背景: 脊髓損傷所引發的癱瘓對病人在身體上和精神上有深遠的影響。近年來儘管對於脊髓損傷致病機轉的了解有很大的進步，但是目前臨床治療的效果仍舊令人失望。有一種造血生長因子，顆粒球生成劑(G-CSF) 已經被證實在神經系統損傷時，具有神經保護的作用，特別是在中風這個疾病中。
目的: 評估顆粒球生成劑是否能在嚴重脊髓損傷的亞急性期展現神經保護的作用。
方法: 本實驗將處於脊髓損傷亞急性期的老鼠分成兩組，損傷後的第九天開始、到第十三天，給予每天皮下施打一劑顆粒球生成劑或生理食鹽水。之後每隔一週利用SSEP和BBB scale 來評估功能性的回復，並分別於受傷後第九、十六、二十三、三十七天作蛋白質分析，最後在受傷後第三十七天利用免疫染色及電子顯微鏡來分析。
結果: 實驗組保留比較多脊髓背柱的體積，同時有比較好的功能回復。電子顯微鏡也呈現比較少的髓鞘分離及斷裂的現象，而且有明顯軸突再生。免疫染色檢查可見較少活化的microglia。神經滋養因子的濃度在兩組間並無差別。
結論: 嚴重脊髓損傷的亞急性期給予顆粒球生成劑可以藉由縮短發炎週期，減少軸突的去髓鞘化，增加髓鞘及軸突再生來促進功能回復。

Background:
Spinal cord injury (SCI) is known as one of the most physically disabling and psychologically devastating conditions to humans. Although there is advancement in understanding of its pathophysiology, current treatments are still disappointed. Granulocyte Colony-Stimulating Factor (G-CSF), a hemotopoietic growth factor, has been demonstrated to have neuroprotective effect in the nervous system, especially in stroke.
Objective:
To assess whether G-CSF exerts neuroprotective effect during the subacute stage of severe SCI.
Materials and methods:
Animals with contusion induced severe SCI were divided into two groups: G-CSF group that received serial subcutaneous injection of G-CSF and saline control group on post-contusion day (PCD) 9 th to 13 th. Functional evaluations with Basso-Beattie-Bresnahan (BBB) scale and cortical somatosensory evoked potentials (SSEPs) were recorded weekly. The neural tissues were harvested at PCD 9 th, 16 th, 23 th, 37 th for protein analyse. Besides, at the end of the study (PCD 37 th), specimens were analyzed by electron microscopy and immunohistochemistry.

Results:
The volumes of dorsal column of the G-CSF group were larger than that of control group. Both the sensory and motor functions were improved after administration of G-CSF. Detachment and disruption of the myelin sheets in the myelinated axons was significantly decreased. Axonal regeneration/sprouting were also noted. The numbers of activated microglia/macrophage were lower than those of the control group. The levels of BDNF were comparable between the two groups.
Conclusion:
In the subacute stage of severe SCI, G-CSF improves the functional outcomes by shortening the inflammatory period, attenuating the extent of demyelination and further promoting remyelination and axonal regeneration.

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