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Objective To observe the ultrastructure of the neurovascular Unit (NVU) in chronic compressive cervical myelopathy rat model at different stages.Methods From March, 2014 to March, 2015, 32 rats were divided into two groups: sham control group (n =8) and compressive spinal cord injury group (n =24).The model was established by inserting the compression sheet made of polyurethane at the level of C6.BBB and somatosensory evoked potentials (SEP) were used to evaluate the spinal cord function status of model rat.Transmission Electron Microscopy (TEM) examination of compressive cervical spinal cords was performed separately at the 14th, 21st, 28th and 42nd day after modeling.Results At the 14th, 21st, 28th and 42nd, the BBB score were 17.571 ± 0.870, 15.952 ± 0.870, 15.476 ± 0.602 and 16.190 ± 0.632 were significantly lower than those in the control group (the BBB score of 4 points were 19.600 ± 0.516, 19.500 ± 0.527, 19.600 ± 0.699 and 19.800 ± 0.6232 respectively) (P ＜ 0.05).Latency prolongation and amplitude reduction of somatosensory evoked potentials (SEP) were presented in the compressive spinal cord injury group.At the 14th day, edema around the capillaries was observed, the morphological structure of endothelial cells and basement membrane was normal, the tight junction between endothelial cell was intact, the mitochondria in the axons, oligodendrocytes and astrocyte foot processes were edematous.At the 21st day, extensive edema, even partial necrosis around the capillaries were found, the surrounding structure were arranged loosely, partial loss of endothelial cells and basement membrane, cavitation occurrence in endothelial cells, basal membrane density was significantly lower, mitochondria vacuoles and shrinkage in the cytoplasm, axon myelin loose or broken;at the 28th day, the edematous range surrounding capillaries narrowed, low density of basement membrane and endothelial cells, vacuoles in endothelial cells, loose axon myelin, while some mitochondrias backed to normal.At the 42nd day, capillary integrity, no abnormalities were found in endothelial cells, basement membrane, tight junction and mitochondria, double layers of endothelial cells and basement membrane could be seen, local broken and loose structure were presented in part of the axons;The TEM of the sham control group showed normal ultrastructure of NVU.Conclusion The ultrastructure of NVU in chronic cervical spinal cord compression presented various in the different periods, NVU disruption were found in the early stages (14th-28th days), and compensatory and repair process were developed incompletely later.
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Objective To evaluate of the efficacy of transcranial electrical stimulation motor evoked potential (TES-MEP)in combination with cortical somatosensory evoked potential (CSEP) monitoring during the anterior or posterior approach spinal surgery for cervical spondylitie myelopathy (CSM).Methods TES-MEP on the bilateral anterior tibial muscle and flexor hallucal brevis and thenar muscles and CSEP on the bilateral posterior tibial nerve and ulnar nerve were observed simultaneously in 135 patients during spinal surgery.Intravenous anesthesia was employed in all the patients.The results of TES-MEP,CSEP and combined monitoring were analyzed statistically.Pre-oporative and post-operative motor and sensory functions of the spinal cord were compared. Result Success rate of TES-MEP,CSEP and the combined monitoring was 87.4%.97.8%and 100%,respectively.Out of 135 patients,nine patients (6.7%) were detected with the positive evoked potentials due to surgical operation.The sensitivity of TES-MEP and CSEP in assessing the spinal cord motor function was 100%and 83.3%,respectively,while that in assessing the spinal cord sensory function was 77.8%and 100%,respectively.The sensitivity and specificity of the combined monitoring was both 100%. Conclusion The successful detection rate and accuracy of the combined monitoring for spinal cord function are apparently higher than that of simple TES-MEP or CSEP.The causes for operative maneuvers evoking a positive evoked potential include complete anterior decompression of the spinal canal,intervertebral bone graft,laminoplasty for OPLL and hematoma compression caused by a failed drainage in a posterior-anterior approach surgery.
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Objective To investigate the changes of somatosensory-evoked potential(SEP)during an mild impact spinal cord injury in rats 80 as to evaluate its potential value in prevention of such iatrogenic damage. Methods Twenty-four SD rats weighing(340±28)g were randomly divided into two groups,ie,sham control group(only exposure without impact at C6)and injury group(mild impact spihal cord injury at C6).SEP wss recorded in both groups.The changes of SEP in waveform,amplitude and latency were observed and compared between groups and between operations.The gross dissection and histologic analysis were performed after surgery for comparative study. Results SEP waveforms,amplitude and latency showed no significant change in the sham control group.In contrast,the SEP waveform and amplitude animals showed significant changes in the injury group after impact spinal cord injury and the amplitude was decreased from pre-injury(1.3±0.7)μV to post-injury(0.5±0.4)μV(P<0.05),while the latency showed no significant difference between(11.1±2.1)ms pre-injury and(10.7±1.3)ms post-injury(P>0.05).However,this abnormal change appeared in a temporary period at(5.7±3.2)minutes after impact and lasted for about(7.1±3.3)minutes.Diffused hemorrhagic nidus could be seen in the injured cord,which was not found in the sham control group. Condusions Mild impact spinal cord injury may induce transient abnormalities of SEP in waveform and amplitude,which requires careful monitoring in clinical practice.The sudden change in SEP may be associated with impact and vibration damage to the spinal cord,suggesting timely use of protection measures for spinal cord.
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ObjectiveTo establish a new biomechanical test for evaluating biomechanical properties of femoral metaphysis in ovariectomized rats.MethodsTwenty-five-month-old female Sprague-Dawley rats were randomly divided into ovariectomized (OVX) group and the sham-operated (Sham) group (n=10).Twelve weeks after operation,femur BMD and histomorphometry of distal femur were detected.Furthermore,femur biomechanical parameters were determined by diaphysis three-point bending test and a new designed metaphysis bending test.The relationships between the biomechanical parameters and BMD or bone histomorphometry were assessed with Pearson correlations.ResultsThe femur BMD,bone histomorphometrical indexes(％Th.Ar,Tb.N,Tb.Th),and biomechanical parameters(maximum load,yield load and stiffness) of OVX group significantly decreased compared with Sham group.In metaphysis bending test,the mean difference of the maximum load(Fmax),yield load(Fy) between group OVX and Sham were significant higher than that in diaphysis three-point bending test.Positive correlations between biomechanical parameters and femur BMD or bone histomorphometry indexes were observed in both the diaphysis bending and metaphysis bending test.The biomechanical parameters in the metaphysis bending test showed stronger correlations with BMD and bone.ConclusionFemur metaphysis bending test could be used to evaluate the biomechanical properties of osteoporosis.When compared with diaphysis bending test,femur metaphysis bending test is more sensitive in evaluating the change of biomechanical properties of femur in osteoporotic rats.
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ObjectiveTo compare the clinical effect of posterior circumferential fusion with versus without intertransverse process fusion on lumbar instability in aged patients. MethodsThe elderly with lumbar instability were treated with the posterior instrumented circumferential fusion technique in 80 cases. Among 58 patients followed up for at least 2 years, 28 cases (group A)underwent posterior circumferential fusion with intertransverse process, while 30 cases (group B)without intertransverse process. X-ray examination was used before and 1, 3, 6, 12 and 24 months after operation to evaluate the fusion condition of the bone graft, and visul analogue scale (VAS) and Oswestry disability index (ODI) questionnaire were applied to assess the pain of center back and leg,and the conventional activity.ResultsThe operation time and blood loss were more in group A[(185.3±56.6) min and (376.3±92.9) m1] than in group B [(146.4±46.3) min and (234.3±64.5)ml (t=12.37, 37.49, P＜0.01)]. All the 58 cases were followed for at least 2 years. The 27 cases (96.4％) of group A and 28 cases (93.3％) of group B got bone fusion (x2 =0.004, P＞0.05).There were marked differences in the VAS of center back at 1 and 3 months after operation between the 2 groups (t=3.178, 2.158, both P＜0.05), while no difference at the other 3 time point. VAS about the leg pain and the ODI showed no differences between group A and B after operation (all P＞0.05). ConclusionsFor the lumbar instability in the elderly, the posterior circumferential fusion with or without intertransverse process fusion can achieve a similar high rate of fusion and satisfactory clinical results,andtheposteriorcircumferentialfusionwithoutintertranaverseprocess is recommended for less trauma.
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Objective To analyze and evaluate the effect of posterior circumferential fusion for treatment of the mechanical instability of lumbar spine, and discuss the relative merits,indications and contraindications in this procedure. Methods Two hundred and two patients with mechanical instability of lumbar spine treated by the posterior instrumented circumferential fusion technique from January 2001 to January 2007. One hundred and thirty-two patients were selected who were treated with only one segment fusion and followed up for at least 1 year, of them 97 patients suffered lumbar spondylolisthesis, 35 patients suffered degenerative lumbar instability. X-ray was used to evaluate the fusion condition of the bone graft, and VAS and ODI questionnaire were applied to assess the pain of back and leg,and the conventional function. Results All patients were followed up for 12-84 months, averaged (43±23) months,125 patients got bone fusion, accounted for 94.7%(125/132). The VAS of low back pain was (6.71 ± 1.31) points before operation, while (3.20 ± 1.14) points after operation (P < 0.05) ,and the VAS of leg pain was (8.33 ± 1.78) points before operation,while (4.31 ± 1.15) points after operation (P< 0.05). The ODI was (68.6 ± 14.7) % before operation, while (13.6 ± 1.5) % after operation (P < 0.05). Conclusions Posterior circumferential fusion is a positive and excellent treatment for the mechanical instability of lumbar spine. With its merits, the high fusion rate and good clinical results can be received.
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BACKGROUND: There have been many methods of fixation between lumbar-sacral spine and pelvis. However, a safe, firm, and ideal method of internal fixation has not been found.OBJECTIVE: This study was designed to investigate the stability of the fixation between lumbar-sacral spine and pelvis with the connectible skills using iliac screw and lumbar-sacral spine pedicle screw.DESIGN, TIME AND SETTING: This study, a control experiment, was performed at the Institute of Biomechanics, Sun Yat-sen University, Guangzhou, Guangdong Province, China between January 2006 and December 2007.MATERIALS: The lumbar-sacral spine and pelvis specimens were collected from six freshly cryo-preserved male adult corpses caused by trauma. Iliac screw (8.5mm×100mm), L5 pedicle screw (6.5mm×45mm), and S1 pedicle screw (6.5mm×35mm) were provided by Sofamor Company, USA. MTS 858 Bionix Material Testing System (USA) was also used.METHODS: The lumbar and iliac vertebrae, pelvis from six fresh frozen cadaveric specimens were operated in three different ways of fixation respectively: iliac ala lag screw, L5-S1 pedicle screw rod system, iliac screw and L5 pedicle screw connecting system. Three ways of fixation as mentioned above were compared with the intact group in biomechanical stability.MAIN OUTCOME MEASURES: The mobility of whirl, lateral bending, proneness, and backward stretching among groups.RESULTS: Using iliac screw for the fixation between lumbar-sacral spine and pelvis turned out to be the best in stability. The range of motion (ROM) decreased obviously in each situation. The three-dimensional mobility in the 6.4Nm moment of force was (1.07±0.86)° for whirl, (0.95±0.47)° for lateral bending, (1.22±0.67)° for proneness, and (1.80±0.73)° for backward stretching. There was significant difference between the intact group and the group carried out by iliac screw and L5 pedicle screw for the fixation between lumbar-sacral spine and pelvis (P<0.01).CONCLUSION: The connectible skills using iliac screw and the lumbar-sacral spine pedicle screw possesses the biomechanical advantages of maintaining the stability between lumbar-sacral spine and pelvis.
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Objective To evaluate the primary outcomes of minimally invasive lumbar microdiscectomy. Methods There were 34 cases with single lumbar disc herniation treatment of tubular retractor access with METRx system and microdiscectomy(MMD group)and same cases with treatment of conventional discectomy(CD group).Operating time,blood loss,time of leaving the bed and length of hospital stay were compared in two groups.The postoperative wound pain was measured using a visual analog scale(VAS).The modified MacNab criteria were used to evaluate the outcomes. ResuIts The mean operating time was 65 min in MMD group,63 min in CD group.The mean blood loss was 34 ml in MMD group,85 ml in CD group.To compare in two groups,there was significant difference(P＜0.05).The mean time of leaving the bed after operation was 3.2 d in MMD group.5.8 d in CD group.The mean length of hospital stay was 5.8 d in MMD group.9.6 d in CD group.The mean VAS of the postoperative wound pain was 3.2 scores in MMD group,5.6 scores in CD group.To compare in two groups,there was significant difference(P＜0.05).There was one complication in MMD group,4 in CD group.Thirty-three cases got follow-up mean 8.5 months in MMD group.The success rate was 93.9%. Conclusion The minimally invasive lumbar microdiscectomy has the advantages on less trauma,safety,quickly postoperative recovery,and satisfactory outcomes.
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[Objective]To investigate the diagnosis and treatment of lumbosacral nerve roots anomalies. [Method]Etiological factors,typing,diagnosis and treatment of lumbosacral nerve roots anomalies confirmed by operation were analyzed.Operative treatment included wide laminectomy(n=8),hemilaminectomy(n=8) and enlargement fenestration(n=9).[Result]The presenting symptoms of lumbosacral nerve roots anomalies often resulted from lumbar disc herniation or spinal canal stenosis.The typs of lumbosacral nerve roots anomalies included conjoined nerve roots(n=10),closely adjacent roots(n=8),thickening of nerve roots(n=2),caudal origin roots(n=2),division of nerve roots(n=1),double nerve roots(n=1),and anastomosis of nerve roots(n=1).The levels of nerve roots anomalies were L4 in 1,L5 in 14,and S1 in 10.Only 5 cases were diagnosed preoperatively by myelography,CT or MRI.The others were found at operation.All patients were followed up for more than 2 years.Postoperatively,the results were rated as excellent in 12,good in 8,and fair in 4.One patient had residual radiating pain in the lower lims and weakness in dorsiflexion of the foot. [Conclusion] Radicular symptoms of lumbosacral nerve roots anomalies are changeable.The preoperative diagnosis is difficult to establish by myelography,CT or MRI(axial and sagittal plane).It is necessary to heighten the sensitivity of diagnostic modalities.It may improve the surgical outcomes to expose sufficiently,to explore the nerve roots carefully and to decompress thoroughly.
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[Objective]To report the initial outcomes of occipitocervical fixation using plate-rod-polyaxial screw system and investigate whether this new system offers any advantage over other existing methods of fixation.[Method]Fourteen cases(male 9,female 5)accepted cervicooccipital fixation with plate-rod-polyaxial screw system.There were 3 cases of odontoid dysplasia with dislocation;spinal canal tumor in 3;2 cases of metastatic carcinoma with pathologic fracture of C_1 and C_2,rheumatoid arthritis with cervicooccipital instability,and fasilar impression;burst fracture of C_1 with oecipital-atlantal-axial instability in 1.Twelve cases had neck pain.Thirteen cases had neurological deficits in different degrees.JOA score was 12.4 on average.[Result]The positions of all screws were good.There was no complication related to inserting screws.All neck pain released.Fourteen-months follow-up was obtained on average in 13 patients.Cervicooccipital nonunion was in one case and its occipital screws were pulled out.Twelve patients had satisfactory fixation and got firm fusion.Ameliotate rate of JOA score of the neurological function was 63.0%.[Conclusion]These initial data indicate that posterior occipitocervical fixation using plate-rod-polyaxial screw system is safe and reliable,and satisfactory clinical outcome can be obtained.The system appears to offer some advantages over other existing methods of fixation.
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BACKGROUND: Epidural block(EB) is one of the effective and widely used remedies for lumbar disc herniation(LDH) . Animal experiments have been conducted to study the changes in the local tissue structure in the spinal canel after several treatments with EB.OBJECTIVE: To study the effect of EB for LDH on the local tissue structures in the spinal canel.DESIGN: A non-randomized and controlled clinical observation.PARTICIPANTS: Department of Pathology and Laboratory of Electron Microscope of an Affiliated Hospital of a University.SUBJECTS: Forty patients with LDP, who failed to respond to EB treatment and subsequently received discectomy in the Department of Orthopaedics,First Affiliated Hospital of Sun Yat-sen University from May 1992 to December 1997, were enrolled in this study, with 20 patients receiving discectomy but not EB treatment serving as the control group.METHODS: From the 60 cases, totally 120 specimens of yellow ligament and the disc tissues were obtained during discectomy for optical microscopical examination. A portion of the yellow ligament and the lumbar disc tissues were chosen from EB group(12 cases) and non-EB group(10 cases), respectively, for electron microscope examination(involving altogether 44specimens) . The changes in histology and ultrastructnres in the specimens were compared between the two groups.MAIN OUTCOME MEASURES: ① Main results: the reactive proliferation of the tunica adventitia and inflammatory reaction of the intervertebral disc and yellow ligament; ② Secondary results: changes in the ultrastructure of the anulus fibrosus, nucleus pulposus and yellow ligament.RESULTS: No significant difference was found between the two groups either in light microscopy or electron microscopy in the degree of smoothness and the inflammatory reaction of the cavosurface of the yellow ligament and the disc tissues, nor in the cellular ultrastructures and fibrous arrangement.CONCLUSION: There is no direct relationship between lumbar EB and epidural scar adhesion formation. EB does not affect the ultrastructures of the local tissues in the spinal canal, but care must be taken of the sterilization in the surgical procedure, as chronic inflammatory reaction in the yellow ligament and disc tissues can be present in some patients.
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Objective To evaluate the effects of adeno-associated virus-enhanced green fluorescent protein (AAV-EGFP)on the biologic behavior of rabbit's bone marrow stromal cells(BMSCs)by means of a simple method of culturing and osteogenic induction in vitro so as to find an ideal viral vector and cell tracing mark for tissue en- gineering.Methods Total bone marrow culture was conducted to obtain rabbit BMSCs which were then induced in the osteogenic direction.The morphology of the cells was observed continuously,and their surface antigen and ossification were detected by alkali phosphatase stain and Von Kossa stain.On the basis of the above results, AAV-EGFP was transfected into the induced cells.The morphologic changes of the cells,the expression time and intensity of fluorescent light were observed.The transfection efficiency was detected to find the best multiplicity of infection(MOI)value.The cell growth curves were drawn to evaluate the biologic effects of AAV-EGFP on the cyto-activity.Results The morphology and purity of the rabbit BMSCs obtained were good.The ossification of the cells was significant after osteogenic induction.The best MOI value was found to be 1?10~5.The expression intensity of fluorescent light was strong with the expression time more than eight weeks so that the fluorescent light could be observed after cell generations.The transfection efficiency of AAV was high without significant biologic effects on the cyto-activity.Conclusions The total bone marrow culture and in vitro cell induction can satisfy the requirements for seeding cells in tissue engineering.AAV is an ideal viral vector for tissue engineering.Transfection of AAV-EGFP to cells could be an ideal method for cell tracing mark.
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Objective To observe the recovery process of hind limb function following complete spinal cord transection injury and discuss corresponding mechanism. Methods The spinal cords of 15 SD rats were transected at T9 plane and a 3 mm spinal cord removed for a complete transection. The functional recovery of the hind limb was evaluated using CBS (combined behavioral score) and Basso Beattle Bresnahan (BBB) 1, 2, 4 and 6 weeks after injury. At the 6th week after injury, also experiment was done on histology, immunohistochemistry, motor evoked potential (MEP) of spinal cord and repeated transection. Results The hind limb function of the injured animals recovered at different degrees, most obvious at the 4th week and BBB was up to 12 at the 6th week. MEP result was related to the site of the stimulating electrode. No MEP was recorded when the stimulating electrode was placed above the injured site. But when the stimulating electrode was placed below the injury level, MEP was normal. The again transection of the spinal cord above the injury level took no effect on the recovered hind limb. However, again transection below the injury level resulted in complete paralysis. Histologic results showed that the injured site was filled with glial scars without axons. There existed a little scattered positive fibers of neurofilament protein 200 (NF200). Conclusions After complete spinal cord injury, there is a significant spontaneous recovery of the hind limb function that is a kind of autonomous functions of the injured distal spinal cord unrelated to repair of descending conducting fasciculus of the spinal cord. The distal spinal cord is intact in function.
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Objective: To evaluate the effects of PD145065(non-selective endothelin(ET)receptor antagonist)on injured spinal cord and explore mechanisms of how ET plays a role in secondary injury following spinal cord injury(SCI).Methods:Spinal cord of rat was traumatized by compression(50g,1min).PD145065 or vehicle was administered intrathecally 10 minutes before SCI.Alterations of spinal cord blood flow(SCBF),molondialdehyde(MDA),the total content of intracellular calcium(［Ca2+］i),Evans blue(EB),and water in spinal cord were inspected.Results:SCBF of injured area decreased obviously 5 minutes after SCI.SCBF was 75.23±9.21% of baseline 5 minutes after SCI,57.06±7.35% 2 hours.SCBF of adjacent area decreased lower.SCBF was 79.82±7.98% of baseline 30 minutes after SCI.SCBF of injured and adjacent areas did not recover 4 hours after SCI.The contents of MDA,［Ca2+］i,EB and water in traumatized spinal cord were significantly more than that of sham(P＜0.05)。PD145065 ameliorated SCBF of injured area obviously and abolished the decrease of SCBF of adjacent area.The contents of MDA,［Ca2+］i,EB and water in spinal cord of PD145065 treated group were significantly less than that of saline treated group(P＜0.05).Conclusion:PD145065 has protective effects on traumatized spinal cord in early phase.ET and its receptors may play a role in secondary injury following SCI by multiple pathways.ETA/ETB receptor antagonist may be useful in treatment of clinical SCI.
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【Objective】To study the effect of light weight-bearing activity on postmenopausal osteoporosis.【Methods】36 female rats were randomly divided into 3 groups:① Sham,② Ovx (ovarietomized),③ Ovx+Im (ovarietomized and immobilized).All the group's maintained daily activity.And because of being immobilized,the right hind limbs of the third group lacked weight-bearing activity.12 weeks after ovarietomy,the BMD (bone mineral density),histomorphometry and biomechanics of the right femurs of rats were measured and analyzed.【Results】Comparing with the Sham group,the Ovx group's right femurs were manifested with the decrease of BMD,TBV (trabecular bone volume),MTT(mean trabecular thickness) and MCT(mean cortex thickness),while the increase of RS(resorption surface) and OS(osteotoid surface).Meanwhile their biomechanic nature declined.But statistically the BMD,MCT and the criteria of mechanical strength were not significant decrease.Otherwise,the Ovx+Im group's right femurs showed more apparent decrease of BMD,TBV,MTT and MCT.And the biomechanic nature was worse.Comparing with the Sham group,the BMD,MCT and the criteria of mechanical strength of the Ovx+Im group were statistically significant decreased.【Conclusion】If maintaining light weight-bearing activity,the ovarietomized rats were able to maintain relatively better bone quality.A lack of light weight-bearing activity wouldcause thedecline of bone quality.Thusthestudy suggested light weight-bearing activity was significantly effective on the prevention and treatment of postmenopausal osteoporosis.
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Objective: To study the effects of soluble multi-peptide agent,marked “Gu Kang Tai Ling”,derived from bone tissue on rat bone fracture healing.Methods 80 right tibia defects of rats were sawed.The “Gu Kang Tai Ling”were intramuscularly injected to the rats.The quality of the defect healing was investigated continuously and respectively by the defect bone histomorphometry,biomechanics,X-ray film,and bone mineral density(BMD).Results: Under the treatment of the agent,at early stage trabecular bone volume (TBV)ratio increased 24.7%,and osteoblast surface(OBS)26.7%,at late stage mean trabecular healing surface rate(MTHSR)was increased 38.8%,tibia anti-fracture strength 0.4527～1.4350N，and BMD 7.65% compared with the control group.Conclusion: “Gu Kang Tai Ling”can accelerate rat fracture healing and improve the quality of healing.
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Objective To observe the survival,conversion and function preservation of mesenchymal stem cells(MSC) after transplantation.Methods MSCs from male Sprague-Dawley(SD) rats were isolated and cultured,then were transplanted to bone defect of female SD rats.Tissues were obtained at defferent periolds.Hybridization in situ was performed on the tissues using Y chromosome specific DNA probe labeled with digoxin to observe the transplanted cells on distribution,quantity and function.Results Allogeneic MSCs could survive and proliferate in the bone defect of recipients and formed bony callus with large quantity and good quality.After 90 days of graft,stem cells still survived and distributed in marrow and newly formed bone tissue.Conclusion After transplantation,allogeneic MSCs have a long-term surviving in marrow and new bone tissue and maintain the characteristic of ossification.
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Objective Investigating transplanted time of periosteal mesenchymal stem cell (PMSC) Methods Rat PMSCs were allografted into rat tibia defects made in different time of granulation Then the quantity of formatted bone,i.e.,trabecular volumm rate (TVR),in the defects were measured in histology and bone histomorphometry by 2,3,4 and 8 weeks respectively after transplantation The long bone draft fracture defects of patients were allografted with PMSC of youth children after 2 week of fracture Results TVR was higher and the defects healed more fast in those rats transplanted PMSCs within 2 weeks after the defect were made However there was insignificant difference between the groups of PMSC transplantation was carried out after two weeks of the defect The fractured defects were healed in 15 cases (57 7%) and were not healed in 11 cases (42 3) after 9 months of transplantation Conclusion That rat bone defects were transplanted PMSC within 2 weeks showed expected bone formed effect and insignificant effect on accelerating defect healing by PMSC transplantation in rats or patients after 2 weeks.
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Objective To search for a more efficient method to induce bone marrow stromal cells (BMSCs) into Schwann-liked cells (SLCs) in vitro. Methods On the base of the method which was used by Dezawa (it was looked as the traditional inducing method),some steps were modified,namely,to use all the reagents in half dose in the same time and two times intervally,this method was looked as the modified inducing method.After induced by the two methods,the cells morphologic characteristic,the positive ratio of immunocytochemical dye with anti-S-100 and anti-GFAP,the cells activity measured by MTT method and the DNA percentage in S period measured by flow cytometry were compared with each other respectively to evaluate the methods'effects. Results Compared with the traditional method,the cells induced by the modified method were more similar to the primary Schwann cells in morphology,more positive proportion in immunocytochemic dye with anti-S-100 and anti-GFAP,less damage in the activity and more percentage in S period. Conclusion The modified method had more advantages such as less damage on cells and more efficiency in inducing BMSCs into SLCs.
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Objective To evaluate the biologic characteristics of a new type femoral stems either coated with gradient hydroxyapatite (HA) or additionally loaded with rhBMP-2. Methods Fifteen dogs were divided into 3 groups according to the implanted hip prosthesis. Each animal received hemiarthroplasty in the right hip with prosthesis made of pure Ti-6Al-4V femoral stem (Ti group), the new gradient HA-coated femoral stem (HA group) with 100 to 150 ?m hydroxyapatite coating, and the new gradient HA-coated femoral stem loaded with rhBMP-2 of 9 mg (BMP-HA group) respectively. The dogs were sacrificed at 12 weeks after operation, and labeled with tetracycline 3 of 30 mg/kg days prior to sacrifice, and then the histological changes of the tissue surrounding the prosthesis were evaluated. The radiographic examinations were taken before and after sacrifice. Results On radiographic examination, local radiolucent line around the prosthesis was observed only in one specimen in Ti group. The new bone formation was found both in HA group and BMP-HA group more obviously than in Ti group. Under microscopy, it was noted that this new gradient HA-coating was intact and no obvious biodegradation in most section, whereas a fibrous membrane was found in Ti group. The average rates of interface osteointergration in Ti group, HA group and BMP-HA group were 4.05%?7.66%, 71.04%?9.81% and 88.86%?6.56%, respectively, those of HA and BMP-HA group were significantly higher than that of Ti group (P