Objective To study the protective effect of exogenous matrix metalloproteinases9(MMP-9) inhibitor Doxycycline against lung injury during cardiopulmonary bypass(CPB) in dogs. Methods Twenty healthy mongrel puppies(weighed 10 -12 kg) were divided into control group (n=10) and experimental group(n=10) with random number table. In control group, no measure was taken to protect lung before and after CPB. In experimental group, the feeding food was mixed with Doxycycline (30 mg/kg, body weight) daily for three days before operation. Enzymelinked immunosorbent assay(ELISA) was used to measure the plasma concentration of MMP-9. Hemodynamic and respiratory parameters in two groups were monitored. The preoperative and postoperative alveolararterial oxygen partial pressure difference (A-aDO2) and respiratory index(RI) were calculated. The myeloperoxidase（MPO）activity of bronchoalveolar lavage fluid（BALF）was determined by colorimetry. The total protein of BALF was measured by Coomassie Brilliant Blue G-250. After CPB, light microscope and electronic microscope were used to observe the morphological changes of lung tissue. The dry to wet weight index(W/D) was calculated. Results In both groups, the plasma concentrations of MMP-9 increased significantly as the time of CPB prolonged. The plasma MMP-9 at 150 min and 270 min after CPB in experimental group decreased significantly than those in control group (9.45±5.29 [CM(159mm]ng/ml vs. 18.66±5.90 ng/ml,t=3.664, P=0.005;16.63±2.90 ng/ml -vs.26.17±5.96 ng/ml, t=5.216, P=0.001). MPO activity, total protein of BALF, W/D, postoperative A-aDO2 and RI in experimental group decreased significantly than those in control group. There were significant differences between two groups（t=5.622,P=0.000; t=5.081, P=0.001; t=2.266, P=0.050; t=4.927, P=0.001; t=6.679,P=0.000）. The lung histopathology and electronic microscope showed that the lung injury reduced significantly. Conclusion Doxycycline plays a role in lung protection by inhibiting the secretion of MMP9, reducing the degradation of cell basement membrane, pulmonary neutrophil infiltration and pulmonary edema. Key words: Cardiopulmonary bypass; Acute lung injury; Matrix metalloproteinase; Doxycycline; Lung protection
Objective To investigate the effect of early postoperative enteral nutrition support on the balance of free amino acid spectrum in plasma for patients with cardiac valve replacement during perioperative period. Methods (Forty-seven) patients undergoing cardiac valve replacement were divided into two groups randomly, the routine diet group and the Nutrison Fibre group. The levels of free amino acids in plasma were measured with pre-column derivatization of high-performance liquid chromatography. Results During perioperative period most free amino acids in plasma decreased significantly in the routine diet group (Plt;0.05). Despite some free amino acids in plasma decreased significantly in the Nutrison Fibre group(Plt;0.05), all free amino acids in plasma returned to (Pgt;05) or were higher than the preoperative levels in the postoperative sixth day (Plt;0.05). At the same postoperative points, most free amino acids in plasma in the Nutrison Fibre group were higher than that of the routine diet group (Plt;0.05). Conclusions The levels of free amino acids in plasma decrease significantly in patients with cardiac valve replacement after operation. Early postoperative Nutrison Fibre enteral nutrition support is helpful for keeping the balance of free amino acids in plasma for patients with cardiac valve replacement.
Objective To summarize the efficacy and clinical experiences of emergent coronary artery bypass grafting (E-CABG) in patients with acute myocardial infarction (AMI) and to discuss the operative opportunity and procedures. Methods We retrospectively analyzed the clinical data of 21 patients with AMI undergoing E-CABG in Sun Yatsen Cardiovascular Disease Hospital between June 1999 and December 2009. Among the patients, there were 14 males and 7 females with their age ranged from 24 to 81 years (63.9±12.4 years). Six patients were operated within 6 hours after the onset of AMI, 7 patients were operated from 6 hours to 3 days after the onset of AMI, and 8 patients were operated from 3 days to 30 days after the onset of AMI. Eight patients had the cardiogenic shock after AMI, one had rupture of ventricular septum and cardiogenic shock, two had rupture of coronary artery after percutaneous transluminal coronary angioplasty, eight had unstable angina and frequent ventricular arrhythmia, one had ventricular fibrillation and cardiac arrest, and one had cardiac trauma. Ten patients were treated with intraaortic balloon pump (IABP). Conventional CABG was performed for 12 patients, off-pump CABG for 5 patients, and on-pump-beating CABG for 4 patients. Results Five patients died after E-CABG with a mortality of 23.8% which was obviously higher than the overall CABG mortality (23.8% vs. 3.1%, χ2=21.184, P＜0.05). There were respectively 2, 2 and 1 deaths with a mortality of 33.3%, 28.6% and 12.5% respectively for operations within 6 hours, 6 hours to 3 days and 3 to 30 days after the onset of AMI. The mortality of those patients who were operated within 3 days after AMI was obviously lower (P＜0.05). The primary causes of death were low cardiac output syndrome, perioperative acute myocardial infarction after CABG and sapremia. There was one death each for patients operated with off-pump and on-pump-beating CABG. Sixteeen patients were discharged from the hospital. The follow-up was from 6 months to 10 years. There were 6 late deaths among which 5 died of cardiac failure accompanied by pulmonary infection, one died of noncardiac factor. Ten patients survived at present, and the quality of life among 5 patients was unsatisfactory. Conclusion The mortality of E-CABG is obviously higher in patients operated within 3 days of AMI. With the support of IABP, if the operation can be carried out 3 days after the onset of AMI, the surgical success rate will be greatly improved by adopting proper offpump and onpumpbeating procedures.
Objective To explore the early diagnostic value of single photon emission computed tomography(SPECT), thoracic computed tomography(CT),and chest X-ray for closed chest trauma. Methods To establish the animal model of unilateral chest impact trauma,to adopt SPECT, thoracic CT, and chest X-ray for early diagnosis of closed chest trauma,and to compare these findings with postmortem examination. Results Thirty minutes after blunt chest trauma, the region of interesting (ROI) between traumatized lung and the heart (ROI2/ROI1) immediately increased to the peak six hours after trauma; on the contralateral lung, the ratio (ROI3/ROI1) increased slowly and reached the peak after six hours, these ratio was still smaller than that of the traumatized lung. These differences were significant (Plt;0.01). Conclusions Chest X-ray is still the most fundamental diagnostic method of chest trauma,but it was thought that the patients of severe chest trauma and multiple injuries should be examined early by thoracic CT. Radionuclide imaging have more diagnostic value than chest X-ray on pulmonary contusion. The diagnostic sensibility to pulmonary contusion of thoracic CT is superior to conventional radiograph,but thoracic CT is inferior to SPECT on exploring exudation and edema of pulmonary contusion. Thoracic CT is superior to conventional radiograph on diagnosis of chest trauma,therefore patients of severe chest trauma and multiple injuries should be adopted to thoracic CT examination at emergency room in order to be diagnosed as soon as possible.
Objective To compare the clinical effect between high flow rate modified ultrafiltration （HMUF） and conventional modified ultrafiltration（CMUF）, and the effect on hemodynamic data and inflammatory mediators. Methods Forty children were divided into two groups with random number table, HMUF group and CMUF group, 20 cases each group. Hematocrit （HCT） and hemodynamic changes were recorded and the concentration of tumor necrosis factor （TNF） and interleukin 6 （IL-6） were measured. Results The operations were done uneventfully with moderate hypothermia cardiopulmonary bypass in 40 patients. Duration of ultrafiltration of HMUF group （7.83±0. 75 min） was less than that of CMUF group （13.86±1.95 min, P〈0.01）. The volumes ultrafiltrated of HMUF group （440.00±91.86ml） was more than that of CMUF group （372.22±56.52ml, P〈0.01）. There are no significant differences about the hemodynamic data, HCT, TNF and IL-6 between two groups. Conclusion The HMUF is safe and efficient,when it was used after pediatric cardiopulmonary bypass, the duration of ultrafiltration can be shortened significantly.
Objective To observe the effect of glutamine （Gln） on intestinal permeability after surgery of children, also its influence on the plama level of interleukin-2（IL-2）, endotoxin and synthesize of protein through a random nutrition trial. Methods Twenty children suffered from congenital heart disease were divided into Gln group and control group with random number table, 10 cases in each group. They were all given isonitrogenous and isocaloric total paraenteral nutrition after 24 h postoperatively. In Gln group the Dipeptiven [-N （2）-L-alanyl-Lglutamine] was used with 2 ml/kg · 24h additionly. Before operation, 24h and 96 h after operation, intestinal permeability, serum level of endotoxin, IL-2, C-reaction protein, prealbumine were measured. Results Intestinal permeability increased in 24 h after cardiac surgery in two groups, while the concentration of endotoxin also increased, 96 h after surgery the intestinal permeability recovered, but the endotoxin level did not decrease in control group （P〈0. 01）. Conclusion Utilization of Gln can improve immune suppression, elevate the IL-2 level, decrease the endotoxin concentration, alleviate the infection, but has no effect on the protein synthesis after congenital cardiac operation of children.
Objective To investigate the suppression effect and mechanism of Astilbin on lung allograft rejection in rats, in order to know the function of Astilbin on rats’ lung acute rejection. Methods The model of rat left lung transplantation was set up. Sixty lung transplanted rats were divided into two groups randomly, control group: rats were fed with normal saline 1ml per day, experimental group: rats were fed with Astilbin 1mg/kg per day. Survival time, transforming rate of T cells in spleen, activity of interleukin 2 (IL-2) in spleen lymph cells and apoptosis of T cells were observed. Changes in ultrastructure of pulmonary arteries were observed by electron microscope. Results The survival time in experimental group was prolonged than that in control group (25.4±2.1 d vs. 13.4±1.2 d;t=2.042, Plt;0.05）. Transforming rate of T cells of spleen in experimental group was significant lower than that in control group (23 465.8±8 783.4 cpm vs. 74 567.3±12 874.6 cpm; t=2.284，Plt;0.05）.Activity of IL-2 of spleen lymph cells in experimental group was significant lower than that in control group (425±2.65U/ml vs. 23.46±1.82U/ml; t=3.165, Plt;0.01).Effectively derive apoptosis of activated T cells in acute rejection were observed in experimental group, the ultrastructure of pulmonary arteries showed attenuated injury in experimental group. Conclusion Astilbin decreased the IL-2 concentration in plasma and induced the apoptosis in activated T cells, then suppressed the acute rejection of lung allograft and prolonged the survival period of lung transplantation rats.
Objective To investigate the hemocompatibility of the acellular valved bovine jugular vein conduit (BJVC) treated with polyepoxy compound (PC), and discuss its application in cardiovascular surgery and tissue engineering in the future. Methods BJVC treated with PC was regarded as the experiment group and BJVC treated with glutaraldehyde (GA) was considered to be the control group. Rat blood was used for in vitro hemolytic test to calculate hemolytic rates of BJVC, and curve of absorbanceclotting time was drawn. Human blood was used to determine the level of D-dimeride and complement activation C3a des Arg, and test its hemocompatibility in vitro. We divided 20 canines into the experiment group (PC group, n=10) and the control group (GA group, n=10) by random digital table. The BJVC treated with PC or GA were implanted between the pulmonary artery and right ventricle. Ten months after the implantation, thrombus and histological observation were performed to evaluate the blood compatibility in vivo. Results The hemolytic rate in the PC group (0.23%) was lower than that in the GA group (0.35%), which was in accordance with the national standard of hemolytic test (lt;5%). The curve of absorbanceclotting time in the experiment group declined more slowly than that of the control group. The D-dimeride level in the experiment group was significantly lower than that of the control group (0.10±0.01 μg/ml vs. 0.12±0.02 μg/ml , t=3.277, P=0.004), but both of them were within the normal level. The level of complement C3a des Arg in the experiment group was significantly lower than that of the control group (0.74±0.09 μg/ml vs. 1.02±0.19 μg/ml, t=4.183, P=0.001). Eight canines survived 10 months after the implantation in both the two groups, and two other canines in each group died due to ventricular fibrillation. Three canines were discovered to have thrombus in the control group while no thrombus was observed in the experiment group. Conclusion Compared with GA, acellular BJVC treated with PC has superiority in hemocompatibility in vitro and vivo, and has potential application in clinical research and practice.
Objective To analyze the relation between preoperative pulmonary artery pressure(PAP) and postoperative complications in heart transplant patients, and summarize the experience of perioperative management of pulmonary hypertension (PH), to facilitate the early period heart function recovery of postoperative heart transplant patients. Methods A total of 125 orthotopic heart transplant patients were divided into two groups according to preoperative pulmonary arterial systolic pressure(PASP) and pulmonary vascular resistance(PVR), pulmonary [CM(1583mm]hypertension group (n=56): preoperativePASPgt;50 mm Hg or PVRgt;5 Wood·U; control group (n=69): preoperative PASP≤50 mmHg and PVR≤5 Wood·U. Hemodynamics index including preoperative cardiac index (CI)，preoperative and postoperative PVR and PAP were collected by SwanGanz catheter and compared. The extent of postoperative tricuspid regurgitation was evaluated by echocardiography. Postoperative pulmonary hypertension was treated by diuresis，nitrogen oxide inhaling，nitroglycerin and prostacyclin infusion, continuous renal replacement therapy(CRRT)and extracorporeal membrane oxygenation(ECMO). Results All patients survived except one patient in pulmonary hypertension group died of multiorgan failure and severe infection postoperatively in hospital. Acute right ventricular failure occurred postoperatively in 23 patients, 10 patients used ECMO support, 10 patients with acute renal insufficiency were treated with CRRT. 124 patients were followed up for 2.59 months，7 patients died of multiple organ failure, infection and acute rejection in follow-up period, the survivals in both groups have normal PAP, no significant tricuspid regurgitation. No significant difference in cold ischemia time of donor heart, cardiopulmonary bypass(CPB) and circulation support time between both groups; but the patients of pulmonary hypertension group had longer tracheal intubation time in comparison with the patients of control group (65±119 h vs. 32±38 h, t=2.17，P=0.028). Preoperative PASP，mean pulmonary artery pressure(MPAP) and PVR in pulmonary hypertension group were significantly higher than those in control group, CI was lower in pulmonary hypertension group ［PASP 64.30±11.50 mm Hg vs. 35.60±10.20 mm Hg; MPAP 43.20±8.50 mm Hg vs. 24.20±7.20 mm Hg; PVR 4.72±2.26 Wood·U vs. 2.27±1.24 Wood·U; CI 1.93±0.62 L/（min·m2） vs. 2.33±0.56 L/（min·m2）; Plt;0.05］. Postoperative early PASP, MPAP and PVR in pulmonary hypertension group were significantly higher than those in control group (PASP 35.40±5.60 mm Hg vs. 31.10±5.70 mm Hg, MPAP 23.10±3.60 mm Hg vs. 21.00±4.00 mm Hg, PVR 2.46±0.78 Wood·U vs. 1.79±0.62 Wood·U; Plt;0.05). Conclusion Postoperative right heart insuficiency is related to preoperative pulmonary hypertension in heart transplant patients. Donor heart can quickly rehabilitate postoperatively by effectively controlling perioperative pulmonary hypertension with good follow-up results.
