Three purification methods ,based on differential centrifugation,precipitation by polyethylene glycol (PEG)and ultra-speed centrifugation,were compared for purification of an alfalfa mosaic virus (AMVSY)previously isolated from Trifolium repens. The Purified virus was observed under electron microscope, measured,by ultra-violet absorpton analysis and protein determination with SDS-polyacrylamide gel electrophoresis. Our results showed that a method by alternative use of sodium phosphate buffers containing 0. 1mol/L EDTA and 0. 1mol/L MgSO4 achieved the best purification with less miscellaneous protein contamination,integrate virus particles and relatively high yield, which was of 47.6mg virion per hundred grams of fresh leaves of Chanopodium quinoa inoculated with AMV-SY. The coat protein of AMY-SY was tested for about 29 kilo-Dalton.

Objective: To determine the overlapping area of the femoral condyle facet on which the patellofemoral and tibiofemoral joint surfaces move and to measure the pressures on such area in order to better design the length of femoral trochlea prosthesis in patellofemoral arthroplasty. Methods: Eight fresh cadaver knees were mounted on Instron 8501 biomechanics tester,and simulated physiologically weight-bearing situation of knee from standing to flexion position. Such overlapping area was drawed up with stain method and the contact pressures were measured with Fuji pressure film. Results: There existed an overlapping contact area on the femoral condyle facet within the patellofemoral contact area when knee flexion was 75? or larger. The tibiofemoral contact pressure was higher than the patellofemoral pressure in the area. Conclusion: The femoral trocher prosthesis should cover the whole contact area of patellofemoral joint.

Objective To discuss the curative effect of minimally invasive percutaneous plate osteosynthesis (MIPPO) in treatment of comminuted fracture of metaphyseal tibia. Methods The study involved 38 patients with comminuted fracture of metaphyseal tibia treated by indirect reduction and MIPPO. Results All patients were followed up for 10-30 months (average 18.6 months), which showed one stage union in all patients. The time for bony union was 4.2-7.8 months (mean 5.4 months). The operation lasted for 50-130 minutes (average 75 minutes). According to Johner-Wruhs system, the outcome was excellent in 26 patients, good in 10 and fair in two, with satisfactory rate of 95%. Conclusion MIPPO takes advantages of minor trauma, few complication, simple manipulation, high success rate and satisfactory recovery of joint function recovery and bony union, and hence is a safe and effective treatment for comminuted fracture of metaphyseal tibia.

Objective To compared the posterior slop between tibial plateau and meniscus in Chinese population for determining the angle of tibial osteotomy during total knee replacement(TKA).Methods Posterior slop of tibial plateau and meniscus in sixty Chinese volunteers were measured on sagital view of MRI image.Results The values of posterior slop of tibial plateau and meniscus were 9.87??1.56?and 0.96??0.09?,respectively.The two angle revealed remarkable difference (P

BACKGROUND:Vertebral compression fractures are the most common vertebral fractures in the elderly patients with osteoporosis, and the correlation between the compression of anterior border of vertebral body and adjacent vertebral refractures is not clear.
OBJECTIVE:To establish a model of different compression of T12vertebral body with finite element method, and analyze the relationship between the compression of T12vertebral body and the stress of adjacent vertebral plate.
METHODS:Based on thoracolumbar CT data of normal adult volunteers, MIMICS/3-matic was imported. Through image segmentation, repair and three-dimensional mesh of accessto thoracic and lumbar T11-L1data, grid assigned material properties was imported to ABAQUS so as to establish ligament, joint and other small features and obtain realistic three-dimensional finite element model. The six degrees of freedom, including anteflexion, posterior extension, left and right flexion, left and right rotation, were loaded, to verify the validity of the normal model. With the frontier of vertebral body compression to 90%, 80%, 70%…10% of the nine states, MISES stressesof the T11andL1segment intervertebral disc endplate were extracted; the relationship curve of compression state and endplate stress was obtained.
RESULTS AND CONCLUSION:(1) The model was highly realistic and could reflect the actual stress state. (2) The stress value of T11vertebral body and L1vertebral body was positively correlated with the compression of T12vertebral body. Increased stress may lead to an increased likelihood of end plate fractures, which increases the risk of fractures in the adjacent vertebralbodies.

Objective To discuss the application of longitudinal reduction of Chinese traditional medicine in surgical treatment of distal radius comminuted fractures in the elderly. Methods Before the operation, the 54 elderly patients with the fracture were reduced by longitudinal direction under anesthesia, then they were treated with minimally invasive plate osteosynthesis in the approach upon the reduction condition and fracture types. Results After 12-month follow-up, the fractures were all healed. The mean healing time of the fractures was 8 weeks (6-12 weeks). At the end of follow -up, the mean range of motion of the wrist was at 50°of flexion, 45°of extension, 30° of ulnar deviation, at 20° of radial deviation. According to the criteria of Gartland and Werley, the results were excellent in 35 cases, good in 17 cases, fair in 2 cases and poor in 0 case. Conclusions It is vital to provide a Chinese traditional longitudinal reduction before invasive surgical plate fixation in treatment of distal radius comminuted fractures, to avoid large-area exposure of fracture site, minimize the damage to the soft tissue, maintain reduction of post operation and achieve good wrist function.

The mechanical model of knee is a system of constructional elements with specific restrains and material properties, which are deduced from the components of knee based on their functions and junctions. Kinematics and kinetics of knee can be calculated from the mechanical model. A review of some mechanical models of knee are shown in this paper.
Biomechanical Phenomena ; Computer Simulation ; Humans ; Knee Joint ; physiology ; Models, Biological ; Range of Motion, Articular ; physiology ; Stress, Mechanical

Objective To explore the treatment method for femoral neck fracture in the young adult patients and discuss the corresponding curative efficacy.Methods Closed reduction and internal fixation with hollow screws were carried out in treatment of 58 young adult patients with femoral neck fracture.There were 37 males and 21 females at age range of 19-56 years(average 37.5 years).According to Garden classification,there were seven patients with type Ⅰ fractures,19 with type Ⅱ,23 with type Ⅲ and nine with type Ⅳ.Results Follow-up lasted for 0.5-7.0 years(average 3.8 years),which showed the average one stage healing time of 5.8 months in 50 patients.Nonunion occurred in three patients and avascular necrosis of the femoral head(ANFH)in five patients,of which six patients were treated with two stage sartorius pedicled iliac graft,with fracture healing in three patients.According to Harris evaluation,the result was rated as excellent in 29 patients,good in 22,fair in two and poor in five,with excellence rate of 88％.Conclusions Closed reduction and internal fixation with hollow screw takes advantages of minor wound,few complications,high healing rate and satisfactory function recovery,and is effective in treatment of femoral neck fracture in the young adult patients.Open reduction and internal fixation with sartorius pedicled iliac graft can be used as remedial treatment for fracture nonunion and avascular necrosis.

A sagittal plane model of knee joint based on crossed-four-bar-linkage-based tibiofemoral joint model has been developed using geometric and force equilibrium constraints. The model predicts and explains the movement of contact point on the patella and femur, variation of patellar and patellar tendon angle, variation of patellar mechanism angle and variation of patellofemoral contact force and patellar tendon force. The computed results agree well with the published experimental results.
Biomechanical Phenomena ; Humans ; Knee Joint ; anatomy & histology ; physiology ; Models, Biological ; Movement ; physiology ; Patella ; anatomy & histology ; physiology

Intrahepatic cholangiocarcinoma is a highly invasive malignant tumor, and at present, surgical resection is the only effective way for cure. Lymph node metastasis makes it difficult to accurately judge the extent of radical resection, and no international consensus has been reached on the need for routine lymph node dissection and the extent of lymph node dissection. This article summarizes and analyzes the disputes and problems in preventive lymph node dissection for patients without lymph node metastasis before surgery, hoping to provide a reference for radical resection of intrahepatic cholangiocarcinoma.