Objective To evaluate the effect of sevoflurane preconditioning on autophagy during ischemiareperfusion (I/R) injury to isolated rat hearts and the role of PI3K/Akt signaling pathway.Methods Healthy adult male Wistar rats,aged 6-8 weeks,weighing 250-280 g,were anesthetized.Their hearts were excised and perfused in a Langendorff apparatus.Eighty-four isolated rat hearts with I/R injury were randomly divided into 7 groups (n =12 each):normal control group (NC group),I/R group,sevoflurane preconditioning group (S + I/R group),normal control plus wortmannin group (NC + W group),I/R plus wortmannin group (I/R + W group),sevoflurane preconditioning plus wortmannin group (S + I/R + W group),and solvent group (S + I/R + D group).In NC group,the hearts were continuously perfused with K-H solution for 180 min.In I/R group,the hearts were perfused with K-H solution for 30 min,and then subjected to ischemia for 30 min followed by 120 min of reperfusion.In S+ I/R group,the hearts were perfused with K-H solution for 10 min,and then with K-H solution saturated with 2.5％ sevoflurane for 15 min,followed by 5 min washout with K-H solution before ischemia.In NC + W group,wortmannin (PI3K inhibitor) 15 μg/kg was injected intraperitoneally at 30 min before chest opening,and the other procedures were similar to those previously described in group NC.In I/R + W group,wortmarnin 15 μg/kg was injected intraperitoneally at 30 min before chest opening,and the other procedures were similar to those previously described in group I/R.In S + I/R + W group,wortmannin 15 μg/kg was injected intraperitoneally at 30 min before chest opening,and the other procedures were similar to those previously described in S + I/R group.In S + I/R + D group,dimethyl sulfoxide 1.5 ml/kg was injected intraperitoneally at 30 min before chest opening,and the other procedures were similar to those previously described in group S + I/R.The HR,± dp/dtmax,left ventricular developed pressure (LVDP) and left ventricular end-diastolic pressure (LVEDP) were recorded at the end of equilibration and reperfusion.At the end of reperfusion,coronary effluent was collected to detect lactate dehydrogenase (LDH) activity,and myocardial specimens were obtained to calculate the percentage of myocardial infract size.The expression of autophagy marker LC3-Ⅱ and Akt,phosphor-Akt (p-Akt),mammalian target of rapamycin (mTOR),and phosphor-mTOR (p-mTOR) was determined by Western blot.Results Compared with NC group,no significant change was found in the parameters of hemodynamics in NC + W group,and HR,± dp/dtmax and LVDP were significantly decreased,LVEDP,myocardial infract size,and LDH activity were increased,LC3-Ⅱ expression was up-regulated,and the expression of p-Akt and p-mTOR was down-regulated in the other groups.Compared with group I/R,HR,± dp/dtmax,and LVDP were significantly increased,LVEDP,myocardial infract size,and LDH activity were decreased,LC3-Ⅱ expression was downregulated,and the expression of p-Akt and p-mTOR was up-regulated in S + I/R and S + I/R + D groups,and no significant change was found in each parameter in S+ I/R+ W group.Compared with S + I/R group,HR,± dp/ dtmax and LVDP were significantly decreased,LVEDP,myocardial infract size and LDH activity were increased,LC3-Ⅱ expression was up-regulated,and the expression of p-Akt and p-mTOR was down-regulated in S + I/R + W group,and no significant change was found in each parameter in S + I/R + D group.Conclusion Sevoflurane preconditioning can decrease autophagy of myocardial cells during I/R through activating PI3K/Akt signaling pathway and enhancing mTOR activity in the downstream,thus protecting isolated rat hearts against I/R injury.

AIM: To explore the effect of protein kinase C-?(PKC-?) in U937 cell line inhibited by short hairpin RNA(shRNA) on the transcription of vascular endothelial growth factor(VEGF) mRNA induced by stromal cell-derived factor-1(SDF-1).METHODS: 64 bp reverse repeated motifs of PKC-? target sequence were synthesized and inserted into the plasmid to construct the plasmid expressing shRNA-PKC-?(pSIRENp) and the pSIRENp plasmid was transfected into U937 cell line.The expression of PKC-? and VEGF mRNA was detected by RT-PCR.RESULTS: The recombinant plasmid pSIRENp was successfully constructed and it nearly completely suppressed the PKC-? expression in U937 cell line.After transfection,both basical and VEGF mRNA induced by SDF-1 significantly reduced compared to control.CONCLUSION: The results shows that the short hairpin RNA of PKC? efficiently reduces its expression in U937 cells and PKC-? may be involved in the regulation of VEGF mRNA expression.

Atropine (Atr) ip 5 - 10mg/kg elevated the threshold dose of ouabain ( 10?g/min, iv ) to induce ventricular premature beats, ventricular tachycardia , ventricular fibrillation and cardiac arrest in guinea-pigs. Atr 2 - 4 mg/kg iv shortened the duration of arrhythmia elicited by Adr ( 40?g/kg, iv ) in conscious rabbits, & delayed the onset of arrhythmia evoked by AC ( 20?g/kg, iv ) or BaCl2 ( 2mg/kg, iv ) in anesthetized rats. It also decreased the incidence of arrhythmia induced by CaCl2 ( 102mg/kg, iv ) in rats. In mice, Atr ( 5~10mg/kg, ip)decreased the incidence of ventricular fibrillation by chloroform and artrial fibrill-ation ( or flutter ) by Ach-CaCl2.

Objective: To develop the matrix-matched calibration curve correction-inductively coupled plasma mass spectrometry (ICP-MS) for the determination of lead in blood. Methods: Whole blood samples and blank whole blood were pretreated by direct dilution with a solution of 0.5% nitric acid and 0.01% TritonX-100 to obtain whole blood sample solutions and matrix-matched solvents at a 10-fold dilution. The mass concentration of lead was determined by using an ICP-MS instrument in He mode. 175Lu was added online as an internal standard. The standard working curve was calibrated with the matrix-matched solvent, and the mass concentration of lead in the whole blood samples was calculated based on the standard working curve. Recovery tests were performed on whole blood blind samples by spiking, and the relative standard deviation and average recovery rate were calculated. The accuracy and precision of this method were assessed by comparing it with the method recommended in the national standard in detection of lead in three types of bovine blood lead standard materials. Results: Good linearity was shown for lead at 0.5 to 100.0 μg/L, with a correlation coefficient of 1.000. The detection limit of lead was 0.4 μg/L, and the quantitation limit was 1.3 μg/L. The relative standard deviations were 0.65% and 1.10%. The average recovery ranged from 96.89% to 99.73%. The lead determination results were all within the normal reference ranges specified by the three certified reference materials for bovine blood samples. Conclusion The matrix-matched calibration curve correction-ICP-MS is suitable for high-throughput determination of blood lead.

Aim To determine the effects and mechanisms of isoflurane on energy metabolism during ischemia and reperfusion in isolated rat hserts.Methods The rat Langendorff model was used,and isolated per-fused rat hearts were separated into untreated,isoflurane,chelerythrine(PKC inhibitor)plus isoflurane,and chelerythrine groups.All the hearts were subjected to treatment before ischemia,followed by 30 min of ischemia and 60 min of reperfusion.Hemodynamic variables were recorded,and metabolites were measured by high-performance liquid chromatography,and analyzed subcellular localization of PKC isoforms by Western blot analysis.Results The recovery of left ventricular developed pressure after ischemia was(33?8)%,(56?9)%,and(30?5)% in the untreated,isoflurane,and isoflurane with chelerythrine groups respectively.Compared with the untreated hearts,isoflurane significantly improved the recovery of left ventricular developed pressure(P

BACKGROUND:As mechanical load-bearing tissues, tendons have unique biomechanical characteristics. Mechanical loading is necessary in tendon development, and the tendon can alter its structure and biological behaviors in response to the various mechanical loading conditions. OBJECTIVE: To fuly understand the healing process and biomechanical properties of the damaged tendon so as to know the researching progress in the role of stress in the tendon healing process. METHODS: An electronic search of Chinese Biomedical Literature Database and PubMed databases was done for colection of reviews and papers addressing stress effects on tendon healing, and then we analyzed the role of stress in the healing process of tendon from the micro and macro levels. RESULTS AND CONCLUSION:Totaly 59 relevant articles were enroled. Tendon is sensitive to stress, and it can change its structure and biological reaction in response to different stress loadings. Proper stress stimulus to the tendon is necessary to the tendon development and healing. How to achieve a good balance between the lowest (resulting in alienation effect) and the highest stress loadings (resulting in minimaly invasive injury) during the clinical tendon healing is a chalenge. At present the treatment of tendon injuries is stil a huge chalenge to clinicians, and the vast majority of tendon injuries belong to tissue healing.

BACKGROUND:Tissue-engineered tendons have been used to repair the damaged tendon tissue. Use of tissue-engineered tendons for repair of tendon injury has become a hot spot in this research field. OBJECTIVE: To elaborate the types, advantages and disadvantages of seed cels, the design method, advantages and disadvantages of scaffold materials, and the factors that induced the formation of tendon, so as to promote the optimization of each joint, al of which benefit for mature construction of tissue-engineered tendons. METHODS: The related reviews and paper reports of tendon tissue engineering published from January 2000 to January 2015 were retrieved from Chinese Biomedical Literature Database (CBM), China Knowledge Resources Database (CNKI) series database, Chinese Citation Database and PubMed database. The key words were “tissue engineering; tendon; tendon defect”. The research progress of seed cels, scaffold material and induction factors were analyzed. RESULTS AND COMCLUSION:The recent research of tissue-engineered tendons for repair of tendon injury has been summarized. Seed cels, scaffold, induction factors were discussed. Tendon stem cels, as a kind of seed cels, are currently the first choice in the process of tissue engineering tendon research, because tendon stem cels have the homology of the homogenous or autologous tendons and possess strong differentiation and proliferation capacities. However, there have been no systematic schemes regarding acquisition and proliferation and culture of tendon stem cels. The currently designed tissue-engineered tendons cannot meet the clinical requirements because of poor mechanical properties of tendon tissue, poor integration with the host tissue, being susceptible to degradation in late period and functional disuse. Induction factors are the laft key factors for tissue-engineered tendons for repair of tendon injury. The selection and use of induction factors are prerequisites for the regulation of tendon tissue development. But the categories of induction factors and the association and interrelationship between induction factors have not been fuly clear and studies are needed to further investigate these uncertainties.

Objective To investigate the relationship between hypoxia and stemness of cancer stem cells ( CSCs ) . Methods U87 cells,U251 cells and primary glioma cells were experienced hypoxia. Detected the ultrastructure of these cancer cells with transmission elec-tron microscopy;detect the cell growth with MTT assay;cell cycle and CD133 expression were detected by flow cytometry;and the cell mi-gration ablity were detected through transwell chamber assay;the colony-forming efficiency were deteced by colony-forming assay; and real-time quantitative PCR and Western blot were carried out to detect the mRNA and protein expression of markers of stem cells and their differ-entiation respectively. Results Hypoxia maintained the undifferentiated state of primary glioma cells, slowed down the growth of glioma cells which were in a relatively quiescent stage, increased the colony forming efficiency and migration of glioma cells, and increased the expression of markers of stem cells, but the expression of markers for stem cell differentiation was reduced after hypoxia treatment. Conclusion Hypoxi-a may induce the “dedifferentiation” of differentiated glioma cells which then acquire the stemness.

AIM:?To?investigate?if?alfentanil?protects?the?isolated?rat?heart?against?myocardial?reperfusion?injury?and?if?the?mechanism?of?this?protection?is?mediated?via?opioid?receptors?and?NO-dependent?pathways. METHODS: Langendorff rat hearts were perfused at constant pressure with Kreb-Henseleit(K-H) buffer for 20 min?and?then?were?perfused?with?test?solution:?K-H?buffer?or?K-H?buffer?containing?alfentanil? 50 ?g?L -1,?alfentanil? 100 ?g?L -1, naloxone 200 ?g?L -1, alfentanil 100 ?g?L -1+naloxone 200 ?g?L -1, L-NAME 100 ?mol?L -1 and alfentanil 100 ?g?L -1+L-NAME 100 ?mol?L -1. After 10 min of this, the hearts were subjected to 25 min normothermic( 37 ℃) global ischemia followed by 30 min reperfusion with the same test solution as before. To evaluate myocardial function, LVEDP, LVDP, ?dp/dt max, HR and CF were measured at the 20th, 25 and 30th minute of perfusion and the 1st, 3rd, 5th, 10th, 20th and 30th minute of reperfusion. After experiment, the NOS and ATP content of myocardium were assessed. RESULTS: Before ischemia, alfentanil 100 ?g?L -1 decreased the HR at the 30th minute compared with the 20th minute(P