Objective To test the hypothesis that marrow stromal cells （MSCs）, when implanted into selfmyocardium in rabbits, can undergo milieu-dependent differentiation and express cardiomyogenic phenotypes and enhance cardiac function of ischemic hearts, through establish a clinically relevant model for autologous MSCs transplantation, Methods Thirteen New Zealand White rabbits were randomly divided into experimental group （n= 7） and control group （n= 6）. In experimental group, autotogous MSCs（3× 106 cells/30μl） labeled with Bromodeoxyuridine （BrdU） were respectively injected into superior, central and inferior sites in the periphery of the myocardial infarct region. Phosphate buffer saline （PBS） was injected into the scar of the control group hearts according to the same procedure used in the experimental group. Four weeks later, the transplanted labeled MSCs were detected by laser scanning confocal microscopy and the cardiac function were examined by echocardiogram and muhichannel physiologic recorder. Results After 4 weeks, transplanted MSCs were demonstrated myogenic differentiation with the expression of α-sarcomeric actin and connexin 43 located in intercalated disk. MSCs increased the number of vessels compared with controls in myocardial ischemia area. MSCs implantation resulted in markedly improved left ventricular contractility[left ventricular ejection fraction （LVEF）： 0. 51 ± 0.07 vs. 0. 43 ± 0.06 ,left ventricular lateral wall motion distance （LVLWMD） ：1. 75±0. 42mm vs. 1.09±0. 28mm, left ventricular systolic wall thickening ratio（LVAT） ：0. 19%±0.05% vs. 0. 11%±0.04%, left ventricular systolic pressure （LVSP）： 113. 1± 6.3mmHg vs. 99, 5 ± 5, lmmHg, left ventricular end diastolic pressure （LVEDP）： 11. 5±2. lmmHg vs, 14, 3 ±3. lmmHg, maximum rate of left ventricular pressure rise （＋dp/dtmax）：4 618. 3±365. 2 mmHg/s vs. 3 268. 1± 436.9 mmHg/s, maximum rate of left ventricular pressure fall （-dp/dtmax） ：3 008.8±346.7 mmHg/s vs. 2 536.9± 380.4 mmHg/s, P〈0.05]. Conclusion Transplanted autologous MSCs are able to undergo differentiation to form myocardial cells and improve the cardiac function of ischemia myocardium effectively. Autologous MSCs transplantation may have significant clinical potential in treatment myocardial ischemia.
Objective To study the feasibility of transplanting human saphanous vein endothelial cells to luminal surface of blood vessel prosthesis and to play a theoretical foundation for the clinical application of autologous endothelial cell transplantation. Methods Human saphanous vein endothelial cells were harvested with 0.1% collagenase and cultivated in vitro for 13.08±1.24 days. The cultures were confirmed as endothelial cells with the fourescent linked anti-Ⅷ antigen antibodies. The content of both 6-keto-PGF1α and Von Willebrand factor (vWF) in the supernatant were detected with ELISA and radioimmunoassay. The multiplied cells were lined in vitro onto the luminal surface of expanded polytetraflouroethylene (ePTFE) grafts precoated with fibrin glue and fibronectin, then cultivated again for 9 days. Results 11.46±2.69×１０６ of available endothelial cells could be regularly obtained, the number of endothelial cells increased 147.93±88.68 times when culture were terminated. All the cells diploid cells with a purity of 99%. The content of both 6-keto-PGF1α and vWF in the media showed no significant difference between the primary and subculture passages. The luminal surface of grafts was covered completely by a spindlelike endothelial monolayer and an even fibrin glue matrix could be seen underneath. Conclusion Endothelial cells derived from human saphanous veins might be feasible to be transplanted onto the luminal surface of ePTFE and present a potential clinical application.
OBJECTIVE To explore the healing mechanism of full-thickness wound treating by the intermingled skin transplantation of large sheet allograft with autograft through studying the expression of laminin (LN). METHODS Thirty-six SD rats with 10% to 15% of total body surface area (TBSA) full-thickness were made. After 3 days, the devitalized tissue were excised and transplanted a large sheet of allograft from Wistar rats and islets of autografts were implanted 3 days later. On day 3, 5, 7, 14, 21 after allografting, the expression of LN in the grafts were detected by immunohistochemistry. RESULTS On the 7th day postallografting, LN, which played positive action of epidermal cell adhesion, still retained in the allodermis after the rejection of alloepidermis occurred. On the 14th day postallografting, there appeared scattered LN underneath the epidermal cells migrating from islets of autografts. On the 21st day postallografting, LN in the basement membrane of skin grafts had completely formed. CONCLUSION The intermingled transplantation of large sheet allograft with autograft may provide components of basement membrane for wound healing, which may help to improve the appearance and function of skin.
OBJECTIVE To investigate the mechanism of xenotransplantation rejection and the interaction between the immunocytes. METHODS: This review concluded the research achievements and new advances in xenotransplantation based on the relevant experimental data. RESULTS: Transgenic pig technology and novel immunosuppressants were applied to suppress hyperacute rejection and acute vascular rejection respectively. Modulation of T cell and antigen presenting cells and induction of tolerance were taken for the prevention of acute cellular rejection. CONCLUSION: In general, the technology of transgenic pig is relatively mature and effective. The mechanism and prevention of acute vascular rejection and acute cellular rejection should be further investigated.
Tissue engineering trachea is an artificial trachea with biological activity, which is constructed in vitro by using tissue engineered principle and technology, and is a tracheal prosthesis for replacing large circumferential defect of the trachea. The course of its construction is as follows. First, seeding cells are cultured and expanded in vitro. Then they are collected, counted and seeded onto the biomaterial scaffold of tissue consistent and biodegradation. Finally, the biomaterial-cells construction is implanted into bio-reaction device or one’s subcutaneous layer. The tissue engineering trachea could be constructed after cultured certain times. Compared with other artificial trachea, the tissue engineering trachea has more advantages, such as nonimmunogenicity, no side-effects related to foreign graft materials, and biologic activity. This will bring some hope to look for an appropriate graft material. However, the study about it is still faced with some difficult problems, such as vascularized trachea, culturing in vitro, and prevention of infection in trachea prosthesia. So there will be long time for tissue engineering trachea to apply clinical tracheal transplantation successfully. This assay has reviewed the study about tissue engineering trachea from three sides——the source of seeding cells, the research about biomaterial scaffold, and the construction of tissue engineering trachea.
Objective To observe the effect of autologous peripheral blood stem cells(PBSC) transplantation in the treatment of ischemic lower extremity disorders. Methods Therapeutic group:fortyfive patients received recombinant human granulocyte colony-stimulating factor 450 to 600 U/d by hypodermic injection for 5 days to mobilize stem cells.On the 6th day,PBSC were collected by COBE 6.1 Spectra Version and were injected into ischemic lower extremity. Control group:33 patients were treated with dilating vessels drugs. After operation some indexes were evaluated. Results After operation, these indexes were improved. Skin temperature and TcpO2 were improved obviously, being statistically significant difference(P＜0.05). Conclusion Autologous PBSC transplantation might be a safe and effective method for treating lower extremity ischemic disorder. It could improve the quality of life of many patients as amputation of lower extremity of foot might be avoided or reduced.
Objective To establish a rat model of pancreas-duodenal transplantation for pancreas transplantation research. Methods A rat model of pancreas-duodenal transplantation was established by using dual cuff technique. The graft affiliated portal vein and abdominal aorta were anastomosed to recipient’s left renal vein and left renal artery by using dual cuff technique without clamping the systemic circulation in order to minimize hemodynamic instability. Simultaneously the graft duodenum was anastomosed to the host jejunum in an end-to-side fashion to reestablish drainage of pancreatic secretion. Fluid replacement, warm keeping and anticoagulation were maintained during perioperative period. Results The average donor operation time was (68.4±7.2) min and recipient operation time was (26.1±3.3) min. Moreover, it took (5.0±1.1) min for cuff preparation in vitro and (9.6±3.5) min for vessel reconstruction in vivo, respectively. Intestinal anastomosis took (7.2±2.3) min. The operation successful rate was about 91.7%. Conclusion This pancreas-duodenal transplantation model avoids systemic circulation clamping. It is simple and stable, with the value in pancreas transplantation research.
Objective To investigate the effect of the neuromuscular pedicle transplantation in prevention against atrophy in the denervated muscle. Methods Fortyeight SD rats were used to establish the right side tibialis anterior muscle denervation model. The long peroneal muscle neuromuscular pedicle was made as a treatment in 12 rats (Group A); the nerve shaft embedding was used in 12 rats (Group B); no treatment was used in 12 rats(Group C); the remaining 12 rats were used as normal controls (Group D). The gait analysis, electromyogram，muscle wet weight, and muscle fiber crosssectional area were used to determine and compare the effect of the operation at 6 and 12 weeks postoperatively. ResultsAt 6 weeks postoperatively, the parameters tested in Group A about the gait analysis (peroneal function index, PFI, －47.20±12.30), electromyogram, muscle wet weight (0.384 0±0.024 6 g)and muscle fiber cross-sectional area (1 040.98±120.54 μm2) were significantly better than those in Group C (PFI, -114.40±14.84; muscle wet weight, 0.173 0±0.019 1 g; muscle fiber cross-sectional area, 585.08±182.93 μm2,Plt;0.05), and the final two parameters were significantly better than those in Group B (0.294 0±0.056 4 g,763.92±82.68 μm2,Plt;0.05). At 12 weeks postoperatively, the musclefiber crosssectional area in Group A(1 360.10±261.45 μm2) had no significant difference from that in Group D (1 544.57±266.92 μm2，Pgt;0.05)，and most of the parameters tested in Group A were better than those in Groups B and C. Conclusion Neuromuscular pedicle transplantation has an excellent effect in prevention against atrophy in the denervated muscle, and the effect of neuromuscular pedicle transplantation is better than that of the nerve shaft embedding.
OBJECTIVE:To investigate the index of the rejection of lJle retinal pigment epithelium(RPE)cells transplantation.
METHOD:Allogenic RPE transplantation on rahbits by transcleral technique, the changes of interleukin-2 (IL-2) activity in peripheral blood and the effect of
immunoinhibitor (methylprednisonlone)were detected.
RESLILTS:In the group of simple transplantation,the IL-2 activity in peripheral blood begin to rise in the first day after operation. The peak value occured in the third day,and is still much higher than that of the control group in the 14th day,whereas in the group treated with immunoinhibitor ,there was no obvious difference in the first day after operatlon,in the third day,the IL-2 activity rises slightly,and returned to normal level in the 7th day.
CONCLUSION: After RPE transplantation, the level of IL-2 activity in peripheral blood might serve as an important index to determining and detecting the rejective response.
（Chin J Ocul Fundus Dis,1996,12: 239-241）
Objective To assess the variation and its significance of messenger ribonucleic acid(mRNA) expression of endothelial nitric oxide synthase (eNOS) in allografts of common carotid transplantation model in white rabbits. Methods To establish an animal model of common carotid transplantation in vivo, 30 rabbits were divided into four groups with random number table. Group A (n=3): autografts; group B (n=9): allografts with the least treated; group C (n=9): allografts treated by penicillin/streptomycin and preserved under room temperature; group D (n=9): allografts treated by penicillin/streptomycin and cryopreserved in liquid nitrogen. All the transplanted grafts were harvested 1-3 weeks later, then compared and evaluated the histomorphological variation and eNOS mRNA expression. Results The vascular structures of autografts in group A were kept approximately normal, only a few infiltration of inflammatory cells could be found. The structural variations of allografts in other trial groups behaved similarly as, intima proliferation in the 1st week, intima hyperplasia in the 2nd week, and both intima and media hypertrophy in the 3rd week. And also there seemed that luminal thrombosis could be found in all the allografts. Allografts in group B were destructed utmost the worst in all the groups. The expression of eNOS mRNA in allografts of group B was significantly less than that in other groups (Plt;0.05). Conclusion The down-regulation of eNOS mRNA expression might lead to intima hyperplasia and thrombosis of allografts.
