[Pretreatment of isolated vein with rapamycin nanoparticles inhibits vein graft stenosis in rabbits].

OBJECTIVE: To explore the effects of pretreatment of carbopol-encapsulated rapamycin-loaded nanoparticles (RPM-NP) on vein graft stenosis in a rabbit vein graft model. METHODS: A segment of common carotid artery was replaced with a segment of external jugular vein in 40 rabbits. They were separated into four treatment groups, i.e. Group A: vein grafts were pretreated with intraluminal RPM-NP perfusion; Group B: peripheral venous veins were injected with RPM-NP; Group C: vein grafts received an equivalent perfusion of empty vehicle; Group D: vein grafts received no treatment. At Day 28 post-operation, the grafts and normal veins were harvested for histological examinations to analyze the indicators of intimal thickness, internal diameter, intimal/media thickness ratio and collagen volume index. RESULTS: At Day 28 post-operation, the intimal/media thickness ratios were 0.26 ± 0.02, 0.73 ± 0.05, 0.71 ± 0.04, 0.69 ± 0.03 and 0.24 ± 0.01 in Groups A, B, C and D and the normal vein; the collagen volume index 0.24 ± 0.03, 0.56 ± 0.06, 0.53 ± 0.07, 0.49 ± 0.08 and 0.21 ± 0.01 respectively. Compared with the normal veins, the pathological indicators of vein graft intimal thickness, internal diameter, intimal/media thickness ratio and collagen volume index had significant differences in Groups B, C and D (all P < 0.05). But there were no significant differences among 3 groups (all P > 0.05). Compared with the normal vein, the parameters of vein graft intimal thickness, internal diameter, intimal/media thickness ratio and collagen volume index had no significant difference in Group A (all P > 0.05). But as compared with other groups, these indicators had statistical significant difference in Group A (all P < 0.05). CONCLUSION: The local pretreatment of isolated vein with rapamycin nanoparticles may inhibit neointimal hyperplasia and prevent effectively vein graft stenosis.

[Effects of immunosuppressive treatment in prevention of calcification in aortic valved homograft: experiment with rats].

OBJECTIVE: To investigate the effects of immunosuppressive treatment in prevention of calcification in aortic valved homograft (AVH). METHODS: 120 Wistar rats were randomly divided into 4 equal groups: Group A (allogene group) undergoing incision of the abdominal aorta and implantation of the AVH with myocardial cuff from SD rats, Group B, injected with cyclosporine A intraperitoneally one day after the implantation, Group C, injected intraperitoneally with anti-dendritic cell monoclonal antibody (DCmAb) one day after the implantation, and Group D (isogenenic or control group), receiving the AVH of another Wistar rats. All groups were further subdivided into 5 equal subgroups to be sacrificed at different time points: 2, 4, 8, 12, and 16 weeks postoperatively. Blood samples were obtained from the vena cava to detect the expression of T-cell antigen receptor (TCR)-alpha and beta and CD28 by flow cytometry. AVH specimens were obtained to observe the changes of endotheliocytes and smooth muscle cells with light and electron microscopy. The expression of CD54 was detected by immunohistochemistry. The calcium content of the AVH tissue after transplantation was examined by flame atomic absorption spectrophotometry. RESULTS: (1) Compared with the isogenic group, the expression levels of TCR-alpha and beta and CD28 in the allogener groups were all significantly higher at all time points (all P < 0.01), peaked 2 approximately 4 weeks after operation, then gradually decreased, and approached the level of the controls 12 weeks after the implantation. Specifically, the expression levels of TCR-alpha and TCR-beta 2 and 4 weeks postoperatively of Group A were 52.4% +/- 3.3% and 43.8% +/- 6.4% respectively, significantly higher than those of Group B [(34.5 +/- 3.5)% and (31.6 +/- 2.6)% respectively], Group C [(31.6 +/- 2.3)% and (29.5 +/- 3.0)% respectively), and Group D (23.2 +/- 1.3)% and (21.6 +/- 2.3)% (all P < 0.01)]; and the CD28 expression level 2 approximately 4 weeks after operation of Group A were (51.7 +/- 7.5)% and (66.3 +/- 4.4)% respectively, both significantly higher than those of Group B [(41.2 +/- 1.6)% and (55.1 +/- 5.1)% respectively], Group C [(36.6 +/- 3.6)% and (51.8 +/- 5.6)% respectively], and Group D [30.7 +/- 1.4)% and (33.3 +/- 0.9)% respectively)] [all P < 0.01 except those levels 12 and 16 weeks after the operation in each subgroup (P > 0.05)] And the levels of TCR-alpha and TCR-beta and CD28 of the 2 treatment groups were all significantly lower than those of the untreated group (Group A) (all P < 0.01). (2) The calcium contents of the AVH tissues of Group A, B, and C significantly increased 4 weeks after the operation and peaked 12 and 16 weeks after operation. No significant difference in calcium level was found in Group D at different time points (all P > 0.05). The calcium contents in AVH tissues 4 and 8 weeks postoperatively of Groups A, B, and C were (2856 +/- 79) microg/g and (3587 +/- 168) microg/g respectively, (2518 +/- 73) microg/g, (3237 +/- 187) microg/g; and (2176 +/- 210) microg/g and (3089 +/- 176) microg/g; all significantly higher than those of Group D (860 +/- 60) microg/g and (870 +/- 50) microg/g respectively, all P < 0.01. CONCLUSION: Immunosuppressive treatment obviously reduces the immune rejection and delays the course of AVH calcification.

[Clinical study on effect of Shenqi Fuzheng Injection on erythrocyte immunity in patients after cardiopulmonary bypass].

OBJECTIVE: To study the effect of Shenqi Fuzheng Injection (SQFZI) on erythrocyte immune function in patients after cardiopulmonary bypass (CPB). METHODS: Twenty patients ready for receiving CPB were randomly assigned to two groups, 10 in each group. Patients in the SQFZI group were treated with 250 mL SQFZI via intravenous dripping starting from 5 days before operation and after ending CPB once a day. Peripheral venous blood samples of all patients were collected at the time points of before anesthesia, and 6 h, 24 h, 72 h and 7 days after CPB, which were anticoagulated with heparin for dynamically detecting the changes of RBC-C3bRR and RBC-ICR. RESULTS: RBC-C3bRR and RBC-ICR in the SQFZI group were significantly higher at 6 h, 24 h, 72 h, and day 7 after operation than those in the control group respectively at the corresponding time points, and they restored to the normal levels at day 7, suggesting the erythrocyte immune function after CPB in the SQFZI group was superior to that in the control group (P < 0.05). CONCLUSION: Application of SQFZI in the peri-operative period can significantly improve the hypo-immunological function of erythrocyte caused by CPB, and promote the recovery of erythrocyte immunity.

[Effects of blood washing and autotransfusion during cardiopulmonary bypass on erythrocyte immune and kidney function].

OBJECTIVE: To study changes of erythrocyte immune and kidney function after autotransfusion washed red blood cells during cardiopulmonary bypass (CPB). METHODS: Thirty-two patients undergoing valve replacement with CPB were randomly divided into study group and control group (16 in each group). In study group, the blood in operative field and the residual blood in the extracorporal machine were collected, centrifuged, washed and retransfused to patients. Patients in control group were transfused with the residual blood in the extracorporal machine without any disposal or banked blood. All patients were used with membrane oxygenator. Before CPB, 12 h, 24 h, 72 h and 7 d after CPB, whole blood were taken, then the erythrocyte immune function (C3bRR, RICR) and level of plasma free hemoglobin (FHB) were assayed, and post-operation renal function was compared between the two groups. Moreover, total volume of banked blood transfused to patients after CPB was recorded. RESULTS: (1) After 12 hours, 24 hours, 72 hours, 7 days of CPB, the RBC-C3bRR (14.3% +/- 4.7%, 15.9% +/- 3.6%, 16.6% +/- 2.8%, 19.9% +/- 4.1%) and RBC-ICR (8.7% +/- 1.9%, 9.2% +/- 2.0%, 9.5% +/- 2.6%, 12.0% +/- 2.0%) in study group were significantly elevated than that in control group (RBC-C3bRR 10.7% +/- 2.4%, 11.3% +/- 3.0%, 12.3% +/- 3.5%, 14.5% +/- 2.0%, RBC-ICR 5.9% +/- 1.4%, 6.0% +/- 1.8%, 7.0% +/- 1.7%, 8.7% +/- 2.7%). The erythrocyte immune function after CPB was better and restored faster in study group than that in control group (P < 0.05 in all). (2) After 12 hours, 24 hours of CPB, the levels of FHB (0.41 g/L +/- 0.13 g/L, 0.03 g/L +/- 0.02 g/L) in study group were significantly lower than that in control group (1.02 g/L +/- 0.23 g/L, 0.54 g/L +/- 0.09 g/L) (P < 0.01). After 24 hours of CPB, the level of urinary protein excretion (0.19 g/d +/- 0.08 g/d) in study group was significantly lower than that in control group (0.32 g/d +/- 0.07 g/d) (P < 0.05). (3) After 24 hours of CPB, the level of 24 h creatinine clearance was significantly elevated in study group (68 ml x min(-1) x 1.73 m(-2) +/- 10 ml x min(-1) x 1.73 m(-2)) than that in control group (45 ml x min(-1) x 1.73 m(-2) +/- 4 ml x min(-1) x 1.73 m(-2)) (P < 0.01). (4) The total volume of banked RBCs transfused after CPB were fewer in study group (2.0 U +/- 1.1 U) than that in control group (7.4 U +/- 2.3 U) (P < 0.01). CONCLUSION: Autotransfusion of washed red blood cells during CPB may improve significantly the erythrocyte immune function and protect kidney function better than transfusion of residual blood in the extracorporal machine or banked blood.

[Influence of pulmonary artery perfusion with solution of washed red blood cells on lung injury after cardiopulmonary bypass].

OBJECTIVE: To observe the influence of intra-operative pulmonary artery perfusion with hypothermic washed red blood cell (RBC) solution on lung injury after cardiopulmonary bypass (CPB). METHODS: Thirty patients of mitral disease with pulmonary hypertension undergoing mitral valve replacement were randomly divided into 2 equal groups: control group, and perfusion group (with the pulmonary artery infused with 4 degrees C washed RBC protective solution during CPB). The blood cell count, pulmonary vascular resistance (PVR), white blood cell (WBC) ratio (venous blood/arterial blood), plasma malonyldialdehyde (MDA), and oxygenation index (OI), were measured and the time of mechanical ventilation was obtained as well. RESULTS: (1) The PVR at the end of CPB, and 12 h and 24 h after CPB of the perfusion group were 46.4 kPa.s.L(-1) +/- 8.1 kPa.s.L(-1), 48.5 kPa.s.L(-1) +/- 7.0 kPa.s.L(-1), and 36.1 kPa.s.L(-1) +/- 6.3 kPa.s.L(-1) respectively, all significantly lower than those of the control group (65.7 kPa.s.L(-1) +/- 5.3 kPa.s.L(-1), 79.8 kPa.s.L(-1) +/- 8.7 kPa.s.L(-1), and 47.9 kPa.s.L(-1) +/- 7.1 kPa.s.L(-1) respectively, all P < 0.05). (2) The levels of MDA at the end of CPB, and 12 h and 24 h after CPB of the perfusion group were 14.3 mmol/L +/- 0.8 mmol/L, 16.1 mmol/L +/- 0.7 mmol/L, and 13.3 mmol/L +/- 0.5 mmol/L respectively, all significantly lower than those of the control group (18.9 mmol/L +/- 0.9 mmol/L, 21.6 mmol/L +/- 0.4 mmol/L, and 22.5 mmol/L +/- 0.7 mmol/L respectively, all P < 0.05). (3) The WBC ratios of vein and artery (V/A) a the end of CPB and 12 h after CPB of the perfusion group were 1.16 +/- 0.05 and 1.20 +/- 0.05 respectively, both significantly lower than those of the control group (1.53 +/- 0.07 and 1.68 +/- 0.25 respectively (both P < 0.01). (4) The OI at the end of CPB, and 12 h and 24 h after CPB of the perfusion group were 370 +/- 33, 388 +/- 41, and 414 +/- 39 respectively, all significantly higher than those of the control group (217 +/- 30, 210 +/- 36, and 222 +/- 33 respectively (all P < 0.05). (5) The time of mechanical ventilation the perfusion group was 13 h +/- 4 h, significantly shorter than that of the control group (27 h +/- 6 h, P < 0.01). CONCLUSION: Pulmonary artery perfusion with hypothermic washed RBC protective solution alleviates the lung injury after cardiopulmonary bypass.

[Analysis of the factors which influence allograft calcification after aorta transplantation of allogenetic rat].

AIM: To explore the factors which influence the calcification of homograft after aorta transplantation of allogenetic rat. METHODS: The research was devided into 2 groups: allogene group and isogenenic group. Allogene group: SD -->Wistar. Isogenenic group: Wistar to Wistar. Aortic valve homograft was heterotopically allografted onto abdominal aorta. The rats were sacrificed in batches at 2, 4, 8, 12 and 16 weeks postoperatively. Blood samples were obtained for accessing the expression of CD25, CD71, and AVH was obtained for accessing the calcium level and the expression of CD40. At the same time, the change of endotheliocyte and smooth muscle cells were observed with transmission electron microscope. RESULTS: (1)Compared with the isogene group, the expression of CD40, CD25 and CD71 in allogene group was much higher at each time point and reached peak at 2-4 weeks after operation. (2)The calcium level in allogene group increased at 4 weeks after operation and reached the peak at 12 weeks after operation. No significant difference in calcium level was found in isogenenic group over 5 different periods. (3)Exfoliation of endotheliacytes as well as necrosis of smooth muscle cells were observed in the graft in allogene group. CONCLUSION: The calcium level of homograft had a relation with immunological rejection. The calcification began at 4 weeks postoperation; the calcium level of homogaft increased gradually and reached the peak at 12 weeks postoperation and then maintained on a stable level.