Protective effect of overexpression of PrxII on H2O2-induced cardiomyocyte injury.

OBJECTIVE: Oxidative stress is one of the main factors leading to myocardial cell damage, and the redox imbalance promotes apoptosis. Therefore, the purpose of this study was to explore the protective effect of PrxII on H2O2-induced H9c2 cell injury. MATERIALS AND METHODS: The overexpressed PrxII cell model was constructed by virus. The H9c2 cells were treated with H2O2, and the supernatant and cells were collected. Then, the chymotrypsin-like activity, caspase-like activity, and trypsin-like activity were detected by the kit, and the expressions of P21, P27, and P53 were detected by the ELISA method. Finally, the expressions of antioxidant factors, apoptosis-related factors, and AMPK/Sirt1 signaling pathway were detected by Western blot and Real-time polymerase chain reaction (PCR). RESULTS: Overexpression of PrxII inhibited the decrease of enzyme activity induced by H2O2, promoted the expressions of anti-oxidation factors GPX1, GPX2, and GSX, and inhibited the expressions of apoptosis-related factors P21, P27, and P53, and activated AMPK/Sirt1 pathway. CONCLUSIONS: Overexpression of PrxII can activate the AMPK/Sirt1 pathway, thereby inhibiting H2O2-induced oxidative stress and slowing apoptosis.

[Long-term outcomes of off-pump coronary artery bypass grafting].

Objective: To investigate the long-term outcomes of off-pump coronary artery bypass grafting (OPCABG). Methods: Clinical data of 1 129 consecutive patients ( 937 males and 192 females) with coronary artery disease receiving OPCABG at Department of Cardiovascular Surgery, Chinese PLA General Hospital between January 2000 and December 2015 was retrospectively analyzed.The age of patients ranged from 29 to 83 years, with a mean age of (62.0±9.6) years. The follow-up data of the patients, including the graft patency and repeated revascularization rate, were analyzed. Results: Of the 1 129 patients analyzed, 1 059 cases (93.8%) were available for follow-up for 29-192 months[with a mean time of (95.6±34.1) months]. The 5-year, 10-year, 15-year and 16-year graft patency rate of arterial graft was 96.1%, 95.4%, 93.7% and 93.2%, respectively. The 5-year, 10-year, 15-year and 16-year graft patency rate of venous graft was 92.8%, 81.4%, 70.9% and 68.3%, respectively. During the follow-up, 69 (6.11%) patients underwent repeated revascularization procedures. Conclusion: OPCABG is safe and effective with a good long-term graft patency rate.

[Clinical application of one-stage operation of epicardial permanent pacemaker implantation and cardiac surgery].

Objective: To summarize the results and clinical application experience of one-stage operation of epicardial permanent pacemaker implantation and cardiac surgery. Methods: From November 2014 to July 2016, 15 patients (9 males and 6 females) with ages ranging from 50 to 73 (63.5±6.2) years requiring cardiac surgery with bradycardia underwent one-stage operation of epicardial permanent pacemaker implantation and cardiac surgery. All operations were performed under general anesthesia with chest median incision approach. Among them, single chamber pacemaker (n=10) and dual chamber pacemaker (n=5) permanent epicardial pacing leads were implanted. Simultaneous procedures included valve replacement in 7 cases, valve replacement combined with atrial fibrillation ablation in 3 cases, coronary artery bypass grafting in 2 cases, aortic root replacement in 2 cases, and valve replacement combined with coronary artery bypass surgery in 1 case. Their parameters of pacemaker including sensitivity, pacing threshold, pacing impedance were measured during surgery and closely followed up at 1 week and 3, 6 months after surgery. Results: All 15 patients with epicardial permanent pacemaker implantation in the same period of cardiac surgery were successfully cured and discharged, without any surgical complications. A total of 20 epicardial electrodes were implanted for them including 5 right atrial electrodes and 15 right ventricular electrodes. The postoperative follow-up period ranged from 3 to 22 months. No electrode fracture and surgical wound infection occurred in those patients, and their impedance, sensing and stimulation thresholds were all in normal ranges during follow-up. Conclusions: For patients with bradycardia who required cardiac surgery, one-stage operation of epicardial permanent pacemaker implantation and cardiac surgery is safe and effective, and the results in the short-term and medium-term are satisfactory, avoiding the risk of staged surgery.

[Robotic mitral valve repair: perioperative and seven-year follow-up results].

OBJECTIVE: To summarize surgical experience during the conduction of robotic mitral valve repair and evaluate the long-term follow-up results. METHODS: From January 2007 to September 2014, 110 consecutive patients underwent robotic mitral valve repair under da Vinci Surgical System (Intuitive Surgical, USA) in Chinese PLA General Hospital were enrolled. The age of the patients was 14 to 65(45±12) years old. The male to female ratio was 2.3∶1. Among them, 95.5%(105/110) of the cases was diagnosed as mitral regurgitation and 4.5%(5/110) of them was diagnosed as mitral stenosis, and most of them (63.3%) needed triangular or quadrangular resection. Nitinol U-clips (58.1%), running suture (31.2%) and Cor-Knot™ suture device (10.8%) were used to secure the annuloplasty ring. The operative data were collected and patients were regularly followed up echocardiographically as long as 7 years. RESULTS: All the surgeries were finished by the same surgeon. One case required conversion to sternotomy. The mean cardiopulmonary bypass (CPB) and cross-clamp time was 70 to 152 (121.0±34.3) and 47 to 122 (82.6±25.3) minutes respectively. After surgery, one death (0.91%) and two cases of stroke (1.82%) occurred. Three cases of early prosthetic failure (2.73%) were noticed. All patients were successfully followed up for a median of 50 (range, 1 month to 7 years) months and 94.5%(104/110) of them had no re-operation. CONCLUSION: Robotic mitral valve repair is a safe and effective surgical method with excellent long-term outcomes.

[Long-term outcome of surgical revascularization in patients with ischemic heart disease and left ventricular dysfunction].

OBJECTIVE: To analyze the long-term results and risk factors of surgical revascularization in patients with ischemic heart disease (IHD) and left ventricular dysfunction (LVD). METHODS: From January 2003 to July 2013, 2 132 patients underwent coronary artery bypass grafting (CABG) in our institution. Among them, 318 patients with LVD[left ventricular ejection fraction (LVEF) ≤50%]were included in the final study. There were 26 6 male and 52 female patients with age from 36 to 83 (63±9) years old. 76 patients underwent off-pump CABG (OPCAB) and 242 patients underwent conventional CABG (CCABG). Risk factors, perioperative results and follow-up data were collected and analyzed with cox hazard ratio model. RESULTS: Among 318 patients, 6 cases died of the operation with a hospital mortality of 1.9%. With follow-up time from 1 to 128(45.5±32.4)months, 25 patients were lost of follow-up, causing a follow-up rate of 92.0%. Among the 287 cases with long-term follow-up results, all-cause death, cardiogenic death and re-hospitalization due to heart failure were 14.6% (42/287), 5.9%(17/287), 14.6% (42/287), respectively. Re-revascularization rate, recurrent angina and myocardial infarction rate and cerebral incidence were 3.5%(10/287), 13.6% (39/287), 1.7%(5/287), respectively. The five-year survival rate was 85.6%. With all-cause death as the endpoint, preoperative LVEF (HR=0.943, 95%CI: 0.893-0.995, P=0.031) and perioperative implantation of IABP (HR=2.509, 95%CI: 1.051-5.992, P=0.038) emerged as the risk factors that affected the long term survival. The five-year survival rate of patients with severe LVD (LVEF≤35%) was significantly lower than that of patients with mild to moderate LVD (35%

Relationship between perioperative cardiovascular risk factors and bone marrow cells from patients undergoing coronary artery bypass grafting surgery.

Cell therapy through the implantation of autologous bone marrow cells has long been used in clinical trials for the treatment of ischemic heart diseases. However, as the outcomes of cell implantation vary among patients, risk factors that might influence the level and function of bone marrow progenitor cells should be determined, to identify patients who would benefit the most from this treatment. We collected clinical and laboratory data from 44 patients scheduled to undergo sternotomy for coronary artery bypass grafting (CABG). Bone marrow was aspirated from the sternum during the operation, and bone marrow mononuclear cells (BMMNCs) were isolated through density centrifugation. A negative correlation was observed between the number of BMMNCs and age (N = 44, r = -0.788, P = 0.001). The level of CD34+ cells in BMMNCs was 0.94 ± 0.39%, CD133+ cells 0.46 ± 0.28%, and CD34+CD133+ cells 0.53 ± 0.26%. The levels of CD34+ and CD133+ cells in diabetic patients were significantly lower than those in nondiabetic patients. Female gender, advanced age, and poor heart function were related with reduced progenitor cell clonogenic function. A positive correlation was observed between the level of CD34+ cells and BMMNC migration ability. Aging and diabetes were the major risk factors that influence the level and function of bone marrow resident progenitor cells in patients with coronary heart disease undergoing CABG. Further study is needed to determine whether these two factors can influence the outcome of bone marrow cell therapy for ischemic heart disease.

Angiotensin-(1-7) upregulates (ATP-binding cassette transporter A1) ABCA1 expression through cyclic AMP signaling pathway in RAW 264.7 macrophages.

OBJECTIVES: ATP-binding cassette transporter A1 (ABCA1) plays a crucial role in reverse cholesterol transport and anti-atherosclerosis. Cyclic AMP (cAMP) could increase the ABCA1 expression. Angiotensin (Ang)-(1-7) can protect endothelial cells, inhibit smooth muscle cell growth, ameliorate inflammation and exert anti-atherosclerotic effects. In this study, we attempted to clarify the effect of Ang-(1-7) on expression of ABCA1, and explored the role of cAMP in the regulation of ABCA1 in RAW 264.7 macrophages. MATERIALS AND METHODS: RAW 264.7 macrophages were cultured. Then the macro-phages were incubated with different concentration Ang-(1-7) or 10 mM MDL respectively, or 10 mM adenylate cyclase inhibitor MDL-12330A (MDL) plus 1000 nM Ang-(1-7) for 24 h. The expression of ABCA1 was examined by real-time quantitative PCR and western blot analyses. cAMP expression was measured by Enzyme-Linked Immuno Sorbent Assay. Cellar cholesterol efflux from RAW 264.7 macrophages was analyzed using liquid scintillation counting assays. The cellular total cholesterol and free cholesterol were performed to determine by High Performance Liquid Chromatography assays. RESULTS: Our results showed that Ang-(1-7) increased ABCA1 expression at both the mRNA and protein levels in a dose-dependent manner. Consequently, the increase in cholesterol efflux was consistent with an ABCA1 expression increase. The cAMP expression was up-regulated by Ang-(1-7). When being treated with MDL and Ang-(1-7), the ABCA1 expression, cellular cholesterol efflux and cholesterol content were partially reversed by MDL. CONCLUSIONS: Ang-(1-7) could increase ABCA1 expression partially due to the cAMP pathway.

Intracoronary trimetazidine does not improve recovery of regional function in a porcine model of repeated ischemia.

We evaluated the effect of trimetazidine (TMZ) on recovery of regional cardiac function in anesthetized open-chest pigs, subjected to fifteen 2-minute occlusions of the left anterior descending coronary artery, separated by 2 minutes of reperfusion and a 120-minute recovery period. Regional myocardial function was evaluated by sonomicrometry-derived segment lengthening and the area enclosed by the left ventricular pressure-segment length loop (external work, EW) in animals, which received either an intracoronary infusion of TMZ (33 micrograms/kg/min, n = 6) or saline (1 ml/min, n = 7), starting 15 minutes before the first occlusion and ending 2 minutes after the 15th occlusion. In addition, myocardial malondialdehyde production to evaluate oxygen free radical production, oxygen consumption, and the ATP, ADP, and AMP content, as well as the energy charge, were determined at regular time intervals. In control pigs the sequences of occlusion-reperfusion did not affect systemic hemodynamics, except for the LVdP/dtmax, which decreased by 11% during the interventions and did not recover during the following reperfusion period of 2 hours (78% of baseline, p < 0.05). Systolic segment length shortening and EW were increased at the end of the first occlusion-reperfusion cycle, decreased gradually during the remainder of the occlusion-reperfusion periods, and did not improve during the recovery period. Energy charge and myocardial blood flow were not impaired, but oxygen consumption was decreased during the recovery period. The malondialdehyde data did not provide evidence for production of oxygen free radicals.(ABSTRACT TRUNCATED AT 250 WORDS)

Prolongation of epidural bupivacaine analgesia with glycerin.

Glycerin has been used as a drug carrier/depot, but never with local anaesthetics. This study was an attempt to use the slow drug release mechanism to prolong the anaesthetic effects of bupivacaine in epidural block. Twenty-seven adults with cancer pain were prospectively selected according to their primary lesions and problems, but their allocation to study groups was randomized. Group I (n = 13), received 5 ml bupivacaine, 0.125% in normal saline via a previous implanted epidural catheter. When the pain returned to its original intensity, the same amount of the same strength anaesthetic dissolved in 50% glycerin was given via the same catheter. Group II (n = 14) received the same solutions, but in the reverse order. Also five patients in each group received plain 50% glycerin prior to administration of the anaesthetic solutions to serve as controls. The pharmacological effects were assessed by the blinded observers. Analgesia produced with glycerin solution was prolonged compared with the saline solution (12.2 vs 7.2 and 11.6 vs 7.4 hr, P < 0.01). The order of giving the solution did not produce any differences. Plan 50% glycerin did not produce analgesic effects. Neither motor blockade nor other adverse effects or complications were observed in either group. It was concluded that 0.125% bupivacaine in 50% glycerin administered epidurally is not neurotoxic. The prolongation of analgesia observed is attributed to the slow release of bupivacaine from the glycerin base which functions as drug depot. In addition to relief of chronic pain, this novel approach may have other clinical applications such as the relief of labour or postoperative pain.

[Epidural administration of bupivacaine in glycerine solution can prolong analgesia].

Glycerine has long been used with phenol as a drug depot in control of intractable pain. However, through our literature review, glycerine has never been used to prolong the pharmacological effects of a local anesthetic, such as bupivacaine. Our study is an attempt to use the same mechanism to further extend the pharmacologic effects of a popular long lasting anesthetic in a commonly used technique. Fifteen adult patients with cancer pain received 0.125% bupivacaine via a chronically implanted epidural catheter. In a blind study of pain control: Group I, consisting of 8 patients, received 5 ml 0.125% bupivacaine in normal saline; group II, consisting of 7 patients, received the same amount of the same strength anesthetic dissolved in 50% glycerine. The pharmacological effect was assessed by evaluation of intensity and duration of sensory as well as motor blockade. Our preliminary experimental experience revealed that significant prolongation (11.8 +/- 2.3 h vs 7.6 +/- 1.8 h, p less than 0.01) of analgesia was observed with the glycerine solution as compared to the saline solution. There was no motor blockade or other adverse effects or complications. This markedly prolonged analgesic effect is attributed to the slow release of the local anesthetic agent from the glycerine base which functions as a drug depot. Other clinical applications of this novel approach in pain relief are currently under investigation.

[Isolation and fermentation conditions of polyvinyl alcohol-degrading enzyme producing strain].

A bacterium D8 strain which high efficiently degrading PVA was isolated from waste water of factory. The strain possesses the abilities of completely degrading 0.5 per cent of PVA (500, 1700) included in the culture medium for four days. It was identified Pseudomonas pseudoalcaligenes. Fermentation conditions of the strain have been investigated. The suitable medium consisted of PVA 1.5% (NH4)2SO40.1%, K2HPO4 0.24%, KH2PO4 0.04%, MgSO4.7H2O 0.035%, NaCl 0.01%, FeSO4 0.001%, yeast extract 0.15%, pH 7.5. The optimal condition for enzyme production are as follows: 250 ml shake filled with 30 ml medium, 30 degrees C, 160n/min incubation period 72 h. Under such conditions enzyme activity is highest.

[Studies on harmful microbes in recirculating cooling water system of oil refinery].

The microbiol counts, type, distribution as well as interrelation between microbial counts and biofouling of the main harmful microbes including slimeforming heterotrophic bacteria, sulfate reducing bacteria, iron bacteria and fungi has been studies in 16 oil refineries of China. The control guideline of the harmful microbes for recirculating cooling water system of refinery were suggested, that is slime-forming bacteria less than 10(5)/ml, sulfate reducing bacteria less than 10(2)/ml. iron bacteria less than 10(3)/ml, fungi less than 10/ml. The appearing rate of the predominant strains from cooling water system of various refineries were calculated and identified and the composition of the main harmful representative microbes in cooling water system were determined.