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.

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.

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.

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

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

Objective To investigate the role of phosphatidyl-inositol 3-kinase-Akt (PI3k-Akt) signal pathway in the attenuation of ischemia-reperfusion (I/R) injury by sevoflurane preconditioning in isolated rat hearts. Methods Ninety-six adult male SD rats weighing 220-280 g were randomly divided into 6 groups ( n = 16 each): sham operation group (group S); I/R group; sevoflurane preconditioning group (group SP); wortmannin group (group W); dimethyl sulfoxide (DMSO) group (group D) and sevoflurane preconditioning + wortmannin group (group SW) . Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95%O2-5%C02 at 37 ℃ . The hearts were continuously perfused for 180 min in group S. After 15 min of equilibration, the isolated hearts were subjected to 30 min of ischemia followed by 120 min of reperfusion in SP, W, D and SW groups. Croups SP, W, D and SW received 10 min of perfusion with K-H solution containing 2. 4% sevoflurane, 100 nmol/L wortmannin, 20 μmol/L DMSO, and 2.4% sevoflurane + 100 nmol/L wortmannin, respectively, followed by 5 min washout before I/R. Eight hearts in each group were selected and HR, left ventricular end-diabetic pressure (LVEDP), left ventricular developed pressure (LVDP), and ± dp/dtmax were recorded at the end of equilibration and at 15 min of reperfusion, Myocardial tissues were obtained at 15 min of reperfusion for determination of apoptosis (by TUNEL) and phosphorylated Akt (p-Akt) expression (by Western blot) . Another 8 hearts were selected at 120 min of reperfusion for determination of myocardial infarct size by TTC staining. Result Compared with group S, LVDP and ± dp/dt,^ were significantly decreased and LVEDP was significantly increased in groups I/R, SP, W, D and SW, and myocardial p-Akt expression was up-regulated in groups I/R, SP and D ( P ＜ 0.05). Compared with group I/R, LVDP and ± dp/dtmax were significantly increased, LVEDP and apoptosis index were significantly decreased, myocardial p-Akt expression was up-regulated, and myocardial infarct size was significantly reduced in group SP (P ＜0.05) . Conclusion Activation of PI3K-Akt signal pathway is involved in the attenuation of I/R injury by sevoflurane reconditioning in isolated rat hearts.

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 study the effect of Sandra Fucile oral stimulation on oral feeding readiness and ability of preterm infants.Methods Sixty-five premature infants were selected in the study.All of the premature infants were recruited randomly in convenience between Jul.and Dec.2012.For a randomized control principle,SPSS 13.0 was performed to achieve complete random design.Objects were divided into control group(receiving routine nursing) and intervention group(on the basis of routine nursing,receiving 15 minutes oral stimulation,1 time/day,for 10 days).Chinese version of Preterm Infant Oral Feeding Readiness Assessment scale(PIOFRA scale-CV) was used when intervention began,and 7 days,10 days,14 days after the start of the intervention.Results PIOFRA-CV scale score was statistically different at different time in both groups(F =169.062,P ＜0.001).The first day ratings were minimum in the 2 groups,after which with an upward trend over time.The control group and intervention group rated a statistically significant difference(F =5.538,P =0.022).Except for no difference on the first day and seventh day (t =1.650,P =0.204 ;t =0.817,P =0.369) between the 2 groups,the intervention group had a higher score than the control group (t =17.339,24.141,all P ＜0.001).Group and time had an interaction effect(F =1 1.561,P ＜0.001).The incidence of vomiting[42.4％ (14/33 cases) vs 34.4％ (11/32 cases)],infection [27.3％ (9/33 cases) vs 9.4％ (3/32 cases)],and gastro-oesophageal reflux[30.3％ (10/33 cases) vs 25.0％ (8/32 cases)] were not significantly different between the 2 groups(x2 =0.445,3.457,0.288,all P ＞ 0.05).Conclusions Saudra Fucile oral stimulation method can significantly promote the development of premature oral feeding ability on the 10 day after the intervention,and will not increase vomiting,gastroesophageal reflux,and infection.It is suitable for clinical application.