Effect of non-anticoagulant N-desulfated heparin on expression of vascular endothelial growth factor, angiogenesis and metastasis of orthotopic implantation of human gastric carcinoma

AIM: To investigate the effect of N-desulfated heparin on tumor metastasis and angiogenesis, and expression of vascular endothelial growth factor (VEGF) of ortho- topic implantation of human gastric carcinoma in male severe combined immune deficiency (SCID) mice.? METHODS: Human gastric cancer SGC-7901 cells were orthotopically implanted into the stomach of SCID mice.? The mice were randomly divided into normal saline group and N-desulfated heparin group.? One week after operation, the mice in N-desulfated heparin group re- ceived i.?v.? injections of N-desulfated heparin (SShhaanngghhaaii Institute of Cell Biology, Chinese Academy of Sciences, 10 mg/kg.?d)) ttwwiiccee wweeeekkllyy ffoorr ???? wwkk..?? ??hhee mmiiccee iinn nnoorrmmaall saline group received i.?v.? injections of normal saline (100 μL) twice weekly for ?? wk.? ?he mice were sacrificed six weeks after implantation.? ?umor metastasis was evalu- ated histologically for metastasis under microscope.? In- tratumoral microvessel density (MVD) and VEGF expres- sion were evaluated immuohistochemically.? VVVEEEGGGFFF mmmRR?NNNAAA expression in gastric tissue of SCID mice was detected by real time PC?.? RESULTS: The tumor metastasis rate was 80% in nor- mal saline group and 20% in N-desulfated heparin group (P ???? 00..??00??))..?? MMVVDD wwaass ??..??00 ???? ????..??11 iinn nnoorrmmaall ssaalliinnee ggrroouupp and 4.??? ?? 1.?? in N-desulfated heparin group (P ???? 00..??00??))..?? VEGF positive immunostaining was found in cytoplasmof cancer cells.? ?he rate of VEGF positive expression was higher in normal saline group than in N-desulfated hepa- rin treated group (90% vs 20%, P ???? 00..??00??))..?? VVEEGGFF mm??NNAA expression was significantly inhibited by N-desulfated heparin and was higher in normal saline group than in N-desulfated heparin group (Ct value 19.??1 ?? 1.?01 vs 22.??? ?? 1.???6, P ???? 00..??00??))..?? NN--ddeessuullffaatteedd hheeppaarriinn ssiiggnniiffii- cantly inhibited the expression of VEGF mRNA in can- cer cells.? No bleeding occurred in N-desulfated heparin group.? CONCLUSION: N-desulfated heparin can inhibit me- tastasis of gastric cancer by suppressing tumor VEGF expression and tumor angiogenesis, but has no obvious anticoagulant activity.?

An anisotropic micromechanics model for predicting the rafting direction in Ni-based single crystal superalloys

An anisotropic micromechanics model based on the equivalent inclusion method is developed to investigate the rafting direction of Ni-based single crystal superalloys. The micromechanical model considers actual cubic structure and orthogonal anisotropy properties. The von Mises stress, elastic strain energy density, and hydrostatic pressure in dif- ferent inclusions of micromechanical model are calculated when applying a tensile or compressive loading along the [001] direction. The calculated results can successfully pre- dict the rafting direction for alloys exhibiting a positive or a negative mismatch, which are in agreement with pervious experimental and theoretical studies. Moreover, the elastic constant differences and mismatch degree of the matrix and precipitate phases and their influences on the rafting direction are carefully discussed.

Orientation-Dependent Morphology and Evolution of Interfacial Dislocation Networks in Ni-Based Single-Crystal Superalloys:A Molecular Dynamics Simulation

In this paper,the morphology and evolution of interfacial dislocation networks of(100),(110)and(111)interphases of Ni-based single-crystal superalloys are studied by molecular dynamics(MD)simulations.Three-dimensional cubic-type and sandwich-type models are chosen to explore the orientation-dependent morphology of dislocation networks,and their respective advantages and disadvantages are compared.From the simulations,it is observed that various lattice orientations and model types lead to different morphologies of dislocation networks.Based on the analysis of average atomic energy and dislocation characteristics,the(100)orientation model has a more regular dislocation network,lower energy and better stability than the(110)and(111)orientation models after MD relaxation,which are supported by previous experimental and numerical simulations.Moreover,the cubic-type model has lower energy and better stability than the sandwich-type model.This will be helpful for choosing a more appropriate and reasonable model for simulating the interfacial dislocation networks of Ni-based single-crystal superalloys.