Robot-assisted core decompression combined with bone grafting in the treatment of early osteonecrosis of femoral head / 中华骨科杂志

Objective:To explore the clinical effect of robot-assisted core decompression combined with bone grafting in the treatment of early-stage osteonecrosis of femoral head.Methods:The data of 49 patients (84 hips) who attended the Department of Orthopedics and Joint Surgery of the Second Affiliated Hospital of Xi'an Jiaotong University from August 2019 to February 2021 were retrospectively analyzed. All the patients suffering Association Research Circulation Osseous (ARCO) II stage of osteonecrosis of femoral head underwent core decompression and bone grafting. Among the patients undergoing surgery, 30 patients (54 hips), including 19 males and 11 females, aged 44.3±5.4 years (range, 21 to 59 years) were treated with conventional surgical methods, and 19 patients (30 hips), including 12 males and 7 females, aged 41.4±7.2 years (range, 20 to 58 years), were assisted by the orthopedic robot navigation system. All operations were performed by the same operator. All patients were informed of the conventional and robotic surgical options by the surgeon at admission, and the patients made the decision. The baseline data of the two groups of patients, the time of unilateral operation, the number of unilateral X-ray fluoroscopy, the Harris hip score at the last follow-up after surgery, the visual analog score (VAS), and the collapse rate at the last follow-up were collected and compared.Results:A total of 41 patients (70 hips) were followed up, including 24 cases (42 hips) in the conventional surgery group and 17 cases in the robot-assisted group (28 hips). The average follow-up time of all cases was 14.6±4.8 months (range, 3 to 21 months). At the last follow-up, a total of 13 patients (13 hips) suffered femoral head surface collapse, including 11 patients in the conventional surgery group (11 hips) and 2 patients in the robot-assisted group (2 hips). The rate of femoral head collapse between the two groups had statistical difference ( P=0.045). The average operation time of unilateral hip in the conventional operation group was 21.3±5.4 min, and 16.8±3.3 min in the robot-assisted group, with significant difference ( t=3.94, P<0.001). The number of X-ray fluoroscopy of unilateral hip in the conventional operation group was 14.4±3.8 times, and 9.6±2.1 times in the robot-assisted group, with significant difference ( t=6.08, P<0.001). The Harris hip score before surgery in the conventional surgery group was 68.4±4.5 points, and 85.1±3.8 points at the last follow-up, while the preoperative Harris hip score of the robot-assisted surgery group was 67.2±3.9 points, and 86.5±4.4 points at the last follow-up. The Harris hip scores at the last follow-up of the two groups were significantly different from those before the operation, but there was no difference between the two groups after surgery ( t=1.09, P=0.283). The preoperative VAS of the conventional surgery group was 4.8±1.7 points, and 1.7±0.8 points at the last follow-up. The preoperative VAS of the robot-assisted surgery group was 5.1±1.5 points, and 0.9±0.3 points at the last follow-up. Τhere were significant differences between the two groups regarding the VAS in the last follow-up ( t=3.92, P<0.001). Conclusion:Core decompression combined with bone grafting have a definite effect in the treatment of osteonecrosis of ARCO II stage of osteonecrosis of femoral head. Compared with conventional surgery, robot-assisted surgery can achieve better short-term results and head preservation rate.

Application status and prospect of domestic artificial intelligence and orthopaedic robot in arthroplasty surgery / 中华骨科杂志

In recent years, artificial intelligence and orthopaedic robots, as a research hotspot and an important development direction in the medical field, provide accurate preoperative planning and surgical navigation for orthopaedic surgery. Artificial intelligence and orthopaedic robotics can truly achieve the precision of arthroplasty surgery. Artificial intelligence has great advantages in image diagnosis of joint disease, image segmentation, preoperative planning and other aspects. Through more accurate intelligent image segmentation and more efficient and accurate preoperative planning, it can effectively reduce the difficulty of complex primary joint replacement and revision surgery, reduce the cost of communication between clinicians and engineers, and theoretically improve the accuracy of prosthesis selection. Based on X-ray or CT scan, the orthopaedic robot can perform accurate bone operation during surgery on the basis of accurate preoperative planning, avoid the deviation brought by the surgeon's experience and operation, achieve the homogeneity of the surgical level of different levels of doctors, reduce the learning curve of arthroplasty surgery, and have theoretical advantages in complex surgery.

Emphasis on prevention and management of refractures after osteoporotic fractures / 中华骨科杂志

With the aging of society, the incidence of osteoporosis is increasing. Osteoporotic fractures are directly related to osteoporosis. In the context of the gradual increase in osteoporosis, the number of osteoporotic fractures is increasing, and the incidence of refractures is also increasing annually. Refracture after an osteoporotic fracture refers to the occurrence of a new fracture after the initial fracture due to the lack of improvement in bone density and quality and the effect of low-energy external force on the bone. The occurrence of refracture has more harm to the patient's treatment plan, fracture healing, rehabilitation training, self-care ability, psychological expectation, compliance and other clinical indicators. Therefore, the prevention and management of refracture after osteoporotic fracture has gradually become a hot topic at home and abroad. At present, in this field of prevention and treatment, both clinicians and community doctors have problems with insufficient awareness and short-sighted clinical management, such as unclear management standards for refracture prevention, unclear division of labor between doctors at all levels and various types of doctors, and inadequate measures to improve patient's compliance. Focusing on the characteristics of osteoporotic fractures, refractures, and refracture prevention and management, the core points of refracture prevention and management are proposed and elaborated, and the corresponding contents, fixed teams, proprietary databases or proprietary books of refracture prevention and management should be clarified, so as to provide reference for further improving the clinical management of refracture prevention and treatment after osteoporotic fractures.

The future of joint surgery: the application of digital orthopaedic technology in joint surgery / 中华骨科杂志

Digital orthopedic technologies are increasingly being applied to the clinical practice of joint surgery. These technologies include artificial intelligence, virtual/augmented/mixed reality, 3D printing, computer navigation, robotic-assisted joint replacement surgery, and other digital orthopedic technologies. Digital orthopedic technologies continue to empower joint surgeons, simplify complex operations, achieve precision in simple operations, and to make precise operations more individualized. Thus, they are becoming important development directions for joint surgery in the future. With the help of advances in computer-aided design and additive manufacturing technology, customized joint prostheses and bone tissue repair materials provide great convenience for reconstruction of complex bone defects during revision surgery. Various types of computer-assisted navigation technologies and robot-assisted surgery technologies can help doctors improve the accuracy of osteotomy and prosthesis implantation significantly. However, to fundamentally improve patients' satisfaction after joint replacements, we need to use digital orthopedics technologies to explore the ideal target value of arthroplasty. Further, we use personalized preoperative planning with objective and accurate assessment technology of soft tissue balance, precise intraoperative operations, and the use of customized prostheses to achieve individualized and precise joint arthroplasty. Various digital orthopedic technologies have their own advantages and disadvantages. Joint surgeons should have an in-depth understanding of these technologies and make full and reasonable use of these technologies to benefit the majority of patients.

Interaction between necroptosis and apoptosis in MC3T3-E1 cell death induced by dexamethasone / 南方医科大学学报

OBJECTIVE@#To investigate the relationship between necroptosis and apoptosis in MCET3-E1 cell death induced by glucocorticoids.@*METHODS@#MC3T3-E1 cells were incubated with 10-6 mol/L dexamethasone followed by treatment with the apoptosis inhibitor z-VAD-fmk (40 μmol/L) or the necroptosis inhibitor necrostatin-1 (40 μmol/L) for 2 h. At 72 h after incubation with dexamethasone, the cells were harvested to determine the cell viability using WST-1 assay and the rate of necrotic cells using annexin V/PI double staining; the percentage of apoptotic cells was determined using Hoechst staining. The mitochondrial membrane potential and the level of ATP in the cells were also evaluated. Transmission electron microscopy was used to observe the microstructural changes of the cells. The expressions of RIP-1 and RIP-3 in the cells were detected by Western blotting.@*RESULTS@#At a concentration of 10-6 mol/L, dexamethasone induced both apoptosis and necroptosis in MC3T3- E1 cells. Annexin V/PI double staining showed that inhibition of cell apoptosis caused an increase in cell necrosis manifested by such changes as mitochondrial swelling and plasma membrane disruption, as shown by electron microscopy; Hoechst staining showed that the percentage of apoptotic cells was significantly reduced. When necroptosis was inhibited by necrostatin-1, MC3T3-E1 cells showed significantly increased apoptosis as shown by both AV/PI and Hoechst staining, and such changes were accompanied by changes in mitochondrial membrane potential and ATP level in the cells.@*CONCLUSIONS@#In the process of dexamethasone-induced cell death, necroptosis and apoptosis can transform reciprocally accompanied by functional changes of the mitochondria.

Relative factors and follow up research of asymptomatic osteonecrosis of the femoral head / 中华外科杂志

Objective@#To evaluate the progress and influence factors of asymptomatic osteonecrosis of the femoral head(ONFH).@*Methods@#MRI was performed on the contralateral hips of 174 patients with unilateral symptomatic ONFH who admitted at Department of Orthopaedics, the Second Affiliated Hospital of Xi′an Jiaotong University from January 2012 to December 2018. Eighty-three of 174 patients with unilateral ONFH were found suffering from contralateral ONFH(47.7%), of which 77 patients were followed up.There were 28 males and 49 females with age of 48.6 years (range: 21-73 years). The pathogenesis, ARCO classfication, areas and position of osteonecrosis were collected.Independent sample t test, χ2 test, Fisher exact test, multivariate Logistic regression were used to analyze the potential influence factors.@*Results@#Patients were followed up for 36.7 months. During the following up period, ARCO classification of 28 patients (36.4%) progressed.The progress of asymptomatic ONFH was not related to the gender, age and original ARCO classification, but related to the pathogenesis, position and area of osteonecrosis (all P<0.05).@*Conclusion@#The progress of asymptomatic osteonecrosis is related to the pathogenesis, position and area of osteonecrosis,but most of asymptomatic ONFH will not progress.

The short-term outcomes and rivision complication analysis of medial unicompartmental knee osteoarthritis treated by unicompartmental knee arthroplasty / 中国医师杂志

Objective To evaluate the short-term outcomes and analyze the complications of medial unicompartmental knee osteoarthritis (MUKOA) treated by unicompartmental knee arthroplasty (UKA).Methods Retrospectively analyzed the patients suffered with MUKOA and registered into our department from Jul 2015 to Jan 2017.71 cases were enrooled in the study,of which 17 are male (19 UKA) and 54 are female (66 UKA).The general information,perioperative data,Hospital for Special Surgery (HSS) score,visual analogue score (VAS) and complications of the group were analyzed.Results Females were three times more than males (54∶ 17).The average age of female subjects was lower than that of male,the difference was significant (P ＜ 0.05).The rate of Osteoporosis of females was significantly higher than that of males (P ＜ 0.05).The operative time,length of incision,total overt blood loss and postoperative in-bed time were (54.06 ± 6.24) min,(8.56 ± 0.83) cm,(86.10 ± 5.44) ml,(3.51 ± 1.01) d,respectively.No significant differences were found between males and females (P ＞ 0.05).The preoperative,3 months and 6 months postoperative HSS scores were 45.2 ± 4.5,80.3 ± 5.7 and 88.4 ± 4.2,respectively.No differences were found between males and females (P ＞ 0.05).The preoperative,3 months and 6 months postoperative VAS scores were 6.6 ± 1.2,1.7 ± 0.7 and 0.5 ± 0.5,respectively.No differences were found between males and females (P ＞ 0.05).There were 2 revised cases,and the reasons for revision were infection and unstability caused by sport injury.Conclusions UKA is an ideal choice for patients with MUKOA,Especially for the ones older than 60 years.However,the corrections on lower-limb forceline and joint unstability are limited,thus,the indications for UKA should be controlled strictly.

Correlation analysis between pre-anesthesia/post-anesthesia range of motion and knee flexion function after total knee arthroplasty / 中国医师杂志

Objective To evaluate the relationship between pre-anesthesia/post-anesthesia range of motion (ROM) and knee flexion function after total knee arthroplasty (TKA).Methods 108 patients with osteoarthritis of knee joint replacement performed by the same surgeon of primary TKA screening from 2016 January to 2017 January in our hospital were enrolled in the study.Correlation analysis were conducted between pre-anesthesia/post-anesthesia ROM and knee flexion function of 1,6,12 months after total knee arthroplasty.Results The Correlation coefficient of the Pre-anesthesia ROM and postoperative ROM are 0.392,0.665,0.708 at 1,6 and 12 months,while the Correlation coefficient of the Pre-anesthesia ROM and Post-anesthesia ROM of postoperative are 0.495,0.759,0.793 (P ＜ 0.001),indicating that the correlation difference between pre-anesthesia/post-anesthesia ROM and knee flexion function of 1,6,12 months after total knee arthroplasty is statistically significant (P ＜ 0.05).Conclusions Post-anesthesia range of motion is a better determinant of postoperative range of motion in patients.This should be taken into consideration by surgeons during preoperative planning and in managing patients'expectations.

Joint registration system under big data background / 中国医师杂志

The arrival of big data era has constantly changed the habits of social behavior,and also brought new opportunities for the medical and health industry.China's joint registration system has not yet been established.How to establish a national joint registration system in line with China's national conditions in the context of the big data era is a direction that every practitioner in relevant industries should pay attention to and work together.

Neuroprotective effects of safranal on a rat model of traumatic injury to the spinal cord by anti-apoptotic,anti-inflammatory and edema-attenuating actions / 西安交通大学学报(医学版)

Objective To investigate the effect of safranal on neurologic functions and histopathologic changes after spinal cord injury (SCI)and the related molecular mechanisms.Methods We randomly assigned 36 rats into six groups:control group,injury group and four treatment groups (namely,A,B,C,and D).The Basso Beattie Bresnahan locomotor rating scale (BBB)and HE staining were applied to evaluate the neuroprotective effect and determine the most effective dosage.Another 60 rats were randomly and evenly assigned to three groups:control group,injury group and treatment group.Nissl staining,TUNEL staining and electron microscopy were used to analyze histopathological changes;RT-PCR,immunohistopathological staining,ELISA,and Western blot were used to detect the expressions of apoptosis-related proteins (Bax and Bcl-2 ),inflammation-related factors (IL-1β, IL-10,TNF-αand P38MAPK),and edema-related factor (APQ-4).Results The optimal dosage for safranal was 100 mg/kg.Neurocyte structure was found more distinct in treatment group than in injury group.In addition,we detected a smaller number of apoptotic neurocyte (26.37±1.54 vs.35.94±1.62,P=0.000),decreased Bax (P=0.000)and APQ-4[(359.55±16.12)% vs.(124.53±20.35)%,P=0.000]expressions,increased Bcl-2 (P=0.036)expression,and obviously lowered P38MAPK [(300.30±33.26)% vs.(132.54±10.21)%,P=0.000]expression. Conclusion Safranal exerts its neuroprotective function through anti-apoptosis,anti-inflammation and anti-edema in the rat model of spinal cord injury.

Cytological study of macrophage migration inhibitory factor in treatment of steriod-induced ischemic osteonecrosis of femoral head / 西安交通大学学报(医学版)

Objective To explore whether macrophage migration inhibitor factor (MIF)can protect human bone microvascular endothelial cells (HBMECs)from glucocorticoid-induced damage.Methods HUVECs were isolated from human femoral head.After HUVECs were cultured and identified,we constructed the ECs damage model with high-dose hydrocortisone.The cells were randomly divided into blank control group,low-dose MIF group,high-dose MIF group with corresponding treatment.Cell activity was detected by AlamarBlue in each group. The number of viable cells was detected in Live/Dead staining.The cell morphology was observed after cytoskeleton staining.Cell migration ability was compared by scratch test and the level of VEGF expression was detected by ELISA.Results Cell model was successfully constructed.The activity of cells in high-dose MIF group (178.3± 15.2)% was significantly higher than that in the control group (100±8.4)% and low-dose MIF group (149.1± 13.8)% (P<0.05).The number of viable cells in high-dose MIF group (139.5±14.3)% was higher than that in low-dose MIF group (121.3±12.9)% while the two groups had more viable cells than the control group (100± 8.4)% (P<0.05).The scratch test results indicated that cell migration ability in high-dose group was the strongest and the scratch disappeared at 24 hours after scratching.The expression of VEGF at 24 hours after intervention was (170±15.7)pg/mL in normal group,(328±25.3)pg/mL in low-dose group and (405±31.2)pg/mL in high-dose group.VEGF level was lower in low-dose group than in high-dose group (P<0.05),but higher than the normal group (P<0.01).Conclusion MIF can promote the proliferation and migration of ECs in a dose-dependent manner and upregulate the expression of VEGF.MIF can improve ECs damage induced by high-dose glucocorticoid.

Effects of miR-125a-3p and miR-17-5p on steroid-induced osteonecrosis / 西安交通大学学报(医学版)

ABSTRACT:Objective To explore the differential expression of microRNAs (miRNAs)in steroid-induced osteonecrosis (ON).Methods Bone tissues were selected from patients with steroid-induced ON between the necrotic zone of femoral heads and its femoral neck to analyze the miRNA expression profile using the microarray. The most differentially expressed miR-125a-3p and miR-1 7-5p in microarray analysis were further confirmed by real-time quantitative PCR.Results According to the microarray screening,8 miRNAs were upregulated and 3 miRNAs were downregulated in the necrotic zone of femoral heads samples (Fold>2,P <0.05 ).Results of real-time PCR revealed that miR-125a-3p was upregulated and miR-1 7-5p was downregulated in the necrotic zone of femoral heads samples,which were in agreement with the microarray data.Conclusion MiRNA’s differential expression profile of human steroid-induced ON samples was obtained.Among the differentially expressed miRNAs, miR-125a-3p and miR-1 7-5p are the most apparently differentially expressed miRNAs,which may be related to the pathogenesis and development of steroid-induced ON.

Circumferential electrocautery of the patellar in primary total knee replacement without patella replacement: a meta-analysis and systematic review / 中国医师杂志

Objective To identify and assess whether circumferential electrocautery is useful to improve outcomes after primary total knee replacement.Methods We searched MEDLINE,EMBASE,PubMed,SpringerLink,Web of Knowledge,OVID CINAHL,OVID EBM and Google Scholar,and included articles published through January 2014.This study used the methods of meta-analysis to assess whether circumferential electrocautery could improve anterior knee pain and knee function after total knee replacement,and identified the function of circumferential electrocautery in total knee replacement.Results A total of eight articles met the inclusion criteria.Among the 1 048 cases included in the analysis,526 cases had patellar denervation,and 522 cases were in the control group.The meta-analysis revealed no significant difference in the incidence of anterior knee pain (P =0.18) and visual analogue scale (VAS) (P =0.23) between two groups.However,patellar score (P =0.01),Western Ontario and McMaster Universities osteoarthritis index (WOMAC) score (P ＜ 0.01),and range of motion (ROM) (P ＜ 0.01) indicated that circumpatellar electrocautery improved clinical outcomes compared to non-electrocautery groups.Conclusions The results indicated that circumferential electrocautery of the patellar did not significantly improve anterior knee pain relative to non-electrocautery techniques.However,circumferential electrocautery significantly improved patients' knee function after surgery.Therefore,circumferential electrocautery might be beneficial to the outcome of primary total knee replacement surgery without patella replacement.

Cervical stability changes following metal rubber cervical disc replacement / 中国组织工程研究

BACKGROUND:Previous studies designed and made titanium metal rubber cervical disc prosthesis, and performed feasible studies on its effect on movement and stress distribution by replicating intervertebral discs. OBJECTIVE:To further observe the changes in the stability of goat cervical vertebra after metal rubber cervical disc replacement. METHODS:Nine goats were randomly divided into experimental group (n=6) and normal control group (n=3). Goats in the experimental group received metal rubber cervical disc replacement at C4/5segment. Goats in the normal control group did not receive any treatment. Radiographic data at anteroposterior and lateral position, hyperextension and excessive flexion were taken to measure intervertebral height, range of motion and intervertebral angle at C4/5 segment before operation, immediately, 4, 8, 12 weeks after operation. Subsequently, slicing and embedding of hard tissue at surgical segment, picric acid-acid fuchsin staining and scanning electron microscopy were conducted.RESULTS AND CONCLUSION:No significant difference in the intervertebral height and spinal range of motion at C4/5 segment at different time points was detected between postoperative results in the experimental group and preoperative results in the experimental group, normal control group. The intervertebral height at C4/5 segment was higher immediately, 4 and 8 weeks after surgery than preoperative result in the experimental group (P < 0.05). No significant difference in intervertebral angle at C4/5 segment was detectable between 4, 8 and 12 weeks postoperatively in the experimental group and normal control group (P < 0.05). At 4 weeks after surgery, bone did not contact with the edge of the prosthesis in the experimental group. At 8 weeks, the gap between bone and the prosthesis became smal, and some new bone attached to the edge of the prosthesis. At 12 weeks, a few osteoblasts were observed on the surface of the prosthesis. New osteogenic tissue grew into the prosthesis. Results suggested that metal rubber cervical disc replacement in the intervertebral space could maintain intervertebral height and range of motion in a short period, and tightly bind to the vertebral body.

Repair effects of co-expression of the VEGF and BMP genes via an adeno-associated viral vector on early steroid-in-duced avascular necrosis of the femoral head in rabbits / 中华骨科杂志

Objective To investigate the repair effects of co-expression of the VEGF and BMP genes via an adeno-as-sociated viral vector on early steroid-induced avascular necrosis of the femoral head in rabbits. Methords To construct ani-mal model of early SANFH and screen by MRI. The SANFH animal were divided into rAAV-IRES-hrGFP(AAV-GFP), rAAV-hVEGF165-IRES-hrGFP(AAV-VEGF), rAAV-hBMP-7-IRES-hrGFP(AAV-BMP)and rAAV-hVEGF165-IRES-hBMP-7(AAV-VEGF/BMP)groups. The four group virus vectors were injected into core decompression region at the dose of 25μl/site after core decompression operation directly. Repair effects of rAAV vector on early SANFH in rabbits were evaluated by Western blot assay, HE staining, immunohistochemical staining, MRI, radionuclide bone scan, blood vessel counting detected by ink perfusion and fro-zen section, Micro-CT and biomechanical strength detection on the 12th week post-injection. Results Model success ratio was 73.33%. rAAV-hVEGF165-IRES-hBMP-7 virus vector efficiently expressed hVEGF165 and hBMP-7 genes on the 12th week after rAAV injection. hVEGF165 protein secreted in vivo promoted metabolism in core decompression region by increasing the quantity of new vessels and improving the blood supply;hBMP-7 protein secreted in vivo promoted new bone formation in core decompres-sion region by increasing bone mineral density and improving bone biomechanical strength. The AAV-VEGF/BMP group can pro-mote repair effects more effectively than AAV-VEGF group or AAV-BMP group. Conclusion The adeno-associated viral vectors co-expressing hVEGF165 and hBMP-7 can promote repair effects on early SANFH in rabbits by increasing the blood supply and strengthening the bone quality of femoral head.

Comparative Study of LISS and the Condylar Support Plates in the Treatment of AO Type C Distal Femoral Fractures in Adults / 天津医药

Objective To summarize complications and early clinical effect of less invasive stabilization system and the femoral condylar support plates in treatment of AO type C distal femoral fractures. Methods We reviewed 46 patients who had internal fixation of AO type C distal femoral fractures. Of all 46 patients, 25 were with less invasive stabilization sys-tem and 21 were with femoral condylar support plates fixation. Comparative analysis was performed using intraoperative in-dex, postoperative complications and the Evanich score at follow-up. Results All 46 patients were followed up with a mean time of 19.6 months after surgery. The difference in incision length, blood loss, fracture healing time was significant between the 2 groups(P＜0.05)but not in the duration of operations and hospital stays(P>0.05). The statistical signifi-cance was also found in the total incidence of postoperative complications and the Evanich score at the last follow-up(P＜0.05). Conclusion Patients with less invasive stabilization system fixation had the characteristics of less trauma, shorter fracture healing time, less postoperative complications and better functional recovery compared with femoral condylar sup-port plates. Less invasive stabilization system had became an ideal internal fixation in treatment of AO type C distal femoral fractures.

Regulatory effects of glucocorticoids on the local renin-angiotensin system in osteoblasts / 西安交通大学学报(医学版)

Objective To investigate the regulatory effects of glucocorticoids on the local renin-angiotensin system in osteoblasts by using MC3T3-E1 cells.Methods Cellular immune histochemistry was carried out to observe the renin-angiotensin system in osteoblasts.And then after 12-hour culture in serum-free solution,MC3T3-E1 cells were divided into four groups:control,dexamethasone (DXM),dexamethasone + mifepristone (DXM+MIF)and mifepristone (MIF).Components of the renin-angiotensin system including angiotensin type 1 receptor (AT1R),angiotensin type 2 receptor (AT2R)and angiotensin converting enzyme (ACE)in osteoblasts were detected at the mRNA and protein levels using Western blot and PCR.The activity of ACE was also measured after 36-hour intervention.Results The results of immunohistochemistry showed that AT1R,AT2R and ACE were all expressed in osteoblasts.The activity of ACE increased obviously after dexamethasone intervention compared with that in the control group,which was blocked by mifepristone.The mRNA levels of AT1R,AT2R and ACE were increased by dexamethasone compared with those in the control group,which was inhibited by mifepristone.The protein levels of AT1R,AT2R and ACE were enhanced by dexamethasone compared with those in the control group, which was blocked when the cells were co-intervened with mifepristone.However,ACE activity and the mRNA and protein levels of AT1R,AT2R and ACE did not change when the cells were intervened with mifepristone alone (P>0.05).Conclusion The local renin-angiotensin system in osteoblasts is activated by dexamethasone through glucocorticoid receptors on osteoblasts,which may be one of the pathogenesis of glucocorticoid-induced osteoporosis.

Allogeneic osteoblasts compounded with beta-tricalcium phosphate for repair of radial defects / 中国组织工程研究

BACKGROUND:As a bone scaffold material,β-tricalcium phosphate has good biocompatibility, osteoinductive, and biomechanical properties. OBJECTIVE:To study the effect of al ogeneic osteoblasts compounded withβ-tricalcium phosphate in repairing rabbit radial defects. METHODS:A total of 45 rabbit radial defect models were made and divided into three groups in random. Experimental group was repaired with the compound of al ogeneic osteoblasts andβ-tricalcium phosphate; control group withβ-tricalcium phosphate;and blank control group with nothing. The new bone formation of each group was observed and assessed by X-ray and histopathological analysis at weeks 4, 8, 16 after implantation for evaluation of the bone repairing effect. RESULTS AND CONCLUSION:With the repair time, the experimental group appeared to complete bone defect repair gradual y. By the end of 16 weeks, the X-ray showed that the bone cal us between the scaffold and the host was completely ossified, and bone defects were completely repaired in the experimental group. Histopathological observation showed continuous cortical bone formed in the defect area, and canal recanalization realized in the experimental group. Additional y, the repair effect in the experimental group was better than that in the control and blank control group at different time points (P<0.01). It is suggested that the al ogenic osteoblasts/β-tricalcium phosphate compound has the better effects on guiding bone regeneration and preventing from nonunion.

Prefabrication of vascularized grafts based on pre-differentiated adipose derived stem cells, fibrin sealant and porous calcium phosphate cement scaffold / 中国组织工程研究

BACKGROUND:Construction of vascularized bone substitutes to mimic free vascularized fibular grafting in treating large bone defects stil remains chal enges to researchers during the past years. OBJECTIVE:To design and construct a new vascularized tissue-engineered bone graft using pre-differentiated adipose derived stem cells, fibrin sealant and porous calcium phosphate cement scaffold. METHODS:Adipose derived stem cells isolated from rats were directly differentiated to endothelial cells and then incorporated in fibrin sealant and porous calcium phosphate cement scaffolds in vitro. Subsequently, the different composites of the three groups including vascularized tissue-engineered bone scaffold (group A), fibrin sealant and porous calcium phosphate cement scaffold (group B) and porous calcium phosphate cement scaffold (group C) were directly embedded into the quadriceps of the rats. Histological quantitative analysis and western blot assay were conducted 2 and 4 weeks after implantation. RESULTS AND CONCLUSION:The pre-differentiated adipose derived stem cells were demonstrated in good condition after 7 days co-culturing with the fibrin sealant and porous calcium phosphate cement scaffold. The results of in vivo experiments showed that the scaffolds were in-grown together with fibrous connective tissues and blood vessels. Newly formed vessels and immature capil aries were observed in the group A. The vessel density, vessel diameter and vascular endothelial growth factor C expression in the group A were significantly higher than those in the groups B and C. Our findings demonstrated that compared with simply fibrin sealant and porous calcium phosphate cement scaffold, the combination of pre-differentiated adipose derived stem cells (endothelial differentiation) and fibrin sealant can achieve rapid angiogenesis of porous calcium phosphate cement scaffold.

Dynamic changes in serum levels of β-amyloid precursor protein and hypersensitive-cross-reactive protein in rats afar acute spinal cord injury / 中华创伤骨科杂志

Objective To investigate the serum levels of β-amyloid precursor protein (β-APP) and hypersensitive-cross-reactive protein(hs-CRP) after acute spinal cord injury(SCI) in rats at different time points and study their roles in secondary spinal cord injury. Methods Ninety healthy adult female SD rats were randomly assigned into 3 even groups.Improved Allen method was used to create models of complete SCI (group A) and models of incomplete SCI (group B).In group C only laminectomy was performed without SCI.The serum was collected at 12 hours,24 hours,3 days,7 days,and 14 days after operation through femoral vein to detect levels of β-APP and hs-CRP by ELISA. ResultsThe serum level of β-APP reached the peak value 24 hours after acute SCI,and the serum level of hs-CRP reached the peak 3 days after acute SCI.There were significant differences between groups A and C in β-APP and hs-CRP levels at all time points( P ＜ 0.05).There were also significant differences between groups B and C in β-APP and hs-CRP levels at all time points (P ＜0.05) except at 14 days (P＞ 0.05). Conclusions The serum levels of β-APP and hs-CRP are positively associated with the severity of traumatic SCI.β-APP may be a more sensitive indicator than hs-CRP in a certain time.The dynamic changes of serum β-APP and hs-CRP suggest involvement of the 2 proteins in the secondary spinal cord injury.