AIM: The aim of this study was to explore the expression of nerve growth factor(NGF) in spinal dorsal horn following crushed spinal cord injury. METHODS: The adult Srague-Dawley rat model of crushed spinal cord injury was established by the method in our laboratory, and intact spinal cord was used as control. The rats were sacrificed respectively after 24 hours, 7 days, and 21 days of operation, and the L3 spinal segments were removed out and fixed in 4% polyformaldehyde. The segments were sectioned into sections of 20 μm in thickness. The sections were stained with anti-NGF antibody by ABC method of immunohistochemistry technique. The immunoreactive intensity of NGF and the number of positive neurons as well as glial cells in dorsal horn were observed and counted under light microscope. RESULTS: The number of positive cells and immunoreactive intensity of NGF increased gradually in the dorsal horn at 24 hours, 7 days and 21 days following crushed spinal cord injury compared with control group (P＜0.01). CONCLUSION: These results indicated that NGF plays an important role in the postoperative reaction during the early period of the crushed spinal cord injury.

AIM: It is well known that different injuries will result in different consequences. In this paper, we investigated the morphological change of spinal cord following crushed, hemi-sectioned and transected injury. METHODS: Sixty Wistar rats were randomly divided into 4 groups: intact group, crushed spinal cord injury group (cSCI), hem-sectioned SCI group (hSCI) and transitioned SCI group (tSCI). The models of SCI were established by the method in our laboratory. The animals in each group were sacrificed respectively at 24 hours, 7 and 24 days after operation. The L2 spinal cord which located in the caudal of injury site was taken respectively from each animal in each group and sectioned into frozen sections (20 μm). The sections were stained by hematoxylin and observed under light microscope. The number of neurons in dorsal and ventral horn was also counted. RESULTS: In cSCI group, some neurons appear to atrophy compared with that of intact group, but the number of neurons did not decrease apparently than that of intact group (P＞0.05). Comparatively, some cavities were observed in dorsal and ventral horn in hemi-sectioned and transitioned SCI group. And the number of neurons in dorsal horn and ventral horn decreased greatly at 24 hours, 7 and 21 days compared with intact group (P＜0.05). The results indicated that the decrease of neuronal number in dorsal horn and ventral horn after injury resulted from hSCI and tSCI, but not from cSCI. As a result, some different strategies should be considered for different injuries. For example, some neurotrophic factors may be useful in cSCI, but, many neurons have disappeared following hSCI and tSCI, therefore, other strategies that increase the number of neurons should be considered too. CONCLUSION: Our results provide the important morphological evidences on the change of spinal cord following cSCI, hSCI and tSCI. The data will be useful in treatment of SCI in the future.

To explore the characteristic features of morpho logical changes of neurons in the spinal dorsal horn result from different types of spinal cord in jury, the adult Srague-Daweley fat models of crushed, hemi-sected and transected spinal cord injury established in our laboratory were used, and the intact spin al cords were as control． 　　These rats were sacrificed after 24 hours, 7 days and 2l days of operation, and the L3, segments were removed out and sectioned continuously into sections of 20 μm in thickness． The sections were stained by hematoxylin and observed under ． 　　 microscope． In addition, neurons in the dorsal horn were counted． 　　 Results: In the crushed spinal horns, bodies of neurons were atrophy, but neuron counting did not decrease markedly; in the hemi-sected and transected dorsal horn, a batch of empty cavities were presented, and neuron counting decreased greatly． The results indicated that different injuries of spinal cord resulted in different damage to neurons in the dorsal horn, i． e． the crushed one, the bad, the hemi-sected one, the worse; and the transected one, the worst．

To solve the problems in the illumination of the portable video monocular telescope for near-obser-vation. Some luminous lamp head and reflective lamp head were customerized for the telescope, and the lumi-nous lamp head was postpositively mounted at the side of the ocular lens, which or the reflective lamp head could be prepositively mounted at the side of the object lens. A wound pit on fresh pitaya was observed using portable video monocular telescope for near-observation equipped with illumination device or not. Luminous lamp head and re-flective lamp head custom-made was able to mount easily and gave the target ample illumination. Portable video monocular telescope for near-observation can be easily and cheaply equipped with luminous device giving ample il-lumination.