Establishment of a cryopreserved tissue bank for the clinical use of a llograft tissues

1.(1)实验性冷冻气管移植：为了明确冷冻气管是否可以降低同种异体免疫反应，我们在无免疫抑制的犬和大鼠移植模型中评估了冷冻气管同种异体移植后的气管活力和组织学变化。我们的实验结果表明，冷冻保存的移植物具有良好的长期生存能力。移植后保留上皮、平滑肌和软骨，无免疫抑制。在实验模型中，低温保存降低了气管的同种异体反应。(2)低温保存对大鼠同种主动脉移植物中成纤维细胞生长因子（FGF）基因表达的影响：为了阐明同种主动脉移植物是否能在受体体内产生FGF，我们将同种主动脉移植物异位植入同种异体受体大鼠体内。采用逆转录聚合酶链反应大鼠a- fgf互补DNA探针检测a- fgf mRNR的表达。新鲜和低温保存的移植物在移植后4周均有显著的a-FGF mRNA表达。a- fgf基因表达的保存提示其具有刺激局部创面愈合的能力。为使异体移植组织的临床系统应用，我们在日本初步建立了异体移植瓣膜的冷冻保存网络和储备系统。由于这个网络系统，同种异体移植瓣膜可以从更年轻的供体中获得，并且在更短的热缺血时间内获得。我们制作的网络可以提供高质量的同种异体移植瓣膜。为了在全国范围内实现组织共享，建立了统一的胸腔和心血管组织冷冻保存数据库。

1.Experimental study cryopreserved tissue transplantation(1)Experimental cryopreserved tracheal transplantation : To clarify whether cryopreserved trachea may reduce allogenic immunoresponse, we evaluated tracheal viability and histlogical changes of cryopreserved tracheal homografts in canine and rat transplantation model without immunosuppression. Our esxperimental results showed excellent long-term viability of cryopreserved grafts. The epithelium, smooth muscle and cartilage were retained after transplantation without immunosuppression. Cryopreservation reduced the allogenic response of the tracheal in experimental models.(2)Effect of cryopresarvation on fibroblast growth factor (FGF) gene expression in cryopreserved rat aortic homografts : To elarify whether cryopreserved aortic homograft may produce FGF in recipients, cryopreserved rat aortic homegrafts were implanted heterotopically into allogenic recipient rats. Reverse transcriptase-polymerase chain reaction with a rat a-FGF complementary DNA probe was used to assess the expression of a-FGF mRNR.Both fresh and cryporeserved grafts exhibited significant expression of a-FGF mRNA 4 weeks after transplantation. Preservation of gene expression for a-FGF suggests a capability for stimulation of topical wound healing.2.Trial to organize a cryopreserved allograft bankFor the systematical clinical use of the cryopreserved allograft tissues, we made an initial trial to organize a network and banking system of cryopreserved allograft valve in Japan. Allograft valves could be procured from younger donors and in shorter warm ischemic period due to this network system. The network we made could provide allograft valves of excellent qualty. The uniform data base of the cryopreserved thoracic and cardiovascular tissues was made for the aim of country-wide tissue sharing.