Objective To study the change of activity and toxicity of superoxide (O - 2 ) produced in polymorphonuclear leukocytes(PMNLs) during ischemia reperfusion cerebral injury.Methods The rats were administrated by both PMA (an activator of single transduction of O - 2 produced in alkaline phosphatase(ALPase) positive granules of PMNLs) and the inhibitor BCA respectively; the model of middle cerebral artery (MCA) occlusion was made by suture cleat mothod,the activity changes of both myeloperoxidease (MPO) and O - 2 were measured at 6, 12, 24, 48, 72 and 168h reperfusion following ischemia 1h, and the pathological ultrastructural changes were observed. Results The MPO activity of both PAM group and BCA group reached the peaks at 24h after reperfusion; however,there were no remarkable differences in MPO activity between these two groups in the same time point. The O - 2 activity in the PAM group was significantly higher than those in the BCA group. The O - 2 activity reached the peak at 72h of ischemia reperfusion. In the same experimental time point, the pathological changes of the ultrastructure in ischemic reperfusive injury brain of the PAM group were much more serious than the those of the BCA group, which showed obviously the neurons edema, the abnormal structures of nerve felt and synapse in the ischemia reperfusion injured brain.Conclusion The increase of brain O - 2 activity from PMNLs during cerebral ischemia reperfusion injury was direct ratio to the degree of cerebral injury. BCA might depress the activity and the toxicity of the O - 2.

A software system of the pulse oximeter is presented in this paper. Based on Franklin C, this software system includes three main parts, one part is to automatically regulates the base line of signal, the second part is a controlled integral module,and the third part is a digital signal processing module. As the result, the pulse oximeter is satisfactory to clinical monitoring.

To enhance the quality project,there are four ways to ensure the quality of the undergraduate thesis and project.The first way is to inaugurate new bases: from school to company.The second is a wide choice of projects.The third way is that the project can be taken ahead of schedule.Finally,two tutors are designated to ensure the quality of thesis.

The system planning of characteristic education in biomedical engineering was performed,in which such ideas were raised as clear-cut cultivation target,self-contained curricula system and flexible experimental technique.The system planning provided systematic knowledge structure and the induction from theory to practice for undergraduates in 5 majors in our school.Based on this system planning,the teaching quality is improved.

Objective To investigate the impact of auto and allogenic mesenchymal stem cells (MSC) transplantation on hematopoietic reconstitution. Methods MSC from auto, donor bone marrow or embryonic tissue were cultured and expanded in vitro in the serum culture system. Five patients received hematopoietic stem cell transplantation (HSCT) were investigated. Case 1 of systemic lupus erythematosus and Case 2 of non-hodgkin' s lymphoma (NHL) received auto MSC transplant before auto-HSCT. Case 3 of paroxysmal nocturnal hemoglobinuria received HLA-identical allogenic MSC transplant before HLA-identical allo-HSCT.Case 4 of chronic myelocytic leukemia and Case 5 of NHL had delayed hematopoietic reconstitution (129th and 78th day, respectively) after allo- and auto-HSCT, respectively, and received MSC from embryonic tissue.Results Case 1, 2 and 3 had no manifested side effects after MSC transplantation combined with HSCT.Neutrophil count of case 1, 2, and 3 were over 0.5 ×109/L at 1st, 10th and 10th day, respectively, platelet count were over 20 ×109/L at 1st, 8th and 33th day, respectively, and agranulocytosis at Ost, 7th and 12th day, respectively. The treatment of embryonic tissue MSC transplant was confirmed to fail for Case 4 and 5.Conclusion The time of MSC transplant has a great impact on hematopoietic reconstitution. MSC transplantation and HSCT performed simultaneously can improve hematopoietic reconstitution. However, the impact of MSC on patients with delayed hematopoietic reconstitution after HSCT needs further study.

OBJECTIVETo test whether Porphyromonas gingivalis (P. gingivalis) could produce bacterial signal molecule, bis-(3'-5')-cyclic dimeric adenosine monophosphate (c-di-AMP) and lay the foundation for explorations of its roles in life metabolism and periodontitis immunity of P. gingivalis.

METHODSP. gingivalis standard strain ATCC33277 was used as the experimental strain to extract nucleic acids from the bacteria. Then, c-di-AMP was detected using high performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS). Subsequently, HPLC was used to validate the sample further.

RESULTSBased on the signal/noise (S/N) for 3 : 1, the limit of determination of HPLC-MS/MS for peak time of c-di-AMP standard substances was 7.49 min and nucleic acid extractions from P. gingivalis was 8.82 min (S/N > 3). Further confirmation of HPLC showed that nucleic acid extractions from both P. gingivalis and c-di-AMP standard substances pre- sented goal absorbent peaks at 15.7 min, with the same ultraviolet absorbent spectrum.

CONCLUSIONThe nucleic acid extrac- tions from P. gingivalis contained c-di-AMP, which shows that P. gingivalis could produce c-di-AMP.

Objective:To observe the effect of tannic acid on renal morphology and function of diabetes mellitus model rats ,and to explore the mechanism of improving effect of tannic acid from oxidative stress , nitrosative stress angle.Methods: 8 rats were randomly selected from 68 6-week-old male Wistar rats as normal control group and the remaining 60 rats accepted high-sugar and high-fat diet for 4 weeks, then were injected streptozotocin ( STZ, 52 mg/kg ) intraperitoneally in order to manufacture a diabetic rat model.Further the diabetic rats were randomly divided into model group ,aminoguanidine group ,low-dose of tannic acid group and high dose of tannic acid group.The rats in aminoguanidine group were injected aminoguanidine [AG,40 mg/(kg· d)] intraperitoneally, those in low-dose of tannic acid group were injected tannic acid [TA,20 mg/(kg· d)] and those in high-dose of tannic acid group were injected tannic acid [TA,30 mg/(kg· d)].The rats in normal control group and model group were injected normal saline [NS, 30 mg/(kg· d)] and all rats were sacrificed and tissues were derived at the end of the week 10.Morphologic changes of kidney in diabetic rats were observed by HE staining and correlative biochemical indices of renal function were detected by biochemical analyzer.8-hydroxy deoxyguanosine (8-OHdG) and 3-nitrotyrosine (3-NT) content of renal tissue in rats in different groups were detected by ELISA method.Mesangial cells cultured in vitro were treated with high concentration of glucose (30 mmol/L) and AGEs (250 mg/L) and at the same time with different concentration of tannic acid (10,20,40 and 80μmol/L) on the basis of setting corre-sponding control group.The contents of 8-OHdG and 3-NT in the culture supernatant were measured by ELISA method after 48 hours.Results:Tannic acid can effectively improve the renal pathological changes and improve renal function of diabetic rats .The contents of 8-OHdG and 3-NT in kidney tissue homogenate of diabetic rats and in the supernatant of GMC cultured with high glucose or AGEs were all significantly increased and can be reduced by tannic acid.Conclusion:Tannic acid improving the structure and function damage of kidney in diabetic rats might be achieved by oxidative stress and nitrosative stress mechanism .

Objective:To observe the specific killing effect on tumor cells of the spleen cells in mice immunized with three tandem repeats of CEA minigene DNA vaccine pcDNA-triCEA625-667 and to evaluate the safety of the vaccine. Methods: The BALB/c mice were randomly divided into blank vector group ( pcDNA3. 0 ) , haploid vaccine group ( pcDNA-CEA625-667 ) and tandem repeats vaccine group (pcDNA-triCEA625-667). The mice received a total of 4 intramuscular immunization every 10 days once. The changes of body weight,survival state were recorded and the levels of serum ALT and serum creatinine were detected. The specific CTL killing activity of spleen cells in accinated mice on mouse hepatoma cells(H22-CEA+),gastric cancer cells(MFC-CEA+),colorectal cancer cells ( CT26-CEA+) with high expression of CEA and mouse hepatoma cells ( H22-CEA-) without expression of CEA was detected. Results:The two vaccines had strong killing activity on CEA positive liver cancer,gastric cancer and colon cancer cells,and the difference was statistically significant ( P<0. 01 ) compared with the PcDNA3. 0 group. And they had almost no effect on CEA negative tumor cells (H22-CEA-). The killing activity on liver cancer cell(H22-CEA+) and gastric cancer cell(MFC-CEA+) induced by pcDNA-triCEA625-667 was stronger than that induced by pcDNA-triCEA625-667(P<0. 05). The survival status,change of body weight and function of liver and kidney of the mice were not affected by the vaccine. Conclusion:There was no adverse reaction in the course of vaccine immunization. The minigene DNA vaccine derived from CEA can induce tumor specific CTL effect and the immune response level elicited by three tandem repeats of minigene DNA vaccine was superior to that elicited by haploid vaccine.

Objective:To investigate mechanism of TRAIL-resistance in A549 cells ( a cell line of non-small cell lung carcino-ma cells) due to Akt phosphorylation .Methods:A549 cells were treated with Akt inhibitor Perifosine and rsTRAIL protein individual-ly and in combination.The expressions of Akt phosphorylation(p-Akt),c-FLIPLL and caspase-8 were detected by Western blot.The apoptotic rate of the A549 cells treated was detected by flow cytometry and the cell proliferation was evaluated by MTT assay .Results:A549 cells showed the increased level of Akt phosphorylation mediated by rsTRAIL protein .Treatment with the Akt inhibitor Perifosine induced a suppression of Akt activation in A 549 cells and a concomitant decrease in the expression of c-FLIPLL .As a result, Perifosine significantly enhanced TRAIL-induced apoptosis rate of (76.5 ±3.02)%and cytotoxic rate of (83.2 ±2.54)%by promoting the activ-ity of caspase-8.Conclusion:Akt activity promotes A549cells survival against TRAIL-induced apoptosis and that the cytotoxic effect of rsTRAIL protein can be enhanced by modulating the Akt phosphorylation in human non -small cell lung carcinoma cells .

Objective To explore the effect of arsenic trioxide (As2O3) on the migration of neurons and the potential mechanism through the establishment of primary neuron culture from the brains of neonatal rats.Methods Brain tissues were selected from SD neonatal rats for primary neuron calture.The cells were divided into 4 groups based on the addition of As2 O3:normal control group,1 μmol/L As2O3 group,10 μmol/L As2O3 group and 20 μmol/L As2O3 group.The primary neurons were treated with different concentrations of As2O3 and cultured for 24 hours.Boyden chamber assay was used to detect the effect of As2O3 on neuronal migration.Immunofluorescence laser confocal microscope was used to observe the structure of actin.Results In the control group,the cultured neurons showed a regular pattern of distribution.In the 3 groups treated with As2O3,the distribution of neurons was loose and disordered,which was most obvious in the 20 μmol/L As2O3 group.The results showed that the higher concentration of As2O3,more difficult it was for the neurons to survive.The number of neuronal migration was 64.6 ± 4.3 for normal control group,63.0 ± 7.0 for 1 μmol/L As2O3 group,54.8 ± 3.6 for 10 μmol/L As2O3 group,and 21.6 ± 3.9 for 20 μmol/L As2O3 group.The results showed that As2O3 might inhibit the migration of primary neurons in a dose-dependent manner (F =49.31,P ＜0.001).The normal actin skeleton was destroyed under the laser confocal microscope in 10 μmol/L As2O3 group and 20 μmol/L As2O3 group,while they remained unaffected in normal control group and 1 μmol/L As2O2 group.Conclusion As2 O3 exposure can reduce the neuron migration in a dose-independent manner probably through disrupting the organization of acting cytoskeleton.