低温保存同种主动脉和肺动脉移植物免疫排斥反应研究
摘要
前言
为探讨同种异体血管移植物对宿主免疫状态的影响以及排异反应对血管移植物的作用,本研究通过低温保存的大鼠同种异体带瓣主动脉和肺动脉异位移植模型的研究,探讨低温保存对同种血管移植物抗原性的影响,观察同种血管移植后宿主体液和细胞免疫指标的变化,以及移植物的病理改变。研究免疫抑制剂治疗对同种血管移植的作用效果。
方法
1、采用液氮低温保存方法长期保存同种主动脉和肺动脉,应用透射电镜观察低温保存对同种主动脉和肺动脉内皮结构和组织完整性的影响。
2、制作动物模型,将低温保存的SD大鼠的主动脉或肺动脉异位植入大鼠的腹主动脉,分组:主动脉移植组、肺动脉移植组、主动脉免疫治疗(CsA)组、对照组。在移植后1、2、3、4、5周收集移植动物血清标本,同时取出血管移植物。
3、移植物切片常规HE染色,测定其增厚内膜与中层比值及移植物外膜单核细胞浸润数。免疫组化染色测量MHCⅡ阳性表达,淋巴细胞涂片免疫组化测定CD4+、CD8+百分率。应用酶联法测定血清中IL-2含量和TNF-α含量。
结果
电镜结果显示低温保存方法能够保存同种主动脉和肺动脉内皮细胞的活性和结构的完整性。大鼠同种移植后1周出现血管内皮细胞损伤,内膜增厚,并逐渐加重。大量炎症细胞浸润移植物外膜和中层,术后炎症细胞浸润数长时间维持在很高水平。移植后1-4周可见MHCⅡ显著阳性,CD4+、CD4+/CD8+比值明显增高。血清中IL-2和TNF-a含量明显增高,并在术后5周内维持很高水平,上述结果与对照组比较均有显著差异(p＜0.05)。CsA治疗对移植物内膜增厚、淋巴细胞浸润、MHCⅡ表达、T淋巴细胞激活、IL-2和TNF-a含量增高具有明显的抑制作用(p＜0.05)。主动脉与肺动脉同种移植在内膜增厚、淋巴细胞浸润、MHCⅡ表达、T淋巴细胞激活、IL-2和TNF-a含量增高方面没有显著差异(p＞0.05)。
结论
一、液氮低温保存同种异体主动脉和肺动脉能保持其生物活性和组织结构完整性。
二、低温保存同种异体主动脉和肺动脉移植后有明确的免疫排斥反应发生,细胞和体液免疫均参与免疫排斥反应过程,慢性免疫排斥反应以细胞免疫为主。
三、低温保存同种异体主动脉和肺动脉移植物的病理改变为内膜进行性增厚、中层平滑肌细胞变性坏死、外膜大量淋巴细胞浸润,导致同种管道钙化和阻塞。
四、低温保存同种异体主动脉和肺动脉移植后在免疫反应方面无显著差异,其移植后的钙化与免疫排斥反应有关。
五、环孢霉素A对同种异体移植后的免疫排斥反应和钙化有明显的抑制作用。
Objective
To investigate the influence of aortic and pulmonary homografts on host and the effect of immunological rejection on the homografts.Rat model of cryopreserved aortic and pulmonary valved homograft heterotopic transplantation was established to investigate the effect of cryopreservationg on the antigenticity of the aortic and pulmonary homografts,,observe the changes of humoral and cellular immunological responses and pathological changes of implanted homografts.to study the effect of immunosuppressive treatment on the aortic and pulmonary homograft transplantation.
Methods
In this study,Liquid nitrogen cryopreservation method was adopted in the long-term storage of the aortic and pulmonary homografts.Transmitting electron microscope was used to observe the effect of cryopreservation on endothelial structure and tissular structure.The animal models of aortic and pulmonary homograft transplantation were established by heterotopic insertion of aortic and pulmonary homografts of SD rats into abdominal aortae of Wistar rats.CsAwas employed in the treatment of immunological rejection in the immuusuppressive treatment group of aortic homograft transplantation.Respectively at 1th,2th,3th 4th,and 5thweeks after implantation,the blood samples of the transplanted animals were collected and the homografts retrieved.The area of intima and media of the implanted grafts was measured and a relative area ratio of intima to media (I/M area ratio) was calculated to estimate the degree of the intimal thickening. In addition,the munbers of nucleated cells in the media and adventitia were counted,and estimated as cell number per 0.1 mm~2.Immunohistochemical staining was performed to detect the MHCⅡdeposition of the aortic and pulmonary homografts and the percentage of CD4 +,CD8 + lymphocytes and the ratio of CD4 +/CD8 + in blood samples of the implanted rats.The biological activities of IL-2 and TNF-a in blood samples of the implanted rats were measured by means of ELISA.
Results
Cryopreservation may maintain viabilities and normal intercellular connections of endothelial cells of the aortic and pulmonary homografts.The pathological changes of the explanted homografts presented damages of the endothelialcells, infiltration of inflammatory cells in media and advenfitia,intimal thickening of the homografts,etc.Intimal thickening progressively increased,the numbers of inflammatory cells infiltrated in the homografts maintain high leveh during the 5weeks after implantation.The MHCⅡdeposition were found respectively about 1 to 4 weeks after the implantation of aortic and pulmonary homografts. Thepercentage of CD4 + and CD8 + T lymphocytes,the ratio of CD4 + to CD8 +(CD4 +/CD8 +),and the biological activities of IL-2 and TNF-a in the blood samples of transphnted rats were remarkably increased after homografts implantation,and maintain high -activity levels during the 5 weeks after implantation. There was significant difference in the results between implantation group and control group(p＜0.05).the treatment of CsA had remarkably suppressive effect on deposition of MHCⅡ,infiltration of inflammatory cells,increase of intimal thickening,increase of the percentage of CD4 +,and the increase of biological activities of IL-2 and TNF-a in blood samples after homografts implantation. There was no obvious difference of infiltration of inflammatory cells,the increase of intimal thickening,and the increase of the percentage of CD4 + T lymphocytes, and the increase of biological activities of IL-2 and TNF-a in-blood samples between the aortic and pulmonary homografts imphatation groups.
Conclusion
1.Liquid nitrogen cryopreservation method may maintain the viability and normal structure of aortic and pulmonary homografts.
2.There was obvious immunological rejection after implantation of aortic and pulmonary homografts,cellular and humoral immunological responses were involved in the process if immunological rejection.Cellular immune played a major role in chronic immunological rejection.
3.the pathological changes of cryopreserved aortic and pulmonary homografts were progressive intimal-thickening,necrosis of smooth muscle cells in the media,and infiltrationg of inflammatory cells in the adventitia,which resulted in calcification and obstruction of aortic and pulmonary homografts.
4.There was no difference in immunological rejection between aortic and pulmonary homografts after implantation.Immunological rejection is an important reason for the calcification of aortic and pulmonary homografts after implantation, while the degree of calcification has close relationship with calcium content in the homografts.
5.The treatment of CsA has marked suppressive effect on immunological rejection and calcification.
为探讨同种异体血管移植物对宿主免疫状态的影响以及排异反应对血管移植物的作用,本研究通过低温保存的大鼠同种异体带瓣主动脉和肺动脉异位移植模型的研究,探讨低温保存对同种血管移植物抗原性的影响,观察同种血管移植后宿主体液和细胞免疫指标的变化,以及移植物的病理改变。研究免疫抑制剂治疗对同种血管移植的作用效果。
方法
1、采用液氮低温保存方法长期保存同种主动脉和肺动脉,应用透射电镜观察低温保存对同种主动脉和肺动脉内皮结构和组织完整性的影响。
2、制作动物模型,将低温保存的SD大鼠的主动脉或肺动脉异位植入大鼠的腹主动脉,分组:主动脉移植组、肺动脉移植组、主动脉免疫治疗(CsA)组、对照组。在移植后1、2、3、4、5周收集移植动物血清标本,同时取出血管移植物。
3、移植物切片常规HE染色,测定其增厚内膜与中层比值及移植物外膜单核细胞浸润数。免疫组化染色测量MHCⅡ阳性表达,淋巴细胞涂片免疫组化测定CD4+、CD8+百分率。应用酶联法测定血清中IL-2含量和TNF-α含量。
结果
电镜结果显示低温保存方法能够保存同种主动脉和肺动脉内皮细胞的活性和结构的完整性。大鼠同种移植后1周出现血管内皮细胞损伤,内膜增厚,并逐渐加重。大量炎症细胞浸润移植物外膜和中层,术后炎症细胞浸润数长时间维持在很高水平。移植后1-4周可见MHCⅡ显著阳性,CD4+、CD4+/CD8+比值明显增高。血清中IL-2和TNF-a含量明显增高,并在术后5周内维持很高水平,上述结果与对照组比较均有显著差异(p＜0.05)。CsA治疗对移植物内膜增厚、淋巴细胞浸润、MHCⅡ表达、T淋巴细胞激活、IL-2和TNF-a含量增高具有明显的抑制作用(p＜0.05)。主动脉与肺动脉同种移植在内膜增厚、淋巴细胞浸润、MHCⅡ表达、T淋巴细胞激活、IL-2和TNF-a含量增高方面没有显著差异(p＞0.05)。
结论
一、液氮低温保存同种异体主动脉和肺动脉能保持其生物活性和组织结构完整性。
二、低温保存同种异体主动脉和肺动脉移植后有明确的免疫排斥反应发生,细胞和体液免疫均参与免疫排斥反应过程,慢性免疫排斥反应以细胞免疫为主。
三、低温保存同种异体主动脉和肺动脉移植物的病理改变为内膜进行性增厚、中层平滑肌细胞变性坏死、外膜大量淋巴细胞浸润,导致同种管道钙化和阻塞。
四、低温保存同种异体主动脉和肺动脉移植后在免疫反应方面无显著差异,其移植后的钙化与免疫排斥反应有关。
五、环孢霉素A对同种异体移植后的免疫排斥反应和钙化有明显的抑制作用。
Objective
To investigate the influence of aortic and pulmonary homografts on host and the effect of immunological rejection on the homografts.Rat model of cryopreserved aortic and pulmonary valved homograft heterotopic transplantation was established to investigate the effect of cryopreservationg on the antigenticity of the aortic and pulmonary homografts,,observe the changes of humoral and cellular immunological responses and pathological changes of implanted homografts.to study the effect of immunosuppressive treatment on the aortic and pulmonary homograft transplantation.
Methods
In this study,Liquid nitrogen cryopreservation method was adopted in the long-term storage of the aortic and pulmonary homografts.Transmitting electron microscope was used to observe the effect of cryopreservation on endothelial structure and tissular structure.The animal models of aortic and pulmonary homograft transplantation were established by heterotopic insertion of aortic and pulmonary homografts of SD rats into abdominal aortae of Wistar rats.CsAwas employed in the treatment of immunological rejection in the immuusuppressive treatment group of aortic homograft transplantation.Respectively at 1th,2th,3th 4th,and 5thweeks after implantation,the blood samples of the transplanted animals were collected and the homografts retrieved.The area of intima and media of the implanted grafts was measured and a relative area ratio of intima to media (I/M area ratio) was calculated to estimate the degree of the intimal thickening. In addition,the munbers of nucleated cells in the media and adventitia were counted,and estimated as cell number per 0.1 mm~2.Immunohistochemical staining was performed to detect the MHCⅡdeposition of the aortic and pulmonary homografts and the percentage of CD4 +,CD8 + lymphocytes and the ratio of CD4 +/CD8 + in blood samples of the implanted rats.The biological activities of IL-2 and TNF-a in blood samples of the implanted rats were measured by means of ELISA.
Results
Cryopreservation may maintain viabilities and normal intercellular connections of endothelial cells of the aortic and pulmonary homografts.The pathological changes of the explanted homografts presented damages of the endothelialcells, infiltration of inflammatory cells in media and advenfitia,intimal thickening of the homografts,etc.Intimal thickening progressively increased,the numbers of inflammatory cells infiltrated in the homografts maintain high leveh during the 5weeks after implantation.The MHCⅡdeposition were found respectively about 1 to 4 weeks after the implantation of aortic and pulmonary homografts. Thepercentage of CD4 + and CD8 + T lymphocytes,the ratio of CD4 + to CD8 +(CD4 +/CD8 +),and the biological activities of IL-2 and TNF-a in the blood samples of transphnted rats were remarkably increased after homografts implantation,and maintain high -activity levels during the 5 weeks after implantation. There was significant difference in the results between implantation group and control group(p＜0.05).the treatment of CsA had remarkably suppressive effect on deposition of MHCⅡ,infiltration of inflammatory cells,increase of intimal thickening,increase of the percentage of CD4 +,and the increase of biological activities of IL-2 and TNF-a in blood samples after homografts implantation. There was no obvious difference of infiltration of inflammatory cells,the increase of intimal thickening,and the increase of the percentage of CD4 + T lymphocytes, and the increase of biological activities of IL-2 and TNF-a in-blood samples between the aortic and pulmonary homografts imphatation groups.
Conclusion
1.Liquid nitrogen cryopreservation method may maintain the viability and normal structure of aortic and pulmonary homografts.
2.There was obvious immunological rejection after implantation of aortic and pulmonary homografts,cellular and humoral immunological responses were involved in the process if immunological rejection.Cellular immune played a major role in chronic immunological rejection.
3.the pathological changes of cryopreserved aortic and pulmonary homografts were progressive intimal-thickening,necrosis of smooth muscle cells in the media,and infiltrationg of inflammatory cells in the adventitia,which resulted in calcification and obstruction of aortic and pulmonary homografts.
4.There was no difference in immunological rejection between aortic and pulmonary homografts after implantation.Immunological rejection is an important reason for the calcification of aortic and pulmonary homografts after implantation, while the degree of calcification has close relationship with calcium content in the homografts.
5.The treatment of CsA has marked suppressive effect on immunological rejection and calcification.
引文
1 Fontan T,Choussant A.Aortic valve homograft in the surgical tueatment of comopex cardiac malformations J Thorac Cardiovasc Stag 1984;87:649-657
2 Albrtt JD,Bishop BA.Conduit reconstruction of the right ventricular outflow trafct.Z Thorac 3Cardiovasc Surg 1993;106 228-236
3.Kouchouks NT,Wareing TH.Sixteen -year expodrence With Aortic Root Replacement.Ann Surg 1991;214:308-318
4.Yacoub M,Rassmi NRH.Fourteen -year experience With Homovital homlgramg for aortic valve replacemet.J Thorac Cardiovasc sure 1995;110:186-194
5.Kirklin JW.Blackstone EH.Intermediate term fate of cryopreserved allograft and xenograft vale conduit.Ann Thorac surg 1987;44:598-606
6.Clrk DR.Extended aortic rootreplacement with cryopreserved homograft.Ann thorac surg 1991;52:669-675
7.Clark DR,Camopbell DN.Degeneration of aortic valve allografts in young recipients.J thorac cardiovasc stag 1993;105:934-942
8.Gallo R,Kumar N.Accelerated degeneration of aortic homograft in an infant.J thorac cardiovasc lurg 1994;107:1161-1162
9.Eguchi S,Asano K.homograft of pulmonary or ascending aorta with valves as a right ventricular outflow.J thorac cardiovasc surg 1968;56:413-420
10.Livi U.Abdulla AK.Viability and morphology of aortic and pulmonaty homograft.J thorac cardiovasc surg 1987;93:755-760
11.Kobando,,Gordon K.outcome of poulmonaty and aortic homografts for right ventricular outflow tract reconstrution.J thorac cardiovasc stag 1995;109:509-5176
12.Gerosa G,Livi U.Aortic valve replacement with pulmonaty homograft.J thotac catdiovasc surg 1994;107:424-437
13.Kouchoukos NT,.Davila - Roman VG.Teplacement of the aortic root with a pulmonary autogtraft in children ang young adults with aortic valve disease N Engl J Med 1994;330;1
14.Elkins RC,Santangelo KL,Pulmonary autograft replacement in children:the iddal solntion? Ann surg 1992;216:363-371
15.Kakoba K,Amiger L,Influence of time from donor death to graft havest on conduit function of cryopreserved aortic allografts lambs circrlation 1991;84(suppl Ⅲ):100-111
16.Yacoub M,Kittle CF.Sterilization of valve homograft by antibiotic solrtions.Circulation 1970;41(suppl):11 29-31
17.Bolooki H,Rubinson RM.A simple method of aortic homoguaft valve sterilization and preservation.J thorac cardovasc surg 1972;63:249-257
18.Jonas RA,Ziemer G.Cryopreserved and fresh antibiotic - sterkilized valved aortic homoguaft conduits in a long- term shddpmodel J thorac cardiovasc surg 1988;96:746-755
19.Shumway NE About viability in valve graft Ann thorac surg 1989;47:795
20.Motomura N,Imakita M,Yutani C et al Chronic Rejection incryopreserved Aortic Allografts Transplatation procedigs;1995;27(3):2105-2106
21.Khatib HE Lupeneetti FM Antigenicity of fresh and cryopresserved Rat Valve Allografts Transplatation 1990;49:765-767
22.Kawanchi M,.Tanaka K Antigenicity of HEART valves and vessels:A Primate Heart Transplant Study.Transplantation Proceedings;1996;28(3):1824-1825
23.Plissonnier D,Nochy D Sequential Immunological targeting of Chronic ExpOeuinental Arterial Allograft.Tuansplantation.1995;60(5):414-424
24.Khatib HE,Thompson SA.Effect of storage at 4C in a nutrient medium on antigenic properties of rat aortic valve allografts.Ann thorac surg 1990;49:792-796
25.Hayry P,Isoniemi H.Clinical and Experimental Chronic Allograft Rejection.Transplantation Proceedings.1994;26(3):1702-1703
26.Lapinetti FM,Cobb S.Effect of immunological differences on rat aortic vahe allograft calcification.J Cardiac surg 1992;7:65070
27.Wee SL,Stroka DM.The effects of OKT4A monoclonal antibody on cellular immunity of nonhuman primane renal allograft recipients.Transplantation 1992;53:501-507
28.Bromborg JS,Chavin KD.Anti -CD2 monoclonal antibodies alter cell-mediated immunity in vivo Transplantation 1991;51:219
29.Hirahara H,Tsuchida M.Long -term survival of cardiac allografts in rats treated before and after surgery with monoclonal antibody to CD2.Transplantation 1995;59:85-90
30.Lin H,Chensue S.W.Antibodies against tumor necrosis factor prolong heart allograft survival in the rat.J heart Lung Transplantation 1999;11:330-337
31.Ru- Qi Wei,hua lin,Gwo -Hsiao chen,Inhibition,of Tumor Necrosis Factor Puoduction by Lymphocutes from Anti -TNF antibody treated,cardioc allografted tats J surg RES 1994;56:601-605
32.Koskinen PK,Karl B How cyclosporine modifies histological and molecular events in the vascular wall during chronic rejection of rat cardiac allograft.Am J Pathlogy.2000;;146:972980
33.Lemstrom KB,Bruing JH.Triple drug immuosuppression significantly reduces immune activation angd allograft arteriosclerosis in cytomegalovirs-infected rat aortic alloguafts and induces early latency of viral infection.Am Jpatyoiogy 2001;144:13
1 Fontan T,Choussant A.Aortic valve homograft in the surgical tueatment of comopex cardiac malformations J Thorac Cardiovasc Surg 1984;87:649-657
2 Albrtt JD,Bishop BA.Conduit reconstruction of the fight ventricular outflow trafct.Z Thorac 3Cardiovasc Surg 1993;106 228-236
3.Kouchouks NT,Wareing TH.Sixteen -year expodrence With Aortic Root Replacement.Ann Surg 1991;214:308-318
4.Yacoub M,Rassmi NRH.Fourteen -year experience With Homovital homlgramg for aortic valve replacemet.J Thorac Cardiovasc sure 1995;110:186-194
5.Kirklin JW.Blackstone EH.Intermediate term fate of cryopreserved allograft and xenograft vale conduit.Ann Thorac surg 1987;44:598-606
6.Clrk DR.Extended aortic rootreplacement with cryopreserved homograft.Ann thorac surg 1991;52:669-675
7.Clark DR,Camopbell DN.Degeneration of aortic valve allografts in young recipients.J thorac cardiovasc surg 1993;105:934-942
8.Gallo R,Kumar N.Accelerated degeneration of aortic homograft in an infant.J thorac cardiovasc lurg 1994;107:1161-1162
9.Eguchi S,Asano K.homograft of pulmonary or ascending aorta with valves as a fight ventricular outflow.J thorac cardiovasc surg 1968;56:413-420
10.Livi U.Abdulla AK.Viability and morphology of aortic and pulmonaty homograft.J thorac cardiovasc surg 1987;93:755-760
11.Kobando,,Gordon K.outcome of poulmonaty and aortic homografts for right ventricular outflow tract reconstrution.J thorac cardiovasc stag 1995;109:509-5176
12.Gerosa G,Livi U.Aortic valve replacement with pulmonaty homograft.J thotac catdiovasc surg 1994;107:424-437
13.Kouchoukos NT,.Davila - Roman VG.Teplacement of the aortic root with a pulmonary autogtraft in children ang young adults with aortic valve disease N Engl J Med 1994;330;1
14.Elkins RC,Santangelo KL,Pulmonary autograft replacement in children:the iddal solntion? Ann surg 1992;216:363-371
15.Kakoba K,Arniger L,Influence of time from donor death to graft havest on conduit function of cryopreserved aortic allografts lambs circrlation 1991;84(suppl Ⅲ):100-111
16.Yacoub M,Kittle CF.Sterilization of valve homograft by antibiotic solrtions.Circulation 1970;41(suppl):11 29-31
17.Bolooki H,Rubinson RM.A simple method of aortic homoguaft valve sterilization and preservation.J thorac cardovasc surg 1972;63:249-257
18.Jonas RA,Ziemer G.Cryopreserved and fresh antibiotic -sterkilized valved aortic homoguaft conduits in a long -term shddpmodel J thorac cardiovasc surg 1988;96:746-755
19.Shumway NE About viability in valve graft Ann thorac surg 1989;47:795
20.Motomura N,Imakita M,Yutani C et al Chronic Rejection ineryopreserved Aortic Allografts Transplatation procedigs;1995;27(3):2105-2106
21.Khatib HE Lupeneetti FM Antigenicity of fresh and cryopresserved Rat Valve Allografts Transplatation 1990;49:765-767
22.Kawauchi M,.Tanaka K Antigenieity of HEART valves and vessels:A Primate Heart Transplant Study.Transplantation Proceedings;1996;28(3):1824-1825
23.Plissonnier D,Noehy D Sequential Immunological targeting of Chronic ExpOeuinental Arterial Allograft.Tuansplantation.1995;60(5):414-424
24.Khatib HE,Thompson SA.Effect of storage at 4C in a nutrient medium on antigenic properties of rat aortic valve allografts.Ann thorac surg 1990;49:792-796
25.Hayry P,Isoniemi H.Clinical and Experimental Chronic Allograft Rejection.Transplantation Proceedings.1994;26(3):1702-1703
26.Lupinetti FM,Cobb S.Effect of immunological differences on rat aortic valae allograft calcification.J Cardiac surg 1992;7:65070
27.Wee SL,Stroka DM.The effects of OKT4A monoclonal antibody on cellular immunity of nonhuman primane renal allograft recipients.Transplantation 199253:501-507
28.Bromberg JS,Chavin KD.Anti-CD2 monoclonal antibodies alter cell-mediated immunity in vivo Transplantation 199151:219
29.Hirahara H,Tsuchida M.Long-term survival of cardiac allografts in mrs treated before and after surgery with monoclonal antibody to CD2.Transplantation 1995;59:85-90
30.Lin H,Chensue S.W.Antibodies against tumor necrosis factor prolong heart allograft survival in the rat.J heart Lung Transplantation 1999 11:330-337
31.Ru-Qi Wei,hua 1in,Gwo-Hsiao chert,Inhibition,of T-mor Necrosis Factor Puoduction by Lymphocutes from Anti-TNF antibody treated,cardioc allografted tats J surg RES 199456:601-605
32.Koskinen PK,Karl B How cyclosporine modifies histological and molecular events in the vascular wall during chronic rejection of rat cardiac allograft.Am J Pathlogy.2000 146:972980
33.Lemstrom KB,Bruing JH.Triple drug immuosuppression significantly reduces immune activation angd allograft arteriosclerosis in cytomegalovirs-infected rat aortic alloguafts and induces early latency of viral infection.Am Jpatyoiogy 2001 144:13
2 Albrtt JD,Bishop BA.Conduit reconstruction of the right ventricular outflow trafct.Z Thorac 3Cardiovasc Surg 1993;106 228-236
3.Kouchouks NT,Wareing TH.Sixteen -year expodrence With Aortic Root Replacement.Ann Surg 1991;214:308-318
4.Yacoub M,Rassmi NRH.Fourteen -year experience With Homovital homlgramg for aortic valve replacemet.J Thorac Cardiovasc sure 1995;110:186-194
5.Kirklin JW.Blackstone EH.Intermediate term fate of cryopreserved allograft and xenograft vale conduit.Ann Thorac surg 1987;44:598-606
6.Clrk DR.Extended aortic rootreplacement with cryopreserved homograft.Ann thorac surg 1991;52:669-675
7.Clark DR,Camopbell DN.Degeneration of aortic valve allografts in young recipients.J thorac cardiovasc stag 1993;105:934-942
8.Gallo R,Kumar N.Accelerated degeneration of aortic homograft in an infant.J thorac cardiovasc lurg 1994;107:1161-1162
9.Eguchi S,Asano K.homograft of pulmonary or ascending aorta with valves as a right ventricular outflow.J thorac cardiovasc surg 1968;56:413-420
10.Livi U.Abdulla AK.Viability and morphology of aortic and pulmonaty homograft.J thorac cardiovasc surg 1987;93:755-760
11.Kobando,,Gordon K.outcome of poulmonaty and aortic homografts for right ventricular outflow tract reconstrution.J thorac cardiovasc stag 1995;109:509-5176
12.Gerosa G,Livi U.Aortic valve replacement with pulmonaty homograft.J thotac catdiovasc surg 1994;107:424-437
13.Kouchoukos NT,.Davila - Roman VG.Teplacement of the aortic root with a pulmonary autogtraft in children ang young adults with aortic valve disease N Engl J Med 1994;330;1
14.Elkins RC,Santangelo KL,Pulmonary autograft replacement in children:the iddal solntion? Ann surg 1992;216:363-371
15.Kakoba K,Amiger L,Influence of time from donor death to graft havest on conduit function of cryopreserved aortic allografts lambs circrlation 1991;84(suppl Ⅲ):100-111
16.Yacoub M,Kittle CF.Sterilization of valve homograft by antibiotic solrtions.Circulation 1970;41(suppl):11 29-31
17.Bolooki H,Rubinson RM.A simple method of aortic homoguaft valve sterilization and preservation.J thorac cardovasc surg 1972;63:249-257
18.Jonas RA,Ziemer G.Cryopreserved and fresh antibiotic - sterkilized valved aortic homoguaft conduits in a long- term shddpmodel J thorac cardiovasc surg 1988;96:746-755
19.Shumway NE About viability in valve graft Ann thorac surg 1989;47:795
20.Motomura N,Imakita M,Yutani C et al Chronic Rejection incryopreserved Aortic Allografts Transplatation procedigs;1995;27(3):2105-2106
21.Khatib HE Lupeneetti FM Antigenicity of fresh and cryopresserved Rat Valve Allografts Transplatation 1990;49:765-767
22.Kawanchi M,.Tanaka K Antigenicity of HEART valves and vessels:A Primate Heart Transplant Study.Transplantation Proceedings;1996;28(3):1824-1825
23.Plissonnier D,Nochy D Sequential Immunological targeting of Chronic ExpOeuinental Arterial Allograft.Tuansplantation.1995;60(5):414-424
24.Khatib HE,Thompson SA.Effect of storage at 4C in a nutrient medium on antigenic properties of rat aortic valve allografts.Ann thorac surg 1990;49:792-796
25.Hayry P,Isoniemi H.Clinical and Experimental Chronic Allograft Rejection.Transplantation Proceedings.1994;26(3):1702-1703
26.Lapinetti FM,Cobb S.Effect of immunological differences on rat aortic vahe allograft calcification.J Cardiac surg 1992;7:65070
27.Wee SL,Stroka DM.The effects of OKT4A monoclonal antibody on cellular immunity of nonhuman primane renal allograft recipients.Transplantation 1992;53:501-507
28.Bromborg JS,Chavin KD.Anti -CD2 monoclonal antibodies alter cell-mediated immunity in vivo Transplantation 1991;51:219
29.Hirahara H,Tsuchida M.Long -term survival of cardiac allografts in rats treated before and after surgery with monoclonal antibody to CD2.Transplantation 1995;59:85-90
30.Lin H,Chensue S.W.Antibodies against tumor necrosis factor prolong heart allograft survival in the rat.J heart Lung Transplantation 1999;11:330-337
31.Ru- Qi Wei,hua lin,Gwo -Hsiao chen,Inhibition,of Tumor Necrosis Factor Puoduction by Lymphocutes from Anti -TNF antibody treated,cardioc allografted tats J surg RES 1994;56:601-605
32.Koskinen PK,Karl B How cyclosporine modifies histological and molecular events in the vascular wall during chronic rejection of rat cardiac allograft.Am J Pathlogy.2000;;146:972980
33.Lemstrom KB,Bruing JH.Triple drug immuosuppression significantly reduces immune activation angd allograft arteriosclerosis in cytomegalovirs-infected rat aortic alloguafts and induces early latency of viral infection.Am Jpatyoiogy 2001;144:13
1 Fontan T,Choussant A.Aortic valve homograft in the surgical tueatment of comopex cardiac malformations J Thorac Cardiovasc Surg 1984;87:649-657
2 Albrtt JD,Bishop BA.Conduit reconstruction of the fight ventricular outflow trafct.Z Thorac 3Cardiovasc Surg 1993;106 228-236
3.Kouchouks NT,Wareing TH.Sixteen -year expodrence With Aortic Root Replacement.Ann Surg 1991;214:308-318
4.Yacoub M,Rassmi NRH.Fourteen -year experience With Homovital homlgramg for aortic valve replacemet.J Thorac Cardiovasc sure 1995;110:186-194
5.Kirklin JW.Blackstone EH.Intermediate term fate of cryopreserved allograft and xenograft vale conduit.Ann Thorac surg 1987;44:598-606
6.Clrk DR.Extended aortic rootreplacement with cryopreserved homograft.Ann thorac surg 1991;52:669-675
7.Clark DR,Camopbell DN.Degeneration of aortic valve allografts in young recipients.J thorac cardiovasc surg 1993;105:934-942
8.Gallo R,Kumar N.Accelerated degeneration of aortic homograft in an infant.J thorac cardiovasc lurg 1994;107:1161-1162
9.Eguchi S,Asano K.homograft of pulmonary or ascending aorta with valves as a fight ventricular outflow.J thorac cardiovasc surg 1968;56:413-420
10.Livi U.Abdulla AK.Viability and morphology of aortic and pulmonaty homograft.J thorac cardiovasc surg 1987;93:755-760
11.Kobando,,Gordon K.outcome of poulmonaty and aortic homografts for right ventricular outflow tract reconstrution.J thorac cardiovasc stag 1995;109:509-5176
12.Gerosa G,Livi U.Aortic valve replacement with pulmonaty homograft.J thotac catdiovasc surg 1994;107:424-437
13.Kouchoukos NT,.Davila - Roman VG.Teplacement of the aortic root with a pulmonary autogtraft in children ang young adults with aortic valve disease N Engl J Med 1994;330;1
14.Elkins RC,Santangelo KL,Pulmonary autograft replacement in children:the iddal solntion? Ann surg 1992;216:363-371
15.Kakoba K,Arniger L,Influence of time from donor death to graft havest on conduit function of cryopreserved aortic allografts lambs circrlation 1991;84(suppl Ⅲ):100-111
16.Yacoub M,Kittle CF.Sterilization of valve homograft by antibiotic solrtions.Circulation 1970;41(suppl):11 29-31
17.Bolooki H,Rubinson RM.A simple method of aortic homoguaft valve sterilization and preservation.J thorac cardovasc surg 1972;63:249-257
18.Jonas RA,Ziemer G.Cryopreserved and fresh antibiotic -sterkilized valved aortic homoguaft conduits in a long -term shddpmodel J thorac cardiovasc surg 1988;96:746-755
19.Shumway NE About viability in valve graft Ann thorac surg 1989;47:795
20.Motomura N,Imakita M,Yutani C et al Chronic Rejection ineryopreserved Aortic Allografts Transplatation procedigs;1995;27(3):2105-2106
21.Khatib HE Lupeneetti FM Antigenicity of fresh and cryopresserved Rat Valve Allografts Transplatation 1990;49:765-767
22.Kawauchi M,.Tanaka K Antigenieity of HEART valves and vessels:A Primate Heart Transplant Study.Transplantation Proceedings;1996;28(3):1824-1825
23.Plissonnier D,Noehy D Sequential Immunological targeting of Chronic ExpOeuinental Arterial Allograft.Tuansplantation.1995;60(5):414-424
24.Khatib HE,Thompson SA.Effect of storage at 4C in a nutrient medium on antigenic properties of rat aortic valve allografts.Ann thorac surg 1990;49:792-796
25.Hayry P,Isoniemi H.Clinical and Experimental Chronic Allograft Rejection.Transplantation Proceedings.1994;26(3):1702-1703
26.Lupinetti FM,Cobb S.Effect of immunological differences on rat aortic valae allograft calcification.J Cardiac surg 1992;7:65070
27.Wee SL,Stroka DM.The effects of OKT4A monoclonal antibody on cellular immunity of nonhuman primane renal allograft recipients.Transplantation 199253:501-507
28.Bromberg JS,Chavin KD.Anti-CD2 monoclonal antibodies alter cell-mediated immunity in vivo Transplantation 199151:219
29.Hirahara H,Tsuchida M.Long-term survival of cardiac allografts in mrs treated before and after surgery with monoclonal antibody to CD2.Transplantation 1995;59:85-90
30.Lin H,Chensue S.W.Antibodies against tumor necrosis factor prolong heart allograft survival in the rat.J heart Lung Transplantation 1999 11:330-337
31.Ru-Qi Wei,hua 1in,Gwo-Hsiao chert,Inhibition,of T-mor Necrosis Factor Puoduction by Lymphocutes from Anti-TNF antibody treated,cardioc allografted tats J surg RES 199456:601-605
32.Koskinen PK,Karl B How cyclosporine modifies histological and molecular events in the vascular wall during chronic rejection of rat cardiac allograft.Am J Pathlogy.2000 146:972980
33.Lemstrom KB,Bruing JH.Triple drug immuosuppression significantly reduces immune activation angd allograft arteriosclerosis in cytomegalovirs-infected rat aortic alloguafts and induces early latency of viral infection.Am Jpatyoiogy 2001 144:13