ABSTRACT
BACKGROUND:Pathological mechanism of femoral head necrosis is not fuly known, and high-dose corticosteroids are prone to induce femoral head necrosis. OBJECTIVE:To investigate the clinical effect of bone marrow mesenchymal stem cels combined with theaflavin on steroid-induced avascular necrosis of femoral head in rats. METHODS: Rat bone marrow mesenchymal stem cels were isolated and culturedin vitro and compounded onto gelatin sponge, and then, divided into four groups: model group, decompression group, cel transplantation group and combined group. Models of steroid-induced avascular necrosis of femoral head were established using liquid nitrogen method. In the combined group, gelatin sponge carrying bone marrow mesenchymal stem cels was transplanted and 250 mg theaflavin was given daily after modeling. RESULTS AND CONCLUSION:At 4 weeks after modeling, the femoral head samples in the four groups were round with exfoliation of articular cartilage that was pale in color. Then, the exfoliation of articular cartilage was aggravated in the model group, and some specimens appeared to colapse; the femoral head specimens in the combined group were round and pale. Until the 8th week after modeling, bone necrosis was increased in the model group; osteoblasts were found in the decompression group with fibrous calus formation; a few of empty bone lacunae appeared with irregular medulary cavity in the cel transplantation group; a large amount of new bone tissues formed in the combined group, and intramedulary adiocytes were in regular array. At 4 and 8 weeks after modeling, the number of empty bone lacunae was significantly lower in the combined group than the other groups (P < 0.05). These findings indicate that bone marrow mesenchymal stem cels combined with theaflavin is an ideal therapy for steroid-induced avascular necrosis of femoral head.
ABSTRACT
Objective To explore the effect of ?-elemece on the reverse of drug resistance and the expression of P-glycoprotein(P-gp) in MDR K562/ADM cells. Methods MTT method was used to detect the sensitivity of cell and its reverse of drug resistance.Immunohistochemistry and immunoelectron microscopy were for observing the expression of P-gp.It's quantitative analysis was determined by flow cytometry.All experimental data were dealt with by SPSS(10.0 production pacility) soft ware. Results 1.Non-cytotoxic dose of ?-elemece(4.0?mg/L) could obviously decrease the IC-(50) value of K562/ADM cells to ADM.The reversing fold was 2.18;2.The level of P-gp expression was higher in K562/ADM cells than that in its parent K562 cells.Our studies also showed that the distribution of P-gp was on membrane of K562/ADM cells;3.Non-cytotoxic dose of ?-elemece(4.0?mg/L) could remarkably decrease the P-gp expression in MDR K562/ADM cells.Conclusion\ ?-elemece could evidently reverse drug resistance of K562/ADM to ADM.Decreasing the P-gp expression in drug resistance cell is one of the main mechanism of reversion.