[Measurement of tacrolimus in blood with the method of high performance liquid chromatography-mass spectrometry].

OBJECTIVE: To develop a simple, precise, and specific method for measurement of tacrolimus in whole blood. METHODS: Tacrolimus was extracted from the blood samples of 40 patients treated with tacrolimus by liquid-liquid extraction. Then high performance liquid chromatography-mass spectrometry (HPLC/MS) was used, with ascomycin as internal marker, to isolate the tacrolimus and measure the concentration thereof. The standard curve was drawn. The linearity of quantitative measurement was determined. Detection limits test, CV test, and recovery test were performed. ELISA was used simultaneously. The results of these 2 methods were compared. RESULTS: A good standard curve was drawn based on the results of HPLC/MS assay (y = 0.2464x + 0.0082, R2 = 0.9996). The detected data were highly related to the detected concentrations. The linearity range was 0.100 - 40.000 ng/ml (y = 1.0294x-0.035, R2 = 0.9998). The detection limit of the assay was 0.100 ng/ml. The CV values by this assay were basically < 5%. The recovery rate ranged 95.67% - 98.30% for tacrolimus over the range 0.300 - 16.016 ng/ml. There was a linear correlation (y = 1.0172x + 0.3742, R2 = 0.9630) between the assay results by HPLC/MS to ELISA in blood. The measurement value of ELISA was (19 +/- 9), significantly higher than that of HPLC/MS (18 +/- 9, P < 0.01). CONCLUSION: This newly developed method of HPLC/MS is simple, precise, and specific and with lower cost, it can be used in the clinical practice and experimental study on tacrolimus.

[The relationship between hyperlipidemia and lower limb arterial disease in elderly diabetes patients].

OBJECTIVE: To evaluate the correlation between hyperlipidemia and lower limb arterial disease in elderly diabetic patients with color Doppler ultrasonography. METHODS: Two hundred and sixty elderly diabetic patients and 206 normal subjects were enrolled in the study. Doppler ultrasonographic manifestations of lower limb arterial disease, blood pressure and blood biochemistry parameters including fasting plasma glucose (FPG), postprandial plasma glucose (PPG), TC, TG, HLD-C, LDL-C, apoprotein B (apoB), very low density lipoprotein cholesterol (VLDL-C), apoprotein A1 (apoA1) and fibrinogen (Fb) were compared between the 2 groups. RESULTS: (1) The blood biochemistry parameters, including the levels of FPG, PPG, TC, TG, VLDL-C, LDL-C, apoB and Fb were higher in diabetic patients than in normal subjects, while HDL-C was lower (all P < 0.05). (2) The thickness of intima-media (IMT) in the lower limb arterial disease group was significantly increased and the presence of arterial stenosis and wall plaques more in diabetic patients [IMT in 205 cases (78.85%), atherosclerotic plaque in 241 cases (92.69%), multivessel disease (more than 2 vessels) in 60 cases (23.08%) and arterial stenosis in 89 cases (34.23%)] than in normal subjects [IMT in 37 cases (17.96%), atherosclerotic plaque in 51 cases (24.76%), multivessel disease in 27 cases (13.11%) and arterial stenosis in 3 cases (0.01%)], all P < 0.01. (3) Regression analysis showed that lower limb arterial disease was correlated with high level of LDL-C and low level of HDL-C. CONCLUSIONS: Arteriosclerotic plaque is one of the early manifestations in elderly diabetic patients and hyperlipidemia may provide the basis of its formation. Doppler ultrasonographic examination of lower limbarterial discloses the early arteriosclerotic changes of lower limb arterial disease in elderly patients and offers the basic data of indication for clinical treatment.