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Objective To explore the relationship between gap junction and glucose uptake of astrocytes under oxygen-glucose deprivation(OGD) and reperfusion.Methods Cerebral cortical astrocyte from 1 day newborn SD rats were undergone the primary culture.The ischemia cell model was established by OGD.This experiment were divided into control group,OGD group and OGD + CBX group.After different reperfusion time (0 h,12 h 24 h and 48 h),the glucose uptake of astrocyte was measured by 2-NBDG through flow cytometry analysis and connexin 43(Cx43) gap junction plaques was detected using immunofluorescene.Results Compared with the control group,the glucose uptake of astrocyte was up-regulated induced by OGD following different reperfusion time.The glucose uptake of OGD group was (2.32 ± 0.43)nmol/μgDNA in 24 hours reperfusion time and was (0.95±0.28)nmol/μgDNA in control group.The upregtulation was up to 2.63-fold increase (t=13.99,P=0.0024) in 24 hours after reperfusion.Compared with the control group,the Cx43 gap junction number was up to 2.5-fold increase(t=11.34,P=0.003) and the size was 1.85-fold increase (t=10.27,P=0.004) in 24 h reperfusion.The glucose uptake of astrocyte after OGD was reduced by CBX and the decrease was 42％ in 48 h after reperfusion.Conclusion Those results urges us consider the clinical treatment for interfering with Cx43 gap junction.
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Objective@#To explore the relationship between gap junction and glucose uptake of astrocytes under oxygen-glucose deprivation(OGD) and reperfusion.@*Methods@#Cerebral cortical astrocyte from 1 day newborn SD rats were undergone the primary culture. The ischemia cell model was established by OGD. This experiment were divided into control group, OGD group and OGD+ CBX group.After different reperfusion time (0 h, 12 h 24 h and 48 h), the glucose uptake of astrocyte was measured by 2-NBDG through flow cytometry analysis and connexin 43(Cx43) gap junction plaques was detected using immunofluorescene.@*Results@#Compared with the control group, the glucose uptake of astrocyte was up-regulated induced by OGD following different reperfusion time.The glucose uptake of OGD group was (2.32±0.43)nmol/μgDNA in 24 hours reperfusion time and was (0.95±0.28)nmol/μgDNA in control group. The up-regulation was up to 2.63-fold increase (t=13.99, P=0.0024) in 24 hours after reperfusion.Compared with the control group, the Cx43 gap junction number was up to 2.5- fold increase(t=11.34, P=0.003) and the size was 1.85-fold increase (t=10.27, P=0.004) in 24 h reperfusion. The glucose uptake of astrocyte after OGD was reduced by CBX and the decrease was 42% in 48 h after reperfusion.@*Conclusion@#Those results urges us consider the clinical treatment for interfering with Cx43 gap junction.
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Objective To investigate the role of Notch signaling pathway to maintain the stem cell-like characteristics of osteosarcoma and its underlying mechanism.Methods Lentiviral NICD1 or Numb-shRNA was transduced into MG63 osteosarcoma cells to activate Notch activity in vitro.The impact of Notch on osteosarcoma stem cells were assessed by the tumor sphere formation assay and flow cytometry analysis of cell surface markers STRO-1/CD117.The expression of stem cell related genes (Sox2,Oct4) were evaluated by Western blot and qPCR.The nude mice were randomly divided into 3 groups:the NICD1 overexpression (NICD-OE) group,the DAPT group and the control (CON) group.The tumor growth was monitored for 8 weeks and the tumor volume and weight were recorded weekly.To investigate whether Notch regulates Eph pathway,Eph pathway related protein EphB,pEphB was measured by Western blot.The impact of ephrinB 1 on NICD overexpression cell were assessed by tumor sphere formation assay.The expression of Sox2 and Oct4 was evaluated by Western blot.Results NICD1 overexpression or Numb-shRNA increased the activity of Notch pathway.The Notch-activated osteosarcoma showed enhanced in vitro tumor spheroid formation capacity,increased Stro-1/CD117double positive ratio,and upregulated expression of Sox2 and Oct4 in vitro.In animal experiments,it was found that activation of Notch pathway promoted tumor formation in vivo and Notch inhibition decreased it.The primary osteosarcoma cells were obtained from mice xenograft treated with DAPT and its tumor sphere formation capacity was significantly reduced.Finally,The Notch pathway inhibits the phosphorylation of EphB,as well as the downstream signal pathway of EphB,but there is no significant change in total EphB.The activation of Eph pathway inhibited Notch induced up-regulation of tumor sphere formation and Sox2 and Oct4 expression.Conclusion Notch signaling pathway maintains the stem cell-like characteristics of osteosarcoma probably by inhibiting the Eph pathway.
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Objective:Cancer stem cells (CSCs) are resistant to chemotherapy. Our study aimed to investigate the stem cell-like proper-ties of doxorubicin-resistant osteosarcoma cell line 143B and its correlation with Notch signaling. Methods:We generated doxorubicin-resistant osteosarcoma cells by treating them with 2μm doxorubicin. Stem cell-like properties such as morphology change, Stro-1/CD117 double positive ratio, stem cell-related gene expression, sphere formation efficiency, and EMT character were assessed on day 5 after doxorubicin withdrawal. Notch receptor and its target genes were examined using qPCR and Western blot analysis. The stem cell-like properties of doxorubicin-resistant osteosarcoma cells were assessed when pretreated with Notch inhibitor or vehicle. The an-ti-tumor effect of Notch inhibitor was tested using a xenograft model. Results:Doxorubicin-resistant osteosarcoma cells were enriched in Stro-1+/CD117+cells, which showed obvious increased expression of stem cell-related genes, and exhibited enhanced spheroid for-mation and evident mesenchymal characteristics unlike doxorubicin-sensitive cells. qPCR and Western blot assays showed that Notch intracellular domain 1 (NICD1) and target genes Hes1 and Hey1 were upregulated in doxorubicin-resistant osteosarcoma stem cells compared with those in vehicle cells. Furthermore, pretreatment with a γ-secretase inhibitor (GSI) to prevent Notch signaling en-hanced chemo-sensitivity and inhibited doxorubicin-enriched osteosarcoma stem cell activity in vitro. Finally, the Notch inhibitor pre-vented tumor growth in mice xenograft models. Conclusion: Doxorubicin induced the enrichment of osteosarcoma stem-like cells through Notch signaling, and inactivation of Notch could be useful for overcoming drug resistance and eliminating osteosarcoma.
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Objective To explore the effect of docosahexaenoic acid(DHA)on the neuro-logical outcome as well as the expression of interleukin-1β,interleukin-6 and interleukin-10 after acute spinal cord injury(SCI).Methods One hundred and eight Sprague-Dawley rats were randomly divided into a spinal cord injury group(group A),a DHA treatment group(group B)and a sham operation group(group C),each with 36 rats.SCI models were established in the rats of groups A and B using a version of Allen's weight drop method(T10 level).Group C had removal of the lamina only.Ten minutes later,group A was injected with 5% ethanol in saline(the MT solvent)and group B with 500 mg/kg of DHA preparation.Basso beattie bresnahan locomotor rating scale(BBB)was used to detect locomotors function at 10,24,48 and 72 hours after operation.Rats were sacrificed at 72 h after operation,IL-1β,IL-6 and IL-10 levels in serum were detected in 6 rats of each group.Results BBB locomotor rating scale indicated that hindlimb motor function in Groups B was higher than that in Group A at 10,24,48 and 72 hours after operation.There was a significant difference in locomotor rating score between DHA injection group and control group(P<0.05).The specimens of group A showed inflammatory reaction and ulceration at 72 h:Group C showed the highest levels of IL-10 in serum ,while Group A showed the lowest level.The differences were statistically significant.Group A had the highest levels of IL-1β and IL-6 while group C had the lowest.The difference between group B and groups A and C was significant.Conclusion DHA could play protective role by balancing the reconstruction of the anti-inflammatory response and inflammation in rats with acute spinal cord injury.
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Objective To evaluate the efficacy of percutaneous endoscopic BEIS technique in the treatment of recurrent lumbar disc herniation and to analyze its possible prognostic factors.Methods A total of 39 patients who are diagnosed as lumbar disc herniation and treated with percutaneous endoscopic BEIS technique were selected from March 2013 to March 2015.The clinical efficacy was evaluated according to VAS,ODI,JOA and modified MacNab criteria in the follow-up,and the possible prognostic factors were analyzed.Results The average follow-up time was 14 months(12 ～ 18 months).According to the MacNab standard,the excellent and good rate was 82.1％.The average score of back and leg pain VSA was reduced from(7.33 ± 1.01)before operation to(2.69 ± 1.50)after operation,t =16.111,the difference was statistically significant (P ＜ 0.05);ODI and JOA were used to evaluate lumbar function,the score of ODI was reduced from (59.08 ± 7.16) to (13.54 ± 3.36),t =35.946,and that of JOA was increased from(14.92 ±3.37) to(26.05 ± 1.76),t =-18.526,the difference was statistically significant (P ＜ 0.05).Patients with symptoms lasting no more than 3 months and with no lateral recess stenosis were able to obtain good therapeutic effect.Conclusion This study indicates that percutaneous endoscopic BEIS technique is effective in the treatment of recurrent lumbar disc herniation,and duration of symptoms and lateral recess stenosis are important prognostic factors.
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Objective To investigate the role of miR-429 in osteosarcoma stem cells.Methods We employed different approaches to test the expression of miR-429 in osteosarcoma stem cells.miR-429-high and miR-429-low cells were separated using molecular probes and their stem cell-like properties were compared.The effect of miR-429 on osteosarcoma stem cell-like properties was further tested through transfection assays.Furthermore,the miR-429 downstream target gene was confirmed by luciferase assay.Results The expression of miR-429 in osteosarcoma stem cells was much lower than that in control cells.miR-429-high cells displayed fewer stem celllike properties than did miR-429-low cells.These observations were confirmed by transfection assays.Additionally,our luciferase assays showed that miR-429 regulates Sox2 at the post-transcriptional level.Conclusion miR-429 negatively regulates osteosarcoma stem celllike properties by targeting Sox2.
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BACKGROUND:The surgical management to reconstruct the stability in lumbosacral region is very chal enging. There are many techniques to reconstruct the stability of the lumbosacral region, but the internal fixation loosening, fracture and pseudoarthosis are not uncommon. OBJECTIVE:Finite element analysis was used to analyze the stability of two types of reconstruction procedures and the stress of the internal fixation system. METHODS:A 64-slice spiral CT scan was used in a subject from L1 to pelvis. The scan data were imported into the Mimics 15.0 software to generate a three-dimensional surface model. The three-dimensional solid model was established using in the SolidWorks software. The solid geometry model of the L3, 4 pedicle screws combined with single iliac screw fixation and L3,4 pedicle screws combined with dual iliac screws and anterior titanium mesh cage support fixation were constructed by the Solidworks software. Two kinds of reconstruction procedures were simulated. The models were given material properties and analyzed by using the ABAQUS software. RESULTS AND CONCLUSION:(1) The maximum stress was 195.3 MPa in the complete model, 189.5 MPa in single iliac screw model, and 149.2 MPa in dual iliac screw+titanium cage model when constrained the roof of double acetabulum and applied a vertical load of 1 000 N. (2) The axial compression rigidity was 551.572 N/mm in the complete model, 613.87 N/mm in the single iliac screw model and 1 683.50 N/mm in the dual iliac screw+titanium cage model. (3) The bending rigidity of the dual iliac screw+titanium cage model was bigger than other models at 6 directions when applied 7 N?m bending loads. The maximum stress of single iliac screw model was bigger than other models. (4) The results suggest that the dual iliac screw+titanium mesh cage reconstruction can effectively restore the stability of the lumbosacral area. The stress of internal fixation system is smal er and more dispersed. There is obvious stress concentration in the connecting rod and the tail of the single iliac screw. The single iliac screw internal fixation system is easy to fatigue fracture and loosening.
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Objective To compare suture bridge and single row techniques in repair of rotator cuff tears in a rabbit model.Methods Seventy-six mature male New Zealand white rabbits were used in this study.The 12-month old rabbits,weighing from 2.5 to 3.0 kg (average,2.8 kg),were made models of full-thickness rotator cuff tear by cutting off at the foot print the supraspinatus tendon.The models were randomly divided into 2 even groups (n =38 each).Their right shoulders were repaired by suture bridge and single row techniques respectively in the 2 groups,with their left shoulders untreated as controls.The rabbits were then sacrificed at the 2nd,4th and 8th weeks after surgery for histological comparisons of healing under microscopy.Biomechanical comparisons were made at the 8th week to analyze advantages and disadvantages of the two methods.Results At 2,4 and 8 weeks postoperatively,there were no significant differences between the anterior and middle 1/3 zones of bone-tendon junction regarding cartilage growth or collagen fiber morphology in the suture bridge group,while the cartilage growth and collagen fiber morphology in the middle 1/3 zone of bone-tendon junction were significantly more mature than in the anterior 1/3 zone in the single row group.At the 8th postoperative week,the load to failure in the suture bridge group (134.59 ± 17.69 N) was significantly higher than that in the single row group (72.23 ± 12.08 N) (P ＜ 0.05),but remained significantly lower than that in the control group (192.61 ± 9.42 N) (P ＜ 0.05).Conclusion The suture bridge technique is a feasible and reliable method for repair of rotator cuff tear and has a better healing effect than the single row technique.
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Objective To compare the effect of compression hollow screw fixation,artificial femoral head replacement and total hip replacement in the elderly.Methods From August 2007 to April 2009,152 cases of femoral neck fracture in the elderly were divided into three groups: compression hollow screw fixation group(54 patients,24 males,with an average age of 59.8±5.3 years);artificial femoral head replacement group(48 patients,16 males,with an average age of 65.3±6.7 years);and total hip replacement group(50 patients,18 males,with an average age of 77.3±6.5 years).The evaluation indicators,including the average sugical time,the average amount of bleeding,the average length of stay and the average postopererative bed time,were compared respectively among the three groups.The postoperative evaluation was made according to Harris Score.Results Harris score in the three groups were 21 excellent and 23 good in the compression hollow screw fixation group,with an average score of 80.52±2.70;26 excellent and 14 good in the artificial femoral head replacement group,with an average score of 86.57±1.90;and 42 excellent and 3 good in the total hip replacement group,with an average score of 96.04±2.10.The total hip replacement group was significantly better than the other two groups(H=0.589,F=12.151,Ps＜0.05).The rate of postoperative complications were 25.93%(14/54) in the compression hollow screw fixation group,18.75%(9/48) in the artificial femoral head replacement group and 4.00%(2/50) in the total hip replacement group(H=1.291,P＜0.05).Conclusion Compared among the three surgery,total hip replacement could resume function and improve the quality of life better,with lower rate of complications.However,the surgical injury and the amount of bleeding were largest.Therefore,we suggest selecting appropriate surgery with considering the patient′s age,physical condition,displacement degree of the fracture,et al.in old femoral neck fractures patients.
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BACKGROUND: The clinical application of one-level osteotomy and multilevel osteotomy has been well documented, but currently few studies were reported to compare their biomechanical characteristics.OBJECTIVE: To investigate the biomechanical characteristics of one-level osteotomy with Dick screw fixation and multilevel osteotomy with Luque instrumentation in the treatment of kyphosis.DESIGN: Randomized comparative experiment.SETTING: Laboratory of the Department of Orthopedics, Renmin Hospital of Wuhan University.MATERIALS: Fresh specimens of thoracic and lumbar spinal segments obtained from 12 3 or 4-year-old calves.METHODS: The experiment was conducted in the laboratory of the Department of Orthopedics, Renmin Hospital of Wuhan University between September 2002 and September 2003. Fresh spinal segments T8-L5 from 12 calves were randomized into an intact group, Dick screw group with one-level osteotomy with Dick screw fixation and Luque group with multilevel osteotomy with Luque instrumentation, with 4 spesimens in each group. Lateral bending test of the specimens was performed to examine the physiological overload using an Instron 5 500 universal material testing machine at the constant speed of 10 mm/minute until fracture or dislocation was induced. Changes in the loading were recorded and the induced injuries observed to obtain the load-displacement curve of the injury test.MAIN OUTCOME MEASURES: The load-displacement curve of the destructive right bending test in each group.RESULTS:All the data of 12 canines were involved in the result analysis.The spinal segments of the intact group yielded to the force of 3 600 N with a flat and smooth load-displacement curve, and those of Dick screw group yielded to a load of 2 800 N with also a relatively flat curve, while in Luque group, the segments did not yield until a load of 7 160 N, followed by drastic decrease of the resistance to less than 4 000 N, generating a flat and smooth curve afterwards.CONCLUSION: Luque instrumentation is a little more preferable than Dick screw in terms of the maximum resistance, but this difference does not justify the clinical decision of their superiority. Both techniques benefit postoperative recovery of spinal function with strong stability.