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.

Objective To evaluate the current status of intestinal nematode infection in Shanghai and make recommendations for further control activities Methods Retrospective review of the control program was made based on the change of nematode prevalence in Shanghai area since the 1950s, and challenges under the current situation were analysed. Results The intervention measures included chemotherapy, health education, sanitary disposal of human excreta and safe water supply. With the control strategy, socio\|economical development and the change of farming patterns, the prevalence of intestinal nematode infection in population was reduced by 88\^5%, from 62\^6% in 1955 to 8\^2% in 2000. Among them, ascaris infection decreased by 89\^0%, from 52\^1% to 6\^3%, hookworm infection decreased by 99\^0%, from 12\^9% to 0\^1%, but pinworm infection was still as high as 18\^9% in 1999. Conclusion Prevalence of nematode infection in Shanghai was considerably reduced. To match it with the current socio\|economical development in the Municipality, however, more needs to be done. Sustainable control activities and surveillance are recommended.

Objective To understand the potential risk for schistosomiasis transmission caused by introduction of infection source from mobile population in Shanghai. Methods Field investigation was conducted in the suburb of Shanghai City by screening the mobile population living in Shanghai for more than 1 month and over 1 years old in a procedure of interviewing, serum indirect hemagglutination (IHA) test, and then fecal examination to detect the eggs with nylon sedimentation approach for those IHA positives. Results Among 2 931 mobile people investigated, 1 575 were male (53.74%) and 1 356 were female(46.26%); 138 out of 2 931 were positive in IHA test (4.71%). 1 938 (66.12%) out of 2 931 came from Schistosoma japonicum-endemic provinces and its positive rate in mobile population (5.99%) was significantly higher than those from the transmission-interrupted provinces (2.6%) (?2=10.28, P