[Transplantation of Autologous Peritoneum Using Ileal Seromuscular Flaps for Orthotopic Neobladder Reconstruction].

Objective To develop an ideal surgical procedure for neobladder reconstruction in experimental porcine models. Methods Six experimental female pigs weighting 28-33 kg underwent transplantation of autologous peritoneum for bladder reconstruction under general anesthesia.The flaps were used to reconstruct the orthotopic neobladder by suturing with the edges of the triangle and neck of the remnant bladder.The ureteral catheters were removed on the 5 th postoperative day and the balloon catheter was removed on the 7 th postoperative day.Voiding behaviour was monitored.The animals were euthanized at week 12 for routine pathology,immunohistochemistry,and electron microscopy. Results All the pigs survived after the surgery,and no postoperative complication such as peritonitis,intestinal obstruction,or urinary fistula was observed.All the peritoneum-ileum composite free valves survived after transplantation.Voiding behaviour was normal after catheter removal,and the urine was clear.At autopsy,reconstructed bladders were healthy.Pathological examination showed the neobladder had been covered by continuous urothelium while the peritoneum disappeared and showed no ileal mucosa regrowth and residual.Scanning electron microscope showed the transitional cells of neobladder were complete and orderly,and the urothelium around suture border was continuous and showed no malposition. Conclusions Reconstruction of bladder by autologous peritoneum and ileal seromuscular flaps is an ideal approach in the experimental pigs as it can prevent regrowth of ileal epithelial cells and avoid the complications of conventional enterocystoplasty.Its clinical application deserves further investigations.

Short-term safety and efficacy of the biodegradable iron stent in mini-swine coronary arteries.

BACKGROUND: To overcome the drawbacks of permanent stents, biodegradable stents have been studied in recent years. The bioabsorbable polymer vascular scaffold (BVS) was the first bioabsorbable stent to undergo clinical trials, demonstrating safety and feasibility in the ABSORB studies. Iron can potentially serve as the biomaterial for biodegradable stents. This study aimed to assess the short-term safety and efficacy of a biodegradable iron stent in mini-swine coronary arteries. METHODS: Eight iron stents and eight cobalt chromium alloy (VISION) control stents were randomly implanted into the LAD and RCA of eight healthy mini-swine, respectively. Two stents of the same metal base were implanted into one animal. At 28 days the animals were sacrificed after coronary angiography, and histopathological examinations were performed. RESULTS: Histomorphometric measurements showed that mean neointimal thickness ((0.46 ± 0.17) mm vs. (0.45 ± 0.18) mm, P = 0.878), neointimal area ((2.55 ± 0.91) mm(2) vs. (3.04 ± 1.15) mm(2), P = 0.360) and percentage of area stenosis ((44.50 ± 11.40)% vs. (46.00 ± 17.95)%, P = 0.845) were not significantly different between the iron stents and VISION stents. There was no inflammation, thrombosis or necrosis in either group. The scanning electron microscopy (SEM) intimal injury scores (0.75 ± 1.04 vs. 0.88 ± 0.99, P = 0.809) and number of proliferating cell nuclear antigen (PCNA) positive staining cells were not significantly different between the two groups. The percentage of neointimal coverage by SEM examination was numerically higher in iron stents than in VISION stents ((84.38 ± 14.50)% vs. (65.00 ± 22.04)%, P = 0.057), but the difference was not statistically significant. Iron staining in the tissue surrounding the iron stents at 28 days was positive and the vascular wall adjacent to the iron stent had a brownish tinge, consistent with iron degradation. No abnormal histopathological changes were detected in coronary arteries or major organs. CONCLUSIONS: The biodegradable iron stent has good biocompatibility and short-term safety and efficacy in the miniswine coronary artery. Corrosion of iron stents is observed at four weeks and no signs of organ toxicity related to iron degradation were noted.

Effect of intracoronary infusion of bone marrow mononuclear cells or peripheral endothelial progenitor cells on myocardial ischemia-reperfusion injury in mini-swine.

OBJECTIVE: To simulate and assess the clinical effect of intracoronary infusion of bone marrow mononuclear cells or peripheral endothelial progenitor cells on myocardial reperfusion injury in mini-swine model. METHODS: Twenty-three mini-swine with myocardial reperfusion injury were used as designed in the study protocol. About (3.54 +/- 0.90) x 10(8) bone marrow mononuclear cells (MNC group, n = 9) or (1.16 +/- 1.07) x 10(7) endothelial progenitor cells (EPC group, n = 7) was infused into the affected coronary segment of the swine. The other mini-swine were infused with phosphate buffered saline as control (n = 7). Echocardiography and hemodynamic studies were performed before and 4 weeks after cell infusion. Myocardium infarction size was calculated. Stem cell differentiation was analyzed under a transmission electromicroscope. RESULTS: Left ventricular ejection fraction dropped by 0% in EPC group, 2% in MNC group, and 10% in the control group 4 weeks after cell infusion, respectively (P < 0.05). The systolic parameters increased in MNC and EPC groups but decreased in the control group. However, the diastolic parameters demonstrated no significant change in the three groups (P > 0.05). EPC decreased total infarction size more than MNC did (1.60 +/- 0.26 cm2 vs. 3.71 +/- 1.38 cm2, P < 0.05). Undermature endothelial cells and myocytes were found under transmission electromicroscope. CONCLUSIONS: Transplantation of either MNC or EPC may be beneficial to cardiac systolic function, but might not has obvious effect on diastolic function. Intracoronary infusion of EPC might be better than MNC in controlling infarction size. Both MNC and EPC may stimulate angiogenesis, inhibit fibrogenesis, and differentiate into myocardial cells.

[Relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model].

OBJECTIVE: To study the relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model. METHODS: Twenty normal minipigs were randomly divided into group A (implanted with 316L bare metal stents), group B (implanted with 605L bare metal stents), group C (implanted with PLGA coating 605L stents), and group D (implanted with rapamycin-loaded PLGA coating 605L stents). Each minipig was implanted with two same stents in left anterior descending artery and right coronary artery. Four weeks later, the animals were sacrificed and histomorphometric measurements on the stent-segment coronary arteries were made to calculate the correlation between inflammation area and neointimal area. RESULTS: Group D had the smallest neointimal area [(0.64 +/- 0.38) mm2, P < 0. 001] and inflammation area (median 0.00 mm2, P = 0.009) among all the groups, while there were no statistical differences among group A, B, and C in neointimal area [(2.09 +/- 0.90), (2.11 +/- 1.07), and (1.42 +/- 0.35) mm2 respectively] and in inflammation area (0.22 , 0.21, and 0.09 mm2, respectively). Bivariate correlation analysis showed that the inflammation area was positively correlated with the neointimal area (P < 0.001, correlation coefficient = 0.719). When stent type, mean injury score, and EEL area were adjusted, partial correlations analysis showed that the inflammation area was still positively correlated with the neointimal area (P = 0.01, correlation coefficient = 0.498). CONCLUSION: Inflammation promotes the neointimal proliferation after coronary stent implantation. Sirolimus-eluting stent may reduce the inflammatory response.

[Lung pathology of complex congenital heart defect with diminished pulmonary blood flow but without aortopulmonary collateral artery and patent ductus arteriosus in infants and young children].

OBJECTIVE: The development of pulmonary vascular bed is strongly flow-dependent. Abnormal pulmonary blood flow leads to pulmonary pathological changes. This study aimed to observe the pathological changes of small pulmonary arteries and alveoli in complex congenital heart defect with diminished pulmonary blood flow but without aortopulmonary collateral artery (APCA) and patent ductus arteriosus (PDA) in infants and young children. METHODS: Autopsy pulmonary specimens obtained from 5 children who died of non-cardiovascular diseases were used as the control group (age: 4-18 months). Fifty-six children (age: 4-36 months) with complex congenital heart defect with diminished pulmonary blood flow but without APCA and PDA served as the study group, including 34 cases of tetralogy of Fallot, 7 cases of double outlet right ventricle with pulmonary stenosis, 9 cases of single ventricle with pulmonary stenosis, 4 cases of tricuspid atresia with pulmonary stenosis and 2 cases of complete atrioventricular septal defect with pulmonary stenosis. Pulmonary specimen sections were stained by hematoxylin-eosin and Weigert-Van Gieson. Percentage of media thickness (MT%), percentage of media section area (MS%), number of small arterial per square centimeter (APSC), mean alveolar number (MAN), mean linear intercept (MLI), proportion of parenchyma area in total area (PPA%) and alveolar to small arterial ratio per unit area (AAR) were measured by morphologic quantitative analysis. RESULTS: MT% (10.93+/-2.87% vs 15.08+/-2.51%), MS% (18.97+/-5.56% vs 25.04+/-3.87%) and APSC (202.43+/-67.45 vs 441.69+/-65.29) decreased significantly in the study group compared with the control group (P<0.01). The internal diameter of small pulmonary artery (80.26+/-21.57 microm vs 58.53+/-10.29 microm; P<0.05), AAR (46.59+/-14.43 vs 34.46+/-4.98; P<0.01) and MLI (144.98+/-44.87 microm vs 108.39+/-20.76 microm; P<0.05) increased significantly compared with the control group. CONCLUSIONS: The media of small pulmonary arteries becomes thinner, the lumen of small pulmonary arteries becomes larger, and the number of small arterial per square centimeter and the mean alveolar number are reduced in infants and young children with complex congenital heart defect with diminished pulmonary blood flow but without APCA and PDA.

[Effect of intracoronary transplantation of autologous bone marrow mononuclear cells on myocardial ischemia reperfusion injury in mini-swine model].

OBJECTIVE: To investigate the therapeutic effectiveness of intracoronary transplantation of autologous bone marrow mononuclear cells (BM-MNC) on myocardial ischemia reperfusion injury in mini-swine model. METHODS: Myocardial ischemia reperfusion injury model was established by ligating in 16 mini-swines, which were further randomized into two groups: (3.54 +/- 0.90) x 10(8) BM-MNC was intracoronarily transplanted in BM-MNC group (n = 9), and phosphate buffer saline was intracoronarily applied in the control group (n = 7). Ultrasonic cardiograhpy, hemodynamics, neovascular density, and myocardium infarction size were evaluated before and 4 weeks after transplantation. RESULTS: In BM-MNC group, left ventricular ejection fraction (LVEF), intra-ventricular septa, lateral wall and anterior wall, cardiac output (CO) and + dp/dt(max) had no significant differences before and 4 weeks after transplantation (P > 0.05). In the control group, LVEF, intraventricular septa, lateral wall and anterior wall, CO, and + dp/dt(max) significantly decreased 4 weeks after transplantation (P < 0.05). Left ventricular end-diastolic pressure and- dp/dt(max) had no significant differences before and after cell transplantation. Capillary density was significantly larger in the BM-MNC group than in the control group [(13.39 +/- 6.96) /HP vs. (3.50 +/- 1.90) /HP]. The percentage and size of myocardial infarction was significantly lower in the BM-MNC group than in the control group. CONCLUSION: Transplantation of BM-MNC into the myocardial ischemic reperfusion-injury area can increase capillary density and decrease infarction area, and thus remarkably improve cardiac systolic function.

Implantation of autologous bone marrow mononuclear cells into ischemic myocardium enhances coronary capillaries and systolic function in miniswine.

OBJECTIVE: To investigate the therapeutic effectiveness of intracoronary implantation of autologous bone marrow mononuclear cells (BM-MNC) in miniswine model of reperfused myocardial infarction. METHODS: Sixteen miniswine myocardial ischemic reperfusion injury models made by ligation of the distal one third segment of left anterior descending artery for 90 minutes were randomized into 2 groups. In BM-MNC group (n = 9), (3.54 +/- 0.90) X 10(8) BM-MNC were intracoronary injected, and in the control group (n = 7), phosphate buffered saline was injected by the same way. Echocardiographic and hemodynamic results, vessel density, and myocardial infarction size were evaluated and compared before and 4 weeks after cell transplantation. RESULTS: In BM-MNC group, there were no differences between before and 4 weeks after transplantation in aspects of left ventricular ejection fraction (LVEF), interventricular septal thickness, left ventricular lateral and anterior septal wall thickness, cardiac output, or +dp/dtmax. In control group, LVEF, interventricular septal thickness, left ventricular lateral and anterior septal wall thickness, cardiac output, and +dp/dtmax decreased significantly 4 weeks after transplantation (P < 0.05). Left ventricular end-diastolic pressure and -dp/dtmax, did not change significantly before and after cell transplantation in both groups. Capillary density in BM-MNC group was greater than that in control group [(13.39 +/- 6.96)/high power field vs. (3.50 +/- 1.90)/high power field, P < 0.05]. Infarction area assessed by tetrazolium red staining and the infarction percentage decreased in BM-MNC group compared with those in control group (P < 0.05). CONCLUSIONS: Transplantation of BM-MNC into myocardium with ischemic reperfusion injury increases capillary density and decreases infarction area. It has significantly beneficial effect on cardiac systolic function rather than on diastolic function.

[Further development of pulmonary artery after Glenn procedure: effect of different antegrade pulmonary blood flows on cyanotic congenital heart defects].

OBJECTIVE: To compare the effect of different antegrade pulmonary blood flow on the further development of pulmonary artery after Glenn procedure in cyanotic congenital heart defects (CHD) patients. METHODS: Between October 2000 and December 2006, 132 CHD patients with decreased pulmonary artery blood flow underwent bidirectional Glenn shunt, among them 18 patients received intraoperative lung biopsy. Patients were divided into two groups according to their different sources of antegrade pulmonary blood flow: antegrade arterial blood flow group (n = 33) and antegrade venous blood flow group (n = 99). The percutaneous oxygen saturation (SpO2), hemoglobin (Hb) concentration, and hemotocrit (Hct) value were examined and recorded before and after operation. The diameters of left pulmonary artery (LPA) and right pulmonary artery (RPA) were measured with two-dimensional echocardiography and the results were used to calculate the pulmonary artery index (PAI). The method of half-quantitative morphometric technique and an image analyzer were used to measure the following indicators of pulmonary microvessels: the percentage of media thickness (MT%), the percentage of media section area (MS%), vascular numbers of per square centimeter (VPSC), and mean alveolar number (MAN). RESULTS: Before the operation, obvious cyanosis was found in both groups, while SpO2, Hct, and Hb were not significantly different (P > 0.05). LPA, RPA, and PAI were not significantly different between two groups (P > 0.05). The MT% and MS% in antegrade venous blood flow group were significantly less than those in antegrade arterial blood flow group (P < 0.05), but VPSC and MAN were not significantly different (P > 0.05). After Glenn procedure, hypoxia and cyanosis were remarkably improved in both two groups. There was a significantly negative correlation between SpO2 and Hct (r = -0.49, P < 0.01) or Hb (r = -0.196, P < 0.01 ). The PAI increased by 22% in antegrade arterial blood flow group and 44% in antegrade venous blood flow group (P < 0.05). The diameters of LPA and RPA in antegrade venous blood flow group were significantly larger than those in antegrade arterial blood flow group (P < 0.05) and the growth of RPA in antegrade arterial blood flow group was not significant. CONCLUSION: A better pulmonary artery growth occurs in the patients of pulmonary stenosis after Glenn shunt than in those of pulmonary atresia, and it contributes to an earlier completion of Fontan procedure.

[Relationship between clinical pathophysiology and pulmonary pathology in patients with congenital heart defects and decreased pulmonary artery blood flow].

OBJECTIVE: To investigate the relationship between pulmonary pathological features and clinical physiology of congenital heart defects (CHD) with decreased pulmonary artery blood flow. METHODS: Between July 2001 and May 2006, 18 patients with CHD with decreased pulmonary artery blood flow undergoing palliative or definitive repair and having lung biopsy intraoperatively were enrolled in this study. The patients' age was 0.4 - 8.0 years, and body weight was 6.0 - 20.0 kg. The method of semi-quantitative morphometric technique and an image analyzer were applied to measure the following indices of pulmonary microvessels: the percentage of media thickness (MT%), the percentage of media section area (MS%) and numbers of microvessels per square centimeter (VPSC). The diameters of left pulmonary artery (LPA) and right pulmonary artery (RPA) were measured with two-dimensional echocardiography. The percutaneous oxygen saturation (SpO(2)), hemoglobin concentration (HB) and hematocrit value (HCT) were examined and recorded preoperatively. RESULTS: There was a significant negative correlation between SpO(2) and HCT or Hb (R(2) = 0.4914, P = 0.001 and R(2) = 0.5505, P < 0.001), the variation trend of these three variables was linked. There was a negative correlation between SpO(2) and the body weight (R(2) = 0.2208, P = 0.049), which is in accordance with clinical features of aggravated process of cyanosis and hypoxia. The morphological observation of lung biopsy specimens indicated that most of peripheral pulmonary arteries were distended, irregular and their walls were uneven, and "lake" type of pulmonary AV malformations were observed. There was a positive correlation between VPSC and the body weight or BSA (R(2) = 0.5472, P < 0.001 and R(2) = 0.5233, P = 0.001). There was a significant correlation between VPSC and LPA or RPA (R(2) = 0.4312, P = 0.003 and R(2) = 0.2463, P = 0.036). It was shown that the diameter of central pulmonary arteries could be a reflection of peripheral pulmonary artery growth. The diameter of LPA also correlated with the diameter of RPA (R(2) = 0.286, P = 0.022). CONCLUSIONS: For patients with congenital heart defects with decreased pulmonary blood flow, the pulmonary pathological changes are the bases of their clinical physiologic features. It is suggested that they should be treated in their earlier stage of life.

[Autologous bone marrow mononuclear cells and peripheral endothelial progenitor cells differentiation in myocardial ischemia reperfusion injury region in swine].

OBJECTIVE: To investigate the differentiation status of autologous bone marrow mononuclear cells (BM-MNC) and peripheral endothelial progenitor cells (EPC) transplanted into myocardial ischemia reperfusion injury region in swine. METHODS: BM-MNC marked with PKH26 (n = 9), EPC marked with CM-DiI (n = 7), phosphate buffer saline (control, n = 7) were transplanted into myocardial ischemia reperfusion injury region of swine by intracoronary artery injection. Specimens were harvested 4 weeks after injection for histological analysis (HE, immunochemical stain for vWF, alpha-sarcomeric-actin and fibronectin antibody). Cell differentiation was observed under transmission electronmicroscope. RESULTS: The number of small blood vessels was similar between BM-MNC group and EPC group (13.39 +/- 6.96/HP vs.12.39 +/- 4.72/HP, P < 0.05), but was significantly higher than that of control group (P < 0.05). Responsive intensity of immunochemical stain for fibronectin antibody was significantly lower in BM-MNC and EPC groups than that in control group. Responsive intensity of immunochemical stain for alpha-sarcomeric-actin antibody was similar among the three groups. Cluster cells were observed in one swine from BM-MNC group which might relate to the proliferation of stem cells in situ. Immature endothelial cells and myocytes were also detected by transmission electronmicroscope in BM-MNC and EPC group. CONCLUSION: BM-MNC and EPC transplanted into myocardial ischemia reperfusion injury region in swine stimulated the formation of blood vessels and inhibited fibrogenesis.

[Effects of intracoronary transplantation of autologous bone marrow mononuclear cells or endothelial progenitor cells in mini-swine model of myocardial ischemia-reperfusion].

OBJECTIVE: To compare the effects of intracoronary transplantation of autologous bone marrow mononuclear cells (BM-MNC) or peripheral endothelial progenitor cells (EPC) in mini-swine model of myocardial ischemia-reperfusion. METHODS: The Mini-swine acute myocardial infarction and reperfusion model was created with 90 min occlusion of the left anterior descending coronary artery followed by reperfusion and the animals were then divided into BM-MNC group (3.54 x 10(8) +/- 0.90 x 10(8), n = 9), EPC group (1.16 x 10(7) +/- 1.07 x 10(7), n = 7) and control group (saline, n = 7). Echocardiography, hemodynamic measurements and myocardium infarction size were evaluated before and 4 weeks after intracoronary cell transplantations. RESULTS: The net decrease from baseline to 4 weeks after transplantation of left ventricular ejection fraction (LVEF), left ventricular end systolic pressure, cardiac output and +dp/dt(max) were significantly attenuated post BM-MNC and EPC therapy compared to control group (all P < 0.05) and were similar between BM-MNC and EPC groups. Transplantation of BM-MNC and EPC also significantly decreased myocardial infarction size compared to control group. CONCLUSION: Autologous intracoronary transplantation of BM-MNC or EPC in this model equally improved cardiac systolic function and reduced infarction area.

[Effects of atenolol and metoprolol on cardiomyocyte apoptosis and related gene expression after acute myocardial infarction in rats].

OBJECTIVE: To compare the beneficial effects of Atenolol and Metoprolol on cardiomyocyte apoptosis and related gene expressions after acute myocardial infarction (AMI) in rats. METHODS: AMI model was established with the ligation of anterior descending coronary artery in 251 randomly selected female SD rats. Twenty-four hours after operation, the 124 survivors were randomly assigned to AMI control group (MI group, n = 43), Atenolol group (group A, 10 mg x kg(-1) d(-1), n = 39), and Metoprolol group (group B, 20 mg x kg(-1) x d(-1), n = 42). Sham operation group (group S, n = 27) was also established. Two subgroup (48 h subgroup and 4 weeks subgroup) was randomly divided in each group according to the time points. Drugs were given to each treatment group by gastric gavage 24 h after ligation. Cardiomyocyte apoptosis was detected with terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) and DNA ladder. Bcl-2, bax and caspase-3 genes were detected with immunohistochemistry and Western blot analysis. RESULTS: Compared with AMI control group, myocyte apoptosis rate (MAR) significantly decreased only in infarction area (P < 0.01) in group B. Bcl-2 expression was found to increase in myocytes of infarction, border and non-infarcted areas except for non-infarcted area of group A. Changes of the expressions of bax and caspase-3 was not significant. Four weeks after AMI, MAR was found to decrease significantly in scar, border and non-infarcted areas (P < 0.05, P < 0.01) in both group A and group B. No significant changes of bcl-2, bax and caspase-3 expressions was found except for a significant decrease of bax expression in non-infarcted area of group A. As indicated by Western blot, no significant change of the expressions of caspase-3, bcl-2 and bax were found in myocytes of group A and group B compared with AMI control group; however, bcl-2/bax ratio significantly increased to the same level of sham-operated group (P < 0.05). CONCLUSION: Both Atenolol and Metoprolol treatment can reduce cardiomyocyte apoptosis in infarction/scar, border and non-infarcted areas after AMI, mainly through the increase of bcl-2 expression and bcl-2/bax ratio.

[Relationship between the quantitative structural study of lung and the right ventricle outflow tract reconstruction in infants with tetralogy of Fallot].

OBJECTIVE: To analyse the relationship between the quantitative structural study of lung and right ventricle outflow tract reconstruction in infants with tetralogy of Fallot. METHODS: Lung biopsies were taken during the operations in 16 infants suffered from tetralogy of Fallot. Autopsy specimens were obtained from 5 infants died of non-cardiovascular diseases as normal control group. All patients underwent one staged repair. The techniques of right ventricular outflow tract reconstruction included pulmonary valve commissurotomy (n = 3), transanular pericardial patch (n = 4), and transannular homologous monocuspid valve patch (n = 8); homograft was used in one patient because of the abnormal coronary artery. The diameters of main pulmonary artery (MPA), left pulmonary artery (LPA), and right pulmonary artery (RPA) were measured during operation. The tissue was fixed with buffered formalin and routinely impregnated in wax. Sections were stained by hematoxylin-eosin, and Weigert's elastic stain counter-stained by van Gieoson's method. Seven parameters of the small pulmonary arteries were obtained, including percentage of media thickness (% MT), percentage of media section area (% MS), numbers of pulmonary small artery per square centimeter (APSC), mean alveolar number (MAN), mean linear intercept (MLI), proportion of parenchyma area in total area (% PPA), and alveolar/ small arterial ratio per unit area (AAR) by a computer-based image processor for quantitative analysis. RESULTS: In the TOF group, % MT, % MS, and APSC significantly decreased, while MLI and AAR significantly increased (P < 0.05, compared with the control group). APSC decreased in turn after separately using three different techniques of right ventricular outflow tract reconstruction (i. e. pulmonary valve commissurotomy, transannular pericardium patch, and transannular homologous monocuspid valve patch), which was paralleled with the diameters of MPA, LPA, and RPA. RPA correlated with APSC (r = 0.754, P = 0.001). CONCLUSIONS: The development of pulmonary small arteries and alveoli are directly affected by the diminished pulmonary flow in infants with tetralogy of Fallot. Right ventricle outflow tract reconstruction may be indicated according to the developmental degree of central pulmonary artery.

[Beneficial effects of carvedilol on cardiomyocyte apoptosis and bcl-2/bax expression after acute myocardial infarction an experiment with rats].

OBJECTIVE: To investigate the beneficial effects of carvedilol on cardiomyocyte apoptosis and related gene expression after acute myocardial infarction (AMI). METHODS: Eighty-three female SD rats underwent ligation of left anterior descending coronary artery, and were randomly assigned to 2 groups 24 hours later: carvedilol (n = 40, 10 mg.kg(-1).d(-1)was administered via direct gastric gavage 24 hs after the ligation, Group C) and AMI control group (n = 43, normal saline of the same volume was given by gastric gavage, Group MI). Another 27 rats were used as sham operation group (Group S, administered with normal saline too). The rats of each group were killed and their hearts were taken out 48 hours and 4 weeks after observation respectively (MI-48 h, MI-4 week, C-48 h, C-4 week, S-48 h, and S-4 week subgroups). TUNEL and DNA gel electrophoresis were used to detect the cardiomyocyte apoptosis. Immunohistochemistry and Western blotting were used to detect the expression of bcl-2 and bax. RESULTS: The apoptotic indices of the infracted/scar, border and non-infarcted areas at any time-point of Group MI were all significantly higher than those of Group S (all P < 0.05). Only the apoptotic indices of the infracted/scar and border areas of the C-4 week subgroup were significantly lower than those of the MI-4 week subgroup (both P < 0.05), and were close to those of the non-infarcted area. DNA gel electrophoresis showed that the positive rate of Group S at any time-point were both 0, the positive rate of MI-48 h subgroup and C-48 h subgroup were both significantly higher than that of Group S (both P < 0.05) without significant difference between these 2 groups, and the positive rates of the MI-4 week subgroup and C-4 week subgroup were both 0. Immunohistochemistry showed that the bax gene expression was slightly to significantly increased in the infarcted/scar, border, and non-infarcted areas of the MI-48 h and MI-4 week subgroups. The bcl-2 expression was significantly increased only in the infracted area of the MI-48 h subgroup. The bcl-2 expression was slightly increased in the infracted and border areas of the C-48 h subgroup and the bax expression was significantly decreased in the infracted/scar area of the C-4 week subgroup. Western blotting showed that (1) the bcl-2 expression of the S-4 week subgroup was significantly higher than that of the S-48 h subgroup (P < 0.05), (2) the bcl-2 expression and bax expression of the MI-48 h subgroup were significantly higher than that of the S-48 h subgroup (P < 0.05 - 0.01), the bcl-2/bax ratio of the MI-48 h subgroup was significantly lower that that of the S-48 h subgroup, however, there were no significant differences in the bcl-2 and bax expression and bcl-2/bax ratio between the MI-4 week subgroup and S-48 h subgroup (all P > 0.05), and (3) There were no significant difference in the bcl-2 and bax expression between Group A and Group S (all P > 0.05), however, the bcl-2/bax ratios at the 2 time-points of Group C were both significantly higher than those of Group MI. CONCLUSION: Cardiomyocyte apoptosis occurs in the infarction/scar, border and non-infarcted areas after AMI. Prolonged treatment with carvedilol reduces cardiomyocyte apoptosis in the scar and border areas and increases the expression ratio of bcl-2/bax.

[Clinicopathologic studies of 11 cases of primary cardiac valve tumors].

OBJECTIVE: To study the clinicopathologic features of primary cardiac valve tumors. METHODS: Eleven cases of primary valve tumors collected from Fuwai Hospital during the period from 1983 to 2005 were enrolled into the study. The tumors were stained with hematoxylin and eosin and Weigert-Van Gieson stain. Immunohistochemistry was also carried out in selected examples. RESULTS: Primary cardiac valve tumors were uncommon and accounted for only 3% (11/426) of all primary cardiac tumors. Most of them (10/11) were benign and malignancy was rarely encountered (1/11). The tumor subtypes included papillary fibroelastoma (4/11), cavernous hemangioma (4/11), glomus tumor (1/11), angiosarcoma (1/11) and hamartoma (1/11). Of the 11 tumors studied, 4 involved the tricuspid valve, 4 involved the mitral valve, 2 involved the pulmonary valve and 1 involved the aortic valve. The diagnosis was established by preoperative echocardiography in 7 patients. The remaining 4 cases were either misdiagnosed or undiagnosed. CONCLUSIONS: Preoperative diagnosis of primary cardiac valve tumors can be difficult due to lack of detailed information related to this group of lesions. Although benign cardiac valve tumors carry a good prognosis, the clinical outcome may be disastrous as a result of hemodynamic disturbances. Intraoperative frozen section examination is advisable for guiding proper surgical management.

[Pathological changes of radial artery used for coronary artery bypass grafting and its related risk factors for intimal hyperplasia].

OBJECTIVE: To examine the degree of intimal hyperplasia and the prevalence of atherosclerosis in radial arteries taken from the patients undergoing coronary artery bypass grafting (CABG), and to analyze the risk factors to obtain some helpful information for choosing arterial conduits. METHODS: Forty-one radial arteries and 11 internal mammary arteries samples were collected. The average age of patients was 48.5 years, and they all were male. Intimal hyperplasia, atherosclerosis, medial calcification were evaluated by routine histological methods, and the severity of diseases was measured on the percentage of luminal narrowing and the intima-to-media ratio (the intima area/media area). The risk factors for coronary heart disease were also analyzed. RESULTS: Ninety-three percent (38 of 41) of radial arteries showed mild intimal hyperplasia, which was not regarded to influence blood flowing after CABG. As a part of them, 54% (22/41) of radial arteries had a lower than 25% of luminal narrowing, meanwhile 39% (16/41) of radial arteries had the percentage of luminal narrowing between 25% and 50%. Only 7% (3 of 41) of radial arteries were found to have occlusive lesions, which made arterial lumen decreased more than 75%. The 3 patients including 2 with severe atherosclerosis and another 1 aged 17 years was involved by fibromuscular dysplasia. The later vessel was discarded after harvesting. The percentage of luminal narrowing and the intima-to-media ratio were higher in radial artery than that in internal mammary artery (t = 3.00, 2.49, P < 0.05). The two parameters were positively correlated with age (r = 0.398, 0.310, P < 0.05), but this study failed to show any relationship between intimal hyperplasia of radial artery and coronary lesions and other risk factors. Medial calcification was not found by routine histological method in all cases. CONCLUSION: Only mild intimal hyperplasia and no medial calcification are found in radial arteries used for CABG in the patients. Because the risk factors could not yet predict the severity of radial arterial lesions, this study strongly suggests that the Doppler ultrasonography and pre-operation clinical consideration should be emphasized to screen out some arteries with occlusive lesions.

[Effects of Tongxinluo and Simvastatin on the stabilization of vulnerable atherosclerotic plaques of aorta in aortic atherosclerosis and molecular mechanism thereof: a comparative study with rabbits].

OBJECTIVE: To evaluate the plaque stabilization effects of Tongxinluo and Simvastatin in aortic atherosclerosis, and to explore molecular mechanism. METHODS: Twenty-three New Zealand white rabbits underwent aortic balloon injury and fed with high-cholesterol diet for 16 weeks and then randomly divided into 3 groups: Tongxinluo group (n = 6, undergoing gastric perfusion of Tongxinluo 1 gxkg(-1)xd(-1)), simvastatin group (n = 9, undergoing gastric perfusion of simvastatin 2 mgxkg(-1)xd(-1)), and model group (n = 8, without drug administration). Another 6 rabbits were used as normal controls. Peripheral blood samples were collected 10 weeks before the administration, and 3 and 16 weeks after the administration to detect the levels of total cholesterol (TG), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), and by the end of experiment peripheral blood samples were collected to detect the levels of serum endothelin (ET) and nitric oxide (NO). Then the rabbits were killed and their aortas were taken out to undergo pathological examination. Western blotting was used to detect the protein expression of Metalloproteinase (MMP)-1 and cyclooxygenase (COX)-2 and RT-PCR was used to detect the mRNA expression of FasL and bcl-2. RESULTS: By the end of the experiment the levels of blood lipids were raised by 1 approximately 2 times in the normal group (P < 0.05), and raised more significantly in the model and intervention groups (P < 0.05 approximately 0.01), especially the TC level of the model group was raised by 40 tomes. The levels of blood lipids of the simvastatin group were significantly lower than those of the model group (P < 0.05 approximately 0.01), however, between the Tongxinluo and model groups there were no significant differences in the levels of blood lipids. In the model group the blood level of ET was raised significantly and the level of NO was significantly decreased (both P < 0.01). The ET levels of the 2 intervention groups were both significantly lower than that of the model group (both P < 0.01), and the NO levels of the 2 intervention groups were both significantly higher than those of the normal group (P < 0.01 approximately 0.05), however, there were no significant differences in the ET and NO levels between these 2 intervention groups (all P > 0.05). Sclerotic plaques were distributed intensely at high degrees in the model group. The sclerotic changes of the 2 intervention groups were significantly milder. The contents of collagen of the 2 intervention groups were 0.11 +/- 0.08 and 0.22 +/- 0.11 respectively, both significantly higher then that of the model group (0.01 +/- 0.01, both P < 0.05). The intima/media ratios of aorta of the 2 intervention groups were 0.25 +/- 0.13 and 0.28 +/- 0.12 respectively, both significantly lower than that of the model group (0.60 +/- 0.37). The macrophage amount in the plaque (RAM-11 positively stained area) of the 2 intervention groups were 0.11 +/- 0.10 and 0.06 +/- 0.43 respectively, both significantly lower than that of the model group (0.24 +/- 0.14). The levels of protein expression of MMP-1 and COX-2 in the atherosclerotic lesions of the model group were both significantly higher than those of the normal group and the MMP-1 and COX-2 protein expression levels of the 2 intervention groups were all significantly lower than those of the model group (P < 0.05 approximately 0.01), however, there were no significant differences between these 2 groups (both P > 0.05). Significant linear correlation existed in the MMP-1 and COX-2 positively stained areas (r = 0.533, P = 0.007) and protein expression level (r = 0.833, P < 0.01). Compared with the normal group, the mRNA expression level of FasL in the aorta tissue of the model group was significantly higher (2.44 +/- 0.44) and the mRNA expression level of bcl was significantly lower (0.17 +/- 0.11). Compared with the model group, the mRNA expression levels of FasL of the 2 intervention groups were 0.47 +/- 0.36 and 1.32 +/- 0.61 respectively, both significantly lower and the mRNA expression levels of bcl were 0.64 +/- 0.16 and 1.66 +/- 0.94 respectively, both significantly higher (all P < 0.05 approximately 0.01), with the FasL mRNA expression of the Tongxinluo group significantly higher than that of the simvastatin group (P < 0.05). CONCLUSION: Tongxinluo and simvastatin have the same effects of stabilizing the vulnerable plaques, and the mechanism may be related with inhibition of expression of COX-2 and MMP and reduction of the apoptosis in the atherosclerotic plaque.

[Comparative study on the ultrastructures of radial and internal mammary arteries used for coronary artery bypass grafting].

OBJECTIVE: The radial artery differs from internal mammary artery in its vascular biology and long-term patency after coronary artery bypass grafting (CABG). This study was designed to investigate their ultrastructural differences that may have implications in arterial remodeling and graft failure. METHODS: Thirty-four radial artery and 11 internal mammary artery samples were obtained from patients underwent CABG, and subjected to routine electron microscopic examination. A semi-quantitative method was used to evaluate secretary endothelial cells, endothelial denudation, synthetic smooth muscle cells (SMCs), matrix accumulation, lipid deposition and medial submicroscopic calcification. RESULTS: Compared with internal mammary arteries, the radial arteries had more secretory endothelial cells (47.1%, 16/34 vs 27.2%, 3/ 11) and synthetic type SMCs in a background (14.4% vs 0.9%) that had more intimal lipid deposition and matrix accumulation (14.7%, 5/34 vs 9.1%, 1/11). Matrix vesicles and calcifications were frequently present in the media of both types of arteries. The calcifications, however, could not be visualized by routine histological stains, and therefore, named as submicroscopic calcification in this study. Fewer endothelial denudations were observed in the radial arteries, but no differences in medial lipid deposition and submicroscopic calcification were observed between these two types of arteries. The ultrastructural features and the arrangement of medial SMCs in radial arteries were similar to those of internal mammary arteries. CONCLUSIONS: Radial arteries have a higher SMC proliferative potential and more actively secretory status of endothelial cells, which may enhance the remodeling process and correlate with a decreased long-term patency. Better preservation of endothelial cells in radial arteries could be attributed to the "no touch" technique utilized in surgical harvesting. The significance of submicroscopic medial calcification during graft remodeling requires further investigations.

[Diagnostic value of echocardiography for cardiac tumors in infancy and childhood].

OBJECTIVE: The present study was designed to evaluate the clinical manifestations, surgical findings, pathologic types and treatment of cardiac tumor and to analyze the echocardiographic characteristics of the cases. METHODS: Records of 19 patients with cardiac tumors confirmed by operations and pathology at Fuwai Cardiovascular Hospital in Beijing, China between Jan, 1983 and Dec, 2003 were reviewed. Clinical and echocardiographic data of all patients were analyzed. RESULTS: The median age of patients was 7 +/- 5 years, ranging from 5 months to 14 years. There were 8 male and 11 female cases. The surgical findings revealed that 57.9% (11 cases) of cardiac tumors were found in left heart, 36.8% (7 cases) in right heart, 5.3% (1 case) in two ventricles. The pathological study revealed that 17 cases (89.5%) were diagnosed as primary cardiac benign tumors including myxoma in 10 cases (52.6%), rhabdomyoma in 4 cases (21.1%), fibroma in 2 cases (10.5%) and lipoma in 1 case (5.3%). Two cases were diagnosed (10.5%) as cardiac malignant tumors including a primary cardiac rhabdomyosarcoma and a metastatic epithelioid sarcoma. By using echocardiography 11 cases were diagnosed as myxomas and rhabdomyoma (11/19, 57.9%), 8 cases were diagnosed as space occupying lesions of the heart or myxoma (8/19, 42.1%). CONCLUSIONS: Myxomas are the most common heart tumors seen in infancy and childhood, followed in frequency by rhabdomyomas, fibromas and lipomas. Surgery is recommended for patients with refractory and severe clinical symptoms.

[Comparison of doxycycline, losartan, and their combination in the prevention of post-infarction remodeling in rats].

OBJECTIVE: To compare the effects of doxycycline, losartan, and their combination in the prevention of left ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in rats. METHODS: Twenty-four hours after the induction of AMI, the 254 survival rats were randomly assigned to the following groups and received drug treatment: (1) AMI controls (n=64), (2) doxycycline (30 mg x kg(-1) x d(-1), n = 63), (3) losartan (10 mg x kg(-1) x d(-1), n = 62), and (4) combination doxycycline and losartan (30 and 10 mg x kg(-1) x d(-1) respectively, n = 65) treatment groups. Also, sham operated rats (n = 30) were selected randomly. Each group was further divided into three subgroups of 1, 2, and 4 weeks of treatment. After the completion of treatment, hemodynamic studies were performed. Then, the heart of rat was fixed and analyzed pathologically. RESULTS: Exclusive of the dead rats and the hearts with the myocardial infarction size < 35% or > 50%, complete experimental data were obtained in 157 rats. Besides sham operated rats, there was no significant difference in myocardial infarction sizes among the 12 subgroups of AMI control and drug treatment groups (P> 0.05). Compared with sham operated rats, left ventricular end diastolic pressure (LVEDP) and left ventricular absolute weight and relative weight (LVAW and LVRW) were significantly increased in 1, 2, and 4 week subgroups of AMI controls (P < 0.05, P < 0.01, and P < 0.001, respectively), with LVEDP elevated more significantly in 4 week than in 1 and 2 week subgroups (P < 0.01); whereas the maximum rising and dropping rate of left ventricular pressure (+/-dp/dt) and its corrected value by left ventricular systolic pressure (+/-dp/dt/LVSP) were all significantly decreased only at 4 week subgroup of AMI controls (P < 0.001). Compared with AMI controls group, LVEDP was significantly decreased in all 1, 2, and 4 week subgroups of the three treatment groups (P < 0.05, P < 0.01, and P < 0.001, respectively); LVAW and LVRW were significantly decreased in 2 and 4 week subgroups of losartan and combination groups (P < 0.05, P < 0.01, P < 0.001, respectively), and in only 4 week subgroup in doxycycline (P < 0.05, P < 0.01, and P < 0.001, respectively); whereas the maximum dropping rate of left ventricular pressure and the corrected value of left ventricular pressure rising and dropping rate were significantly increased only in 4 week subgroups of all three treatment groups (P < 0.05, P < 0.01, respectively). There is no significant difference in all indices above among the three treatment groups at all three time points (P > 0.05). CONCLUSION: It is indicated that doxycycline can prevent left ventricular remodeling and improve its systolic and diastolic function after AMI in rats, with the equivalent effect to that of losartan. There seems no additive effect when the two drugs are used in combination.