The effects of urinary macromolecul e chondroitin sulfate A(C 4 S)and L-glutamic acid(L-Glu)on the crys-tallization of calcium oxalate were studied using Langmuir-Blodgett(LB)film of dipalmitoylphosphatidylch oline(DP...The effects of urinary macromolecul e chondroitin sulfate A(C 4 S)and L-glutamic acid(L-Glu)on the crys-tallization of calcium oxalate were studied using Langmuir-Blodgett(LB)film of dipalmitoylphosphatidylch oline(DPPC)as templet.All the calcium oxalate c rystals induced by the LB film of DPPC were calcium oxalate monohydrate(COM).However,the morphology of COM was i nfluenced by the additives of C 4 S and L-Glu.C 4 S induced thin and long hexagonal COM c rystals;L-Glu made one or two (010)crystal face of COM crystals dis-appeared.The crystallization time had no effect on the morphology of COM crystals,but the concentration of C 4 S and L-Glu changed it.As increasing the co ncentration of C 4 S,the amount of COM crystals with a hexagonal prism decreased and that with a thin hexago nal slice increased.When the concen tration of C 4 S was 0.50mg ·mL -1 ,all the calcium oxalate crystals were th in hexagonal slice COM crystals.How ever,as the concentration of L-Glu in-creased from 0.01to 0.50mmol·L -1 ,the hexagonal prism-like COM crystals gradually transformed to COM crystals with one or two (010)crystal face disappearance.展开更多
Urinary phospholipids are shown to be sensitive biomarkers for kidney injury. Many works have been reported on qualitative analysis of phospholipids and relative components in human urine while quantitative analysis i...Urinary phospholipids are shown to be sensitive biomarkers for kidney injury. Many works have been reported on qualitative analysis of phospholipids and relative components in human urine while quantitative analysis is rare. We have therefore developed a reliable and convenient quantitative method to evaluate the accuracy and specificity of dipalmitoylphosphatidylcholine （DPPC） as a biomarker for kidney injury diagnosis. Chromatographic separation was achieved using a HILIC Silica Column （2.1 ram^50 mm, 5 p.m）. Gradient elution was performed with 5 mM ammonium formate （0.1% formic acid） and acetonitrile （0.1% formic acid）, at a flow rate of 0.3 mL/min. This method was validated in a linear range of 2-200 ng/mL DPPC with inter-day precision of less than 6.5% and accuracy within 111.2% in human urine. Recovery rate, stability, dilution effect and matrix effect also met the requirements for drug evaluation and research issued by FDA. As the first HPLC-MS/MS method for quantitative determination of DPPC, it has been successfully applied to determine levels of DPPC in clinical urine samples and evaluated for potential use in the measurement of DPPC as a biomarker for kidney injury.展开更多
文摘The effects of urinary macromolecul e chondroitin sulfate A(C 4 S)and L-glutamic acid(L-Glu)on the crys-tallization of calcium oxalate were studied using Langmuir-Blodgett(LB)film of dipalmitoylphosphatidylch oline(DPPC)as templet.All the calcium oxalate c rystals induced by the LB film of DPPC were calcium oxalate monohydrate(COM).However,the morphology of COM was i nfluenced by the additives of C 4 S and L-Glu.C 4 S induced thin and long hexagonal COM c rystals;L-Glu made one or two (010)crystal face of COM crystals dis-appeared.The crystallization time had no effect on the morphology of COM crystals,but the concentration of C 4 S and L-Glu changed it.As increasing the co ncentration of C 4 S,the amount of COM crystals with a hexagonal prism decreased and that with a thin hexago nal slice increased.When the concen tration of C 4 S was 0.50mg ·mL -1 ,all the calcium oxalate crystals were th in hexagonal slice COM crystals.How ever,as the concentration of L-Glu in-creased from 0.01to 0.50mmol·L -1 ,the hexagonal prism-like COM crystals gradually transformed to COM crystals with one or two (010)crystal face disappearance.
文摘Urinary phospholipids are shown to be sensitive biomarkers for kidney injury. Many works have been reported on qualitative analysis of phospholipids and relative components in human urine while quantitative analysis is rare. We have therefore developed a reliable and convenient quantitative method to evaluate the accuracy and specificity of dipalmitoylphosphatidylcholine （DPPC） as a biomarker for kidney injury diagnosis. Chromatographic separation was achieved using a HILIC Silica Column （2.1 ram^50 mm, 5 p.m）. Gradient elution was performed with 5 mM ammonium formate （0.1% formic acid） and acetonitrile （0.1% formic acid）, at a flow rate of 0.3 mL/min. This method was validated in a linear range of 2-200 ng/mL DPPC with inter-day precision of less than 6.5% and accuracy within 111.2% in human urine. Recovery rate, stability, dilution effect and matrix effect also met the requirements for drug evaluation and research issued by FDA. As the first HPLC-MS/MS method for quantitative determination of DPPC, it has been successfully applied to determine levels of DPPC in clinical urine samples and evaluated for potential use in the measurement of DPPC as a biomarker for kidney injury.
