Objective To investigate the correlation between the CD40 gene( - 1 C/T)single nucleotide polymorphism(SNP) and acute coronary syndromes(ACS), and the expression of CD40 on platelets. Method A total of 562 patients with ACS canfirmed by coronary angiography were divided into 3 groups according to the clinical characteristics, namely ACS patients( n = 210), stable angina(SA) patients( n = 189) and control group( n = 163).ACS was defined as ischemic chest pain at rest resulting in admission to hospital and > 50% stenosis in a major coronary artery with or without a rise in troponin Ⅰ. SA was defined as stable effort-related angina without change in angina pattern in 3 months. Patients with infection, tumor, or liver or kidney disease were excluded The gene polymorphism was measured by the polymerase chain reaction and restriction fragment length polymorphism(PCR-RFIP) and identiffed by sequencing. The expression of CD40 on platelets was detected by flow cytometry. The frequency, distribution of genotypes was compared using cross-tabulation and standard X~2 test. Result The CC genotype(31% ) and C allele of frequency(57.9%)of CD40 gene in ACS patients were significantly higher than those in SA(15.9%, 43.1% ) and control groups( 16.1%, 42.6% ). No significant difference of the genotypes or allele frequencies was found between SA and control group(X~2 = 0.053, P = 0.974;X~2 = 0.017, P = 0.897). 1he expression of CD40 on platelets in patients with C alleles carries was significandy higher than that of T allele carries in each group( P <0.0001). Conclusions CD40- 1C/T polymorphism was associated with ACS in Chinese Han nationallity.

A 54-year-old female patient with congenital heart disease had a persistent complete left bundle branch block three months after closure by an Amplatzer ventricular septal defect occluder. Nine months later, the patient suffered from chest distress, palpitation, and sweating at daily activities, and her 6-min walk distance decreased significantly (155 m). Her echocardiography showed increased left ventricular end-diastolic diameter with left ventricular ejection fraction of 37%. Her symptoms reduced significantly one week after received cardiac resynchronization therapy. She had no symptoms at daily activities, and her echo showed left ventricular ejection fraction of 46%and 53%. Moreover, left ventricular end-diastolic diameter decreased 6 and 10 months after cardiac resynchronization therapy, and 6-min walk dis-tance remarkably increased. This case demonstrated that persistent complete left bundle branch block for nine months after transcatheter closure with ventricular septal defect Amplatzer occluder could lead to left ventricular enlargement and a significant decrease in left ventricular systolic function. Cardiac resynchronization therapy decreased left ventricular end-diastolic diameter and increased left ventricular ejection fraction, thereby improving the patient’s heart functions.

Objective To examine the biomechanical properties of three-dimensional(3D) printed electron beam melting(EBM) Ti-6AI-4V mesh as scaffold for mandibular repairment.Methods We fabricated Ti-6Al-4V samples of different structures with strut,sheet and 3D mesh scaffolds(a controllable diameter 0.35,0.50,0.70 mm,distribution density:intensive sparse) by EBM process.The mechanical properties of these structures were examined by X-ray energy dispersive spectrum(EDS),uniaxial tensile test,three-point bending test,under compression load and compared with their different microstructure and mechanical properties.Results Compressive deformation behavior of these cellular structures exhibited brittle character that had a typical irregular plateau region in the stress-strain curves.The mesh of larger diameter(d=0.70 mm) showed higher specific strength than the meshs of small diameter(d=0.35 mm) did,and the other 3D mesh under the same condition showed identical specific stiffness.Conclusions EBM was successfully used to fabricate novel 3D mesh Ti-6Al-4V structures for applications.By optimizing the buckling and bending deformation,Ti-6Al-4V cellular solids with high strength,low modulus.Furthermore,the results of mechanical property and chemistry composition showed that the scaffold could completely satisfy the requirement of hard tissue repairment.

Objective To investigate the biocompatibility of Ti-6Al-4V scaffolds fabricated by electron beam melting(EBM).Methods Bone marrow mesenchymal stem cells(BMSC) co-cultured with Ti-6A1-4V specimens fabricated with EBM was prepared as experimental group and the regular cells culture was employed as control.The biocompatibility was detected using CCK-8 and cytoskeleton staining.The osteogenic differentiation ability was assessed using mineralization nodule formation.A 24 mm defect was created on the right mandibular body in 12 beagles.The mandibular defects were repaired with Ti-6A1-4V scaffolds mesh fabricated by EBM.General observation,CT and histology examination was carried out to evaluated the biocompatibility of Ti-6A1-4V scaffolds in vivo.Results CCK-8 result showed the A values of the two groups had no significant difference(P ＞ 0.05).There was no significant difference between the two groups (P＞0.05).Cytoskeletal staining showed that cells were fully stretched out and grew well on T-i6A1-4V specimen.The actin fibers were arranged in parallel and stained uniformly with fluorescent.After osteogenic culture,the quantity of the nodule formation of the experimental group and control group were 5.7±0.7 and 5.1 ± 0.6,respectively(P＞0.05).All animals had tolerated the surgery and healed well.CT examination showed that Ti-6A1-4V scaffolds mesh had good retention with surrounding bone and the continuity of mandible was restored.Histological examination showed that no inflammation reaction or toxity was caused in the soft tissue surrounding the scaffolds and in the liver and kidney after implantation.Ti-6A1-4V scaffolds had good retention with surrounding bone.Conclusions Ti-6Al-4V fabricated with electron beam melting has good biocompatibility.

Objective To evaluate the surface characteristics and cytocompatibility of Ti-6Al-4V alloy fabricated using select laser melting (SLM) and electron beam melting (EBM) technique.Methods Ti-6Al-4V alloy specimens were fabricated with SLM and EBM.A wrought form of Ti-6Al-4V alloy was used as a control.Its properties were evaluated using component analysis,contact angle test,surface roughness,surface topography,cell ultrastructure,cell attachment and proliferation observation,metal ion precipitation examination.Results The roughness of SLM and EBM specimens was suitable for cell attachment but not the best.The character of SLM and EBM specimens was hydrophobic (＞65°).The surface topography of EBM and SLM specimens were similar,but were not the best type for cell attachment.The components of Ti-alloy oxide film were detected in all the specimens.The content of Ti,A1,V ions of EBM,SLM and wrought specimens were very low and did not affect the cell attachment and proliferation.The ultrastructure of cell was normal,and the cytomembrane was intact.The number of cells was similar to each other among the three kinds of specimens and increased obviously with the culture time.Conclusions The results of the study suggested that EBM and SLM Ti-6A1-4V specimens possessed good surface characteristics.However,the surface modification are needed further.

OBJECTIVETo investigate an ideal modeling method of designing 3D mesh scaffold substitutes based on tissue engineering to restore mandibular bone defects. By analyzing the theoretical model from titanium scaffolds fabricated by 3D printing, the feasibility and effectiveness of the proposed methodology were verified.

METHODSBased on the CT scanned data of a subject, the Mimics 15.0 and Geomagic studio 12.0 reverse engineering software were adopted to generate surface model of mandibular bone and the defect area was separated from the 3D model of bone. Then prosthesis was designed via mirror algorithm, in which outer shape was used as the external shape of scaffold. Unigraphics software NX 8.5 was applied on Boolean calculation of subtraction between prosthesis and regular microstructure structure and ANSYS 14.0 software was used to design the inner construction of 3D mesh scaffolds. The topological structure and the geometrical parameters of 3D mesh titanium scaffolds were adjusted according to the aim of optimized structure and maximal strength with minimal weight. The 3D mesh scaffolds solid model through two kinds of computer-aided methods was input into 3D printing equipment to fabricate titanium scaffolds.

RESULTSIndividual scaffolds were designed successfully by two modeling methods. The finite element optimization made 10% decrease of the stress peak and volume decrease of 43%, and the porosity increased to 76.32%. This modeling method was validated by 3D printing titanium scaffold to be feasible and effective.

CONCLUSIONS3D printing technology combined with finite element topology optimization to obtain the ideal mandibular 3D mesh scaffold is feasible and effective.

Feasibility Studies ; Humans ; Mandible ; anatomy & histology ; Porosity ; Printing, Three-Dimensional ; Tissue Engineering ; methods ; Tissue Scaffolds ; Titanium