Objective To study the effects of preconditioning treadmill exercise on excitatory amino vacid changes in rats after the cerebral infarction and the protective effects against cerebral isehemia brain injury. Methods Thirty Sprague-Dawley rats were used in this study. Twenty-five rats were subject to an operation to establish the animal model of middle cerebral artery occlusion and divided into a isehemia group, an 1-week ex- ercise group (trained in the 4th week) , a 2-week exercise group (trained in the 3rd and 4th weeks) and a 4- week exercise group (trained for 4 weeks) , while the remaining 5 rats were subject to sham operation, and served as the controls. After 4 weeks of experiment, all the the rats were fixed on stereotactie apparatus for the brain microdialysis of the striatum. Then the focal middle cerebral artery ischemia and reperfusion were made with thread oeclussion in rats and microdialysis technique was used to collect extraeellular fluid in each period of pre-ischemia, ischemia (40, 80 and 120 min), and reperfusion (40, 80, 120, 160, 200 and 240 min) to detect the changes of the excitatory amino acid. At the same time the infarction volume was also measured at 24 hours after ischemia-reperfusion of the brain. Results The difference between any two groups was significant with regard to the volume of cerebral infarction (P < 0.05). Two weeks and four weeks of the preconditioning treadmill exercise couled significantly reduce concentration of Glu excessively released due to the ischemia (P < 0.01). Conclusion At least two weeks of preconditioning treadmill exercise can inhibit the excessive release of the important excitatory amino acid neurotransmitter glutamate, to some extent, in the process of the subse- quent ischemic brain injury and during reperfusion, which might be one of the protective mechanisms of move- ment against the early isehemie brain injury.

The expression of multidrug resistant proteins in bladder cancer and clinical implication was studied. Expression of multidrug-associated protein (MRP), P-glycoprotein (P-gp), P53 and Bcl-2 proteins were detected by using immunohistochemical method in 40 specimens of bladder transitional cell carcinoma. The results showed that the positive rate of MRP, P-gp, P53 and Bcl-2 was 52.5 %, 57.5 %, 47.5 % and 62.5 % respectively. The positive rate of MRP, P-gp, P53 and Bcl-2 in the grade Ⅰ, Ⅱ and Ⅲ of tumors was 46.3 %, 38.5 %, 38.5 %, 23.1 %； 52.9 %, 39.8 %, 47.1 %, 76.4 %； 60.0 %, 80.0 %, 60.0 %, 90.0 % respectively. The positive rate of MRP, P-gp, P53 and Bcl-2 in 24 primary tumor specimens was 37.5 %, 41.7 %, 33.3 %, 45.8 % and that in 16 cases in recurrent specimens receiving chemotherapy 75.0 %, 81.3 %, 68.8 %, 87.5 % respectively. It was suggested the positive rate of MRP, P-gp, P53 and Bcl-2 was increased with the advance of tumor grade. The positive rate of four proteins in all recurrent cases was significantly increased (P<0.05). The expression of MRP, P-gp, P53 and Bcl-2 proteins might be the important factors for chemotherapy failure.

The expression of multidrug resistant proteins in bladder cancer and clinical implication was studied. Expression of multidrug-associated protein (MRP), P-glycoprotein (P-gp), P53 and Bcl-2 proteins were detected by using immunohistochemical method in 40 specimens of bladder transitional cell carcinoma. The results showed that the positive rate of MRP, P-gp, P53 and Bcl-2 was 52.5 %, 57.5 %, 47.5 % and 62.5 % respectively. The positive rate of MRP, P-gp, P53 and Bcl-2 in the grade Ⅰ, Ⅱ and Ⅲ of tumors was 46.3 %, 38.5 %, 38.5 %, 23.1 %； 52.9 %, 39.8 %, 47.1 %, 76.4 %； 60.0 %, 80.0 %, 60.0 %, 90.0 % respectively. The positive rate of MRP, P-gp, P53 and Bcl-2 in 24 primary tumor specimens was 37.5 %, 41.7 %, 33.3 %, 45.8 % and that in 16 cases in recurrent specimens receiving chemotherapy 75.0 %, 81.3 %, 68.8 %, 87.5 % respectively. It was suggested the positive rate of MRP, P-gp, P53 and Bcl-2 was increased with the advance of tumor grade. The positive rate of four proteins in all recurrent cases was significantly increased (P<0.05). The expression of MRP, P-gp, P53 and Bcl-2 proteins might be the important factors for chemotherapy failure.