Objective:To investigate the expression of Smad1 in gastric carcinoma and the influence on the migration ability of gastric cancer cells.Methods:Collected the protein from the gastric cancer tissues and corresponding adjacent tissues,the expression level of Smad1 was detected by Western blot.In HGC-27 gastric cancer cells as the research object,the carrier cells transfected with overexpression of Smad1 (p-EGFP-C1/Smad1) and Smad1 small interfering RNA (Smad1 siRNA),while transfection of p-EGFP-C1 and siRNA control as control.MTT to detect cell proliferation.Cell migration ability was detected with cell scratch test.The expression levels of MMP-9,MMP-2,p-Akt and Akt in ceils were detected by Western blot.Akt signal pathway inhibitor LY294002 (20 μg/ml) in gastric adenocarcinoma ceils,MTT for cell proliferation,cell scratch assay for cell migratior.The expression levels of MMP-9,MMP-2,p-Akt,Akt were detected by Western blot.Results:Smadl in gastric carcinoma was significantly lower than the adjacent tissues (P＜ 0.01).The cell survival rate and migration rate of p-EGFP-C1/Smad1 group were significantly lower than that of p-EGFP-C1 group (P＜0.01).The cell survival rate and migration rate of Smad1 siRNA group were significantly higher than those in the siRNA control group (P＜0.01).The expression levels of Akt protein in P-EGFP-C1,p-EGFP-C1/Smad1,Smad1 siRNA,siRNA control cells did not change.The expression levels of MMP-9,MMP-2 and p-Akt in p-EGFP-C1/Smad1 group were significantly lower than that in p-EGFP-C1 group (P＜0.01).The expression levels of MMP-9,MMP-2 and p-Akt in Smad1 siRNA group were significantly higher than that in control siRNA (P＜0.01).The cell proliferation and migration trends in gastric cancer cells effected by Akt signaling pathway inhibitor consistent with the p-EGFP-C1/Smadl group.Conclusion:Low expression of Smad1 in gastric cancer tissue.Smad1 can inhibit the proliferation and migration of gastric cancer cells,the mechanism of action is related to the Akt signaling pathway.

BACKGROUND:To construct a normal animal model of femoral head necrosis contributes to the research of the pathogenesis of femoral head necrosis, which can provide theoretical basis for the prevention and treatment of femoral head necrosis.
OBJECTIVE:To research the experimental effect of lipopolysaccharide combined with dexamethasone injection in the induction of rabbit femoral head necrosis.
METHODS:Thirty-six New Zealand white rabbits were randomly divided into model group (n=21) and control group (n=15). The rabbits in the model group were injected with 10μg/kg lipopolysaccharide daily and continuous for 2 days, and then injected with 25 mg/kg dexamethasone daily for 3 days continuously. The rabbits in the control group were injected with the normal saline at the same volume.
RESULTS AND CONCLUSION:After 4 weeks, the X-ray film of the rabbit in the model group showed the joint gaps were widened, the density was increased, the articular subchondral bone mineral density was increased, the femoral head was flat, trabecular bone was fuzzy, the boundaries between subchondral bone and cancel ous bone was unclear, and the patchy high-density areas were observed in the femoral head with shortened femoral neck. The bone mineral density of partial femoral head was measured with dual-energy X-ray absorptiometry, and found that the bone mineral density of femoral head and the bone mineral content of the model group were significantly lower than those of the control group (P<0.05). Histological section observation showed that the bone cel lacuna was empty and shal ow, fat cel s were increased and vascular thrombosis was observed, meanwhile, the osteonecrosis rate and lacunae rate of the survival animals were significantly higher than those in the control group. Dexamethasone combined with lipopolysaccharide can effectively construct the model of steroid-induced avascular necrosis of the femoral head.

BACKGROUND:Animal death is a main influential factor for experimental results in establishment of animal models of steroid-induced necrosis of femoral head.
OBJECTIVE:To observe models of femoral head necrosis established using lipopolysaccharide and dexamethasone so as to elevate success rate of model induction.
METHODS:A total of 48 New Zealand white rabbits were equal y and randomly divided into model group, gentamicin group, gentamicin+lansoprazole group and control group. The first three groups were injected with lipopolysaccharide for 2 consecutive days via the ear vein, and then they were injected with dexamethasone via intramuscular injection in the buttocks for 3 consecutive days to establish models of femoral head necrosis. The rabbits of gentamicin group, gentamicin+lansoprazole group were intragastrical y administered gentamicin for 7 consecutive days after success model induction. Simultaneously, gentamicin+lansoprazole group received intramuscular injection with lansoprazole. Rabbits in the control group were only injected with saline.
RESULTS AND CONCLUSION:Models were successful y established in the model, gentamicin, gentamicin+lansoprazole groups. Their conditions were best in the gentamicin+lansoprazole group. Mortalities in above-mentioned groups were 33.3%, 25%and 8.3%, respectively. Significant differences in the number of dead rabbits were detected in the model, gentamicin, gentamicin+lansoprazole and control groups (P<0.05). Results indicated that the combined use of gentamicin and lansoprazole can elevate survival rate of experimental animals during the establishment of rabbit models of steroid-induced necrosis of femoral head.