Effects of ursolic acid on activation of NOX2/ROS/NLRP3 inflammasome in liver fibrosis rats / 基础医学与临床

Objective To investigate the effect of ursolic acid(UA) on NOX2/ROS/NLRP3 inflammasome activation in carbon tetrachloride(CCl4)-induced liver fibrosis SD rat,and to observe the improvement of collagen deposition in liver tissues. Methods All rats were randomly divided into 3 group:control group,CCl4model group,UA treatment group. Liver fibrosis model SD rats was established by the CCl4-induced method and half of them was used as UA treatment group. Serum ALT was detected by ALT detection kit.The liver pathology and collagen deposition were ob-served by HE and Sirius-red staining. The mRNA expression of Nox2,Nlrp3,Caspase1,IL-1β in liver tissues was detected by RT-qPCR. The protein expression of NOX2,NLRP3,caspase-1 and IL-1β in liver tissues was detected by Western blot and immunohistochemistry and the ROS generation in liver tissues was detected by DCFH-DA fluores-cence probe. Results Compared with control group,in the CCl4model group,the serum ALT was much higher (P<0.05);the Ishak's fibrosis score and collagen deposition was significantly increased(P<0.05) and mRNA of Nox2, Nlrp3,Caspase1,IL-1β was increased.In addition,both the NOX2,NLRP3,caspase-1 p10 and IL-1β protein expres-sion and ROS level (P<0.05) of CCl4model group were significant increased.Compared with CCl4model group,in the UA treatment group Ishak's fibrosis score,collagen deposition and ALT decreased.Both mRNA expression of the Nox2, Nlrp3,Caspase1,IL-1β and protein expression of NOX2,NLRP3,caspase-1 p10 and IL-1β as well as ROS were signif-icant decreased,but the caspase-1 p45 protein level has no difference among all these groups (P>0.05). Conclusions Ursolic acid attenuates the liver injury and reduces the collagen deposition,which may relate to its inhibitory effects on NOX2/ROS/NLRP3 inflammasome activation to reduce IL-1β releasing.

Mechanical strength of biological canulated cancellous screw / 医用生物力学

Objective To develop a biological canulated screw and evaluate its mechanical properties, so as to provide theoretical basis for the bio therapy of fracture with enrichment technique of bone marrow stem cells, which could be diffused through the canula, particularly for promoting bone union of femoral neck fracture and preventing avascular necrosis of femoral head. Methods TC4 titanium alloyed canulated cancellous screw (7.3 mm in diameter) commonly used for internal fixation of femoral neck fracture was improved by designing an end sealing plug and side holes in a 900 mm-long canulated screw. The side holes were arranged along the axis of screw, and the first side hole was 20 mm away from the screw tip. The distance between each side hole was 10 mm, and the number of side holes ranged from 0 to 6. The screws without holes were tested as control, and the rest were divided into two groups, i.e., group A: force direction parallel to the side hole, group B: force direction perpendicular to the side hole. Three point bending test on the screw was conducted by using Instron material testing machine, so as to study the relationship between the mechanical strength of the screw and the number of side holes, and the loading direction. Results (1) When the force direction was parallel to the side hole, which was confined within 0, 1 or 2, the bending deformation of the screw reached 3 mm, and no differences were found in the maximum loads and elastic modulus of the screw. However, when the number of side holes was increased to 3 or more, a significant reduction in the maximum load and elastic modulus of the screw was found (P＜0.05). (2) When the force direction was perpendicular to the side hole, which was confined within 0,1 or 2, and the bending deformation of the screw reached 3 mm, no significant differences were found in the maximum loads of the screw. While no significant difference was found in the elastic modulus of the screw when the side hole was 0, 1, 2 and 3. With an increase in the number of side holes, the maximum loads (≧ 3 side holes) and elastic modulus (≧ 4 side holes) were significantly reduced (P＜0.05). (3) When the force direction was perpendicular to the side hole and the number of side holes was 3 or more, the maximum loads and elastic modulus of the screw were all significantly higher than the screw with the same number of side hole under force direction parallel to the side hole. Conclusions (1) For achieving better mechanical properties of the screw, the number of side holes in titanium alloyed canulated cancellous screw (7.3 mm in diameter) should be within 2; (2) If the number of side holes was equal or over 3, screws under force direction perpendicular to the side hole could provide better mechanical properties than screws under force direction parallel to the side hole. This study may provide some theoretical evidence and support for future clinical development and practice of the biological canulated screw.

Clinical study of lumbar fusion by hybrid construct of stem cells technique and biodegradable material / 中华外科杂志

<p><b>OBJECTIVE</b>To explorer the effectiveness of enriched bone marrow stem cells technique for lumbar fusion.</p><p><b>METHODS</b>With the randomization and control principles, 2 graft materials [Enrichment bone marrow mesenchymal stem cells hybridized with beta-tri calcium phosphate (composite graft group), autologous iliac crest bone graft (autograft group)] were compared in posterior lumbar fusion procedures. 56 patients with degenerative disc disease, lumbar instability or spinal stenosis, were included. The volume of cells suspension in pre- and post-enrichment and the number of nucleated cells (NCs) were identified. The number of osteoprogenitor cells was estimated by counting the colony-forming units which express alkaline phosphatase (CFUs/ALP+). Then the efficiency of the enrichment was evaluated. Clinical follow-up with roentgenogram and Oswestry scale scores was performed for outcome evaluation.</p><p><b>RESULTS</b>(249 +/- 31) ml bone marrow per patient from bilateral iliac crests was aspirated peri-operatively. About (43 +/- 11) ml enriched bone marrow was collected. The number of NCs was concentrated from (15.9 +/- 3.3) x 10(6)/ml to (44.1 +/- 10.8) x 10(6)/ml, CFUs/ALP+ was significantly increased from (118 +/- 86)/ml to(486 +/- 305)/ml. The follow-up was about (26.3 +/- 7.5) months. There was no significant differences in age, gender, disease and fusion segments between the two groups. The fusion rate was 93.3% and 96.2% for composite graft group and autograft group, respectively (chi2 = 0.2146, P = 0.6432). There was no difference in operation time between the two group (t = 0.5243, P = 0.6022), but blood loss in composite graft group was more than that in autograft group (t = 6.4664, P < 0.01). Cell salvage for auto-transfusion could transfuse back half of the blood loss during operation. No hematoma or chronic soreness in the bone marrow donor sites of composite graft group occurred, but a little exudation or moderate swelling in the wound happened in 4 cases which disappeared under medical treatment. Meanwhile, 15.4% patients had hematoma in the iliac bone donor site and 26.9% patients had chronic soreness, but no case had wound problem in autograft group. As for Oswestry scale scores, there was no significant difference between the two groups.</p><p><b>CONCLUSIONS</b>The enrichment technique of autologous bone marrow stem cells can greatly increase the concentration of MSCs. It is a rapid and safe method used peri-operatively. The composite material of enriched MSCs and porous beta-TCP is a good bone substitute in posterior spinal fusion.</p>

In vitro gene transfection by magnetic iron oxide nanoparticles and magnetic field increases transfection efficiency / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility of using iron oxide nanoparticles as gene vector and the effect of magnetic field on efficiency of transfection.</p><p><b>METHODS</b>Iron oxide nanoparticles were prepared by alkaline precipitation of divalent and trivalent iron chloride. The surface of iron oxide nanoparticles was modified by self-assembled poly-L-lysine to form particle complexes (IONP-PLL). Transfection was determined by delivering reporter gene, PGL2-control encoding luciferase, to different cell lines using IONP-PLL as vector. The effect of magnetic field on efficiency of transfection was determined using Nd-Fe-B permanent magnet.</p><p><b>RESULTS</b>Foreign gene could be delivered to various cell lines by IONP-PLL and expressed with high efficiency, but the transfection efficiency and time course varied in the different cell lines studied. Magnetic field could enhance the efficiency of transfection by 5 - 10 fold.</p><p><b>CONCLUSION</b>IONP-PLL can be used as a novel non-viral gene vector in vitro, which offers a basis for gene delivery in vivo.</p>