ABSTRACT
Stroke is a cerebrovascular disease that damages brain tissue due to blockage or rupture of blood vessels, and is one of the leading causes of death and disability worldwide. Diagnosing, monitoring stroke and the treatment effects all rely on neuroimaging that detects changes in the brain. Near-infrared spectroscopy (NIRS) is a novel neuroimaging technique which is based on the non-invasively measuring of concentration changes of oxyhemoglobin and reduced hemoglobin. This review summarizes the underlying mechanisms of NIRS and its current clinical application in stroke, as well as the limitations of NIRS in broader clinical applications.
ABSTRACT
Objective To establish a real-time fluorescence quantitative PCR method for detection of the different expression level of FPGS in methotrexate enantiomer-resistant A549 cell lines,and observe FPGS mRNA expression in patients with leukemia.Methods A real-time fluorescence quantitative PCR method for detection FPGS mRNA was established using SYBR Green Ⅰ as fluorescence and β-actin as reference.The method was evaluated by Ct,correlation coefficient,slope,repeatability curve,melting curve and amplification efficiency curve.The expression levels of FPGS gene in methotrexate enantiomer-resistant A549 cell lines and methotrexate resistant leukemia cells in bone marrow were detected by the method.Results The standard curves had a high linear relationship between cycle threshold and template concentration.The correlation coefficients of FPGS and β-actin were 0.996 8 and 0.998 7,and the slopes were -3.595 and -3.740,respectively.The inter-coefficient of variation was from 1.27% to 2.95%.The intra-coefficient of variation was 3.82%.The method was characterized with specific melting curve and similar amplification efficiency(slope was 0.021 7).The relative contents of FPGS mRNA were(3.51 ±0.66),(0.16 ±0.01) and(1.00 ±0.31) in L-(+)-MTX/A549 cells(L),D-(-)-MTX/A549 cells(D)and A549 parent cells,and there was statistically difference among the three groups(F = 64.45 ,P＜ 0.01)Statistical difference was observed between L and D(q =9.29,P＜0.01).After treated with MTX,the expression level of FPGS mRNA was(0.35 ± 0.04) in methotrexate resistant leukemia patients,compared with(1.00 ± 0.44) before treatment.Statistical difference was observed(t = 8.83 ,P＜ 0.01).Conclusions The real-time fluorescence quantitative PCR is suitable for the quantification of FPGS.The expression levels of FPGS in methotrexate resistant leukemia cells in bone marrow and drug resistant cells are different.Two enantiomer forms of methotrexate may play different roles in drug resistance mechanisms.
ABSTRACT
Objective:To investigate the effect of traditional Chinese medicine (TCM) icariin (ICA) on metastatic phenotype of methotrexate (MTX)-resistant lung cancer A549 cells and elucidate the action mechanism and therapeutic value of ICA. Methods:The half inhibition concentration(IC_(50))value of ICA in inhibiting the growth of A549/MTX cells was measured by MTT assay. The colony formation rates and the morphology of cell cluster of A549/MTX and ICA-treated A549/MTX cells were determined by double-layer soft agar colony formation assay. The migration abilities of A549/MTX and ICA-treated A549/MTX cells were evaluated by cell scratch assay. The invasion ability of cells was tested by using Transwell chamber assay. Results:MTT assay showed that the IC_(50) value of non-toxic ICA plus MTX was reduced compared with that induced by equal dose of MTX (35.50±1.85 μmol/L vs 52.17±2.25 μmol/L). The colony formation rate of ICA-treated A549/MTX cells was 0.94±0.09, less than that of A549/MTX cells (1.56±1.07, P<0.05). Cell scratching assay demonstrated that the migration capability of A549/MTX cells was stronger than that of ICA-treated A549/MTX cells at 72 h (P<0.05). Transwell experiment revealed that more A549/MTX cells passed through artificial basement membrane than ICA-treated A549/MTX cells (P<0.05), indicating that the invasion capability of ICA-treated A549/MTX cells was weaker than that of A549/MTX cells.Conclusion:TCM ICA can reverse the metastatic phenotype of MTX-resistant A549 cells.