitude and latency began to gradual y recover; at 360 minutes of reperfusion, the latency showed no significant difference compared with the pre-ischemic value, while the somatosensory evoked potential amplitude in-creased, and severe hindlimb motor dysfunctions were detected. Experimental findings suggest that changes in somatosensory evoked potential latency can reflect the degree of spinal cord ischemic injury, while the amplitude variations are indicators of the late spinal cord reperfusion injury, which provide evidence for the assessment of limb motor function and avoid iatrogenic spinal cord injury.

作者： 刊期： 2013年第33期

Endoplasmic reticulum stress is closely involved in the early stage of diabetic retinopathy. In the present study, a streptozotocin-induced diabetic animal model was given an intraperitoneal injection of tauroursodeoxycholic acid. Results from immunofluorescent co-localization experiments showed that both caspase-12 protein and c-Jun N-terminal kinase 1 phosphorylation levels significantly in-creased, which was associated with retinal ganglion celldeath in diabetic retinas. The C/ERB ho-mologous protein pathway directly contributed to glial reactivity, and was subsequently responsible for neuronal loss and vascular abnormalities in diabetic retinopathy. Our experimental findings in-dicate that endoplasmic reticulum stress plays an important role in diabetes-induced retinal neu-ronal loss and vascular abnormalities, and that inhibiting the activation of the endoplasmic reticulum stress pathway provides effective protection against diabetic retinopathy.

作者： 刊期： 2013年第33期

The neuropeptides, substance P and calcitonin gene-related peptide, have been shown to be involved in pain transmission and repair of sciatic nerve injury. A model of sciatic nerve defect was prepared by dissecting the sciatic nerve at the middle, left femur in female Sprague Dawley rats. The two ends of the nerve were encased in a silica gel tube. L5 dorsal root ganglia were harvested 7, 14 and 28 days post sciatic nerve injury for immunohistochemical staining. Results showed that substance P and cal-citonin gene-related peptide expression increased significantly in dorsal root ganglion of rats with sci-atic nerve injury. This increase peaked at 7 days, declined at 14 days, and reduced to normal levels by 28 days post injury. The findings indicate that the neuropeptides, substance P and calcitonin gene-related peptide, mainly increased in the early stages after sciatic nerve injury.

作者： 刊期： 2013年第33期

There are several major pathological changes in Alzheimer’s disease, including apoptosis of cho-linergic neurons, overactivity or overexpression ofβ-site amyloid precursor protein cleaving enzyme 1 (BACE1) and inflammation. In this study, we synthesized a 19-nt oligonucleotide targeting BACE1, the key enzyme in amyloid beta protein (Aβ) production, and introduced it into the pSilenCircle vector to construct a short hairpin (shRNA) expression plasmid against the BACE1 gene. We transfected this vector into C17.2 neural stem cells and primary neural stem cells, resulting in downregulation of the BACE1 gene, which in turn induced a considerable reduction in reducing Aβprotein production. We anticipate that this technique combining celltransplantation and gene ther-apy wil open up novel therapeutic avenues for Alzheimer’s disease, particularly because it can be used to simultaneously target several pathogenetic changes in the disease.

作者： 刊期： 2013年第33期

A previous study of European Caucasian patients with sporadic amyotrophic lateral sclerosis demonstrated that a polymorphism in the microtubule-associated protein Tau (MAPT) gene was significantly associated with sporadic amyotrophic lateral sclerosis pathogenesis. Here, we tested this association in 107 sporadic amyotrophic lateral sclerosis patients and 100 healthy controls from the Chinese Han population. We screened the mutation-susceptible regions of MAPT-the 3′and 5′untranslated regions as wel as introns 9, 10, 11, and 12-by direct sequencing, and identified 33 genetic variations. Two of these, 105788 A>G in intron 9 and 123972 T>A in intron 11, were not present in the control group. The age of onset in patients with the 105788 A>G and/or the 123972 T>A variant was younger than that in patients without either genetic variation. Moreover, the pa-tients with a genetic variation were more prone to bulbar palsy and breathing difficulties than those with the wild-type genotype. This led to a shorter survival period in patients with a MAPT genetic variant. Our study suggests that the MAPT gene is a potential risk gene for sporadic amyotrophic lateral sclerosis in the Chinese Han population.

作者： 刊期： 2013年第33期

Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as wel as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. Electro-physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation il ustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits com-bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits.

作者： 刊期： 2013年第33期

Medical-grade synthetic poly(lactic-co-glycolic acid) polymer can be used as a biomaterial for nerve repair because of its good biocompatibility, biodegradability and adjustable degradation rate. The stress relaxation and creep properties of peripheral nerve can be greatly improved by repair with poly(lactic-co-glycolic acid) tubes. Ten sciatic nerve specimens were harvested from fresh corpses within 24 hours of death, and were prepared into sciatic nerve injury models by creating a 10 mm defect in each specimen. Defects were repaired by anastomosis with nerve autografts and poly(lactic-co-glycolic acid) tubes. Stress relaxation and creep testing showed that at 7 200 seconds, the sciatic nerve anastomosed by poly(lactic-co-glycolic acid) tubes exhibited a greater decrease in stress and increase in strain than those anastomosed by nerve autografts. These findings suggest that poly(lactic-co-glycolic acid) exhibits good viscoelasticity to meet the biomechanical require-ments for a biomaterial used to repair sciatic nerve injury.

作者： 刊期： 2013年第33期

This is an expert consensus on the evaluation and treatment of thoracolumbar spinal injury, estab-lished from February 2009 to July 2010. The expert consensus consists mainly of six parts with a total of 54 recommendations including the overview (one item);pre-hospital care (one item);evalu-ation and diagnosis (13 items);treatment (23 items); prevention and treatment of major complica-tions (12 items);and rehabilitation (four items). This is the first time that Chinese experts have pub-lished a consensus on spine and spinal cord injury. The expert consensus was established based on Delphi methods, literature analysis, and clinical experiences. Each recommendation is supported by and was interpreted using multi-level evidences. The level of agreement with the recommenda-tion among the panel members was assessed as either low, moderate, or strong. Each panel member was asked to indicate his or her level of agreement on a 5-point scale, with “1” corre-sponding to neutrality and“5”representing maximum agreement. Scores were aggregated across the panel members and an arithmetic mean was calculated. This mean score was then translated into low, moderate, or strong. After al of the votes were col ected and calculated, the results showed no low-level recommendations, 10 moderate-level recommendations, and 44 strong-level recom-mendations. An expert consensus was reached and was recognized by Chinese spine surgeons. Wide-scale adoption of these recommendations is urgent in the management of acute thoracol-umbar spine and spinal cord injury in a broader attempt to create a standard evaluation and treat-ment strategy for acute thoracolumbar spine and spinal cord injury in China.

作者： 刊期： 2013年第33期

Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli-gomers and constructed a na?ve human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that spe-cifical y recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked immunosorbent assay demonstrated this antibody bound specifical y to human amyloid-beta 42 te-tramer and nonamer, but not the monomer or high molecular weight oligomers. This study suc-cessful y constructed a human phage display library and screened a single-domain antibody that specifical y recognized amyloid-beta 42 oligomers.

作者： 刊期： 2013年第33期