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ObjectiveTo study the synergistic effect of p38MAPK and ERK1/2 in bone marrow mesenchymal stem cells (BMSCs), and to explore their influence on osteogenic differentiation in BMSCs cultures. MethodsMouse BMSCs were cultured in phenol red-free α-MEM containing osteogenic supplements (OS) for inducing osteogenic differentiation. The temporal sequence of osteogenic differentiation in BMSCs cultures was assayed by measuring alkaline phosphatase activity (ALP) and calcium deposition gene expression. The activation of p38MAPK and ERK1/2 was detected by western blotting using phospho-specific MAP kinase antibody. BMSCs were treated with the inhibitor of p38MAPK pathway(SB203580) or ERK1/2 pathway (PD98059), and osteogenic differentiation was measured. BMSCs were treated with SB203580 or sodium arsenite(ARS), a strong activator of p38MAPK, and the phosphorylation of ERK 1/2 was measured. BMSCs were treated with PP2A inhibitor, Okadaic acid(OA), the phosphorylation of ERK1/2 and osteogenic differentiation were measured. lmmunoprecipitation was used to test the binding interaction between PP2A and ERK1/2, and the effect of SB203580 on the interaction. ResultsTreatment of BMSCs with osteogenic supplements resulted in activation of p38MAPK and ERK1/2 that coincided with osteogenic differentiation. Inhibition of p38MAPK activation by SB203580, blocked the osteogenic differentiation, whereas inhibition of ERK1/2 activation by PD98059, enhanced the osteogenic differentiation in a dose-dependent manner.SB203580 treatment resulted in increased ERK1/2 phosphorylation. By contrast, ARS treatment resulted in decreased ERK1/2 phosphorylation. Inhibition of PP2A by OA resulted in increased ERK1/2 phosphorylation. OS-induced osteogenic differentiation was also attenuated by PP2A inhibition. Immunoprecipitation confirmed the association of PP2A with ERK1/2 in BMSCs cultures, which was decreased by SB203580 treatment. ConclusionThe present study demonstrates a synergistic effect between p38MAPK and ERK1/2 signaling pathways via PP2A in BMSCs cultures, which may regulate the osteogenic differentiation of BMSCs.
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OBJECTIVE:To establish an RP-HPLC method for determination of the content of bortezomib in its crude drug. METHODS: Bortezomib was separated on Phenomenex-C18 chromatographic column with mobile phase consisted of methanol-phosphate buffer (pH 2.0) (60∶40) at a flow rate of 1.0 mL?min-1.The detection wavelength was set at 254 nm. RESULTS: The linear range of bortezomib was 50.72～152.16 ?g (r=0.999 9) with an average recovery rate of 99.62% (RSD=0.39%,n=6). CONCLUSIONS: The method is sensitive,specific and simple in operation,and it is applicable for the determination of bortezomib in its crude drug.
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OBJECTIVE:To discuss the general pattern and the characteristics of macrolides-induced anaphylactic shocks. METHODS:The original articles of 78 macrolides-induced anaphylactic shocks cases reported in Chinese medical science journals during the period from 1985 to 2009 were retrieved from CNKI literature base,and a related database was established for statistical analysis. RESULTS:Seven kinds of macrolides involved in the anaphylactic shocks,with azithromycin,erythromycin and kitasamycin respectively dominated the first 3 places. The anaphylactic shocks were predominantly induced by intravenous drip infusion(88.46%). Of all the 78 cases,4 cases were dead. CONCLUSION:Great attention should be paid to the macrolides-induced anaphylactic shocks in clinical practice to ensure medication safety.
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Objective To determine the content of paeoniflorin with different medicinal parts in Radix Paeoniae Alba and offer a reference for collection and processing. Methods The content of paeoniflorin was measured by HPLC method. Combining air drying with weight relief condition, the content of paeoniflorin was calculated in fresh Radix Paeoniae Alba. Results There was the highest content of paeoniflorin in Radix Paeoniae Alba in 24～48 hours after collection, and the another increasing of the content was founded 120 hours after collection. Conclusion Radix Paeoniae Alba should be processed in 48 hours after collection.