Mitogen - activated protein kinases (MAPKs), including extracellular signal - regulated kinases (ERKs), c - Jun NH2 - terminal kinases (JNKs) and p38 MAPK, play an important role in transducting environmental stimuli to the transcriptional machinery in the nucleus in mammalian cells by virtue of their ability to phosphorylate and regulate the activity of various transcription factors. It was recently found that the changes in activity of MAPKs occurred during ischemia/reperfusion, but the biological significance of the changes was still controversial.

The impairment of learning and memory function in the central nervous system(CNS)is one of the main features of aging and Alzheimer' s disease (AD). Many experimental results have showed that long- term memory(LTM) is related to long- term potentiation(LTP) and long- term depression (LTD). They intluenee each other. The relationship between LTP and LTD is complex. Therefore, it is important to study the learning and memory mechanism from LTP、LTD and gene expression in the CNS.

Fractalkine has been recognized as the first member of the fourth chemokine family recently and its receptor, CX3CR1, was identified afterwards. This pair of ligand/receptor play important roles in the migration and adhesion of peripheral leukocyte through different ways. They are also likely to be related to the embryogenesis and regeneration of several organs and may possess some functions in the central nervous system.

AIM: To investigate the possible role of P97 in non - transferrin bound iron uptake by rabbit reticulocytes. METHODS: The iron uptake were measured by the method of radioisotope (5gFe). RESULTS: (1) Only PI - PLC treatment had no apparent effect on iron uptake by reticulocytes (P > 0.05); (2) Reticulocytes, pretreated by pronase and then by PI - PLC, give a significant decrease in iron uptake in cytosol and in hemne ( P < 0.01). CONCLUSION: The results support the possibility that P97 might be able to be expressed on the membrane of reticulocytes and plays a role in non - transferrin bound iron uptake by this type of cells in the rabbit.

AIM: In order to explore the mechanism of the GC - like effect of Tsiao Shaihutang (TSS), the down - regulation of glucocorticoid receptor and mRNA by TSS were studied. METHODS: GR sites were determined by receptor radio ligand binding assay method. At the same time, GR mRNA level was determined by quantitative reverse- transcriptive polymerase chain reaction (RT- PCR) method. RESULTS: (1) GR sites and GR mRNA level were down - regulated significantly after GC, TSS (P < 0.01 ) treatment . (2) GR sites and GR mRNA level in GC plus TSS group were obviously higher than those in GC group (P < 0.01 ). CONCLUSIONS: These data suggested that TSS can significantly down- regulate GR and GR mRNA level.

AIM: To investigate the effects of Lipopolysaccharide(LPS) and interieukin 1 receptor antagonist (IL- 1ra) on mesangial cells proliferation and nitric oxide synthesis. METHODS: Glomerular mesangial cells from SD rats were cultured. The first and second passages of cultured cells were used for the experiment. LPS and LPS plus IL- 1ra were added in cell cultures, respectively. By using chemical method the nitrite in supernatants was measured ,3H- TaR incorporation was determined to evaluate the GMC proliferation. Northern and slot hybridizations were performed to detect the expression of iNOS mRNA. RESULTS: There were expression of iNOS mRNA, more production of nitrite(0.64 + 0.25 vs 0. 12 + 0.06 nmol/104 cell) in supernatants and GMC proliferation(3735 + 1177.9 vs 1785 + 280.6) in LPS group compared to the control. While compared with LPS group, in LPS + IL- 1ra GMC group, expression of iNOS mRNA decreased by 40%, nitrite increased(3.28 + 0.33 nmol/104 cell), proliferation of GMC decreased (818 + 77.27). CONCLUSION: LPS could activate the GMC to express iNOS mRNA and produce more nitrite. IL - 1ra could partially inhibit the effects of LPS on the expression of iNOS mRNA in GMC, but not nitrite. There is no synchronous correlation between NO production and GMC proliferation.

AIM:To investigate LPS(lipopolysaccharide)stimulated cytokine secretion from normal rat kupffer cells in vitro. METHODS: Kupffer cells were isolated from wistar rats liver and cultured. Tumor necrosis factor - α (TNF- α) and endothelin- 1 (ET- 1 ) secreted by LPS stimulated kupffer cells were detected. RESULTS: LPS had an stimulative effect on kupffer cell activity. LPS in definite concentrations promoted kupffer cell secretion. CONCLUSION: LPS promotes kupffer cell secretion, which may be associated with liver injury induced by LPS.

AIM: To investigate relationship between activity of matrix metalloproteinases - 2 ( MMP - 2, 72 kD) and invasion, metastasis of breast cancer. METHODS: Useing zymography and computer software assisted analysis, the activitive levels of MMP- 2 (72 kD) in tissues from breast cancer were measeured. RESULTS: Mean activitive levels of MMP- 272 kD (13.93 + 3.60) in breast cancer were lower than those in benign disease (21.43 + 8.31), P < 0.05. There was no difference (P > 0.05) in MMP - 2 62 kD + 72 kD of benign and malignant dis ease, but MMP - 262 kD ( 13.83 + 4.53) and MMP - 262 kD/62 kD + 72 kD (0.48) respectively were significantly higher in malignant disease (P < 0.01). It was also found that MMP- 262 kD/62 kD + 72 kD were apparently higher in invasive carcinomas (0.48) and lymph node metastases (0.61), P < 0.01, respectively. CONCLUSION: These results demonstrated that a clear relationship between MMP - 2 activity and the invasion and metastasis of breast carcinoma.

AIM: To study the effects of nitric oxide (NO) on mitochondrial damage caused by exogenous calcium. METHODS: Normal myocardial mitochondria were divided into three groups; L- arginine control group (CG), Ca2 + - damaged group (DG) and L - NAME - preserved group (PG). Mitochondria of all groups were incubated at 30℃ with reaction medium containing 20μmol/L EDTA, 100μmol/L CaC12 and 1 μmol/L L- NAME with 100μmol/L CaCl2 respectively. Then the NO2-/NO3- contents, mitochondrial viability and membrane potential were investigated. RESULTS: The NO2-/NO3 contents of DG was obviously higher than that of CG and PG, meanwhile, there was no obvious difference between CG and PG. Mitochondrial viability and membrane potential of DG were significantly lower than that of CG and PG, and negatively related to NO2-/NO3- contents ( r = - 0.5297, P < 0.01; r = -0.6041, P < 0.01 ). But, the mitochondrial viability and membrane potential of PG were still lower than that of CG. CONCLUSION: Exogenous calcium could activate mitochondrial nitric oxide synthase resulting in NO production and the latter play an important role in decreasing mitochondrial viability and membrane potential.

AIM: To investigate the clinical significance in determination of the P- selectin levels in subjects with prethrombotic state or thrombosis by flow cytometry (FCM). METHODS: The P- selectin expression on platelet membrane in 42 patients with diabetes mellitus, 33 with hyperlipidemia, 23 with cerebral infarction and 20 healthy individuals, were analyzed using fluorescently - labeled SZ - 51 by direct FCM comparing with indirect FCM and enzyme- linked immunosorbent assay (ELISA). RESULTS: The level of P- selectin on platelet membrane is higher in DM (23.92 % + 15.83 % ), in hyperlipidemia ( 18.34 % + 9.46 % ) and in cerebral infarction ( 19.32 % + 10.38 % ) than normal subjects (3.38 % + 1.11% ) ( P < 0.01 ). In addition, similar results on P - selectin were obtained by indirect FCM and ELISA in patients with DM and cerebral infarction. CONCLUSION: FITC - labeled SZ - 51 - IgG can be used in FCM, and it would be a new and sensitive method in detecting platelet activation.