Effects of different organic solvents on slow-release recombinant human bone morphogenetic protein-2 microcapsules / 中国组织工程研究

BACKGROUND:In literatures, the recombinant human bone morphogenetic protein-2 (rhBMP-2) loaded microcapsules can be fabricated by double emulsion solvent evaporation method with different organic solvents, such as methylene chloride, ethyl acetate or their mixture. But so far it is not determined yet which one is better. OBJECTIVE: To optimize the preparation method of microcapsules encapsulating rhBMP-2 and to compare the effects of different organic solvents on the microcapsules. METHODS:Polylactic acid-polyethylene glycol-polylactic acid copolymer as microcapsules was used to prepare rhBMP-2 loaded microcapsules with double emulsion solvent evaporation method. Four kinds of organic solvents, methylene chloride (group A), mixture of methylene chloride and ethyl acetate (group B), ethyl acetate (group C) and acetyl acetone (group D) were chosen as oil phases to compare their effects on microcapsule's morphology, diameter, and encapsulation efficiency. Passage 3 bone marrow mesenchymal stem cels from rats were co-cultured with prepared microcapsules for 14 days, and then alkaline phosphatase activity was detected. RESULTS AND CONCLUSION:Compared with the other organic solvents, dichloromethane could cause microcapsules with the smaler and more uniform shape (4-10 microns) and the highest encapsulation efficiency; the microcapsules prepared by mixture of methylene chloride and ethyl acetate had relatively wide size distribution and moderate encapsulation efficiency; the microcapsules prepared by acetylacetone were difficult to form and keep the bioactivity of rhBMP-2. After cultured with rat bone marrow mesenchymal stem cels for 14 days, the alkaline phosphatase activity in groups A, B and C was significantly higher than that in group D and there was no significant difference between group A and group B; the alkaline phosphatase activity in groups A and B was significantly higher than that in group C (P< 0.05). The results show the rhBMP-2-loaded microcapsules prepared by methylene chloride as organic solvent have good shape, high encapsulation efficiency, and good biological activity.

Factors influencing the indication for tracheostomy following cervical spinal cord injury / 中华创伤骨科杂志

Objective To determine the factors influencing the indication for tracheostomy following cervical spinal cord injury.Methods A retrospective study was performed to analyze the 118 patients who had been treated for cervical fracture/dislocation along with cervical spinal cord injury from July 2004 to June 2014 and whose abbreviated injury scale score (AISS) was lower than 3.They were 96 men and 22 women,19 to 68 years of age (average,45.2 years).The patients were divided into a tracheostomy group (n ＝ 28) and a non-tracheostomy group (n =90).The 2 groups were compared in terms of gender,age,presence or absence of complete spinal cord injury at admission,injured segment,injury mechanism,smoking history,injury severity score (ISS),motor AISS,systolic pressure at admission,hospital stay,and ICU stay to determine the factors influencing allocation of tracheostomy.Results Compared with the non-tracheostomy group,the tracheostomy group had a higher rate of complete spinal cord injury at admission,a higher rate of smoking,a higher ISS at admission,a lower motor AISS,and longer hospital and ICU stay,with statistically significant differences (P ＜ 0.05).There were no significant differences between the 2 groups in gender,age,injured segment,injury mechanism,or systolic pressure at admission (P ＞ 0.05).Increased severity of cervical spinal cord injury was associated with significantly decreased motor AISA,increased rate of tracheostomy and increased ISS (P ＜ 0.05).Conclusion The influencing factors for indication of tracheostomy after cervical spinal cord injury are complete cervical spinal cord injury irrespective of the level of injury,ISS,motor AISS,and history of smoking.

Titanium cageversuspolyetheretherketone cage in posterior lumbar interbody fusion with pedicle screw fixation / 中国组织工程研究

BACKGROUND:Due to the higher modulus of elasticity, titanium cages are prone to have the folowing shortcomings: adjacent vertebral sinking and delayed fusion resulting from stress shielding; therefore, in recent years, it has been gradualy replaced by polyetheretherketone cages. OBJECTIVE:To compare the clinical and radiographic outcomes of patients undergoing posterior lumbar interbody fusion with pedicle screw fixation in which either a polyetheretherketone cage or a titanium cage was implanted. METHODS: The pre- and postoperative data of 104 patients who underwent single-level posterior lumbar interbody fusion were colected and analyzed, including 57 males and 47 females, aged (41.2±10.5) years. The 58 of 104 patients received the titanium cage and the remaining 52 patients received the polyetheretherketone cage. Visual analog scale scores and Japanese Orthopaedic Association Scores of the lumbar and lower limbs were recorded at 24 hours of postoperative folow-up; CT scan was used to detect bone fusion and cage subsidence. RESULTS AND CONCLUSION:After 12 and 24 months of folow-up, the visual analog scale scores and Japanese Orthopaedic Association Scores of the lumbar and lower limbs were al improved in the two groups compared with the previous (P < 0.05), but there was no difference between the two groups. At 12 and 24 months of folow-up, the fusion rates were 94% and 100% in the titanium cage group as wel as 74% and 84% in the polyetheretherketone cage group, respectively, and a significant difference was found between the two groups (P=0.012 andP=0.016). At 24 months of folow-up, the subsidence rate was 36% in the titanium cage group and 30% in the polyetheretherketone cage group, and there was no difference between the two groups. These findings indicate that the superiority of polyetheretherketone cages over titanium cages has not been demonstrated.

Analysis of risk factors of nonspecific low back pain in a community population: a case-control study / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the risk factors of nonspecific low back pain in community populations.</p><p><b>METHODS</b>Two community populations were investigated using questionnaires in this case-control study. The questionnaire was designed to collect data including age, gender, body weight, marriage, education, income, occupation, labor intensity, smoking, alcohol drinking and social mental status. The subjects with low back pain constituted the case group and those without low back pain served as the control group, and the data was analyzed by a Logistic regression model.</p><p><b>RESULTS</b>A total of 1747 community residents participated in this survey, among whom 398 subjects had low back pain and 1126 subjects without low back pain were selected as the control group. Of all the latent risk factors of low back pain in Logistic regression model, gender was the most relevant factor (OR=3.5522) followed by education (OR=1.958), labor intensity (OR=1.956), marital status (OR=1.612), vibration source exposure (OR=1.491), BMI (OR=1.127) and age (OR=1.060).</p><p><b>CONCLUSION</b>Gender, education, labor intensity, marriage, vibration source exposure and BMI are risk factors of nonspecific low back pain in community populations, and exercises and mental status can be protective factors against low back pain.</p>

Posterior fixation and fusion for treatment of Os odontoideum complicated by atlantoaxial dislocation / 南方医科大学学报

<p><b>OBJECTIVE</b>To summarize the techniques and evaluate the therapeutic effect of posterior fixation and fusion in the treatment of Os odontoideum complicated by atlantoaxial dislocation.</p><p><b>METHODS</b>From March, 2007 to October, 2010, 10 patients with Os odontoideum (including 6 male and 4 female patients aged from 20 to 65 years, mean 39.8 years) were treated in our hospital. Before and after the operation, the patients underwent X ray, CT and MRI examinations to measure and evaluate the degree of dislocation and neural compression. After preoperative traction for 1-2 weeks, all the 10 patients showed deductible atlantoaxial dislocation. Through a posterior approach, Atlantoaxial pedicle screws fixation were performed in 9 cases, and C2/3 pedicle-Occiput screw fixation was performed in 1 case. All the patients wore cervical collars as external support for 3 months after the operation.</p><p><b>RESULTS</b>The mean operative time was 3 h in these patients with a mean intraoperative blood loss of 420 ml. The symptoms were relieved after the surgery in all the patients, who showed no neck pain or neurological defects. The patients were followed up for 6 to 52 months (mean 22 months), and bony fusion was observed in all the 10 cases within 6 to 8 months without such complications as internal fixation failure or redislocation of the atlas.</p><p><b>CONCLUSION</b>Patients with Os odontoideum complicated by atlantoaxial dislocation should undergo surgical stabilization to avoid severe neurological injury. Pedicle screw instrument in the atlas allows restoration of the spinal stability, short-segment fusion, and maximal preservation of the mobility of the neck.</p>

Biomechanical study of bioactive cervical fusion cage with different types of fixation in cervical spinal fusion / 国际外科学杂志

ObjectiveTo investigate the biomechanical characteristics of different types of fixation with bioactive cervical fusion cage made of hydroxyapatite and poly L-lactic acid in cervical spinal fusion.MethodsIliac crest bone,bioactive cervical fusion cage and bioactive cervical fusion cage with plate fixation were used for anterior interbody implants after anterior discectomy across C5-6 in six fresh human cervical spine specimens respectively,and the range of motion of the cervical vertebrae interbody fusion were measured through the motional stability test.Results After discectomy,Bioactive Cervical Fusion Cage with plate fixation exhibited a significant increase in stability and a decrease of range of motion in angular motion than others in all motional directions ( P ＜ 0.005 ). Bioactive cervical fusion cage exhibited a decrease in stability and an increase of range of motion (6.25 ± 0.29) in angular motion than the intact spine (5.76 ± 0.40) in extension,but the difference was not significantly ( P ＞ 0.05 ).Bioactive cervical fusion cage exhibited a decrease in angular motion than iliac crest bone and a significant increase in stability in all motional directions except extension (P ＜ 0.005).ConclusionsBioactive cervical fusion cage' s biomechanical performance was excellent and bioactive cervical fusion cage with plate fixation was excellent in stability in all motional direction,and could remain initial stability of cervical vertebrae.

Effects of the adjustive tractor in treatment of cervical dislocation / 中华骨科杂志

Objective To observe the clinical effects of the adjustive tractor for cervical dislocation.Methods Forty-seven patients were included between September 2007 and November 2011.There were 36 males and 11 females with age ranged from 7 to 62 (mean,35 years).The mean interval from injury to admission was 8.6 h (range,0.5-72 h).There were atlanto-occipital dislocation in 2 cases,C1.2 in 2 cases,C2.3 dislocation in 5 cases,C3.4 dislocation in 2,C4.5 in 9,C5.6 in 13,C6.7 in 14.Thirty cases were complicated by fracture.No facet locking occurred in sixteen cases.Facet locking was found in ten cases and bilateral facet locking was in 21 cases.After reduction,brace or internal fixation followed.According to American Spinal Injury Association (ASIA) spinal function impairment scale standard,there were 4 cases in level A,10 cases in level B,18 in C,10 in D,and 5 in E.According to Japanese Orthopaedic Association (JOA) spinal function rating standard,the mean JOA score was 9 (range,2-14).Results All 47 cases were reduced successfully without neuronal function aggravation.Traction power ranged from 7 to 60 kg (mean,25.6 kg),the mean time of traction was 8 min (range,3-10 min).The mean follow-up was 38 (range,6-48) months.All the patients achieved normal alignment and intervertebral height.The intervertebral body fusion was observed in all of cases,the mean fusion time was 3.3 months (range,3-6 months).One patient who experienced nonunion of vertebral arch fracture didn't receive further treatment because of absence of symptoms.At last follow-up,there were 3 cases in level A,1 in level B,4 in C,8 in D,and 31 in E according to ASIA scale.The mean JOA score was 12 (range,2-17).Conclusion The adjustive tractor is simple and safe for prompt reduction.

Clinical outcome of expansive unilateral open-door laminoplasty in cervical myelopathy with OsteoMed M3 plate and screws / 国际外科学杂志

Objective To retrospectively describe the technique and review the surgical results of OsteoMed M3 titanium plate and screws used to secure the posterior elements in the open position after expansive unilateral opendoor laminoplasty.Methods Twenty-six patients with multilevel cervical disc herniation and canal stenosis were treated with an expansive unilateral open-door laminoplasty with OsteoMed M3 plate and screws.The follow-up period was over 1 year.The improvement of spinal function after surgeries under JOA was evaluated to analyse the effects and releated factors.Results All of 26 cases' follow-up period was over 1 year.The mean JOA score increased significantly from 9.40 ± 1.658 ( range,5 to 13 ) points before surgery to 13.80 ± 1.958 ( range,7 to 16) points at final follow- up ( t =- 21.137,P =0.000 ).Mean recovery rate was 57.9％.Postoperative radiography,magnetic resonance imaging and computed tomography scan demonstrated significantly increased sagittal diameter and canal expansion.Two cases without relief of nurological symptoms underwent an additional anterior multilevel corpectomy.One case with ossification of the posterior longitudinal ligament had not good enough neurologic improvement after surgery.No neurologic deterioration owing to hinge reclosure or major surgery-related complications were observed.It would reduce the recovery for those with old age,long history,worse symptoms,cervical kyphosis and abnormal signal in MR imaging.It was good for patients to do early active cervical exercises after surgery.Conclusion Unilateral open- door laminoplasty with OsteoMed M3 titanium plate and screws fixation effectively maintains expansion of the spinal canal and resists closure while preserving alignment and stability.This modified technique is easy to perform with a low complication,is and economic,and is good for clinical application.

Chronic spontaneous cervicothoracic epidural hematoma in an 8-month-old infant

Spontaneous spinal epidural hematoma is an uncommon cause of cord compression in children, especially in infants. An 8-month-old infant was admitted to our hospital for a 40-day history of paraparesis in the lower extremities. This rapidly progressed to paraparesis with an inability to move the lower extremities. MRI of the cervicothoracic spine revealed an epidural mass with compression of the spinal cord. The infant underwent C7-T3 total laminectomies. The pathology and postoperative MRI confirmed spinal epidural hematoma from a vascular malformation. We present the case to highlight the significance of recognizing this chronic spontaneous spinal epidural hematoma and discuss the diagnosis, treatment options and prognosis

Effects of rehabilitation training combined with bone marrow mesenchymai stem cell-derived neural stem cells transplantation on the expression of Nogo-A and NgR proteins after spinal cord injury / 中华物理医学与康复杂志

Objective To study the effects of rehabilitation training combined with the transplantation of bone marrow mesenchymal stem cells-derived neural stem cells (BMSC-D-NSCs) on the expression of Nogo-A and NgR protein in rats after spinal cord injury (SCI).Methods The spinal cords of eighty Sprague-Dawley rats were injured using a modified Allen′s impactor (H = 25 mm) at T10. The injured rats were randomly divided into a combination therapy group which was given rehabilitation training and cell transplants, a cell graft group, a rehabilitation training group and a control group. At the 7th day post SCI, BMSC-D-NSCs were transplanted into the injured spinal cords of the rats in the combination therapy and cell graft groups. Hindlimb movement was assessed using the BassoBeattie-Bresnahan (BBB) scale every week, and protein was extracted from the injured spinal cord tissue for Nogo-A and NgR determination by Western blotting at the 1st, 3rd and 7th day after cell transplantation.Results The average BBB score of the rats in the combination therapy group was significantly higher than that of the other groups from 2 weeks post transplantation. The scores in the rehabilitation training group were significantly higher than in the control group from the 5th week post transplantation. Western blotting showed high expression of Nogo-A and NgR protein 24 h post surgery, but these declined with time. For Nogo-A there was a significant difference among the groups at all three time points. In the combination therapy group the expression declined to a minimum by the 7th day. For NgR protein there was no significant difference between the 1st and 3rd day in any group.Conclusions Rehabilitation training combined with BMSC-D-NSC transplantation can have a synergistic effect on functional recovery from SCI. It can down regulate the expression of Nogo-A and NgR protein.

Effects of continuous passive motion on early healing of rabbit rotator cuff bone-tendon junction:MRI verification at varied time points / 中国组织工程研究

BACKGROUND: Supraspinatus tendon injury is common in rotator cuff injury, the repair difficulty of which is reconstructing the bone-tendon interface. Currently, there are no effective therapeutics and suitable experimental animal models.OBJECTIVE: To establish rabbit rotator cuff injury prosthetic experimental animal model and to observe the effect of continuous passive motion (CPM) on early healing of rabbit rotator cuff bone-tendon interface by MRI, which can provide guidance for preparing an optimal rehabilitation strategy after rotator cuff injury.METHODS: Sixteen male New Zealand rabbits, aged 8 months, were received a rotator cuff acute injury and reconstructing insertion of supraspinatus tendon on greater tuberosity of humerus. The rabbits were randomly divided into cage activity group (n=4) and CPM group (n=12). At 2 days after operation, rabbits were treated by rabbit shoulder joint continuous passive motion apparatus of 75°～75° flexion-extension with various CPM speeds[2 (°)/s, 4 (°)/s, and 10 (°)/s)]. General state and MRI changes of rabbit rotator cuff bone-tendon interface was observed prior to and at weeks 1,2, and 4 after operation.RESULTS AND CONCLUSION: Gross observation showed that the incisions healed very well at 2 weeks after operation. There was no infection, haematoma or disruption after removing the suture. Compared to the cage activity group, the tendon-bone interface of CPM group heeled better at weeks 1, 2 and 4, especially at the speed of 4°/s with 75°-75° flexion-extension. Results demonstrated that this animal model can be satisfied to experimental study. From the following day after operation, various CPM speeds can accelerate the healing of tendon-bone interface, and the optimal speed of CPM was 4 (°)/s.

Biomechanical response to stress stimulation with different intensities during early repair period of acute rotator cuff injury / 中国组织工程研究

BACKGROUND:Continuing stress stimulation has been confirmed to promote repair of rotator cuff injury.This experiment attempts to fu rther quantify the intensity of stress stimulation in order to reach a better therapeutic effect in the entire process of rotator cuff injury repair.OBJECTIVE:To explore the biomechanical performance of stress stimulation with different intensities on repair of acute rotator cuffinjuryMETHODS:Sixteen male New Zealand rabbits were randomly divided into high intensity,low intensity and control groups,with 12 animals in each group.Rabbits were received a rotator cuff acute injury and reconstructing insertion of supraspinatus tendon on greater tuberosity of humerus.At 1 week after operation,rabbits were treated by continuous passive motion(CPM)apparatus,which was-60°to 60° flexion-extension for the high intensity group,and-15° to 15° for the low intensity group.At 2 weeks after operation,the CPM was performed every other day,with 10 minutes per time;which was changed to daily training from week 3 with the same frequently,and 15 minutes per time at week 4.Rabbits in the control group were housed freely.Each 4 animals were sacrificed at weeks 2,3 and 4 after operation,and the largest tensile strength and severity at osteotendinous junction were compared.RESULTS AND CONCLUSION:The maximum tensile intensity and stiffness of the supraspinatus tendon in the low intensity group were greater than that of the control and high intensity group(P＜0.05),which was smallest in the high intensity group.All the breakage point existed at the intra-articular portion.The result demonstrated that low intensity stimulation exhibits superior repair effect in acute rotator cuff injury,while high intensity stimulation is harmful to the early repair of acute rotator cuff injury.

Preparation and characteristics of doxorubicin microspheres-coated bone cement / 中国组织工程研究

BACKGROUND: Bone cement coated by different materials has various characteristics and causes varying therapeutic effects. OBJECTIVE: By comparing characteristics of CPC, CPC/D, and CPC/M/D3 to investigate the preparation of doxorubicin microspheres-coated bone cement. METHODS: Doxorubicin microspheres were prepared with multiple emulsion solvent volatilixation method. Doxorubicin microspheres were mixed with CPC as the ratio of 3:7 to prepare doxorubicin microspheres-coated bone cement. The samples were randomly divided into three groups: CPC group, containing bone cement alone; CPC/D group, containing doxorubicin;CPC/M/D group, containing doxorubicin microspheres. Scanning electron microscope at varying magnification was used to observe structural characteristics and measure the diameter of microspheres. X-ray diffraction was used to estimate the extent of CPC and CPC/M/D samples. The initial and final setting time of cement samples in the three different groups was measured at 25 ℃ and 37℃ respectively. The injectability and interval porosity of different samples were tested. The compressive strength of the specimens was measured using a universal material testing machine to record the maximal compressive strength and breaking strength. RESULTS AND CONCLUSION: PLGA microspheres (100-150 μm) were globular and the surface was slick and sly. Micrestructure of bone cement was not obviously changed following mixing with drugs, thus the location and characteristics of drugs in bone cement were not determined. Micrespheres-coated bone cement (100-150 μm) was distributed among CPC powder. All the X-ray diffraction pattern of three different samples was in coincidence with standard X-ray diffraction pattern of hydroxyapatite, i.e., the major peak was located near 32°. Additional drugs and microspheres did not cause new phases. Obvious collapsing was not observed in the three samples following immediately adding in saline, but the collapsing appeared in both CPC/D and CPC/M/D samples after 24 hours. The setting-up time of CPC/M/D was the longest, but that of CPC was the shortest. On the other hand, the setting-up time was the longest at 37℃. The final setting-up time of CPC/M/D group was 45 minutes. The doxorubicin microspheres-coated bone cement showed the best property of injectability among the three kinds of cement. The interval porosity was the highest in the CPC/M/D group but the lowest in the CPC group. Interval porosity of doxorubicin microspheres-coated bone cement was up to 61.67%. The yield stress was the strongest in the CPC group but the weakest in the CPC/M/D group. Additionally, the yield stress of calcium phosphate cement dramatically decreased while doxrorubicin microspheres were coated. However, there was no significant difference between them. The preparation of doxorubicin microspheres-coated bone cement was reliable and the product had good structures and properties.

Biomechanical studies of single segmental spinal interbody fusion with bisegment fixation for thoracolumbar burst fracture type B / 中国组织工程研究

BACKGROUND: Thoracolumbar burst fracture Dennis type B does not have significant damage in the intervertebral discs of the inferior vertebral body. To reduce fusion segment and remain normal intercalated disc, single discectomy (damaged vertebral body and supervisor vertebral body) is proposed, but because of the damage to the vertebral body, implanted screw is easy to loose following excising partial vertebral body, even cannot be fixed. However, it is still unknown whether implanted screw in the inferior vertebral body of the damaged vertebral body was stabilized using two segment discectomy with fixation.OBJECTIVE: To analyze the feasibility of single segmental spinal interbody fusion with bisegment fixation for thoracolumbar burst fracture type B.DESIGN, TIME AND SETTING: The randomized controlled in vitro study was conducted at the Laboratory of Biomechanics, Southern Medical University from June 2007 to June 2008.MATERIALS: A total of 20 fresh freezing 7-9 months pig samples (T_(13)?L_3 segment) were used, comprising 10 integral samples and 10 L_1 type B thoracolumbar burst fracture samples prepared by pre-injury and weight dropping technique.METHODS: Pig fresh thoracolumbar specimens from T_(13)?L_3 were collected to create models of type B thoracolumbar burst fracture. There were 4 groups in this study. Ten of them were selected as intact group (n=10) (fresh pig T_(13)?L_3 segment). T_1 vertebral endplate pre-injury and weight dropping technique and incremental trauma approach were used. Denis' type B burst fracture was produced, and ten of them were selected as unstable group (n=10). Firstly, unstable group was decompressed by discectomy and semivertebraectomy in upper half of the vertebral body, single level was fused with iliac and U-FRONT anterior thoracolumbar system were placed between T_(14) and L_2, as single discectomy with fixation group (n=10). Then lower disc of injury vertebra discectomy and vertebraectomy, fused with iliac U-FRONT anterior thoracolumbar system were placed between T_(14) and L_2, as two segment discectomy with fixation group (n=10). The bone graft was longer 1 mm than the bone graft region.MAIN OUTCOME MEASURES: The flexion, extension, right/left lateral bending, and right/left axial rotation range of motion (ROM) of T_(14)?L_2 were measured in each group on the spinal three-motional test machine at 10 N穖.RESULTS: The flexion, extension, right/left lateral bending, and right/left axial rotation were not stable in the unstable group.ROM was significantly increased in the unstable group compared with the intact group (P< 0.01). The primary stability was significantly elevated in the single discectomy with fixation and two segment discectomy with fixation groups. The flexion, extension, right/left lateral bending, and right/left axial rotation ROM were significantly reduced in the single discectomy with fixation and two segment discectomy with fixation groups compared with the unstable group (P < 0.05). The flexion, extension, right/left lateral bending ROM was significantly decreased in the two groups compared with the intact group, but axial rotation ROM was significantly increased (P< 0.05). Axial rotation ROM was smaller in the single discectomy with fixation group compared with the two segment discectomy with fixation group (P < 0.05).CONCLUSION: Single segmental spinal interbody fusion with bisegment fixation for thoracolumbar burst fracture type B had a good immediate stability in flexion, extension, lateral bending motion. Compared with traditional partial corpectomy L_1 between the caudal and cranial endplate of the adjacent vertebrae with bisegmental fixation, it had a better immediate stability in axial rotation.

Changes of excitatory amino acids of cerebrospinal fluid in patients with delayed encephalopathy after acute carbon monoxide poisoning / 中国医师进修杂志

Objective To investigate the changes of excitatory amino acids (EAAs) of cerebrospinalfluid (CSF) in patients with delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Method The EAAs levels of CSF including glutamate (Glu) and aspartate (Asp) in 24 patients with DEACMP and 20 controls with migraine were measured by high performance liquid chromatography( HPLC ).Results Glu and Asp levels in patients with DEACMP were significantly higher than those of the controls [(3.76 ± 1.52) μmol/L vs ( 1.55 ± 1.03 ) μmol/L, (0.73 ± 0.44) μmol/L vs (0.38 ± 0.33 ) μmol/L, P all <0.01]. Glu and Asp levels in moderate and severe DEACMP patients were higher than those in mild DEACMP patients. Conclusion It suggests that EAAs participated in the pathogenesis of DEACMP. The Glu and Asp levels in CSF may be regarded as indicator of DEACMP.

Biomechanical study of neotype shape memory alloy cervical hook for atlantoaxial instability / 中国组织工程研究

BAcKGROUND:In recent years,the pedicle screws fixation technique,which is used in fixation for atlantoaxial instability associated with trauma,severe degeneration and tumorectomy,has been developed.However,this kind of technique easily causes several complications,including malpositional screws,vascular injuries,and even vertebral artery injury.Based on the biomechanical characteristics of memory alloy and determination of atlantoaxial data,a neotype shape memory alloy cervical hook was designed to treat atlantoaxial instability.OBJECTIVE:To investigate the biomechanieal characteristics of the neotype shape memory alloy cervical hook for atlantoaxial instability.DESIGN,TIME AND SETTING:Repeated measurement analysis of variance test was performed in the Laboratory of Clinical Anatomy and Medical Biomechanics,Southern Medical University between March and April 2008.MATERIALS:Eight fresh adult craniocervical specimens(C0-C4)were provided by Department of Clinical Anatomy,Southern Medical University.Atlantoaxial neotype shape memory alloy cervical hook(50.8%-51.8%nickel and the remaining part was titanium)was fabricated by Shanghai Xinchang Memory Alloy Co.,Ltd.METHODS:The included eight C0-C4 specimens were used to test three-dimension ranges of motion(ROM)by fixation and neotype shape memory alloy cervical hook fixation.Then,the positions of spine varying from no loading to the maximum loading status were scanned and analyzed using image processing software to determine the three-dimensional ROM under different statuses.MAIN OUTCOME MEASURES:Three-dimensional ROM of tested specimens.RESULTS:Neotype shape memory alloy cervical hook fixation and Germany AESCULAP SSE hanger fixation had similar flexion-extension range of motion(P=0.595).Lateral bending three-dimensional ROM was greater in the neotype shape memory alloy cervical hook fixation group than in the Germany AESCULAP AAE hanger fixation(P< 0.05).The rotatory three-dimensional ROM was smaller in the neotype shape memory alloy cervical hook fixation group than in the Germany AESCULAP AAE hanger fixation(P<0.05).CONCLUSION:Neotype shape memory alloy cervical hook fixation had comparative post-surgery immediate stability with the Germany AESCULAP AAE hanger fixation.Neotype shape memory alloy cervical hook fixation produced a little worse biomechanical lateral bending stability and a little better biomechanical rotatory stability than Germany AESCULAP AAE hanger fixation.

Effect of acid fibroblast growth factor/fibrin gelatin on preventing denervated motor end-plate degeneration:An immunohistochemical analysis / 中国组织工程研究

BACKGROUND:We previously demonstrated that the acid fibroblast growth factor/fibrin gelatin implantation could greatly relieve denervated motor end-plate degeneration and myatrophy. OBJECTIVE:To study the effect of acid fibroblast growth factor/fibrin gelatin on preventing denervated motor end-plate degeneration using immunohistochemical method. DESIGN,TIME AND SETTING:A randomized controlled animal experiment was performed in Zhujiang Hospital,Southern Medical University from June to December 2006. MATERIALS:A total of 24 SD rats of clean grade were randomly divided into three groups:acid fibroblast growth factor/fibrin gelatin group,fibrin gelatin group,and blank control group,with 8 rats for each group. METHODS:Under the general anesthesia,right common peroneal nerves of rats in each group were cut off 1 cm away from the nerve muscle entry point. Acid fibroblast growth factor/fibrin gelatin group,perilemma was sutured and the compound was implanted into spatium intermusculare around denervated tibial muscle nerve region;fibrin gelatin group,perilemma was sutured and fibrin gelatin was implanted;perilemma was sutured without medication in the blank control group. MAIN OUTCOME MEASURES:After 6 weeks,neuromuscular junction of tibial muscle branch of common peroneal nerve and its peripheral muscles were separated. Acidic fibroblast growth factor receptor was detected by SP immunohistochemistry to observe expressive site of acidic fibroblast growth factor receptors,and count positive blood capillary. Gray scale of the acidic fibroblast growth factor receptor was detected using image analysis system. RESULTS:The acidic fibroblast growth factor receptor was mainly located in capillary vessel wall. High density of expressing area of acidic fibroblast growth factor receptor and intensive capillary vessels were in acid fibroblast growth factor/fibrin gelatin group. In contrast,low density of masculine expressing site of acidic fibroblast growth factor receptor in capillary vessel and rare capillary vessels were in fibrin gelatin group and blank control group. The positive percentage of acidic fibroblast growth factor receptor expression of capillary vessels in acid fibroblast growth factor/fibrin gelatin group was higher than fibrin gelatin group and blank control group. The expressing amount of acidic fibroblast growth factor receptor in acid fibroblast growth factor/fibrin gelatin group was also higher than fibrin gelatin group and blank control group CONCLUSION:Acidic fibroblast growth factor can protect motor end-plate by improving the surrounding blood circulation.

Effects of lithium chloride on endogenous neural stem cells in rats after spinal cord injury / 中国组织工程研究

BACKGROUND:For treatment of spinal cord injury, exogenous neural stem cell transplantation still faces many problems.Thus, the strategy of supplementary treatment of activating exogenous neural stem cells has been a hot focus.It has been found that lithium chloride can significantly inhibit differentiation and promote proliferation of neural stem cells, whose effects are correlated to Wnt signal pathway.OBJECTIVE:To investigate the effect of lithium on endogenous neural stem cells after spinal cord injury in rats.DESIGN, TIME AND SETTING:The randomized controlled animal study was performed at the Central Laboratory, Zhujiang Hospital from March to August 2008.MATERIALS:A total of 55 adult female Wistar rats were assigned into normal control group(n=5), simple injury group(n=25), and lithium chloride group(n=25).Lithium chloride was purchased from Guanghua, Guangzhou, China.METHODS:In the simple injury group and lithium chloride group, rat models of acute spinal cord injury at T10 segment were made by Allens method.From 1 hour following model induction, rats in the lithium chloride group received 3 mmol/kg per day lithium chloride through intraperithoneal injection.Samples were directly obtained.In the simple injury group, rats received an equal volume of saline.Rats in the normal control group were left intact.24 hours before samples were obtained, rats in each group were intraperitoneally injected with Brdu solution for labeling, once every 8 hours, totally 3 times.Spinal cord at 5 mm from the center of damage region received Brdu, catenin immunohistochemistry.MAIN OUTCOME MEASURES:BrdU-positive cell number and area of catenin-positive expression were measured.RESULTS:There were a few Brdu-positive cells and less expression of catenin in the center canal and adventitia of spinal cord in the normal control group.Many Brdu-positive cells and a little expression of catenin were found in gray matter and ependyma of injury area in the simple injury group 24 hours after model induction, which reached the peak at 1 week, and declined gradually at 2 weeks.Just a few Brdu-positive cells and little expression of catenin existed at 4 weeks.Compared with the simple injury group, there was no difference in Brdu-positive cells and the expression of catenin at 24 hours following model induction in the lithium chloride group.There were more Brdu-positive cells and the expression of catenin in the center canal and adventitia of spinal cord at 1 week(P

Effects of wing-like memory alloy intrasegmental fixator on healing of lumbar spondylolysis in dogs / 中国矫形外科杂志

[Objective]To investigate the influence of wing-like memory alloy intrasegmental fixator(WMAIF)on healing of lumbar spondylolysis.[Method]Eighteen healthy hybrid adult dogs were used in the experiment,regardless of gender,the L_6 isthmic portion were injured by operation randomly and equally divided into three groups.Group Ⅰ were fixed with WMAIF,groupⅡ were fixed with steel wire,group Ⅲ were treated with nothing.Every group was examined through CT at 2,4,6,8 and 10 weeks.[Result]In group Ⅰ,the fracture achieved healing at 6 weeks after operation.In group Ⅱ,the fracture achieved healing at 10 weeks after operation,while no repair of fracture was found in group Ⅲ.[Conclusion]Lumber spondylolysis fixation with WMAIF has stable and continued axial stress,WMAIF is beneficial to fracture healing,and is a new and reliable intrasegmental instrument for direct repair of lumbar spondylolysis.

Study of chondrocyte on the layered scaffold under minic microgravity culture / 中国矫形外科杂志

[Objective]To evaluate the feasibility of the minic microgravity as a method and the layered cylindric collagen-chitosan-?-tricalcium phosphate composite as a scaffold for the cartilage tissue engineering after an observation of how it absorbs the chondrocytes and affects the cell behavior.[Method]The chondrocytes were isolated and multiplied in vitro,and then the chondrocytes were seeded onto the porous collagen-chitosan-?-tricalcium phosphate composite scaffold and were cultured in both minic microgravity and ordinary environment for 3 weeks.The effects of the composite scaffold on the cell adhesivity,proliferation,morphological changes and synthesis of the extracellularmatrix were observed by the growth curve,phase-contrast microscopy,histology,scanning electron microscopy and immunohistochemistry.[Result]The chondrocytes that adhered to the scaffold increased significantly and secreted extracellular matrix in the center of the porous scaffold around the chondrocytes under minic microgravity compared with ordinary environment.Immunohistochemistry of type Ⅱ collagen was positive.[Conclusion]The minic microgravity environment will be a good method for the cartilage tissue engineering.And the layered cylindric collagen-chitosan-?-tricalcium phosphate composite scaffold has a good cellular compatibility.It will be an ideal scaffold for the cartilage tissue engineering.