Abstract: Objective To assess the feasibility of transferring major histocompatibility complex (MHC) gene into the thymus to mitigate xenograft rejection. Methods By molecular cloning technique, we extracted and proliferated the-H-2K d gene from donor mice (MHC class Ⅰ gene of Balb/c mice) and constructed the expression vector plasmid of pCI-H-2K d. Twenty SD rats were selected as receptors, and by using random number table, they were divided into the experimental group and the control group with equal number of rats in each group. By ultrasoundguided puncture and lipofection method, the pCI-H-2Kd was injected into thymus of SD rats in the experimental group and meanwhile, empty vector plasmid of pCIneo was injected into thymus of SD rats in the control group. Subsequently, we transplanted the donor mice myocardium xenografts into the receptor rats, and observed the xenograft rejection in both the two groups. Results The survival time of the xenotransplanted myocardium in the experimental group was significantly longer than that in the control group (14.61±2.98 d vs. 6.40±1.58 d, t=-7.619,Plt;0.05). Microtome section of transplanted myocardium in the control group showed a relatively large amount of lymphocyte infiltration and necrosis occurred to most part of the transplanted myocardium, while microtome section of experiment group showed no lymphocyte infiltration and most of the cells of the transplanted myocardium were still alive. After mixed lymphocyte culture, the reaction of receptors to donor cells in the experiment group was obviously lower than that in the control group (t=4.758, P=0.000).After the count by flow cytometer, the xenoMHC molecules were expressed in the receptors’ thymus with a transfection efficiency of 60.7%. Conclusion Our findings suggest that xenograft rejection can be mitigated substantially by donor’s MHC gene transferring into receptor’s thymus. This may provide theoretical and experimental evidence for inducing xenotransplantation tolerance.
ObjectiveTo discuss the safety and effectiveness of combined dynamic cervical implant (DCI) and Cage fusion in the treatment of two-level cervical disc protrusion. MethodsBetween September 2009 and June 2011, 16 cases of two-level cervical disc protrusion were treated with combined DCI and Cage fusion. Of 16 cases, 10 were male and 6 were female, with a mean age of 44.1 years (range, 37-64 years) and with a mean disease duration of 5.1 years (range, 2-8 years), including 8 cases of cervical myelopathy, 5 cases of nerve root cervical myelopathy, and 3 cases of mixed cervical myelopathy. Radiological results indicated degenerative intervertebral discs and compressed never root or spinal cord. Involved discs included C3,4 and C4,5 (1 case), C3,4 and C5,6(5 cases), C4,5 and C5,6 (3 cases), C4,5 and C6,7 (5 cases), and C5,6 and C6,7 (2 cases). The neck disability index (NDI), Japanese Orthopedic Association (JOA) score, and visual analogue scale (VAS) were used to evaluate the neurological function and pain relief. The stabilities and activities of involved segments, intervertebral fusion, and displacement of Cages were observed during follow-up. ResultsPrimary healing of incisions was obtained in all cases; no complication of hematoma, infection, cerebrospinal fluid leakage, or neural function damage occurred. All 16 patients were followed up 18 months on average (range, 6-36 months). The cervical X-ray results indicated that the activities of involved segments was (7.8±3.1)°, showing no significant difference (t=0.655, P=0.132) when compared with preoperative value [(7.3±2.6)°]. No implant loosening was observed; slight heterotopic ossification occurred in 1 patient at the posterior rim of intervertebral space. No cage loosening or sinking was seen, and good fusion was achieved. The mean time of fusion was 4.5 months (range, 3-8 months). NDI, JOA, and VAS scores at last follow-up (18.3±5.1, 15.7±1.5, and 3.4±1.8 respectively) were significantly improved (t=2.131, P=0.016; t=3.126, P=0.024; t=6.102, P=0.038) when compared with preoperative scores (49.6±11.3, 12.8±2.0, and 6.7±1.2 respectively). ConclusionA combination of DCI and intervertebral Cage fusion has satisfactory early effectiveness in treatment of two-level cervical intervertebral protrusion for maintaining the stability and activity of cervical vertebrae.
Objective To evaluate the effect of anterolateral approach in treating thoracolumbar disc protrusion. Methods From May 2004 to May 2008, 11 patients with thoracolumbar disc protrusion (T10-L3) underwent discectomy, autologous il iac bone graft, and internal fixation via anterolateral approach. There were 9 males and 2 females aged 26-57 years old (average 42.8 years old). The course of disease was 1 week-11 years (average 2.7 years). Nine patients showed the lower l imbs weakness, 8 had sensory disturbance, 6 presented with lumbodorsal pain, 5 had the lower l imb pain, 4 presentedwith sphincter muscle disturbance, 3 suffered from foot drop, and 5 had a history of lower back injury. X-ray, CT, and MRI test showed that 9 cases had the single-segmental protrusion, 2 cases had double-segmental protrusion, 2 cases were accompanied with ossification of the thoracic vertebra yellow l igament, 2 cases were combined with ossification of the vertebra posterior longitudinal l igament, and 1 was compl icated with Scheuermann disease. Preoperatively, the intervertebral height was (7.2 ± 1.3) mm and JOA score was 6.4 ± 2.8. Results The time of operation was 2.5-5.5 hours (average 3.5 hours); the blood loss during operation was 500-1 200 mL (average 750 mL). During operation, intraoperative pleural tear occurred in 1 patient, peritoneal tear in 1 patient, and dural laceration in 1 patient. Repairing was performed intraoperative and preventive suction drainage was used for 3-5 days. No postoperative hydropneumothorax and cerebrospinal fluid leakage occurred. All incisions healed by first intention. No postoperative compl ications of nerve system occurred. All the patients were followed up for 1-4 years (average 2.4 years). X-ray films showed that all the patients achieved bony fusion without the occurrence breakage and loosening of titanium plate and screw 6-9 months after operation. Three cases displayed subtle scol iosis (10-15°) without influence on spinal equil ibration. The intervertebral height increased to (12.3 ± 1.5) mm 2 weeks after operation, indicating there was a significant difference compared with preoperative value (P lt; 0.05). The intervertebral height 1 year after operation when the bony fusion was reached decreased to (7.5 ± 1.2) mm, indicating there was no significant difference compared to the preoperative value (P gt; 0.05). The JOA score increased to 7.6 ± 3.2 at 1 year after operation, indicating there was a significant difference compared with preoperative value (P lt; 0.05). The symptoms and signs of all the patients were improved to various degrees after operation. According to improvement rate evaluation system proposed by Hirabayashi t al., 4 cases were graded as excellent, 6 as good, 1 as fair, and the excellent and good rate was 90.9%. Conclusion Treating thoracolumbar disc protrusion via anterolateral approach is safe and effective.
Objective To review the development and quality control of modern tissue banks. Methods The rules, regulations and the management literatures about tissue banks were extensivelyand comprehensively reviewed. Results Tissue banks havea significant progress and are developing to concentration, industrialization and standardization gradually. Quality control is being paid more attention in modern tissue banks. Conclusion Modern tissue banks will have a good future and the quality control must be intensified.
Abstract: Objective To investigate the influence of cryopreservation on cellular viability of latepregnancy fetal valved allografts in human. Methods The fetal valved allografts with gestational ages ranged from 24 to 40 weeks were sterilely procured within 6 hours after brain death. Each sample was bisected into control group and experiment group. The cellular viability of control group was directly tested and that of experiment group was examined after being storaged in liquid nitrogen for a week through a programmed frozen procedure. The light microscopy, tissue culture and Methylthiazol tetrazolium assay (MTT assay) were used to determine the cellular viability. Results Twelve latepregnancy fetal valved aortic allografts were procured. Light microscopy showed the integrity of the basic structure of the thawed aorta, the normal structure of the collagen and elastic fibers, with part of vascular endothelium lost. There were lots of cells deriving from both groups,but the cellular growing rate of the experiment group was relatively slower. At 490 nm, MTT assay valve of control group was 0.442±0.046, and that of experiment group was 0.424±0.041. The difference between two groups failed to statistically significance(t=1.617, P=0.328). Conclusion There were viable cells in latepregnancy fetal valved allografts after cryopreservation.
【Abstract】 Objective To investigate the protective effect of early motion on articular cartilage after joint allograft by performing a controlled trial between different post-operation strategies after joint allograft in an animal model. Methods Twenty hemi-knee joints were harvested from 10 6-month-old New Zealand white rabbits (male or female, weighing 2.5-3.0 kg); 10 hemi-knee joints by deep frozen treatment (donors) were transplanted to unilateral knee joints (recipients) of 10 6-month-old Chinchilla rabbits (male or female, weighing 2.5-3.0 kg), which were divided into early motion group (n=5) and sustained fixation group (n=5); and 10 hemi-knee joints were used as blank control (n=5) and frozen control (n=5). The articular cartilage of allogenic joints was detected by X-ray film, gross, and histology at 6 weeks after operation. Results Gross observation: no obvious limitation of joint movements was observed in early motion group, but obvious limitation in sustained fixation group. X-ray films: the bone ends between donor and recipient healed well with good paraposition and alignment on the operation day and 2 weeks after operation; at 6 weeks, angulation deformity was observed in early motion group of 3 rabbits, and paraposition and alignment were satisfactory in sustained fixation group. Histological observation: HE staining showed that the chondrocytes had normal quantity and morphology with few nuclear fragmentation and karyolysis in early motion group, but the quantity of chondrocytes sharply decreased with dissolved nuclei and numerous fibrous tissues in the cartilage matrix in sustained fixation group. The cell survival rate of the early motion group (49.66% ± 2.15%) was significantly higher than that of the sustained fixation group (20.68% ± 1.24%) (P lt; 0.05). Scanning electron microscopy observation: nuclear membrane was intact with chromatin condensation and edema of mitochondria and rough surfaced endoplasmic reticulum in early motion group, and that the membrane of chondrocyte vanished with blurring border between chondrocyte and matrix, rupture of nuclear membrane and the disappearance of chromatin and organelles could be found in sustained fixation group. Conclusion Early motion has protective effect on articular cartilage after joint allograft, but cannot completely prevent degeneration of the allogenic articular cartilage.
The sternum is the pivotal component of the thoracic cavity. It is connected with the clavicle and ribs on the upper part and both sides respectively, and plays an important role in protecting the stability of the chest wall. Sternal resection usually results in a large segmental chest wall defect that causes the chest wall to float and requires sternal reconstruction. This paper reports a 62 years male patient with thymic squamous cell carcinoma with sternal metastasis, who underwent thymotomy, sternal tumor resection and autologous lilum graft combined with sternal reconstruction by titanium plate after relevant examination was completed and surgical contraindications were eliminated. The patient was followed up for 6 months, the respiratory and motor functions were normal and the thoracic appearance was good.
Objective To investigate the way to reconstruct bone scaffold afterremoval of giant benign bone tumor in extremities of children. Methods From June 1995 to October 2000, 6 cases of benign bone tumor were treated, aged 614 years. Of 6 cases, there were 4 cases of fibrous hyperplasia of bone, 1 case of aneurysmal bone cyst and 1 case of bone cyst; these tumors were located in humerus (2 cases), in radius (1 case), in femur (2 cases) and in tibia(1 case), respectively. All patients were given excision of subperiosteal affected bone fragment, autograft of subperiosteal free fibula(4-14 cm in length) and continuous suture of in situ periosteum; only in 2 cases, humerus was fixed with single Kirschner wire and external fixation of plaster. Results After followed up 18-78 months, all patients achieved bony union without tumor relapse. Fibula defect was repaired , and the function of ankle joint returned normal. ConclusionAutograft of subperiosteal free fibula is an optimal method to reconstruct bone scaffold after excision of giant benign bone tumor in extremities of children.
Objective To investigate the clinical effect of reconstructed bone xenograft plus buttress plate (T or L type) fixation in treating tibial plateau fracture. Methods From June 2001 to March 2003, 32 cases of tibial plateau fractures were treated by means of open reduction,reconstructed bone xenograft plus buttress plate (T or L type) fixation. There were 23 cases of bumper fracture, 5 cases of falling injury and 4 cases of crush injury by a weight; 20 males and 12 females, aged from 18 to 69 years with an average of 38 years. All patients had close fracture. Results All the patients were followed upfor 9 months to 23 months, tibial plateau fracture healed satisfactorily without sunken articular surface. According to Pasmussen criterion, the results were excellent in 16 knees, good in 12knees and moderate in 3 knees. The satisfactory rate was 87.5%. Conclusion Reconstructed bone xenograft plus buttress plate internal fixation has good effect in treating tibial plateau fractures because it can avoid the complication of transplantation of ilium.
Objective To study efficiency of vascularized bone graft combining with reconstituted bone xenograft (RBX) in repairing bone defect and the expression of the vascular endothelial growth factor (VEGF) in serum. Methods From January 1998 to December 2002, 27 cases of bones defects were treated and randomly divided into 3 groups according to different repair materials: group A (the vascularized bone graft-RBX group, n=9), group B (the vascularized bone graft group, n=10)and group C(the RBX group, n=8). The bone defect repair, the bone healing time and the bone graft resorption were observed by radiograph after 3 months, 6 months and 12 months of operation, and the expression of VEGF in serum was assayed with lumino-enzyme immunoassay before operation and after operative 2 weeks, 4 weeks, 6 weeks and 8 weeks respectively. Results The X-ray films showed that the bonehealing was achieved in 8 cases of group A, in 6 cases of group B and in 3 cases of group C after 3 months; in 1 case of group A, respectively in 3 cases of both group B and group C after 6 months. The bone graft resorption was observed in1 case of group B and in 2 cases of group C after 12 months. The serum VEGF values after operative 2 weeks and 4 weeks were higher than those before operation in all of 3 groups(Plt;0.05), and the VEGF values of groups A and B were higher than that group C(Plt;0.05) after 4 weeks. There were no significant differences (Pgt;0.05) in serum VEGF level between postoperative 6, 8 weeks and preoperation in 3 groups. Conclusion The expression of serum VEGF obviously increase in the early period of bone transplanting, it is value of clinical evaluation of reparative efficiency of bone defect.