Sphingomyelin In Amniotic Fluid Research Articles

Determination of lecithin and sphingomyelin in amniotic fluid by ultra-performance liquid chromatography-tandem mass spectrometry

Determination of lecithin and sphingomyelin in amniotic fluid by ultra-performance liquid chromatography-tandem mass spectrometry

Relationship between total bile acid concentration and fetal pulmonary surfactant in intrahepatic cholestasis of pregnancy

To explore the relationship between total bile acid (TBA) concentration and fetal pulmonary surfactant in intrahepatic cholestasis of pregnancy (ICP). Fifty five patients with ICP (ICP group) who received cesarean section from April 2008 to February 2010 in Second Xiangya Hospital, Central South University, were recruited. The general conditions of the neonates within 7 days after birth in ICP group were recorded. Those with fetal distress, neonatal asphyxia, or neonatal respiratory distress syndrome were referred as pathological neonates, others were referred as normal neonates. Over the same period, 23 healthy gravidas were recruited as control group. Enzymatic method was used to detect the TBA concentrations in maternal blood, cord blood and amniotic fluid. ELISA was employed to measure the urfactant protein A (SP-A) concentration in cord blood. High performance liquid chromatography system was used to detect the concentrations of phosphatidylcholine (PC), phosphatidylinositol (PI), lysophosphatidylcholine (LPC), and sphingomyelin (SM) in amniotic fluid. (1) The concentrations of TBA in maternal blood, cord blood and amniotic fluid were (30.1 ± 7.9), (9.3 ± 3.3) and (4.4 ± 1.5) mmol/L in ICP group, (4.8 ± 2.2), (4.9 ± 0.9) and (1.4 ± 1.1) mmol/L in control group, respectively. The differences between the two groups were significant (P < 0.05). (2) The SP-A concentration in cord blood in ICP group was (29.5 ± 6.4) µg/L, significantly higher than that in control group, which was (22.6 ± 7.4) µg/L (P < 0.05). (3) There were 20 pathological neonates and 35 normal neonates in ICP group. In pathological neonates, the concentrations of TBA and SP-A in cord blood were (10.9 ± 2.2) mmol/L, (37.0 ± 5.9) µg/L, respectively; and were (8.0 ± 2.8) mmol/L, (26.7 ± 4.8) µg/L in normal neonates. The differences were significant (P < 0.05). (4) There was a positive correlation between TBA concentration in cord blood and in maternal blood (r(1) = 0.706, P < 0.05). The TBA concentration in cord blood was positively correlated with SP-A concentration as well (r(3) = 0.494, P < 0.05). (5) The PC and PI concentrations in amniotic fluid were (65.4 ± 7.2) mg/L and (3.8 ± 0.6) mg/L in ICP group, (69.7 ± 3.7) mg/L and (4.3 ± 0.7) mg/L in control group, respectively. The differences were significant (P < 0.05). The concentration of LPC in amniotic fluid in ICP group was (4.8 ± 0.9) mg/L, significantly higher than that in control group (P < 0.05), which was (4.2 ± 0.6) mg/L. The concentration of SM in amniotic fluid was (3.5 ± 0.8) mg/L in ICP group, (4.0 ± 0.5) mg/L in control group, with no significant difference (P > 0.05). (6)The ratio of PC/LPC in ICP group (14.2 ± 3.2) was significantly lower than that in control group (16.9 ± 2.5) (P < 0.05). (7)The TBA concentration in cord blood was negatively correlated with PC and PI concentrations (r(1) = -0.561, r(2) = -0.407, P < 0.05), and had no correlation with LPC concentration (r(3) = 0.260, P > 0.05). (1) The fetal TBA concentrations in both cord blood and amniotic fluid of patients with ICP was higher than those of healthy gravidas, they were also positively correlated with maternal TBA concentration. (2) ICP resulted in the change of fetal pulmonary surfactant and this change was associated with TBA concentrations in both cord blood and amniotic fluid.

Measurement of the ratio of lecithin to sphingomyelin in amniotic fluid by fast atom bombardment mass spectrometry

We describe a fast atom bombardment mass spectrometric method to determine the ratio of lecithin to sphingomyelin in amniotic fluid. Between m/z 400 and 1000, amniotic fluid extracts showed clear peaks for only sphingomyelin and lecithin. The molecular species of fatty acid in the phospholipids were analyzed quantitatively and quickly in a small volume of the extracts. The dipalmitoyllecithin/palmitoylsphingomelin ratio, determined by the proposed method, showed a reasonable correlation to the lecithin/sphingomyelin ratio measured by thin-layer chromatography. This method allows rapid and sensitive measurement of these phospholipids.

Rapid enzyme analysis of amniotic fluid phospholipids containing choline: a comparison with the lecithin to sphingomyelin ratio in prenatal assessment of fetal lung maturity.

The relation between the choline containing surfactant phospholipids lecithin and sphingomyelin in amniotic fluid and fetal lung maturity is well established. An enzymatic method that had been automated and optimised for use on a centrifugal analyser was used to measure the total choline containing phospholipids in amniotic fluid. The total time taken for this assay was 10 minutes. The results obtained from 100 patient samples, using this procedure, compared favourably with the results obtained by the thin layer chromatography procedure used to determine the lecithin to sphingomyelin ratio (r = 0.93). A clinical study of 60 patients showed that this assay predicted prenatal respiratory distress syndrome as well as the lecithin to sphingomyelin ratios. The advantage of this assay over existing procedures is that it requires minimum preparation of the specimen and no extraction, is quick, and shows a high degree of precision.

Isclation of Lecithin and Sphingomyelin from Lipid Mixtures for Quantitation by Infrared Spectroscopy

Abstract A new procedure for the determination of lecithin and sphingomyelin in amniotic fluid is described. rapid column chromatography in the sample preparation steps with computer-assisted infrared spectroscopy in the final determination. Lipids are extracted from amniotic fluid with a chloroform/methanol solvent. The organic layer is separated and evaporated to dryness. The residue is The new method couples the use of simple, redissolved i n chloroforn and Fassed through a hydroxyapatite column to remove interfering constituents. The complete isolation cflecithin and sphingomyelin fror other li Fidsis confimec by both infrared spectroscopy and thin layer chronatcgrayhy.

Enzymatic colorimetry of lecithin and sphingomyelin in aqueous solution.

A procedure for the enzymatic determination of lecithin and sphingomyelin in aqueous solution is described. The phospholipids are first dissolved in chloroform:methanol (2:1 by vol), the solvent is evaporated, and the residue is redissolved in an aqueous zwitterionic detergent solution. The enzymatic reaction sequences of both assays involve hydrolysis of the phospholipids to produce choline, which is then oxidized to betaine, thus generating hydrogen peroxide. The hydrogen peroxide is subsequently utilized in the enzymatic coupling of 4-aminoantipyrine and sodium 2-hydroxy-3,5-dichlorobenzenesulfonate, an intensely red color being formed. The presence of a non-reacting phospholipid enhances the hydrolysis of the reacting phospholipid. Thus we added lecithin to the sphingomyelin standards and sphingomyelin to the lecithin standards. This precise procedure may be applicable to determination of lecithin and sphingomyelin in amniotic fluid.

Quantitative determination of lecithin and sphingomyelin in amniotic fluid.

A quantitative method for lecithin and sphingomyelin is presented. In this method, which may be calibrated with a primary standard phosphate salt or pure phospholipids, 2 mL of amniotic fluid is extracted, and the solvent passed through a column of hydroxyapatite to remove all phospholipids except lecithin and sphingomyelin. After evaporation, the residue is treated with methanolic sodium hydroxide, which hydrolyzes lecithin to inorganic phosphate and a methyl ester. The unreacted sphingomyelin is removed by extraction, and the solvent evaporated. Both fractions are digested and assayed for phosphate by reduced phosphomolybdate. The total time required is 2 h. Analytical recoveries were 91-97%, and excellent agreement was found for controls. Amniotic fluid specimens were assayed to illustrate application of the proposed method. If this method is used for obtaining a lecithin/sphingomyelin ratio, a new ranges must be established, as this method is not equivalent to thin-layer chromatographic ones.

New method for determining lecithin and sphingomyelin in amniotic fluid.

We describe a new method of complete analysis for lecithin, lysolecithin, and sphingomyelin in amniotic fluid. The analysis is based on alkaline hydrolysis of the lecithins and the enzymic hydrolysis of sphingomyelin. The choline formed in each instance is enzymically phosphorylated with [gamma-32P]ATP to yield [gamma-32P]phosphorylcholine, which is isolated by anion-exchange chromatography and shown to be stoichiometrically related to lecithin, lysolecithin, and sphingomyelin. Other phospholipids do not interfere. Using this methodology, we developed three potential approaches to the assessment of fetal lung maturity: the ratio of lecithin plus lysolecithin (total lecithin) to sphingomyelin, the total lecithin concentration, and total lecithin as a percentage of total amniotic fluid phospholipids. All three indices were compared with the lecithin/sphingomyelin ratio obtained by a chromatographic procedure. Our data suggest that measuring the percentage of total lecithin may provide the best means of evaluating fetal lung maturity, but a final judgment must await clinical investigation.

The Prevention of Hyaline Membrane Disease: New Concepts and Approaches to Therapy

New approaches to hyaline membrane disease have emerged in recent years. These developments are principally attributable to advances in our understanding of the following: (1) the pathophysiology and pathogenesis of HMD in relationship to pulmonary surfactant, (2) fundamental aspects of fetal lung development, including the movement of surfactant phospholipids from fetal pulmonary fluid to the amniotic space, (3) mechanisms for accelerating lung maturation, particularly with maternally administered prenatal glucocorticoids, and (4) ventilatory techniques effective in protecting and conserving alveolar surfactant by the continuous application of end expiratory pressure. Prenatal assessment of the risk for developing hyaline membrane disease is now routinely possible by amniocentesis and analysis of the ratio of lecithin to sphingomyelin in amniotic fluid. Such predictability, coupled with the ability to postpone delviery, allows the perinatologist in some instances to provide the fetus with ample opportunity for lung development in utero. Recent clinical trials around the world with pregnant women in premature labor document a significantly lower incidence of hyaline membrane disease after antenatal glucocorticoid treatment. In neonates with the disease weighing more than 1500 gm, it is now established that reduced mortality rates accrue from the use of end expiratory positive pressure. These clinical advances offer great promise in changing the nature of HMD management from procedures that are largely supportive to approaches that are truly preventative.

Hyaline membrane disease.

In addition to confirmation of earlier epidemiologic observations, major advances have occurred in the past few years with respect to the diagnosis and treatment of hyaline membrane disease. Prenatal assessment of the risk for developing the disorder is now routinely possible by amniocentesis and analysis of the ratio of lecithin to sphingomyelin in amniotic fluid, or by surfactant titer ("shake test"). Such predictability and numerous other lines of evidence provide strong support for the hypothesis that hyaline membrane disease fundamentally reflects a deficiency of pulmonary surfactant. In accordance with the apparent primacy of surfactant deficiency, recent improvements in management are directed toward either increasing lung volume at end expiration by application of continuous distending airway pressure, or accelerating fetal lung maturation, with respect to the synthesis and secretion of surfactant, by prenatal administration of glucocorticoids.

A method for determination of lecithin and sphingomyelin in amniotic fluid

A method for the visualization of lecithin and sphingomyelin is presented. The procedure allows the use of commercially prepared silica gel thin-layer sheets. Phosphomolybdic acid and stannous chloride solutions have been combined with a novel acetone decolorization which circumvents the usual fixing of the silica gel layer prior to color development. The method produces a permanent record which is suitable for densitometry, facilitating quantitative analysis of the lecithin/sphingomyelin ratios.

Simple, Rapid Determination of Lecithin and Sphingomyelin in Amniotic Fluid

Abstract We describe a rapid and very sensitive modified determination of lecithin and sphingomyelin in amniotic fluid. It requires 1.5 ml of amniotic fluid and can be done in less than 40 min. Modifications include "Instant Thin Layer Chromatography" plates (Gelman) with a punched disc system of sample application, as well as elimination of the acetone wash steps, and substitution of Rhodamine B dye for the corrosive sulfuric acid char technique of detection. The procedure can be quantified, and exact concentrations of lecithin in amniotic fluid can be determined by a standard addition procedure, or from a standard curve.

Rapid TLC Separation and Detection of Lecithin and Sphingomyelin in Amniotic Fluid

Rapid TLC Separation and Detection of Lecithin and Sphingomyelin in Amniotic Fluid