OBJECTIVE: To investigate the expression and distribution of xenoantigen in intervertebral disk of Chinese banna minipig inbred line, and to study the availability of xenograft transplantation of intervertebral disk. METHODS: Samples of intervertebral disk were collected from six Banna pigs of 8 to 11-month-old. The fixation, embedment and slice were performed. α-Gal specific binding lection (BSI-B4) were used as affinity reagents and affinity-immunohistochemistry assays (SABC methods and DAB stain) were conducted to detect the expression and distribution of xenoantigen (α-Gal). RESULTS: alpha-Gal was found in chondrocyte cell and chondrocyte-like cell in intervertebral disk which have the positive yellow-stained particulate aggradation. There was no stain in the matrix, elastic fiber and collagen fiber. CONCLUSIONS: The distribution of xenoantigen is locally in the tissue of intervertebral disk and its expression is weak. This suggests that the intervertebral disk of Banna pig may be alternative donor for xenotransplantation.
Objective To evaluate the immunological reaction and the outcome of allogeneic chondrocyte transplantation in repairing articular cartilage defects in porcins. Methods Full articular cartilage from the knee of two Shanghai white porcins about one-month-old was removed and cut mechanically, digested by 0.25% trypsin and 0.2% type Ⅱ collagenase and cultured in 10％ DMEM medium. Defects of 0.5 cm×0.5 cm involving the subchodral bone were created in both the left and right femur condyloid in 8 two-month-old Yunnai bama porcins. Allogeneic chondrocyte transplantation were implanted in defects at a density of (1.0-2.0)×106,0.2 ml. The lymphocytes from the receivers’ blood were collected before transplantation and after 3, 5, 7 and 12 weeks of transplantation, then mixed with allogeneic chondrocytes to determin the lymphocyte stimulation index(SI) in vitro. The histological observation in vivo was made after 5, 7 and 24 weeks of transplantation. Results Lymphocyte SI at 3, 5, 7 and 12 weeks(1.457±0.062,1.739±0.142,1.548±0.047，1.216±0.028) after transplantation was higher than that before transplantation(1.102±0.034，Plt;0.05). SI began to increase in the 3rd week and reached the peak value in the 5th week, then gradually declined at the 7th and 12th weeks, showing significant differences when compared with in the 5th week (Plt;0.05). Inflammation and lymphocytes infiltration could be seen in subchondral bone and the intergration area between repair tissue and normal cartilage in the 5th week, and then decreased and limited in subchondral bone in the 7th week. Defects were filled with cartilage tissue, which had good intergration with subchondral bone at 24 weeks after transplantation. Conclusion Immunological reactions can be found at early stage of allogeneic chondrocyte transplantation and then decreased with the time, the fullthickness articular cartilage defects could be repaired mainlywith hyaline cartilage by the allogeneic chondrocyte transplantation. This may provide a new method to repair articular cartilage defects clinically.
Objective To construct recombinant lentiviral expression vectors of porcine transforming growth factor β1 (TGF-β1) gene and transfect bone marrow mesenchymal stem cells (BMSCs) so as to provide TGF-β1 gene-modified BMSCs for bone and cartilage tissue engineering. Methods The TGF-β1 cDNA was extracted and packed into lentiviral vector, and positive clones were identified by PCR and gene sequencing, then the virus titer was determined. BMSCs were isolated frombone marrow of the 2-month-old Bama miniature pigs (weighing 15 kg), and the 2nd and 3rd generations of BMSCs wereharvested for experiments. BMSCs were then transfected by TGF-β1 recombinant lentiviral vectors (TGF-β1 vector group)respectively at multi pl icity of infection (MOI) of 10, 50, 70, 100, and 150; then the effects of transfection were detected bylaser confocal microscope and Western blot was used to determine the optimal value of MOI. BMSCs transfected by empty vector (empty vector group) and non-transfected BMSCs (non-transfection group) were used as control group. RT-PCR, immunocytochemistry, and ELISA were performed to detect the expressions of TGF-β1 mRNA, TGF-β1 protein, and collagen type II. Results Successful construction of recombinant lentiviral vectors of porcine TGF-β1 gene was identified by PCR and gene sequencing, and BMSCs were successfully transfected by TGF-β1 recombinant lentiviral vectors. Green fluorescence was observed by laser confocal microscope. Western blot showed the optimal value of MOI was 70. The expression of TGF-β1 mRNA was significantly higher in TGF-β1 vector group than in empty vector group and non-transfection group (P lt; 0.05). Immunocytochemistry results revealed positive expression of TGF-β1 protein and collagen type II in BMSCs of TGF-β1 vector group, but negative expression in empty vector group and non-transfection group. At 21 days after transfection, high expression of TGF-β1 protein still could be detected by ELISA in TGF-β1 vector group. Conclusion TGF-β1 gene can be successfully transfected into BMSCs via lentiviral vectors, and long-term stable expression of TGF-β1 protein can be observed, prompting BMSCs differentiation into chondrocytes.
目的:探讨双猪尾型输尿管内支架(Double pigtail stent,DPS)作为泌尿外科上尿路疾病手术辅助治疗的适应症、并发症及并发症的治疗。方法:总结我院2004年6月至2008年12月共122例施行输尿管内支架放置术患者的适应症、并发症及并发症的治疗结果。结果:24例患者(19.6%)在置管期间出现1个或以上并发症。主要并发症包括肉眼血尿(9例)、疼痛(16例)、膀胱刺激征(12例)、高热(1例)。大部分并发症是轻微和可以耐受的,并迅速得到了适当的处理。2例须拔除内支架,其中剧烈疼痛1例、高热1例。结论:DPS用于上尿路疾病手术辅助治疗是安全和有效的,DPS引起的并发症大部分易于处理。
Limitation of donor source for allograft makes the research on xenograft progress. Pig is regarded as one of the ideal donor animals. The major obstacle in xenograft is hyperacute rejection, which is caused by complements after they are activated by xenogeneic antigens combined with natural antibodies. It has been confirmed that alpha-Gal is the major target antigen, whose expression is incharged by alpha-1,3 galactosyltransferase (alpha-GT). The approaches to overcome hyperacute rejection against alpha-Gal included: immunoadsorption of xenogeneic natural antibodies, lysis of antigen by enzyme and genetic manupilation to obtain animal lack of alpha-GT. Besides alpha-Gal, there were other antigens binding to human serum antibody, such as gp65 and gp100, which was expressed on PAEC after induced by TNF, the A-like antigen. But their function was still unknown. It was debatable on the role of MHC in xenograft. Both direct and indirect pathway were involved in cellular response in xenograft.
OBJECTIVE: To explore the kidney anatomic structure of banna minipig inbred-lines, and to provide data for kidney xenotransplantation. METHODS: The fresh and infused kidneys of banna minipig (including the vessel and the ureter) were checked by anatomic microscope and vernier caliper in original location and away body. The tissue structure was observed by HE stain. RESULTS: The structure of kidney of banna minipig inbred-lines (including the vessel and the ureter) are similar to that of human being. The fascia propria of kidney is divided into three layers including capsula fibrosa, capsula adipose and fascia renalis. The thickness of cortex renalis is (20.0 +/- 2.4) mm. The average diameter of renal artery is 5.1 mm and is similar to that of human being. All the kidneys of banna minipig inbred-lines have a single branch renal artery. The diameters of left and right ureters are 5.1 mm and 4.7 mm, respectively. CONCLUSION: The kidney of banna minipig inbred-lines is an ideal replacement of human kidney for xenotransplantation.
Objective To study degradation of the antigen-extracted meniscus in PBS solution with no enzyme or with different enzymes. Methods Four types of enzymes (collagenase, hyaluronidase, trypsin, papain) were used to enzymolyze the antigen-extracted meniscus and the fresh meniscus for 3, 7, 15 and 30 days (37℃). The antigenextracted meniscus and the fresh meniscus were immersed in PBS solution (37℃) for 30 days. Weight loss measurement, UV spectrophotometry, and scanning electron microscopy (SEM) were used to characterize the degraded materials. Results The two types of the materials were remarkably digested under the enzymes, especially under trypsin. The degradation curves showed that the antigen-extracted meniscus was enzymolyzed less than the fresh meniscus. The degradation products were grouped as amino, peptide, and polyose by the analysis. Both of the materials could hardly behydrolyzed in PBS solution without the enzymes. The four different enzymes had different surface morphologies under the examination of SEM. Conclusion The antigen-extracted meniscus is enzymolyzed more slowly than the fresh meniscus in vitro, and the result can be used as a guideline to the further research.
Objective To explore the histological changes of bio-derived bone prepared by different methods after implantation, and to provide the scaffold material from xenogeneic animal for tissue engineering. Methods Theextremities of porcine femur were cut into 0.5 cm×0.5 cm×0.5 cm. Then they were divided into 5 groups according to different preparation methods: group A was fresh bone just repeatedly rinsed by saline; group B was degreased; group C was degreased and decalcificated; group D was degreased, acellular and decalcificated; group E wasdegreased and acellular. All the materials were implantated into femoral muscle pouch of rabbit after 25 kGy irradiation sterilization. The cell counting ofinflammatory cells and osteoclasts, HE and Masson staining, material degradation, collagen and new bone formation were observed at 2, 6, and 12 weeks postoperatively. Results The residue level of trace element in biomaterials prepared by different methods is in line with the standards. All the animals survived well. There were no tissue necrosis, fluid accumulation or inflammation at all implantation sites at each time point. The inflammatory cells counting was most in group A, and there was significant difference compared with other groups(P＜0.05). There was no significant difference in osteoclasts counting among all groups. For the index of HE and Masson staining, collagen and new bone formation, groups C and D were best, group E was better, and groups A and B were worse. Conclusion The degreased, acellular and decalcificated porcine bone is better in degradation,bone formation, and lower inflammatory reaction, it can be used better scaffold material for tissue engineered bone.
OBJECTIVE: To isolate and characterize mesenchymal stem cells (MSCs) derived from bone marrow of Banna minipig inbred line (BMI). METHODS: BMI-MSCs was isolated from bone marrow by density gradient centrifugation and cultured in DMEM (containing 15% bovine serum) at 37 degrees C with humidified 5% CO2. These cultured stem cells were characterized in clonal growth, expression of specific markers and capability of differentiation. RESULTS: Mesenchymal stem cells were proliferative and could be expanded rapidly in vitro. Clonal growth of these cells can be observed when small amount of cells was inoculated. These cells were SH2, SH3, SH4, SB10 and SB21 positive. And it was proved that these cells possess osteo-differentiation ability, up-regulated alkaline phosphatase expression and calcium secretion after osteosupplement was added into the media for several days. CONCLUSION: Mesenchymal stem cells derived from bone marrow of BMI possess the general characters of stem cell.
ObjectiveTo determine the optimizing parameters in transfecting the SV-40-PED cells mediated by oligofectamine. Methods With a change of Decoy oligodeoxynucleotides(ODNs)/oligofectamine in ratio and the transfection time, the uptake rate and the mean fluorescence intensity of SP1 ODNs in the SV-40-PED cells were measured by flow cytometry to evaluate the transfection efficiencies. 4 μl oligofectamine with different concentrations of ODNs(2.5，5.0，7.5，10.0 and 12.5 μl) were put into 100 μl of DMEM without serum and antibiotics. the (SV-40-PED) cells were transfected after 20 min at room temperature. the final concentration of SP1 decay ODNs were 50，100，150，200 and 250 nmol/L. Transfection effieiency was detected at 26 h after transfection. The intracellular distribution ofSP1 ODNs was determined with a fluorescence microscope. The lactate dehydrogenase (LDH) activity in the supernatant was measured to assess the cytotoxicity.Results The uptake of SP1 ODNs into the SV-40-PED cells was significantly improved by oligofectamine. The cell appearance did not change much in the groups of 50, 100 and 150 nmol/L. In the groups of 200 and 250 nmol/L, the cell reverted after being shrinked and altered to round. At 26 h after the transfection, there was no marked change in the cell form at the concentration of 250 nmol/L. There was floatation at 48 and 72 h after the transfection. Under the fluorescence microscope, we observed fluorescent materials distributed in the cell nucleus in the successfully-transferred groups. We could see the nucleoli clearly in the groups of 200 nmol/L and 250 nmol/L. There was a ber fluorescence intensitywith a higher concentration and the fluorescent materials gathered at the cell nucleus. At the final concentration of 250 nmol/L, the LDH level was 137.12±3.92 U/L in the 72hgroup, which was significantly higher those that in the 26h group（49.61±17.13 U/L）and the 48h group（120.26±8.42 U/L）(Plt;0.01). At 26 h after the transfection, there were no statistical differences at the above LDHlevels in the different-concentration groups（Pgt;0.05）. Conclusion Transfection efficiency is the highest when the final concentration of the SP1 decoy ODNs is 250 nmol/L during the incubation of for 24 h in transfecting the SV-40-PED cells.