Removing Lipemia in Serum/Plasma Samples: A Multicenter Study

BACKGROUND: Lipemia, a significant source of analytical errors in clinical laboratory settings, should be removed prior to measuring biochemical parameters. We investigated whether lipemia in serum/plasma samples can be removed using a method that is easier and more practicable than ultracentrifugation, the current reference method. METHODS: Seven hospital laboratories in Spain participated in this study. We first compared the effectiveness of ultracentrifugation (108,200×g) and high-speed centrifugation (10,000×g for 15 minutes) in removing lipemia. Second, we compared high-speed centrifugation with two liquid-liquid extraction methods—LipoClear (StatSpin, Norwood, USA), and 1,1,2-trichlorotrifluoroethane (Merck, Darmstadt, Germany). We assessed 14 biochemical parameters: serum/plasma concentrations of sodium ion, potassium ion, chloride ion, glucose, total protein, albumin, creatinine, urea, alkaline phosphatase, gamma-glutamyl transferase, alanine aminotransferase, aspartate-aminotransferase, calcium, and bilirubin. We analyzed whether the differences between lipemia removal methods exceeded the limit for clinically significant interference (LCSI). RESULTS: When ultracentrifugation and high-speed centrifugation were compared, no parameter had a difference that exceeded the LCSI. When high-speed centrifugation was compared with the two liquid-liquid extraction methods, we found differences exceeding the LCSI in protein, calcium, and aspartate aminotransferase in the comparison with 1,1,2-trichlorotrifluoroethane, and in protein, albumin, and calcium in the comparison with LipoClear. Differences in other parameters did not exceed the LCSI. CONCLUSIONS: High-speed centrifugation (10,000×g for 15 minutes) can be used instead of ultracentrifugation to remove lipemia in serum/plasma samples. LipoClear and 1,1,2-trichlorotrifluoroethane are unsuitable as they interfere with the measurement of certain parameters.

Experimental study of a novel phase change nanodroplets enhanced high intensity focused ultrasound ablation / 中国介入影像与治疗学

Objective To investigate the effect of lipid encapsulated 1,1,2-trichlorotrifluoroethane phase change nanodroplets for high intensity focused ultrasound (HIFU) ablation.Methods The lipid encapsulated 1,1,2-trichlorotrifluoroethane phase change nanodroplets was prepared with membrane hydration method,and its physicochemical properties were examined.The synergistic effect of HIFU ablation was verified with experiments in vitro and in vivo experiments.For in vitro experiment,the isolated bovine liver tissues were irradiated with HIFU (250 W,10 s,continuous wave).For in vivo experiment,the livers of New Zealand rabbits were irradiated with HIFU (200 W,5 s,continuous wave).The volume of coagulative necrosis,energy efficiency factors (EEF) and the volume of the hyperechoic area after HIFU radiation were measured.And the statistical analysis was performed.Results Phase change nanoparticles were spherical in solution and uniform in size.For in vitro experiment,the coagulative necrosis volume,EEF and hyperechoic area of bovine liver tissue injected with nanodroplets were significantly higher than those of untreated bovine liver tissue (t=28.80,19.55,14.30;P=0.01,0.02,0.02) after HIFU.For in vivo experiment,the coagulative necrosis volume,EEF and hyperechoic area of rabbit liver tissue injected with nanodroplets were significantly higher than those of untreated rabbit liver tissue (t=9.41,13.52,15.67;P=0.02,0.01,0.01) after HIFU.Conclusion The lipid encapsulated 1,1,2-trichlorotrifluoroethane phase change nanodroplets can significantly improve the efficiency of HIFU ablation significantly.