Bacterial outer membrane vesicles: a new approach to diseases therapy / 药学学报

Outer membrane vesicles (OMVs) are nano-sized spherical vehicles, with a size range between 20-250 nm. OMVs are spontaneously secreted from Gram-negative bacteria and formed by lipid bilayer membranes, comprising multiple parent bacteria-derived components including bacterial antigens, pathogen-associated molecular patterns, proteins and lipids. OMVs have shown multiple potentials for the treatment of various diseases, including cancer therapy and bacterial infection. In this review, the structure, composition and methods for isolating and characterizing of OMVs were introduced. The applications of OMVs for diseases therapy were summarized and future perspectives were discussed.

Effects of lipid-rich food on lymphatic transport of puerarin microemulsion / 中草药

Objective To study the effects of lipid-rick food on lymphatic transport absorption of puerarin microemulsion based on the puerarin microemulsion prepared before. Methods Cycloheximide was used to block lymphatic transport of the microemulsion, and the concentration of puerarin in plasma was determined by HPLC. Bioavailability of blocking group and unblocking group were compared to calculate the proportion of puerarin absorbed by lymphatic transport. Results Administration of lipid did not enhance the proportion of puerarin absorbed by lymphatic transport, compared to administration of water as controls, but microemulsion formulation contribute to the improved lymphatic transport and bioavailability of puerarin. Besides, administration of lipid failed to further increase the lymphatic transport of puerarin microemulsion, but it was evidenced that microemulsion formulation could decrease the effects of lipid-rich food on bioavailability of oral drugs. Conclusion Lipid in food could not enhance the lymphatic transport of puerarin microemulsion and show no significant effects on the bioavailability.

Femoral tunnel positioning in posterior cruciate ligament double-bundle reconstruction by computer aided design / 中国骨伤

<p><b>OBJECTIVE</b>To study mechanical affect of knee joint of reasonable positioning of femoral tunnel during knee posterior cruciate ligament (PCL) double-bundle reconstruction and graft fixation after reconstruction by virtual reality interactive technology and evaluate the biomechanical response of knee after reconstruction by finite element analysis.</p><p><b>METHODS</b>Knee specimens from five fresh frozen cadavers were used. Computer simulations and biomechanical experiments were used in this study. Experiments on flexion and extension movements of the knee joint were performed on specimens of fresh human knee joint. Laser three dimensional scanning was used to record and calculate the indexes of movements. Three-dimensional models of knee joint bone structure were then reconstructed on computer with the experimental data. Simulations of flexion and extension movements were carried out on the models to show the spatial positions of femur and tibia and label the attachment sites of PCL. Ten test points in the anterior,posterior, proximal, distal at the femoral attachment area of anterior and lateral bundle (ALB) and postoperior medial bundle (PMB) were selected and the central points of tibial en attachment areat anchored. The distance btween each two points of two article surface was calculated and contacted by software of Geomagic. Model was import software Ansys, adopting the tetrahedron unit a finite element model of complex tibial and femoral was set up to simulat human walking in one leg,on this condition the the joint surface force of model under weight impact load were analyzed.</p><p><b>RESULTS</b>The three-dimensional models could demonstrate the spatial positions of the bone structure of the knee in different flexions and extensions. The models could be used to measure the spatial distance between 2 points on the femoral and tibial planes by software Geomagic. There was significantly difference among the length changes of anterolateral bundle and posteromedial bundle at every fixed point with different flexion angles (P<0.05), so the fixed angle with different points. The length changes of anterior lateral bundle's A2, A1 and posterior medial bundle's B3, B1 points were (1.35±0.19) mm, (5.41±1.22) mm, (1.95±0.04) mm and (5.23±2.21) mm, respectively. The A2 and B3 points' length changes were the less, and that of the Al and B1 points were the more. It had no significant difference between the length changes of anterior lanteral bundle's A2 and A3 point (P=0.913>0.05). All of the maximal length changes of anterior lateral bundle's A2, A3 and postterior medial bundle's B3 points were less than 2 mm.</p><p><b>CONCLUSION</b>The models of knee joint were builded through computer technology and it can be measure the lenth of cruciate ligament with software Geomagic exactly. The femoral tunnel for the PCL double-bundle reconstruction should be located as follows: ALB at the middle point of upper edge of femoral attachment site (proximal point),while PMB at the middle point of femoral attachment site (proximal point). This model provides a satisfactory method for the evaluation of the biomechanical response of knee after cruciate ligament reconstruction.</p>

Three-dimensional finite element analysis on mechanical behavior of the bone remodeling and bone integration between the bone-implant interface after hip replacement / 中国骨伤

<p><b>OBJECTIVE</b>To discuss the primary stability of the fixed interface between the cementless prosthesis and femur, and its influence on bone ingrowth and secondary stability under the roughened surface and press fit of different prostheses by finite element analysis.</p><p><b>METHODS</b>:A three-dimensional finite element module of total hip arthroplasty (THA) was developed with Mimics software. There was a collection of data when simulating hip arthroplasty. The frictional coefficient between the fixed interface was 0,0.15,0.40 and 1.00 representing the roughness of prosthesis surface. The press fit was 0, 0.01,0.05 and 0.10 mm according to the operation. The Vion Mises stress distribution and the contact pressure,friction stress and relative sliding displacement between the interface were analysed and compared when simulating the maneuver of climbing stairs.</p><p><b>RESULTS</b>At a fixed press fit of 0.05 mm,the contact pressure between the interface was 230 , 231, 222 and 275 MN under four different frictional coefficient (0,0. 15,0.40 and 1.00) with little change; the relative sliding displacement was 0.529, 0.129, 0.107 and 0.087 mm with a consistent and obvious decline. As the fixed frictional coefficient was 0.40,the contact pressure between the interface were 56.0,67.7 ,60.4 and 49.6 MN under four different press fit (0, 0.01, 0.05 and 0.10 mm) with a reduction; the relative sliding displacement was 0.064,0.062,0.043 and 0.042 mm with an obvious decline, and there was a maximal friction stress when press fit of 0.01 mm.</p><p><b>CONCLUSION</b>There is a dynamic process of the bone remodeling and bone integration between the interface after hip replacement, determining the long-term outcome. The interface clearance and the frictional coefficient are the key factors of the bone integration.</p>

Treatment of type C pelvic fracture with Stoppa approach and posterior percutaneous plate fixation / 中国骨伤

<p><b>OBJECTIVE</b>To explore the clinical effects of Stoppa approach and posterior percutaneous plate in treating type C pelvic fracture.</p><p><b>METHODS</b>From June 2009 to July 2011,16 patients with type C pelvic fracture were treated with reconstruction plate fixation in Stoppa approach for anterior lesions combined with posterior percutaneous plate fixation for posterior lesions.There were 11 males and 5 females,with an average age of 38.8 years (ranged, 22 to 59 years). According to the Tile classification,10 cases belonged to C1,4 belonged to C2,2 belonged to C3. Tometta and Majeed score standards were used to evaluate clinical results.</p><p><b>RESULTS</b>Sixteen patients were followed up from 4 to 13 months with an average of 7.3 months. Operative time was from 80 to 140 min with an average of 100 min;blood loss volume was from 200 to 500 ml with an average of 280 ml; and the healing time of fracture was from 12 to 16 months with an average of 14 months. According to the Tometta score classification, 9 cases got excellent results, 6 good, 1 fair. According to the Majeed score classification, 9 cases obtained excellent results, 5 good, 2 fair.</p><p><b>CONCLUSION</b>Reconstruction plate fixation in Stoppa approach for anterior lesions combined with posterior percutaneous plate fixation for posterior lesions is an ideal minimally invasive operation in treaing type C pelvic fracture. It can early exercise and has the advandages of small trauma, safe operaton,less complication, stable fixation.</p>

The cup safe-zone and optimum combination of the acetabular and femoral anteversions that fulfills the desired range of motion of the hip / 中国骨伤

<p><b>OBJECTIVE</b>To investigate safe range of acetabular prosthesis angle and the optimum combination of cup and neck in the range of activities of daily living (ADL).</p><p><b>METHODS</b>A three-dimensional generic parametric and kinematic simulation module of THA was developed. Range of motion (ROM) of flexion > or = 110 degrees, internal-rotation > or = 30 degrees at 90 degrees flexion, extension > or = 30 degrees and external rotation > or = 40 degrees were defined as the normal criteria for desired ROM for activities of daily living (ADL), and ROM of flexion > or = 120 degrees, internal-rotation > or = 45 degrees at 90 degrees flexion, extension > or = 30 degrees and external rotation > or = 40 degrees as the severe criteria. The range of the changes in the general head-neck ratios (GR), the femoral neck anteversion (FA), the operative anteversion (OA) and operative inclination (OI) of the cup component were 2-2.92, 0 degrees-30 degrees, 0 degrees-70 degrees, 10 degrees-60 degrees respectively. For the collodiaphyseal angle (CCD) of 135 degrees, the corresponding OA related to the OI which every 5 degrees was calculated, and described using dots and lines in a coordinate system in which OI of acetabular cup was the horizontal ordinate and OA of acetabular cup was the vertical ordinate. All data was analyzed by SAS 6.12 software.</p><p><b>RESULTS</b>Large GR greatly increased the size of safe range and it was recommended that GR be more than 2.37 when the CCD-angle was 135 degrees as it further increases the size of safezone. The size of cup safety range of the severe criteria was smaller than normal criteria. When the CCD-angle was 135 degrees, the optimum relationship between OA of acetabular and FA of the normal criteria and the severe criteria can be estimated by the formula: Y1=-0.816X1 + 39.76 (R2=0.993), Y2=-0.873X2 + 47.04 (R2=0.999) respectively.</p><p><b>CONCLUSION</b>Large GR greatly increases the size of safe-zone and it is recommended that GR be more than 2.37, so it extends the acceptable range of error that clinicians cannot avoid it completely. The larger range of the hip motion, the smaller size of the cup safe-zone,but can retrieve by increase the GR. The OA is negative with FA.</p>

Clinical apprehension on application of metal on metal total hip arthroplasty with large diameter heads / 中国骨伤

<p><b>OBJECTIVE</b>To approach the short-term result and clinical application of metal on metal total hip arthroplasty with large diameter heads and evaluate its safety and efficacy clinically.</p><p><b>METHODS</b>From January 2007 to March 2008, 39 hips in 37 patients (24 males and 13 females,ranging in age from 43 to 75 years, with an average of 58.5 years) were treated with metal on metal total hip arthroplasty with large diameter heads (ASRTM XL) included 14 cases of osteonecrosis (ON), 2 cases of osteoarthritis (OA), 18 cases of fresh femoral neck fracture, 3 cases of developmental dysplasia of the hip (DDH). All patients were evaluated by self assessment form, hip function examination, radiographs, preoperative and postoperative Harris hip score. Based on the short-term results, its design characteristic and clinical properties were analyzed.</p><p><b>RESULTS</b>All the incision healed well and there were not any complications such as femoral fracture, infection, dislocation and neurovascular injury. All patients obtained the follow-up and an average time was 16.5 months (12 to 19 months), all the joints had good or excellent clinical results. Radiographically, the positions of the prostheses were normal, the average limbs length and femoral eccentricity recovered as normal. The average range of motion of the hip improved remarkable, such as flexion improved from (20.1 +/- 8.2) degrees to (85.7 +/- 9.8) (t = 32.86, P < 0.01), abduction improved from (10.2 +/- 4.4) degrees to (41.5 +/- 9.1) degrees (t = 19.34, P < 0.01), adduction improved from (16.3 +/- 8.8) degrees to (40.3 +/- 10.4) (t = 11.00, P < 0.01),external rotation improved from (12.3 +/- 5.2)0 to (42.0 +/- 7.7) degrees (t = 19.96, P < 0.01), internal rotation improved from (3.4 +/- 1.1) degrees to (23.0 +/- 9.8) degrees (t = 12.41, P < 0.01). The Harris score rose from preoperative (39.3 +/- 5.6) to (91.4 +/- 10.3) at the latest follow up (t = 27.75, P < 0.01).</p><p><b>CONCLUSION</b>Short-term results show that metal on metal hip joint prosthesis with large diameter heads has advantages of small deformation of acetabular cup, lower wearing, large range of motion and few dislocation. It offers a newly valuable technology for treatment of osteonecrosis, osteoarthritis, femoral neck fracture and DDH with the higher requirement of movement after the operation.</p>

Influences of head/neck ratio and femoral antetorsion on the safe-zone of operative acetabular orientations in total hip arthroplasty / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study the influences of head/neck ratio and femoral antetorsion on the safe-zone of operative acetabular orientations, which meets the criteria for desired range of motion (ROM) for activities of daily living in total hip arthroplasty (THA).</p><p><b>METHODS</b>A three-dimensional generic, parametric and kinematic simulation module of THA was developed to analyze the cup safe-zone and the optimum combination of cup and neck antetorsion. A ROM of flexion > or =120 degree internal rotation > or = 45 degree at 90 degree flexion, extension > or = 30 degree and external rotation > or =40 degree was defined as the criteria for desired ROM for activities of daily living. The cup safe-zone was defined as the area that fulfills all the criteria of desired ROM before the neck impinged on the liner of the cup. For a fixed stem-neck (CCD)-angle of 130 degree theoretical safe-zones fulfilling the desired ROM were investigated at different general head-neck ratios (GR=2, 2.17, 2.37, 2.61 and 2.92) and femoral anteversions (FA equal to 0 degree,10 degree,20 degree and 30 degree).</p><p><b>RESULTS</b>Large GRs greatly increased the size of safe-zones and when the CCD-angle was 130 degree, a GR larger than 2.37 could further increase the size of safe-zones. There was a complex interplay between the orientation angles of the femoral and acetabular components. When the CCD-angle was 130 degree the optimum relationship between operative acetabular anteversion (OA) and femoral antetorsion (FA) could be estimated by the formula: OA equal to -0.80 multiply FA+47.06, and the minimum allowable operative acetabular inclination (OI(min)) would be more than 210.5 multiply GR(-2.255).</p><p><b>CONCLUSIONS</b>Large GRs greatly increase the size of safe-zones and it is recommended that the GR be more than 2.37 so as to extend the acceptable range of error that surgeons cannot avoid completely during operation. As to the optimum operative acetabular inclination (OI), surgeons need to make a decision combining with other factors, including stress distribution, soft tissue and cup wear conditions, as well as patients'individual situations and demands. The data obtained from this study and the module of THA can be used to assist surgeons to choose and implant appropriate implants.</p>

Prevention of prothesis dislocation after the revision of total hip arthroplasty / 中国骨伤

<p><b>OBJECTIVE</b>To explore the role of reconstruction of the posterior capsule and external rotators in prevention of postoperative dislocation in total hip arthroplasty revision following the posterolateral approach.</p><p><b>METHODS</b>Forty-five patients (47 hips) with the mean age of 65 years (55 to 78 years)of failed total hip arthroplasty were revised following the posterolateral approach. Posterior capsule was sutured to the anterosuperior portion of the capsule from where it had been detached, and the external rotators were then reattached to the soft tissue at the tip of the greater trochanter using 1.0 silk suture in surgery. The dislocation rate and risk factors were reviewed retrospectively to determine if closing the posterior capsule resulted in fewer dislocations. The femoral prosthesis and acetabular prosthesis were revised in 29 patients (31 hips), the liner was exchanged in 5 patients (5 hips), and the acetabular prosthesis or femoral components were revised in 10 patients (10 hips) and one patient (one hip) respectively. The procedure was the patient's first revision in 29 patients (30 hips), the second revision in 15 patients (16 hips), and the third revision in one patient(one hip). Radiographic evaluation included lower limb discrepancy, acetabular phase, femoral offset, anteversion angle, prosthetic loosening before and after revision. Function evaluation based on Harris score system.</p><p><b>RESULTS</b>All patients were followed up with an average of 2.7 years. None of the patients sustained dislocation or infection, except one patient felt the anterior instability but without dislocation, X-ray revealed the acetabular component was in excessively anteversion. Lower leg discrepancy, acetabular abduction, anteversion femoral offest and collodiaphyseal angle were restored to normal level after operation on the basis of X-ray. One of the acetabular components and one of the femoral components were loose without dislocation. The Harris hip score improved from (49.13 +/- 15.53) points preoperatively to (83.59 +/- 6.93) points at the final follow-up (P < 0.05). According to Harris functional evaluation, 36 hip got an excellent result, 5 good, 5 fair and 1 bad.</p><p><b>CONCLUSION</b>The historically high dislocation rate with the posterolateral approach for total hip arthroplasty revision can be reduced by careful soft tissue balancing,correction of implant alignment, meticulously closure of the posterior capsule, and reattaching the external rotators.</p>