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Objective: To investigate the protective effect of high-pressure carbon monoxide for preservation of ex vivo rabbit heart graft in comparison with the conventional HTK cardioplegic solution preservation., Methods: Heart grafts isolated from 85 New Zealand rabbits were randomly divided into Naive group (n=5), HTK group (n=40) and CO group (n=40). The grafts underwent no preservation procedures in Naive group, preserved at 4 degrees celsius; in HTK cardioplegic solution in HTK group, and preserved at 4 degrees celsius; in a high-pressure tank (PO2: PCO=3200 hPa: 800 hPa) in CO group with Krebs-Henseleit solution perfusion but without cardioplegic solution. After preservation for 2, 4, 6, 8, 10, 14, 18, and 24 h, 5 grafts from the two preservation groups were perfused for 30 min with a modified Langendorff apparatus and examined for left ventricular systolic pressure (LVSP), left ventricular diastolic pressure (LVDP), arrhythmia score (AS), myocardial ultrestructure, and cardiac enzyme profiles., Results: After preservation for 6 to 24 h, the cardiac enzyme profiles and systolic and diastolic functions were significantly better in CO group than in HTK group, but these differences were not obvious between the two groups after graft preservation for 2 to 4 h. Significant changes in the myocardial ultrastructures occurred in the isolated hearts after a 24-h preservation in both CO and HTK groups, but the myocardial damages were milder in CO group., Conclusion: Preservation using high-pressure carbon monoxide can better protect isolated rabbit heart graft than the conventional HTK preservation approach especially for prolonged graft preservation.

Objective: To evaluate the clinical efficacy of low molecular weight heparin (Fraxiparine) in rescuing venous crisis of island skin flap., Methods: Of the 73 patients with venous crisis of island skin flap, 47 received subcutaneous injection of low-molecular-weight heparin (group I) and 26 were treated with phlebotomy, local compression and topical application of unfractionated heparin solution gauze (group II)., Results: The flap survival ratio was (88.46∓8.64)% in group I and (38.37∓6.53)% in group II (P<0.001). At 0, 2, and 4 h after injection of low-molecular-weight heparin, the activated partial thromboplastin time (APTT) was obviously delayed (24.28∓6.71, 41.35∓7.64 and 32.34∓6.35, respectively, P<0.01), FXa:C level was significantly decreased (152.4∓30.7, 65.8∓24.4 and 83.4∓18.4, respectively, P<0.01), while FIIa:C level underwent no obvious alterations (155.70∓31.61, 143.20∓24.75, and 143.4∓23.35, respectively, P=NS)., Conclusion: Fraxiparine has good antithrombotic efficacy in rescuing venous crisis of island skin flap without adverse effect on systemic coagulation.

Objective: To summarize the experience with surgical treatment of coronary artery disease with severe ischemic mitral valve regurgitation (IMR)., Methods: From January 2006 to December 2009, 45 patients (35 males, 10 females aged 32-74 years) with the diagnosis of coronary artery disease complicated by IMR underwent coronary artery bypass grafting (CABG) combined with mitral valve plasty (MVP, 24 cases) or mitral valve replacement (MVR, 21 cases)., Results: Perioperative deaths occurred in 2 cases due to multiple organ failure (MOF). Echocardiography showed a significant reduction of the mitral regurgitation area (from 11.80∓2.45 cm(2) to 2.83∓0.98 cm(2), t=22.80, P=0.00) after CABG combined with mitral valve surgery, with also significantly reduced postoperative left ventricular end diastolic diameter (LVEDD) (from 57.61∓10.06 mm to 51.84∓8.98 mm, t=2.85, P=0.005). No significant difference was detected in the left ventricular ejection fraction after the operation [(52.7∓15.4)% vs (53.2∓13.2)%, t=0.16, P=0.87)]., Conclusions: CABG combined with mitral valve surgery can improve early postoperative left ventricular function in patients with ischemic coronary heart disease complicated by severe mitral regurgitation, but further follow-up study is still needed for evaluation of the long-term results.

Objective: To identify the candidate auto-antigen of rheumatic heart disease as a molecular marker for this disease., Methods: The total RNA of the heart tissue of patients with rheumatic heart disease was extracted and reverse-transcribed into long cDNA to construct the phage expression library. The library was screened using the serum from patients with active rheumatic fever, and the positive clone was identified and analyzed by bioinformatics and expressed in vitro. The expressed products were evaluated with Western blotting and its cross-reactivity was assessed., Results: The phage expression library of the heart tissue of patients with rheumatic heart disease was constructed, with the titer of the primary library of 3.3×10(6) pfu/ml, recombinant rate of 99%, and 81% of the inserted segments were larger than 1 kb. An auto-antigen RHDAG1 was identified by screening, which was homologous to keratin 18. RHDAG1 was detected in the serum of patients with active rheumatic fever and of those with rheumatic heart disease, but not in the serum of healthy subjects., Conclusion: Phage display library can be an effective strategy to screen the auto-antigens of rheumatic heart disease. The auto-antigen RHDAG1 can be a candidate molecular biomarker of rheumatic heart disease and/or rheumatic fever.

Objective: To investigate the expression and functional role of the small conductance Ca(2+)-activated K(+) channels in human atrial myocytes., Methods: We collected the right atrial appendage tissues from 8 patients with congenital heart defect with sinus rhythm undergoing open-heart surgery. Immunohistochemistry was performed to identify the expression of 3 isoforms of SK channel (SK1, SK2 and SK3). Using the classical two-step enzymatic isolation method, perforated patch clamp and conventional voltage-clamp techniques were performed to record the action potentials (APs) and the whole-cell Ca(2+)-activated K(+) current (I(K, Ca)) in the single atrial myocyte. We compared the changes in action potential duration (APD) before and after the application of a specific SK channels blocker apamin (100 nmol/L)., Results: Human atrial myocytes showed positivity for all the SK1, SK2 and SK3 isoform channels. Patch-clamp recording confirmed the presence of I(K,Ca), and apamin significantly prolonged APD at 90% repolarization (APD(90)), but produced no obvious effect on APD(50)., Conclusion: The three isoforms of SK channels are all expressed in human atrial myocytes. SK channels play a prominent role in the late phase of repolarization in human atrial myocytes, which is distinct from their functional roles in neurons where they mediate the process of afterhyperpolarization following APs.

Objective: To analyze the changes in the cardiac function after St. Jude Regent mechanical valve replacement and assess the prosthesis-patient matching., Methods: From October 2007 to March 2009, 44 patients received implantation of 17 mm St. Jude aortic prostheses in our hospital. The patients were followed up for clinical symptoms, signs, electrocardiogram (ECG), echocardiogram and cardiac functions, and the results were compared with those of randomly selected 44 patients receiving 21 mm St. Jude aortic prostheses., Results: In 17 mm St Jude Medica Regent valve group, 8 patients presented with ECG ST segment changes, 3 complained of chest tightness, 3 had occasional chest pain and discomfort, and 8 had grade II and 4 grade III cardiac function. In 21 mm St Jude Medical Regent valve group, 6 patients had ECG ST segment changes, 2 complained of chest tightness, 2 reported occasional chest pain and discomfort, 11 had grade II and 2 grade III cardiac function. No significant differences were found in these indices between the two groups (P=0.32). Compared with those before operation, the two groups showed significant improvements in the left ventricular end-diastolic diameter, left ventricular posterior wall thickness, left ventricular mass index, and aortic pressure gradient (P<0.05). A significant increase in the left ventricular ejection fraction occurred 6-12 months after operation, but without statistical difference between the two groups (P>0.05)., Conclusion: For underweight patients (<60 kg) and those with small body surface area (<1.6 cm(2)), 17 mm St. Jude Medical Regent valve prosthesis may produce good therapeutic effect, and some indices are even close to those after placement of 21 mm St. Jude Medical Regent valve prosthesis. No obvious prosthesis-patient mismatch occurs after the placement of the 17 mm valve prosthesis and aortic valve ring expansion is not necessary.

Objective: To summarize the experience with surgical treatment of constrictive pericarditis., Methods: A retrospective analysis of the post-operative clinical data was conducted in 128 surgical patients with chronic constrictive pericarditis., Results: Two early postoperative death occurred in this group due to severe low cardiac output syndrome, with the mortality rate of 1.57%. The postoperative complications included low cardiac output syndrome (13.2%), arrhythmia (7.02%), acute renal insufficiency (3.9%), respiratory insufficiency (3.1%), wound infection (2.3%), postoperative chest bleeding (1.6%) and cerebral infarction (0.78%). Relapse occurred in one case because of incomplete pericardial resection., Conclusions: Constrictive pericarditis should be confirmed as soon as possible with actively surgery, and the extent of pericardial resection should be decided according to the individual conditions. Complete untethering of the diseased pericardium should be performed with active prevention of postoperative complications.

Objective: To establish a rat model of full-thickness skin defect to receive bone marrow mesenchymal stem cell transplantation for wound repair., Methods: A full-thickness skin defect measuring 4 cmx4 cm in 36 F344 rats, which were divided into 3 groups with the wound covered with alloskin graft, acellular dermal matrix, or petrolatum gauze. In vitro cultured BMSCs in the 5th passage were transplanted into the skin defect, and the time of wound dressing dissociation and number of transplanted Brdu-positive cells in the wound were observed 14 days later., Results: The alloskin graft resulted in significantly longer time before dressing dissociation, with greater number of Brdu-positive cells in the wound than the other two wound dressings (P<0.001). The acellular dermal matrix showed better effect than petrolatum gauze in terms of the dressing dissociation time and the viable transplanted cell number in the wound., Conclusion: Alloskin graft can be ideal for covering the wound surface to protect the transplanted BMSCs in rats.

Objective: To test the effect of intramyocardial injection of autologous bone marrow mononuclear cells (MNCs) in improving the cardiac function and myocardial revascularization in miniswine models of myocardial infarction., Methods: The miniswine models of myocardial infarction established by ligation of the anterior descending coronary artery were divided into 3 groups including a control and two MNC injection groups. Autologous bone marrow MNCs were injected via the epicardium into the infarcted area in the latter two groups at 1 and 2 weeks after the infarction, respectively. The ventricular segmental wall motion was evaluated after the treatment, and the infarcted myocardium observed with immunohistochemistry on frozen sections., Results: The left ventricular segmental wall motion differed significantly between the control and the MNC injection groups at 1 and 2 months after the treatment. CM-DiI-positive cells were detected in the infarcted myocardium where MNCs were implanted., Conclusion: Intramyocardial injection of autologous bone marrow MNCs improves the infarcted ventricular segmental wall motion, and significantly increases the number of blood vessels in the infracted area. The transplanted cells can be integrated into the vascular walls of the capillaries and arterioles and differentiate into cardiomyocytes.

Objective: To observe the effect of perivenous support with autologous pericardium on neointimal thickening in canine vein grafts., Methods: An autologous pericardium graft of 7 cm x 4 cm was harvested in right anterolateral thoracotomy. Two equal segments of the jugular vein were transplanted to both sides of the femoral arteries in 12 dogs, and on one side of the vein graft, perivenous support with autologous pericardium was applied. The vein grafts were harvested 2 and 4 weeks after operation and the thickness and area of the neointima calculated using computerized image analysis system. Scanning electron microscopy and PCNA immunohistochemistry were also performed., Results: The thickness and area of the neointima were significantly greater in the control grafts than in the grafts with perivenous support (P<0.05), and the proliferation of vascular smooth muscle cells in the supported graft was less active (P<0.05). Electron microscopy showed extensive destruction of the endothelium in the control graft, but only slight damage was found in the graft with perivenous support., Conclusion: Perivenous support of the vein graft with autologous pericardium can reduce intimal and medial hyperplasia in the graft.

Objective: To evaluate the value of laminar flow in the treatment of burns., Methods: The air in the laminar flow chamber and the wound tissues of the patients were sampled for bacterial detection. The number and stains of bacterial colony from different classes of laminar air flow chambers at different time points were inspected and compared., Results: The bacterial number was 0 in the laminar flow chamber of 1000 grade, which was obviously different from that in the public area. The mortality was obviously decreased in the laminar air flow chamber with shorter treatment time and hospitalization. No wound infection occurred and the wounds healed smoothly in all these patients., Conclusion: The application of laminar air flow can be helpful for the treatment of severe burns.

Objective: To explore early diagnosis, treatment and prevention of gastrointestinal (GI) bleeding after cardiac surgery., Methods: In the last 13 years, cases complicated with GI bleeding after cardiac surgeries were analyzed retrospectively., Results: Fourty-four GI bleeding occurred post-operatively in (6 +/- 3) d. The mortality was 23% (10/44). Thirty-eight were located in upper GI tract, of them 26 underwent conservative therapy while 4 died of other than GI bleeding cause; six underwent laparotomy while 1 and 3 died of septicemia and multi-organ failure respectively; six underwent gastric endoscopic hemostasis by electrocautery or clipping the bleeding vessel while all survived. Six were located in lower GI tract, and 2 of them underwent laparotomy without finding bleeding section and died of multi-organ failure. By multivariable logistic regression analysis, deaths were highly related to the post-operative ventilator-dependence, acute renal insufficiency, intra-aortic balloon pump (IABP) assisting and laparotomy., Conclusion: The mortality of GI bleeding after cardiac surgeries is very high, early gastrointestinal endoscopic examination and minimally invasive intervention can treat this complication more effectively. GI bleeding must be prevented whenever complicating post-operative ventilator-dependence, acute renal insufficiency, and IABP assisting after cardiac surgery.

Objective: To investigate the protective effect and safety of coronary sinus retroperfusion (CSR) with aortic oxygenated blood for acute myocardial ischemia during off-pump beating heart surgery in pigs., Methods: Eighteen pigs were subjected to 120 min of acute myocardial ischemia by ligation of the lateral anterior descending branch (LAD) of the coronary artery followed by 60 min of reperfusion by lifting LAD ligation. The pigs were divided into 3 groups after the above operation, including a control group (group 1) and low- and high-pressure retroperfusion groups (groups 2 and 3), and in the latter two groups the pigs received 60 min of aorta-coronary sinus shunt retroperfusion (ACSSR) following 60 min of ischemia with self or manually inflated balloon-tipped cannula inserted to induce low or high-pressure, respectively. The left ventricular function and measurements of coronary sinus nitric oxide (NO), endothelin-1 (ET-1) and infarct size were recorded., Results: Three hours after ischemia, the maximal left ventricular pressure increment to reduction rates in groups 2 and 3 were much higher than those of group 1, with also higher NO and lower ET-1 concentrations in the coronary sinus blood. The infarct size was reduced by 45%; and 61%; in groups 2 and 3, respectively, as compared with that of group 1., Conclusion: ACSSR can reduce left ventricular systolic and diastolic dysfunction, protect coronary endothelial function, and reduce infarct size for rescue of the acutely ischemic myocardium in pigs during off-pump beating heart surgery.

Objective: To investigate the changes in protein catabolism and immunocompetence in severely burned patients after operations and observe the therapeutic effect of recombinant human growth hormone (rhGH) in these patients., Methods: The changes in plasma protein concentration and immune function and the clinical results of 38 severely burned patients after three operations were retrospectively analyzed. These patients were assigned to GroupI(control, n=20) and GroupII (rhGH treatment, n=18), and matched for age, total body surface area (TBSA), surgical approaches and times, perioperative bleeding volume and nutrition support etc. The patients in groupII received intramuscular injection with 0.2-0.4 U/d x kg x b.w. rhGH after the first operation, till the healing of the wounds., Results: The concentration of retina-binding protein, transferrin, prealbumin, albumin, and IgG, the number of CD4 and CD8 cells, as well as the ratio of CD4/CD8 cells prior to the operation were below the normal levels in the two groups of patients. All these indexes in GroupII recovered to a great extent after three operations and were significantly higher than those in GroupI(P<0.05)., Conclusion: Nutritious state and immunocompetence of patients with severe burns are severely compromised after operations, and nutrition support and rhGH treatment may produce rapid improvement of the patients' conditions.