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Objective To explore the effects of different doses of dexmedetomidine on acute brain edema in mice with traumatic brain injury (TBI).Methods A total of 132 male C57BL/6J mice were randomly divided into six groups:control group (group C),sham-operation group (group Sham),traumatic brain injury group (group TBI),Dex 20 μg/kg (group D20),40 μg/kg (group D40),and 60 μg/kg (group D60),n=22 in each group.The TBI animal model was established by electric controlled cortical impactor (eCCI),then intraperitoneal injected by the administration of different doses of dexmedetomidine at 0,2 and 4 h after TBI.Twenty-four hours post-TBI,brain water content was measured by the dry-wet method,histological observation was performed using HE staining,and aquaporin 4 (AQP4) and NF-κB expression were detected using Western blot assay,respectively.Then,the modified neurological scale scores (mNSS) on 1,2,3,and 7 d and Morris water maze (MWM) test on 4,5,6 and 7 d post-TBI were used to evaluate the neurologic deficit of TBI mice.Results After traumatic brain injury,the mNSS scores,the escape latency,the brain water content and the expression of AQP4 and NF-κB increased significantly in group TBI (P＜0.01).Different doses of dexmedetomidine significantly reduced the mNSS scores,the escape latency,the brain water content and the expression of AQP4 and NF-κB (P ＜ 0.05 or P ＜ 0.01).And meanwhile dexrnedetomidine can lessen neuronal degeneration,and inflammation response.Additionally,the effect was remarkably in group D60 compared with group D20 (P ＜ 0.05 or P ＜ 0.01).Conclusion Dexmedetomidine can lessen brain edema and cognition impairment induced with traumatic brain injury,which is a dose-effect relationship within 20-60 μg/kg,and this effect may be related to the downregulation of AQP4 and NF-κB expression.
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BACKGROUND:In previous experiments, a polymer-shel ed microbubble contrast agent was successful y prepared using L-polylactic acid-polyethylene glycol methyl-covered liquid fluorocarbon perfluoropentane, which developed wel in vivo and in vitro under a second harmonic contrast-enhanced ultrasound with a low mechanical index OBJECTIVE:To optimize the conditions for preparing polymer-shel ed microbubble contrast agents with high yield and suitable size. METHODS:The polymer-shel ed microbubble contrast agent containing perfluoropentane was prepared by single emulsion method. Three preparation conditions, including polymer mass/perfluoropentane volume ratio (4/1, 2/1, 1/1, 1/2), hemogenate speed (18 000, 26 000, 35 000 r/min) and time (15, 30, 60, 120 seconds), were optimized, and the microbubble yield and size were set as judge standard. The contrast-enhanced ultrasonography of rabbit kidney was performed using the optimized microbubbles, and the arrival time, time to peak, half time of descending and peak intensity were analyzed by TCA software. RESULTS AND CONCLUSION:The preparation conditions were optimized as a polymer mass/perfluoropentane volume ratio of 2/1, homogenate speed of 26 000 r/min and homogenate time of 60 seconds, which presented a high microbubble yield of (1.8±0.4)×109/mL and mean size of (3.7±1.3)μm with uniform distribution. The arrival time, time to peak, half time of descending and peak intensity were detected as (3.1±0.6) seconds, (2.9±0.5) seconds, (4.0±0.7) seconds and (4.7±1.1)×10-5 AU, respectively. The polymeric microbubbles prepared by optimized conditions were of high yield, with suitable size and good contrast-enhanced effect in vivo.
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Objective To evaluate the short-term results of ARCH plate in cerical expansive open-door laminoplasty(ELAP)for OPLL.Methods From June 2010 to September 2011,a total of 12 cases with OPLL underwent open-door ELAP by ARCH plate fixation and were followed up in our hospital.8 cases were males and 4 cases were female.The average age was 60.5 years.The neurological effect was evaluated by use Japanese Orthopedic Association(JOA)scoring criteria for cervical myelopathy.The ana-tomical effect was analyzed by compare roentgenogram and CT before and after surgery.Results The JOA scores were improved for 39% after the operation,while the saggital diameters of the cervical spinal canaldural after operation was enlarged for 82%(P<0.05).X-ray films and CT scan after operation that there was no occurrence of re-close of door,there was no occurrence of anchor loosing.Conclusion For OPLL,ELAP using ARCH plate fixation bring less occurrence of re-close of door,slight postoperative neck AS,and satisfactory clinical outcomes.