ABSTRACT
A sensitive method based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the simultaneous determination of folic acid (FA) and its active metabolite, 5-methyltetrahydrofolic acid (5-M-THF), in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/mL of 2-mercaptoethanol and 0.025% (v/v) ammonium hydroxide. FA and 5-M-THF were more stable after the addition of 2-mercaptoethanol and ammonium hydroxide in the sample preparation procedures of this study than they were in the previously published methods. Chromatographic separation was performed on a Hedera ODS-2 column using a gradient elution system of acetonitrile and 1 mM ammonium acetate buffer solution containing 0.6% formic acid as mobile phase. LC-MS/MS was carried out with an ESI ion-source and operated in the multiple reaction monitoring (MRM) mode. The assay was linear over the concentration ranges of 0.249-19.9 ng/mL for FA, and 5.05-50.5 ng/mL for 5-M-THF. The developed LC-MS/MS method offers increased sensitivity for quantification of FA and 5-M-THF in human plasma and was applicable to a pharmacokinetic study of FA and 5-M-THF.
ABSTRACT
Objective To assess the changes of left ventricule and analyze the influential factors in pulmonary hypertension (PH) by comparing the changes of left ventricular volume and function using single cardiac cycle real-time three dimensional echocardiography ( sRT-3DE ) and two-dimensional echocardiography (2DE).Methods In case group,there were 30 inpatients diagnosed as PH,systolic pulmonary artery pressure(PASP)≥40 mmHg estimated by echocardiography,excluding left heart disease or congenital systemic-pulmonary circulation shunt.There were 30 healthy people as control group.Conventional 2DE and sRT-3DE were performed in both groups and obtained 2D and 3D parameters.Results ①In case group,the 2D-LVEF were significantly larger than 3D-LVEF (P ＜ 0.01 ).There was less agreement of 2DE and 3DE in case group than in control.②Comparing with the control group,left ventricular EDV,ESV and SV in ease group decreased ( P ＜0.01 ),so as to 3D-LVEF ( P ＜0.05).The left ventricular spherical index(SIs,SId)and eccentric index (EId,EIs ) in case group were significantly larger than those in control group ( P ＜0.01 ).③LVEDV in case group was negatively correlated with PASP (r =- 0.47),and positively correlated with RVSV and RVEF ( r =0.84,0.66) ;3D-LVEF in case group was negatively correlated with PASP ( r =- 0.54),and positively correlated with RVSV and RVEF ( r =0.58,0.53); there was no significant correlation between LVEDV and RVEDV.LVEDV was negatively correlated with SIs and SId ( r =-0.65,-0.61),so as to EId and EIs ( r =-0.67,0.67).LVEF was negatively correlated with SIs and SId ( r =-0.64,-0.61),so as to EId and EIs ( r =-0.66,-0.68),and the corresponding P all above were less than 0.01.Conclusions PH can result in reductions of left ventricular volume and systolic function,and the variations of which have the correlations with the severity of PH and the increase in SI and EI.sRT-3DE can provide a method to get more accurate information of left ventricle.