Effects of different oxygen flow rates on myocardial ischemia-reperfusion injury in rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effects of different oxygen flow rates during cardiopulmonary bypass (CPB) on myocardial ischemia-reperfusion (IR) injury in rabbits.</p><p><b>METHODS</b>Thirty rabbits were randomized equally into groups A, B and C to receive controlled oxygen reperfusion at low, normal and high flow rates (25, 50, and 80 ml.kg(-1).min(-1), respectively). Serum concentration of CK-MB and cTnT were tested by ELISA before the operation (T0) and after 30 min (T1), 2 h (T2), 12 h (T3) and 24 h (T4) of reperfusion. W/D, SOD and MDA of the myocardium were determined before and at 60 min after reperfusion. The ultrastructural alterations of the myocardium were observed.</p><p><b>RESULTS</b>Serum concentration of CK-MB and cTnT in the 3 groups increased significantly after the operation, and their levels were the lowest in group A (P<0.05). W/D and MDA in the myocardium was also the lowest, while SOD the highest in group A (P<0.05). Ultrastructural pathologies were found in all the 3 groups, but relatively mild in group A.</p><p><b>CONCLUSION</b>Low oxygen flow rate during controlled reperfusion may protect the myocardium from IR injury in rabbits.</p>

Connective tissue growth factor and pulmonary allograft fibrosis in rats / 中南大学学报(医学版)

OBJECTIVE@#To investigate the role of connective tissue growth factor (CTGF) in pulmonary allograft fibrosis in rats.@*METHODS@#The lungs of 20 Wistar rats were transplanted into 20 Sprague-Dawley(SD) rats. Ten allograft lungs were harvested 1 week postoperatively (acute rejection group,AR); the other 10 allografts were harvested 6 weeks postoperatively (chronic rejection group,CR); and ten normal Wistar rats served as a control group(normal lung, NL). Paraffin embedded sections of the harvested lung specimens were stained with hematoxylin and eosin (HE), Van Gieson (VG) for the examination of tissue morphology under the microscope. The scores of lung fibrosis were measured and the wet/dry ratio of the lung specimens was evaluated. The CTGF expression was determined by immunohistochemical method.@*RESULTS@#The wet/dry ratios of lung decreased gradually(AR group vs. control group: 3.48+/-0.47 vs. 4.67+/-0.51, P<0.05; CR group vs. AR group: 2.85+/-0.52 vs. 3.48+/-0.47, P<0.05). The transplanted lungs showed massive lymphocytic infiltration, interstitial fibrosis, destroyed alveolus architecture, obliterative bronchiolitis, and lung tissue consolidation. These pathological changes were more severe in the CR group than in the AR group, but there were no such changes in the control group (scores of pulmonary fibrosis: NH, 0.00+/-0.00; AR, 0.98+/-0.47; CR, 2.35+/-0.52; AR vs. NH, P<0.01; CR vs. AR, P<0.01). CTGF was not expressed in the normal rat lungs (0.00+/-0.00); however, it was detected in the lung allograft after the operation. The CTGF expression in the CR group was significantly higher than that in the AR group (P<0.01).@*CONCLUSION@#The expression of CTGF protein is related to the transplanted pulmonary fibrosis,and is involved in the pathogenesis of transplanted pulmonary fibrosis.

Influence and significance of intermittent ventilation on lung cytokines during cardiopulmonary bypass / 中南大学学报(医学版)

OBJECTIVE@#To determine the influence and significance of intermittent ventilation on lung cytokines during cardiopulmonary bypass (CPB).@*METHODS@#Thirty-six patients with rheumatic heart disease (RHD) were divided into 2 groups randomly: Treatment group (n = 18, given intermittent ventilation once every 5 minutes during CPB; control group ( n = 18), no ventilation during CPB. A brochioalveolar lavage was performed at 2 hours after the CPB. The numbers of granulocytes and the contents of IL-1, IL-6, TNF-alpha, and LDH in the brochioalveolar lavage fluids were measured, and lung PaO2/FiO2 were measured preoperatively and at 1 hour, 4 hours, and 8 hours after the CPB termination.@*RESULTS@#The numbers of granulocytes and the contents of IL-1, IL-6, TNF-alpha, and LDH of the treatment group in the brochioalveolar lavage fluids were significantly lower than those of the control group (P < 0.05), and the lung PaO2/FiO2 of the treatment group at 1 hour, 4 hours, and 8 hours after the CPB termination significantly increased than those of the control group (P < 0.05). A significant decrease of lung PaO2/FiO2 occurred in both groups at 1 hour, 4 hours, and 8 hours after the CPB compared with the same group at the baseline before the CPB (P < 0.01).@*CONCLUSION@#Intermittent ventilation has protective effects on the lung injury during CPB by decreasing granulocyte adhesion and the level of lung cytokines, alleviating the lung inflammatory reaction and endothelial cell injury.

Protective effects of ulinastatin on the lung injury during cardiopulmonary bypass / 中南大学学报(医学版)

OBJECTIVE@#To determine the protective effects and mechanism of ulinastatin on the lung injury during cardiopulmonary bypass (CPB).@*METHODS@#Thirty patients with rheumatic heart disease (RHD) were divided into 2 groups randomly. The ulinastatin group (Group U, n = 15) received 1 x 10(4)U/kg ulinastatin intravenously before the CPB and the same amount of ulinastatin was added into the primary solution. The control group (Group C,n = 15) received normal saline instead of ulinastatin. A brochioalveolar lavage was performed at 2 h after the cardiopulmonary bypass. Polymorphonuclear neutrophil elastase, tumor necrosis factor-alpha and MDA contents in the brochioalveolar lavage fluids were measured, and the lung oxygenate index was measured preoperatively and at 1 and 4 h after CPB termination.@*RESULTS@#Polymorphonuclear neutrophil elastase, tumor necrosis factor-alpha and MDA contents of Group U in the brochioalveolar lavage fulids were significantly lower than those of Group C (P < 0.05), and the lung oxygenate index of Group U at 1 and 4 h after CPB termination was also significantly lower than that of Group C. A significant increase of lung oxygenate index occurred in both groups at 1 and 4 h after CPB when compared with the same group at the baseline before CPB (P < 0.05).@*CONCLUSION@#Ulinastatin has the protective effects on the lung injury during CPB by decreasing polymorphonuclear neutrophil elastase, alleviating lung inflammatory reaction and reducing oxygen free radicals.