0.05).CONCLUSION:Niaoxue Mixture has a good effect on treating primary glomerular hematuria as new medicine.

Objective To optimize the extraction methods of mitochondrial genome DNA(mtDNA)of Oncomelania hupen-sis. Methods The pyrolysis,protein K variable-temperature digestion and high-concentration potassium acetate purification were applied to optimize the high-concentration-salt precipitation method,and then the optimized method was compared with two common extraction methods,the sucrose density gradient centrifugation method and traditional high-concentration-salt pre-cipitation method. The mtDNA samples were identified by using spectrophotometry,agarose gel electrophoresis and the amplifi-cation products of COX1. The nuclear DNA contamination was tested by the amplification products of ITS. Results The concen-tration and yield of the improved method was significantly higher than those of the traditional method(F=3032.65,10185.00, both P<0.01). The mtDNA samples extracted were essentially free of nuclear DNA and protein,meeting PCR,sequence analy-sis and other molecular biology research requirements. Conclusions The improved high-concentration-salt precipitation meth-od for isolating mtDNA is simple,and it has high yield and low cost. The extracted mtDNA can meet relevant analysis require-ments.

AIM:To study the telomere maintenance mechanism in mesenchymal stem calls(MSCs).METHODS:MSCs were isolated from healthy human bone marrow by their adherence to plastic and then were checked with CD14-FITC,CD45-FITC,CD44-FITC,HLA-DR-FITC,CD34-PE,CD29-PE and CD166-PE.Telomere length and ECTR DNA in MSCs were detected by Southern blotting.The localization of TRF1 and promyelocytic leukemia(PML)in MSCs were detected with immunofluorescence staining.TRAP protocol was performed to detect the telomerase activity in MSCs and MSCs-derived adipocytes.Western blotting and TRAP protocol were applied to measure telomerase activity of MSCs,which were synchronized by serum starvation and aphidicolin treatment.RESULTS:The telomere in length seemed shorter and relatively more homogeneous in MSCs and HeLa cells than that in WI-38-2RA cells.TRF1 did not concide with PML nuclear body in MSCs and HeLa cells while it exclusively did in WI-38-2RA cells.ECTR DNA was negative in MSCs and HeLa cells but positive in WI-38-2RA cells.Telomerase was negative in MSCs but it was positive in MSCs-derived adipocytes detected by TRAP.Moreover,a cell cycle-dependent expression profile of telomerase was found in MSCs when they were synchronized by serum starvation and aphidicolin treatment.Untreated MSCs expressed very low level of telomerase probed by Western blotting with 2C4 mAb,but the telomerase level had significantly increased when these cells were trapped in S phase.CONCLUSION:The telomere of MSCs is maintained by telomerase pathway instead of alternative lengthing of telomere(ALT)and the level of telomerase expression is associated with cell cycle stage.[