Neuroprotection by ischemic preconditioning has been confirmed by many studies, but the precise mechanism remains unclear. In the present study, we performed cerebral ischemic pre-conditioning in rats by simulating a transient ischemic attack twice (each a 20-minute occlusion of the middle cerebral artery) before inducing focal cerebral infarction (2 hour occlusion-reper-fusion in the same artery). We also explored the mechanism underlying the neuroprotective effect of ischemic preconditioning. Seven days after occlusion-reperfusion, tetrazolium chloride staining and immunohistochemistry revealed that the infarct volume was signiifcantly smaller in the group that underwent preconditioning than in the model group. Furthermore, vascular endothelial growth factor immunoreactivity was considerably greater in the hippocampal CA3 region of preconditioned rats than model rats. Our results suggest that the protective effects of ischemic preconditioning on focal cerebral infarction are associated with upregulation of vascu-lar endothelial growth factor.

Previous studies have shown that vagus nerve stimulation can improve the prognosis of trau-matic brain injury. The aim of this study was to elucidate the mechanism of the neuroprotective effects of vagus nerve stimulation in rabbits with brain explosive injury. Rabbits with brain ex-plosive injury received continuous stimulation (10 V, 5 Hz, 5 ms, 20 minutes) of the right cervical vagus nerve. Tumor necrosis factor-α, interleukin-1βand interleukin-10 concentrations were detected in serum and brain tissues, and water content in brain tissues was measured. Results showed that vagus nerve stimulation could reduce the degree of brain edema, decrease tumor necrosis factor-αand interleukin-1βconcentrations, and increase interleukin-10 concentration after brain explosive injury in rabbits. These data suggest that vagus nerve stimulation may exert neuroprotective effects against explosive injury via regulating the expression of tumor necrosis factor-α, interleukin-1βand interleukin-10 in the serum and brain tissue.

Objective: To study the effect of IGF-1 on the expression of Bcl-2 of NSCs and the protective effect of Bcl-2 on the NSCs deprived of browth factors. Methods: The neural stem cells wereisolated from hippocampi of newborn rats and were cultured by using serum-free medium containing EGF 20ng/ml and bFGF 20ng/ml. Expression of Bcl-2 and nestin antigen were observed by using immunocytochemistry method, MTT method was used to analyse the vitality change of NSCs cultured with IGF-1 and without IGF-1 after withdrawing growth factors. Results: After cultured 7d with IGF-1,the cells were almost positive expression of nestin antigen, and (21.3±0.4)% of all NSCs were Bcl-2 positive cells, furthermore, these cells had a larger survival term against withdrawing growth factors than that cultured without IGF-1.Conclusion: IGF-1 could promote the expression of Bcl-2 in NSCs without affecting the characters of positive expression of nestin antigen, moreover, could increase the self-protection ability through elevating expression of Bcl-2 against deprivation of growth factors in the NSCs.

大蒜对锅炉工生物膜和细胞免疫的保护作用

The workers exposed to coke oven volatile are the risk population of occupational lung cancer than genera population. Polycyclic aromatic hydrocarbons (PAHs),a component of coke oven volatile (COE), are the species considered to be the responsible for this high risk of occupational lung cancer. One of most important mechanism of occupational lung cancer induced by PAHs is believed to be due to the accumulation of free radicals associated with COV and subsequent biological member injury caused by free radical reaction as well as decrease in cell immunity. Garlic is the consumed vegetable with a variety of medical functions.