Quick blocking screw insertion in closed reduction and intramedullary nailing for distal tibial metaphyseal fractures / 中华创伤骨科杂志

Objective To explore the technique and clinical efficacy of quick blocking screw insertion in closed reduction and internal fixation with intramedullary nails for distal tibial metaphyseal fractures.Methods The data of 24 distal tibial metaphyseal fractures were retrospectively analyzed which had beentreated with closed reduction and internal fixation with intramedullary nails from October 2013 to December2014 at Department of Orthopaedics,Zhoukou Central Hospital.They were 17 males and 7 females,with anaverage age of 39.7 years (from 21 to 60 years).There were 2 open fractures of Gustilo type Ⅰ.According toAO/OTA classification,3 cases belonged to type 42-A2,4 to type 42-A3,6 to type 42-B1,2 to type 42-B2,3 to type 42-B3,2 to type 42-C1,3 to type 42-C2,and 1 to type 42-C3.In the internal fixation with in-tramedullary nails,the varus or valgus malalignment of the distal tibia was corrected by manual reduction.According to the fracture type,a 3.0 mm Schanz pin was placed in the concave or convex side of deformityfirst and then gradually replaced by a 4.5 mm blocking screw to maintain reduction.The operation time,bleeding volume,fracture healing time,and complications (including infection,hardware loosening orbreakage,delayed union and nonunion) were recorded.The reduction quality and alignment were evaluated bypostoperative X-ray and CT 3D reconstruction.The clinical efficacy was evaluated at the final follow-up based on the Johner-Wruhs criteria.Results The 22 patients were followed up for a mean time of 35.5 months (from 24 to 48 months).The average operation time was 68.3 minutes (from 50 to 85 minutes),and the average bleeding volume was 95 mL (from 60 to 150 mL).One case of delayed union was healed after dynamic treatment.The average healing time was 3.9 months (from 3 to 8.5 months).No infection,hardware loosening or breakage,or malunion was observed.According to the Johner-Wrubs evaluation at the final follow-up,12 cases were excellent,10 good and 2 fair,giving an excellent to good rate of 91.7％.Conclusion In the closed reduction and internal fixation with intramedullary nails for distal tibial metaphyseal fractures,the yarus or valgus malalignment of the distal fragment can be quickly corrected by manual reduction and quick insertion of a blocking screw to gradually replace a preceding Schanz pin.

Role of platelet-activating factor receptor in adhesion and invasion of Aggregatibacter actinomycetemcomitans in human umbilical vein endothelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the role of platelet-activating factor receptor (PAFR) in adhesion and invasion of phospho- rylcholine (PC)-positive Aggregatibacter actinomycetemcomitans in cultured human umbilical vein endothelial cells (HUVEC).</p><p><b>METHDOS</b>Cultured HUVECs were pretreated with the PAFR antagonist CV3988 or anti-human PAFR monoclonal antibody for 30 min before infection with PC-positive or -negative A. actinomycetemcomitans strains. The bacterial adhesion and invasion and cytotoxicity in the cells were examined using MTT assay.</p><p><b>RESULTS</b>Pretreatment with PAFR antagonists at 100, 200 and 500 nmol/L significantly reduced the adhesion rate (36.29∓3.52)%, (19.04∓3.35)% and (7.69∓3.19%), respectively] and invasion rate [(12.12∓1.58)%, (7.08∓0.29)% and (2.60∓2.26)%, respectively] of PC-positive A.actinomycetemcomitans in HUVECs. Similarly, pretreatment with anti-PAFR antibody also significantly reduced A.actinomycetemcomitans adhesion and invasion in HUVECs [(50.05∓5.28)% and (39.09∓6.50)%, respectively]. Pretreatment with PAFR antagonist (200 and 500 nmol/L) and anti-PAFR antibody (25 µg/mL) significantly increased the viability of HUVECs incubated with PC-positive A.actinomycetemcomitans from (25.39∓9.33)% to (91.12∓3.14)%, (94.12∓2.15)% and (65.5∓1.87)%, respectively, but such pretreatments did not increase the viability of cells incubated with PC-negative A.actinomycetemcomitans.</p><p><b>CONCLUSIONS</b>PAFR plays an important role in the adhesion, invasion, and cytotoxicity of PC-positive A.actinomycetemcomitans in cultured HUVECs.</p>

Role of MUC2 gene in the regulation of rat intestinal barrier function by probiotics / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate MUC2 expression in rat colons induced by probiotics and its effects on the inhibition of E.coli K1 (E44) penetration of the intestinal barrier by probiotics.</p><p><b>METHODS</b>SD rats were subjected to intragastric administration of probiotics, E44, or probiotics +E44 on a daily basis for 7 days, and MUC2 expression in the colons was determined by RT-PCR. MUC2-targeted shRNA (shRNA MUC2) and scrambled shRNA plasmids (shRNA NC) were respectively transfected into Lovo cells, and the efficiency of MUC2 knockdown was determined using qRT-PCR. Competitive exclusion assay was used to evaluate the effects of the probiotics against E44 adhesion and invasion.</p><p><b>RESULTS</b>Intestinal MUC2 mRNA expression was up-regulated in the rats after intragastric administration of probiotics, while E44 administration caused significantly lowered MUC2 expression. MUC2 expression was down-regulated (by 66.7%) by transfection with shRNA MUC2 in Lovo cells as compared with the negative control and mock control cells. The inhibition of E44 adherence and invasion by probiotics was significantly attenuated in transfected Lovo cell culture (in which the relative adhesion and invasion rates of E44 were 56.64% and 66.64%, respectively) as compared with those in the control group.</p><p><b>CONCLUSION</b>The up-regulation of MUC2 in rat colons can be one of the mechanisms of the probiotics in antagonizing the translocation of the pathogenic bacteria. Silencing MUC2 expression causes attenuated inhibitory effect of the probiotics on E. coli K1 penetration across human intestinal epithelial cells.</p>

Construction of dengue virus-specific full-length fully human antibody libraries by mammalian display technology / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct dengue virus-specific full-length fully human antibody libraries using mammalian cell surface display technique.</p><p><b>METHODS</b>Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) from convalescent patients with dengue fever. The reservoirs of the light chain and heavy chain variable regions (LCκ and VH) of the antibody genes were amplified by RT-PCR and inserted into the vector pDGB-HC-TM separately to construct the light chain and heavy chain libraries. The library DNAs were transfected into CHO cells and the expression of full-length fully human antibodies on the surface of CHO cells was analyzed by flow cytometry.</p><p><b>RESULTS</b>Using 1.2 µg of the total RNA isolated from the PBMCs as the template, the LCκ and VH were amplified and the full-length fully human antibody mammalian display libraries were constructed. The kappa light chain gene library had a size of 1.45×10(4) and the heavy chain gene library had a size of 1.8×10(5). Sequence analysis showed that 8 out of the 10 light chain clones and 7 out of the 10 heavy chain clones randomly picked up from the constructed libraries contained correct open reading frames. FACS analysis demonstrated that all the 15 clones with correct open reading frames expressed full-length antibodies, which could be detected on CHO cell surfaces. After co-transfection of the heavy chain and light chain gene libraries into CHO cells, the expression of full-length antibodies on CHO cell surfaces could be detected by FACS analysis with an expressible diversity of the antibody library reaching 1.46×10(9) [(1.45×10(4)×80%)×(1.8×10(5)×70%)].</p><p><b>CONCLUSION</b>Using 1.2 µg of total RNA as template, the LCκ and VH full-length fully human antibody libraries against dengue virus have been successfully constructed with an expressible diversity of 10(9).</p>