Objective To explore the mechanism of the femoral head necrosis induced with long term glucocorticoid treatment by means of microvascular density and cellular ultrastructure. Methods 40 Japanese rabbits were used to establish an animal model of the femoral head necrosis induced by long term glucocorticoid treatment using injection with methylprednisolone 8 mg/kg weekly. In studying cellular ultrastructure and microvascular density of the femoral head necrosis models, the slides were made after vascular infusion with Chinese ink on 4th, 8th, and 12th week of the experiment. The network of microvasculature of the rabbit ear was photographied as a reference data before and after methylprednisolone treatment. Results Microvascular density in bilateral cancellous and compact bone of the femoral head became decreased statistically after 12 weeks of glucocorticoid treatment(P

Objective To explore the relationship between blood flow viscosity and femoral head necrosis after long-term glucocorticoid treatment (FHNG). Methods Blood and plasma viscosity, blood flow speed, RBC fragility, electrophoresis time, and the speed of blood flow were measured. Cellular ultrastructural changes of FHNG were studied with electron microscope. Results Blood viscosity of the treatment group increased obviously at the 8th week compared with that of control group (P

Objective To investigate the effect of human bone marrow mesenchymal stem cells (BM-MSCs) stimulated by platelets in vitro on the metastasis of cancer cells.Methods The BM-MSCs were isolated and cultured in vitro and platelets from the peripheral blood of healthy persons were purified.The MSCs (control),platelets + MSCs,and platelets treated with culture media (CM) of SGC-7901 tumor cells + MSCs (T-platelets + MSCs) were cultured,respectively,and the MSCs and supernatants (MSCs-CM and SGC-7901-CM) were collected,respectively,after 24 hours.The expressions of markers of cancer-associated fibroblasts (CAF),such as α-SMA and Vimentin,were determined by Western-blotting.The immigration ability of BM-MSCs were analyzed by Transwell assay.The levels of P-selectin in platelets stimulated by MSCs-CM or SGC-7901-CM were detected with flow cytometry.The metastasis model of gastric cancer SGC-7901 cells was established in BALB/c nude mice by the injection of tail vein,and the tumor metastasis in vivo was observed.Results The expression levels of P-selectin in platelets stimulated by MSCs-CM ([21.37 ± 1.00] ％) or SGC-7901-CM ([31.4 ± 1.71] ％ were significantly higher than that in the control ([3.17 ± 0.40] ％,t =27.85 and 29.18,P ＜ 0.01).The expression levels of α-SMA and Vimentin in platelets + MSCs group (0.79 ± 0.08 and 0.88 ± 0.01) and T-platelets + MSCs group (0.90 ±0.06 and 0.96 ±0.04) were significantly higher than that in the control (0.64 ±0.02 and 0.75 ±0.05,t =2.96 and 6.45 forα-SMA,t =4.73 and 5.73 for Vimentin,P ＜0.01).The amounts of immigration cells in platelets + MSCs group (340.3 ±27.7) and T-platelets ± MSCs group (424.3 ± 17.6) were significantly higher than that in the control (220.7 ± 19.4,t =6.14 and 13.48,P ＜ 0.01).The in vivo experimental results showed that the metastatic foci in platelets ± MSCs group (4 ± 2) and T-platelets ± MSCs group (21 ± 4) were significantly higher than that in the control (0.33 ± 0.06,t =3.051 and 8.857,P ＜ 0.01).Conclusion Platelets promote the immigration and the enhanced tumor metastasis in vivo of BM-MSCs.

In cardiac ablation procedures,the accuracy of catheter positioning determines the authenticity of the cardiac model and the accuracy of the ablation target.This article reviews the literature on catheter positioning in electrophysiology and summarizes the key technologies for catheter positioning,such as magnetic-electric fusion and interference suppression.Addressing the limitations of electric and magnetic positioning individually,the paper elaborates on the rationale for catheter positioning technology based on magnetic-electric fusion.It also outlines the framework of a complex catheter positioning system.Specifically,the magnetoelectric conversion matrix is established first,followed by the optimization of the catheter shape.The interference factors such as magnetic field interference,body movement,respiration,and heartbeat in catheter positioning and their suppression methods are analyzed and discussed in detail.Finally,the development trend of three-dimensional electrophysiology catheter positioning technology is prospected,offering feasible insights for the research on catheter positioning technology based on magnetic-electric fusion.