ABSTRACT
Objective To establish a mini-column centrifugation-HPLC method to determine the entrapment efficiency of levodopa-loaded PEGylated-solid lipid nanoparticles.Methods A dextran gel(Sephadex G-50) mini-column centrifugation was employed to separate the free drug from solid lipid nanoparticles.The content of levodopa was qualified by HPLC.Results Under the applied chromatographic condition,the excipients had no influence on the determination of levodopa.A calibrated linear of levodopa concentration was within 10.54-527.00 μg·mL-1.The recoveries of high,medium and low concentrations of levodopa were 99.13%,99.51% and 99.04%(RSD were 1.25%,1.91% and 1.71%), respectively.The free levodopa was well separated from solid lipid nanoparticles by using mini-column centrifugation.The addition of blank solid lipid nanoparticles recovery was 98.84% with RSD of 0.80%(n=3).The average adsorption rates of the three concentrations of free levodopa were 100.00%,98.75% and 98.56%(RSD were 0.00%,0.19% and 0.18%,n=3),respectively.The adsorption rate of the physical mixtures of three different concentrations of drugs and empty PEGylated solid lipid nanoparticles were 99.68%,98.46% and 99.21%(RSD were 1.52%,0.23% and 0.21%),respectively.Conclusion The method was simple,accurate and reproducible,which can be used for determination of the entrapment efficiency of levodopa-loaded PEGylated-solid lipid nanoparticles.
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Objective To observe the rotation of subendocardium and subepidium by two-dimensional speckle tracking imaging(2D-STI),and to evaluate its performance in diastolic heart failure patients(DHF)with a normal left ventricular ejection fraction. MethodsNinety-seven consecutive clinically stable patients were enrolled in this study [41 healthy controls,36 with diastolic heart failure,20 with systolic heart failure (SHF)]. High frame rate dynamic two-dimensional images were recorded at the left ventricular short-axis view,including basal, papillary muscle and apical planes. Subendocardial and subepicardial global rotation were measured using Q-lab 7.0 software offline. Results ① In all the subjects, the rotation of the subendocardium was obviously greater than that of subepicardium. ②As seen from the apex,left ventricular subendocardium and subepicardium performed a wringing motion with a clockwise rotation at the base and countclockwise rotation at the apex. ③In the apical plane, subendocardial rotation was significantly lower in both heart failure groups than in controls,and was depressed to a larger extent in SHF patients than in those with DHF. Subepicardial rotation was no significant difference between the DHF group and the control group, though it was significantly lower in patients with SHF. ④At the base, the rotation of subendocardium and subepicardium were not different between DHF and control groups, but it was significantly reduced in patients with SHF. Conclusions The subendocardial rotation is reduced, but subepicardial rotation is normal in DHF patients. On the other hand, in patients with SHF, subendocardial and subepicardial rotation are both reduced. The left ventricular systolic properties are impaired in DHF patients.
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Objective To explore the characteristics of resting myocardial perfusion of type 2 diabetes mellitus(T2DM) by real-time myocardial contrast echocardiography(RT-MCE). Methods Thirteen patients with T2DM and 12 in control were enrolled in the study. RT-MCE was performed using a continuous infusion of SonoVue with vena mediana in elbow. Images of left ventricle filled with contrast were acquired from apical 4-, 2-chamber and long axis views with real-time myocardial contrast mode of GE Vivid 7 Dimension system. All above images were captured in continuous 3 cardiac cycles before "flash" ,and then 15 cardiac cycles after "flash". All clips were stored for off-line analysis. Results In quiescent condition, there were significant decrease on indices of A,k and A × k in patients compared with control group (A:6.46 ±1.60 vs 6.81 ± 1.53, P ＜0.05;k:1.04 ± 0.39 vs 1.28 ± 0.31*, P ＜0.01;A× k:6.55 ± 2.72 vs 8.78 ±3.16, P ＜ 0.01, respectively). Conclusions RT-MCE could evaluate the early change of myocardial perfusion in T2DM patients and offers important reference for clinical diagnosis and treatment.
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Objective To explore the clinical value of color Doppler flow imaging(CDFI) combined with quantitative analysis technique to evaluate renal flow perflusion. Methods Twenty patients with different renal diseases matched with healthy control subjects were examined with Philips iU22 CDFI system. CDFI system and Qlab quantitative technique were used to measure renal restrictive index(RI), vascularization index(VI), flow index(FI), vascularization-flow index (VFI). The patients all received renal single-photon emission computed tomography (SPECT) examination. Results The RI of 32 kidney with lower flow perfusion in SPECT were higher than in the contol group (P <0.01). VI,FI, VFI were lower than those in control(VI, VFI, P <0.01 ;FI, P <0.05). Conelusious The renal blood flow perfusion of patients with renal diseases are lower than that of healthy people. It has high clinical value using CDFI combined with quantitative analysis technique to evaluate the renal perfusion of the patients with renal diseases.
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Objective To assess the value of quantitative color Doppler sonography in patients with systemic lupus erythematosus (SLE). Methods The right renal in 21 patients with SLE and 22 normal subjects were examined with Philips IU22 ultrasonic diagnostic device. Resistence index (RI) of interlobar artery and interlobular artery were measured with color Doppler sonography, vascularity index (VI), flow index (FI) and vascularization flow index (VFI) which reflecting the renal cortical blood flow were calculated with quantitated analysis software. All the parameters between two groups were compared and analyzed. Results The color signals of renal cortical blood flow in patients with SLE were inferior to those of the normal group, especially in the area near the edge of renal. No statistical difference of RI was found between the two groups (P>0.05), while VI, FI and VFI in SLE group were significantly lower than those of the normal group (VI, VFI, P<0.01, FI, P=0.01). Conclusion Color Doppler sonography combined with blood flow quantitative technique provide a helpful, sensitive and convenient tool to detecte the renal changes in SLE patients.