BACKGROUND: Systemic administrations are widely used in preventing or curing bone infections, however, it accompanied by great adverse reactions and limited local blood drug levels. Therefore, local administration becomes a research focus, which aimed to explore a carrier possess good biocompatibility and slow-release antibiotics. OBJECTIVE: To explore the effect of calcium alginate gel compound vancomycin on prevention of bone infection, simultaneously, single drug was injected or implanted into models to compare the results.METHODS: A total of 60 healthy adult New Zealand white rabbits were prepared for osteomyelitis models by injecting Staphylococcus auraus to right tibiae medullaris, and randomly divided into systemic treatment, tricalcium phosphate and calcium alginate gel groups. After model preparation, rabbits in the systemic treatment group were intramuscular injected vancomycin (0.03 g, twice per day, for 4 successive days); in the triceicium phosphate group, 1 g tricalcium phosphate combined with 0.1 g vancomycin.was filled in the defects, sealed with bone wax. In the calcium alginate gel group, calcium alginate gel combined with vancomycin was implanted. Gross observation, radiological image and histological analysis were performed at weeks 4 and 8 after operation.RESULTS AND CONCLUSION: Local swelling and partial sinus were found in the systemic treatment and tricalcium phosphate groups after operation. The pathological slice showed that there were a large number of lymphocytes and some sequestrum in the systemic treatment and tricelcium phosphate groups. However, there was no manifestation of osteomyelitis in the calcium alginate gel group. The results suggested that calcium alginate gel compound vancomycin exhibit superior therapeutic effect on prevention of bone infection to local administration of calcium alginate gel combined with vancomycin or systemic application of vancomycin.

[Objective]To study diagnosis and treatment of insidious infection after the internal fixation of long bone fracture.[Method]Thirteen patients with insidious infection after internal fixation of long bone fracture were treated with irrigation after debridment. Among the 13 cases 8 fractures were dislodged internal fixation and then were fixed with the external fixation. 5 fractures were remained the internal fixation and were instilled after debridment. All of the patients were given with antibiotics for 2～3 weeks after operation.[Result]All the 13 patients were followed up. The follow-ranged from 8 to 48 months with an average of 23.5 months. Among the thirteen patients 11 fractured-bone had bony union, one nonunion and one case had fistula, Infection relapsed in two patients.[Conclusion]Bone defects, fracture nonunion often occur on patients who have insidious infection after internal fixation of long bone fracture. These patients need to be operated. In slight infections fracture can be remained after debridement. Fractures with seriously infectious have to dislodge internal fixation and to be fixed with made according to its radiographic changes.

Objective To investigate the effects of a proliferation-inducing ligand(APRIL) on migration and invasion of colorectal cancer (CRC) and matrix metalloproteinases (MMPs) expression in order to observe the role of APRIL in CRC metastasis.Methods The siRNA plasmid vector targeting APRIL gene (siRNA-APRIL) was transfected into SW480 cells and recombinant human APRIL(rhAPRIL) was used to stimulate HCT-116 cells.Tumor cell migration and invasion were measured by Transwell chambers.RT-PCR and ELISA were applied to examine the expression level of MMPs.Results Metastatic and invasive capacities of siRNA-APRIL transfected SW480 were significantly inhibited,and these capacities of APRIL stimulated HCT-116 cells were significantly enhanced compared with their respective controls( all P＜0.05 ),accompanied with the alterations of MMPs mRNA and secreted protein expression( P＜0.05).The number of invading cells of SW480 control and rhAPRIL stimulated HCT-116 was significantly decreased by a MMP inhibitor GM6001 ( P＜0.05 ).Conclusion APRIL facilitates migration and invasion of CRC via regulation of MMPs,which suggests that APRIL might be used as a new target for the intervention and treatment of CRC metastasis.

Background and purpose: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a new minimally invasive method in the dignosis for mediastinal lymph nodes. This study was to evaluate the diagnostic yield of EBUS-TBNA for mediastinal lymph nodes. Methods: Twenty patients with mediastinal lymph nodes found by CT underwent the dignosis by EBUS-TBNA form April 1st 2009 to July 16th 2009. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of EBUS-TBNA were evaluated. Results: Twenty patients with 37 lymph node groups were studied. Overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of EBUS-TBNA for diagnostic were 84.62%, 100%, 100%, 77.78% and 90.00%, respectively. The diagnostic accuracy for cancer was 100%. The operation time was 11.9min per group in average with no serious complication. The median length of hospital stay was 1 (range from 1 to 17 days) day after operation. There were significant differences in the average operation time between the first three patients and the others (36.25 min vs. 7.76 min; z=3.247, P=0.001). Conclusion: Endobronchial ultrasound-guided transbronchial needle aspiration proved to be a safe procedure with a high yield for the diagnosis of mediastinal lymph nodes.

Objective To analyze the relationship between fatigue strength and connector length of intracranial artery stents, so as to investigate the exact location of fatigue fracture for the stent. Methods The fatigue life for 3 kinds of artery stents were analyzed by finite element analysis method of fatigue fracture, and distribution map of dangerous points was drawn by means of Goodman curve. Based on F2477-07 standard from American Society for Testing and Materials (ASTM), the fatigue life for 3 kinds of stents was tested. Results If the length of the support connector was longer, the maximum equivalent stress and the average stress in dangerous points of the stent would be larger. If the distribution of dangerous points was more close to the curve of fatigue limit, and fatigue fracture was more likely to occur in the stent. Goodman curves indicated that 3 kinds of stents was safe to be used in the body for ten years. Finite element analysis and experimental result showed that fatigue life near the stent junction was relatively lower, and dangerous points of the stent was located at the arc junction. Conclusions It is reasonable to study stents by finite element analysis, whose results are basically coincided with the experimental data. Fatigue life can be extended by reducing connector’s length for the design of stent structure.

BACKGROUND AND OBJECTIVEIt has been proven that endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was a new minimally invasive method in the diagnosis for mediastinal lymph nodes. The aim of this study is to evaluate the diagnostic and staging yield of EBUS-TBNA for lung cancer.

METHODSSeventy-five patients with tumors and enlarged mediastinal lymph nodes found by CT underwent the diagnosis by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) from April 1, 2009 to Febuary 8, 2010. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of EBUS-TBNA were evaluated.

RESULTSSeventy-five patients with 177 lymph node groups (2.4 groups in average) were studied. Histopathological samples were found in 49.33% patients and in 28.81% groups. Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of EBUS-TBNA for diagnostic were 98.43%, 100.00%, 100.00%, 91.67% and 98.66%, respectively, in per patient analysis and were 95.10%, 100%, 100.00%, 82.93%, and 96.05%, respectively, in per group analysis, higher than CT examination (P < 0.05) expect for sensitivity (P = 0.435). Staging changed in 19 (26.03%) patients after EBUS-TBNA.

CONCLUSIONEBUS-TBNA proved to be a safe procedure with a high yield for the diagnosis of lung cancer.

Adult ; Aged ; Aged, 80 and over ; Biopsy, Fine-Needle ; methods ; Bronchi ; diagnostic imaging ; pathology ; Endosonography ; methods ; Female ; Humans ; Lung Neoplasms ; diagnosis ; pathology ; Male ; Middle Aged ; Neoplasm Staging

Objective To reduce the thrombosis probability and hemolysis risk of the meglev left ventricular assist device (LVAD), so as to increase the efficiency of blood supply. Methods The influences of the pump outlet diameter, exit angle, fillet size between the outlet and the inner wall of the pump, as well as gap between the rotor and the shell on internal flow field of the pump were studied by using the computational fluid dynamics (CFD) method, so as to optimize the internal structure and improve the hydrodynamic performance of the pump. Results Compared with pump of the previous generation, the maximum wall shear stress (WSS) of the pump inner wall, the maximum WSS of the pump rotor, the area with WSS >200 Pa were reduced by 23.6%, 47.4%, 76.2%, respectively, while the outlet flow was increased by 14.4%. Conclusions For the meglev LVAD of the new generation, its internal blood flow tended to be smooth, and the hemodynamic performance of blood flow was improved comprehensively. The research findings provide references for optimization design of the meglev LVAD and related experimental researches in the future.

Objective To conduct simulation analysis on support performance of the stent by using finite element method, and optimize structure parameters of the stent by using Kriging surrogate model, so as to provide more scientific guidance for clinical treatment with design and development of the stent. Methods The contact model was established by penalty function method. The generalized variational principle was selected as theoretical basis of the numerical simulation, and the theory of Kriging surrogate model was used for finite element optimization on support stiffness of the stent, so as to study the effect from the number of circumferential support, the length of the support and the initial diameter on support performance of the stent. Results With the increase of the number of circumferential support or the length of the support, the support performance showed the decreasing tendency; with the increase of the initial diameter, the support performance showed the increasing tendency. From seven stents by using the theory of Kriging surrogate model, it was concluded that structural parameters of the optimal stent were: the number of circumferential support was six, the length of the support was 1.15 mm, and the initial diameter was 1.65 mm. Conclusions The numerical result agreed well with the experimental data and the error was smaller than 5%, and the error rate of experimental repeatability was within 0.5%, which verified effectiveness and rationality of the finite element analysis. The optimization of support performance provides an important reference for design and exploration of new magnesium alloy stent.

Lower extremity movement is a complex and large range of limb movement. Arterial stents implanted in lower extremity are prone to complex mechanical deformation, so the stent is required to have high comprehensive mechanical properties. In order to evaluate the mechanical property of different stents, in this paper, finite element method was used to simulate and compare the mechanical properties of six nitinol stents (Absolute Pro, Complete SE, Lifestent, Protégé EverFlex, Pulsar-35 and New) under different deformation modes, such as radial compression, axial compression/tension, bending and torsion, and the radial support performance of the stents was verified by experiments. The results showed that the comprehensive performance of New stent was better than other stents. Among which the radial support performance was higher than Absolute Pro and Pulsar-35 stent, the axial support performance was better than Complete SE, Lifestent and Protégé EverFlex stent, the flexibility was superior to Protégé Everflex stent, and the torsion performance was better than Complete SE, Lifestent and Protégé Everflex stent. The TTR2 type radial support force tester was used to test the radial support performance of 6 types, and the finite element analysis results were verified. The mechanical properties of the stent are closely related to the structural size. The result provides a reference for choosing a suitable stent according to the needs of the diseased location in clinical applications.
Alloys ; Femoral Artery ; Finite Element Analysis ; Lower Extremity ; Mechanical Phenomena ; Prosthesis Design ; Stents ; Stress, Mechanical

Objective To study the hemodynamic effect of the convertible vena cava filters on treating pulmonary embolism with different thrombus diameters and contents. Methods Three kinds of simulated filter models with the same diameter but different filtering structures (L-style, S-style and W-style) were built and then the hemodynamics of the filter after its implantation into the vessels was analyzed by using computational fluid dynamic (CFD) method. Results Without thrombus in the vessels, three kinds of filters in blood had some obstructive effects and increased the average outlet velocity. While the L-style filter caused the maximum average outlet velocity, the S-style filter was in the middle, and the W-style filter was the lowest. Under the condition of thrombus, the structures of the filter rods had no obvious effect on the average outlet velocity of blood flow and thrombus, and differential pressure of blood flow and thrombus between inlet and outlet. With the increase of thrombus’s diameter and content, the hemodynamic factors showed varying degrees of decreasing tendency. The wall shear stresses (WSS) on three kinds of filter rods caused by blood flow were in normal ranges, and WSS on the lower end of filter supports, the joints of supports and filter rods were below the minimum value, where thrombosis was easy to occur. Conclusions The hemodynamic effect of three kinds of convertible vena cava filters with different filtering structures, different thrombus diameters and contents in vessels were analyzed by using CFD method, which would provide theoretical references for the design and development of novel filters.