Objective To investigate the effect of N-acetylcysteine (NAC) on the apoptosis during myocardial ischemia reperfusion injury in rats’ heart transplantation, and to explore the possible role of NAC in myocardial apoptosis. Methods Sixty healthy male Lewis rats (weighing, 200-220 g) were randomly divided into 3 groups, 20 rats each group (10 donors and 10 recipients). In control group, 1 mL normal saline was infused via inferior vena cava at 30 minutes before donor harvesting; in donor preconditioning group, NAC (300 mg/kg) was infused via inferior vena cava at 30 minutes before donor harvesting, but no treatment in recipients; and in recipient preconditioning group, NAC (300 mg/kg) was infused via inferior vena cava at 30 minutes before recipient transplantation, but no treatment in donors. Heart transplantation was established in each group. Blood was drawn at 6 and 24 hours after reperfusion for analysis of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) as markers of graft injury; myocardial tissue was harvested to determine the superoxide dismutase (SOD) and lipid hydroperoxide (LPO) activity at 24 hours after reperfusion and to observe the histology and ultrastructural changes. Graft active Caspase-3 protein expression was measured by immunohistochemistry staining, and apoptosis index (AI) was calculated by TUNEL. Results The heart transplantation operation was successfully completed in all groups, and the rats survived to the end of the experiment. The serum levels of AST, ALT, and LDH in donor and recipient preconditioning groups were significantly lower than those in control group at 6 hours after reperfusion (P lt; 0.05); the levels of AST and ALT in donor preconditioning group and the levels of AST and LDH in recipient preconditioning group were significantly lower than those in control group at 24 hours (P lt; 0.05); and no significant difference was found between donor and recipient perconditioning groups (P gt; 0.05). The levels of AST, ALT, and LDH at 24 hours were significantly lower than those at 6 hours in each group (P lt; 0.05) except the level of ALT in recipient preconditioning group (P gt; 0.05). SOD activity and SOD/LPO in donor and recipient preconditioning groups were significantly higher than those in control group (P lt; 0.05), but no significant difference between donor and recipient preconditioning groups (P gt; 0.05); there was no significant difference in LPO activity among 3 groups (P gt; 0.05). Histological staining and transmission electron microscope showed that myocardial injury in recipient preconditioning group was obviously lighter than that in donor preconditioning group and control group. Active Caspase-3 in recipient pretreatment group was significantly higher than that in donor preconditioning group and control group (P lt; 0.05). AI of donor and recipient preconditioning groups was significantly lower than that of control group (P lt; 0.05), but no significant difference was found between donor and recipient preconditioning groups (P gt; 0.05). Conclusion NAC can relieve ischemia reperfusion injury in rats’ heart transplantation by improving myocardial SOD content, and reducing active Caspase-3 activity and AI, which has a protective effect on myocardial cell of donor heart.
Objective To insure early detection and hence efficient prevention of allograft rejection in transplanted heart, investigate possible applications of NAD(P)H fluorescence components analysis at the level of living cardiac cells to propose new approaches for diagnosis of rejection. Methods NAD(P)H was studied for noninvasive fluorescent probing of the mitochondrial function. Human cardiomyocyte were isolated from one additional endomyocardial biopsy (EMB) of 14 pediatric patients with heart ransplantation. Rat cardiomyocyte (n=5, 13-14 week old) were also isolated by the same approach for human myocytes. Autofluorescence(AF) was recorded in living cardiomyocytes following excitation with 375 nm UVlight and detection by spectrallyresolved time correlated single photon counting (TCSPC), based on the simultaneous measurement of the fluorescence spectra and lifetimes. Rat cardiac cells were divided into four groups: normoxic condition, normoxia with Rotenone, ischemic condition and ischemia with Rotenone. Comparison of cardiomyocyte AF between human and rat; compared kinetics of rat cardiomyocytes AF in normoxic conditions to ischemiamimicking ones, induced at physiological temperatures by reducing cell pH and oxygen content; comparison of cardiomyocyte AF dynamic changes in transplanted pediatric patients presenting either no rejection (R0) or mild rejection (R1). Results We have achieved appropriate isolation of living cardiomyocytes from human biopsies, as well as from rat cardiac tissues and determined their AF. At least a 3-exponential decay with 0.5-0.7ns, 1.9-2.4 ns and 9.0-15.0 ns lifetime pools is necessary to describe human cardiomyocyte AF within 420560 nm spectral range. Rat cardiomyocyte steadystate AF in ischemiamimicking condition was significantly increased when compared normoxic ones (Plt;0.05); application of Rotenone induced a significant increase in AF intensity in ischemic and normoxic condition, however no significant difference between the two groups (Plt;0.05).Human cardiomyocyte AF was found significantly lower in comparison to experimental rat model in the same condition(Plt;0.05). A correlation between changes in steadystate NAD(P)H fluorescence and rejection grades was found when comparison of R1 to R0. R1 showed significantly increased fluorescence intensity (Plt;0.05), without change in the spectra shape, results can be comparable to the effect of ischemiamimic conditions. Conclusion Our studies clearly demonstrated that spectrallyresolved fluorescence spectral analysis coupled to fluorescence lifetime are high sensitive approaches to examine mitochondrial metabolic oxidative state directly in living human cardiomyocytes with good reproducibility. Human cardiomyocytes are more metabolically active than the rat ones, while this activity (and thus ATP production) seems lowered during rejection process. In perspective, the advantage of this method is the possibility of its combination to multiphoton confocal microscopy, which can result in the adaptation of this approach directly to tissue biopsy, as well as in vivo directly via cardiac catheterization without the necessity of cell isolation. This approach provides promising new tool for clinical diagnosis and treatment of allograft rejection, and will enhance our knowledge about cardiomyocyte oxidative metabolism and/or its dysfunction at a cellular level.
Abstract:Objective To investigate immunoinh.ibitory effects of paclitaxel on acute rejection of allogeneic heart transplantation in rats. Methods Heterotopic abdominal cardiac transplantation was performed from Wistar rats to SD rats. Seventy recipients were randomly divided into five groups,14 rats in each group. Control group： rats didn＇t receive any immunoinhibitory drug; group Ⅰ ： low-dose paclitaxel （0.75 mg/kg · d） was injected intraperitoneally; group Ⅱ ： high-dose paclitaxel （1.5 mg/kg ·d） was injected intraperitoneally; group Ⅲ ： cyclosporin A（CsA, 5 mg/ kg·d） was administered orally; group Ⅳ ： low-dose paclitaxel （0. 75 mg/kg · d） was injected intraperitoneally in combination with CsA （5 mg/kg · d administered orally）. General conditions of recipient, allograft survival and pathologic lesion at 7th day posttransplantation were observed. Results Allograft survival in treating groups were significantly prolonged compared with control group （P〈 0. 05）. Moreover, allograft survival in group IV was significantly prolonged compared with those in group Ⅰ and group Ⅲ （P〈0.05）. On 7th day posttransplantation, cardiac allograft looked swollen and International Society for Heart and Lung Transplantation （ISHLT） score was 3 or 4 in control group; cardiac allograft beat vigorously, showed pink in color and felt tender in group Ⅰ and group Ⅱ , ISHLT-score was 2 or 3. Compared to control group, pathologic lesion of grafts in group Ⅰ and group Ⅱ were significantly relieved （P〈0.05）. Cardiac allograft beat well and ISHLT-score was 2 in group Ⅲ. Cardiac allograft looked as normal and beat vigorously, ISHLT-score was less than 2 in group IV ; the protective effects on cardiac allograft was better than those in group Ⅰ and group Ⅱ （P〈0. 05）. Conclusion Paclitaxel could obviously suppress acute rejection and prolong survival of rat cardiac allograft. Paclitaxel and CsA has synergistic effect on prevention acute rejection.
Objective To summarize the experiences of donor heart procurement of heart transplantation so as to improve the efficiency of donor heart protection. [WTHZ]Methods [WTBZ]From April 2002 to October 2006, sixtyone patients with endstage heart disease had undergone orthotopic heart transplantation. Donors were all male brain deaths, aged from 21 to 53, and 5 of them were older than 40. There were 6 cases in which the weight difference between donor and recipient＞20%, and the rest ≤±20%. Fortyfive cases had the same ABO blood type, and 16 had matching ABO blood type. Four donor hearts were procured under the condition of stable hemodynamics and enough oxygen after brain death(typeⅠ), fortyfour donor hearts were procured under the condition of brain death with acute hemorrhage and hypovolemia (typeⅡ), and 13 donor hearts were procured under the condition of brain death with cardiac arrest (typeⅢ). Twenty cases underwent standard transplantation procedure, one underwent total heart transplantation procedure and 40 underwent bicaval transplantation procedure. The donor heart cold ischemic period ranged from 52 to 347 min（92±31 min）, and 13 cases were more than 240 min. Results Two cases died of low cardiac output syndrome on 7th and 9th day after operation respectively, and their donor heart cold ischemic period were 327 and 293 min respectively. The rest of patients all recovered and discharged. One died of acute rejection on 18th month after operation because of rejecting immunosuppressive agents, and 1 died in traffic accident on 23rd month after transplantation. The rest 57 cases survived 6-59 months(mean 35 months), and had good life quality with NYHA cardiac function classification in 0-I grade. Conclusions Heart transplantation with donor aged over 40 may also have satisfactory results. Patients with endstage dilated cardiomyopathy can procure donor heartsfrom donors with heavy weight. Using different techniques to procure donor hearts may furthest reduce myocardial injury. Donor hearts which have been protected by myocardium protecting liquid for a long time should be used with caution.
Abstract: Human leukocyte antigen (HLA) is the key antigen mediating rejection and panel reactive antibody (PRA) represent anti-HLA antibodiesin circulation. HLA typing and PRA testing are carried out generally before organ transplantation. With research on the relationship among HLA, PRA and heart transplantation developing, the value of HLA typing and PRA testing in heart transplantation has received more attention and their clinical using strategy has been improved. This article will review the strategy of HLA typing, the clinical value of HLA typing, time-selection in HLA typing, reason and mechanism of rising PRA, clinical sense of PRA testing and treatment of sensitized patients.
ObjectiveTo explore the correlation between perioperative blood transfusion and acute kidney injury (AKI) after heart transplantation.MethodsA retrospective study was performed on 67 patients who underwent heart transplantation in the Department of Cardiac Surgery, Guangdong Provincial People's Hospital from January 2016 to December 2018, and finally 63 patients were included according to the exclusion criteria. There were 53 males and 10 females with an average age of 44.3±12.9 years. Twenty patients who adopted continuous renal replacement therapy (CRRT) after heart transplantation were divided into a RT group and the other 43 patients who did not use CRRT were divided into a non-RT group. Baseline characteristics, perioperative blood transfusion data and clinical prognosis were compared between the two groups.ResultsThe preoperative baseline characteristics of the two groups were basically the same. There were significant differences in perioperative infusion of red blood cells and plasma, postoperative 24 h bleeding and re-exploration (P<0.05) between the two groups. The area under the receiver operating characteristic (ROC) curve was 0.923 (95%CI 0.852 to 0.995, P<0.001). The ROC curve showed that perioperative infusion of red blood cells more than 18 mL/kg would increase the incidence of AKI after heart transplantation.ConclusionPerioperative blood transfusion is closely related to AKI after heart transplantation. The more blood transfusion is in clinics, the higher incidence of renal injury is and the worse prognosis is. It is suggested that various blood-saving measures can be carried out.
Objective To study the relationship between Th1/Th2 cytokines messenger ribonucleic acid (mRNA) expression and immune tolerance to cardiac allografts in rats. Methods Male DA rat hearts were transplanted to male Lewis rats using Ono’s model and randomly divided into three groups: control group, rejection group, and tolerance group (each group 10 rats). Mean survival time (MST), histological changes, mRNA expression level of Th1/Th2 cytokines interleukin-2 (IL-2), interferon-γ (IFN-γ), interleukin-4(IL-4), interleukin-10(IL-10) were measured. Results MST (85.28±7.48 d) of heart allografts in tolerance group was significantly longer than that(7.33±1.03 d) in rejection group. Only a few inflammatory cells infiltrated in cardiac allografts in tolerance group. The mRNA expression of IL-2, IFN-γ (Th1 cytokines) in rejection group were much ber than those in control group, and in tolerance group were much lower; mRNA expression of IL-4, IL-10 (Th2 cytokines) in rejection group were much ...更多lower than those in control group,and in tolerance group were much ber than those in control group. Conclusions The dynamic equilibrium of Th1/Th2 cytokines is very important in immune tolerance. The deviation of Th1 to Th2 is one of the mechanisms in immune tolerance.
Objective To investigate the rat model of cardiac allograft vasculopathy after heart transplantation in rat abdominal cavity. Methods Forty Wistar rats and 40SDrats were divided into control group and experiment group randomly pair-matching. Rat model ofheterotopic heart transplantation was developed. Low doseCyclosporine A were injected into the abdominal cavity in experiment group, while the control group had not received the Cyclosporine A. Transplant hearts were harvested at two weeks and four weeks post-operatively and changes of coronary artery were observed by light microscope. Results There were no alteration of tunica intima of coronary artery in control group at two weeks and four weeks post-transplantation. Tunica intima of coronary artery increased in thickness at two weeks post-transplantation in experiment group and concentric circular change occurred at four weeks post-transplantation. Lumen of coronary artery constricted transparent and cardiac allograft vasculopathy occurred. Conclusion This animal model is reliable of cardiac allograft vasculopathy.
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.
Objective To study efficiency and security of the recombinant adenoviralmediated gene transfer to the donor heart during the heart transplantation. Methods A total of 140 healthy male Wistar rats,aged 10 weeks, weighing 200250 g, were equally divided into the donor group and the recipient group, and then 70 rats in the recipient group were randomly andequally divided into 2 subgroups: the gene transfer group and the control group. The rat model of heterotopic heart transplantation(Abdomen)was developed, the donor hearts were removed and their coronary arteries were perfused with 800 μlof the recombinant adenoviral vectors encoding the β-galactosidase gene（Ad-LacZ）. The grafts were stored in the 4℃ cold saline solution for 30 minutes, and then the syngeneic transplant was performed. In the control group, saline of tales doses was perfused. The donor hearts were harvested at 3, 5, 7, 14, and 28days (n=7)after transplantation, and the β-galactosidase activity was assessed by the X-gal staining. At 28 days the major organs of the recipients were tested by the histopathological analysis and the polymerase chain reaction of the adenoviral E1A sequences. Results The successful gene transfer of the βgalactosidase gene was demonstrated in the adenovirus-perfused hearts, with no staining in the control group. The gene expression reached a peak level at 3, 5 and 7 days, and the averaged numbers of the total βgalactosidase positive staining cells per slice were 66.4±23.1, 91.3±32.4 and 68.7±22.7, respectively, with no significant difference between the groups (Pgt;0.05). At 14 days the gene expression gradually declined (32.1±13.9), and the significant difference was found when compared with that at 3, 5 and 7 days (Plt;0.05). At 28 days the cells positive for β-galactosidase were sparse (3.9±3.4), and the gene transfer was significantly less efficient compared with that at 3, 5, 7 and 14 days (Plt;0.05). The major organs of the recipients were not affected seriously at 28 days. No virus spread to other organs in this experimental protocol. Conclusion The ex vivo adenoviralmediated gene transfer intracoronarily to the donor heart during the heart transplantation is feasible and safe.