Quantitative determination of phosphatidylglycerol in amniotic fluid by enzymatic assay

PHOSPHATIDYLGLYCEROL STUDY AS FETAL LUNG MATURATION PARAMETER AFTER DEXAMETHASONE ADMINISTRATION FOR WOMEN AT RISK OF PRETERM BIRTH

Phosphatidylglycerol is an important indicator of fetal lung maturation, which plays a role in stabilizing surfactant lipoprotein complex. Corticosteroid antenatal can stimulate the synthesis of pulmonary surfactant in infants with preterm birth. The objective of this study is to examine the phosphatidylglycerol levels as fetal lung maturation parameter after dexamethasone administration in women with preterm birth compared to L/S ratio parameter. This study was prospective longitudinal (cohort). The samples were pregnant women with preterm birth risk at 28-34 weeks gestation getting the therapy of antenatal dexamethasone 6 mg IM every 12 hours given 4 times in 48 hours. The samples were 17 patients. Determination of L/S ratio and PG levels was performed by ELISA. The study was conducted from May - November 2015 and reviewed to obtain ethics eligibility permit by the research ethic committees of Dr. Soetomo General Hospital. The results show that the mean value of L/S ratio is 2.28 with a range of 1.35 to 9.06 and the mean of PG level is 1.17 with a range from 0 to 3.79. L/S ratio and PG show no significant relationship between the two of them. Increased levels of PG on the gestational age of 28-32 weeks have not demonstrated clinically significant changes yet. The highest PG level occurs in the gestational age of 32-34 weeks.

Planar chromatographic techniques in biomedicine: current status

In planar chromatography (PLC), the solvent flows through a layer either by means of capillary forces [conventional thin-layer chromatography (TLC)] or by a forced-flow system (over-pressured layer chromatography). Phases and instrumentation currently available are briefly examined. The main applications in biomedicine are reviewed. Although silica gel TLC plates still predominate, interest in other phases is increasing. Unique detection features such as immunostaining are emphasized. Although gas chromatography and high-performance liquid chromatography have superseded TLC in the analysis of carbohydrates, amino acids and indole derivatives, interest in PLC continues to be high in lipid analysis.

Current perspectives in assessment of fetal pulmonary surfactant status with amniotic fluid

In recent years, improvements in analytical methodology and clinical management of maternal-fetal diseases have altered the understanding of data from amniotic fluid analysis. Delays in phospholipid production or lung function are not currently reported in maternal diabetes. Fetal lung function following glucocorticoid therapy or premature membrane rupture is uncoupled from amniotic fluid phospholipid concentrations, which do not have the usual significance in these circumstances. Phosphatidylglycerol (PG) is present prior to the usual time it is detected by thin layer chromatography (TLC) methods, which vary in sensitivity for PG. Consequently, the significance of its "absence" is highly varied. These observations are discussed in light of the earlier methods and data, along with new perceptions of the functions of the individual phospholipids and apoproteins, the regulatory mechanism of surfactant production, and the relationship of amniotic fluid components to neonatal lung function.

Combined enzymatic assay of phosphatidylglycerol and phosphatidylcholine in amniotic fluid

We present here a combined, quantitative enzymatic procedure for determining amniotic fluid phosphatidylglycerol and phosphatidylcholine and relate these findings to the assessment of fetal lung maturity. Under the assay conditions described phospholipase C specifically hydrolyses phosphatidylglycerol (PG) and phosphatidylcholine (PC) but not sphingomyelin, precluding the need for removal of sphingomyelin prior to analysis. Solvent extraction of the phospholipids from the amniotic fluid is, however, employed to avoid spurious elevation of PG and PC results by endogenous glycerol and choline. Of 45 amniocentesis fluids examined, 28 yielded detectable PG concentrations (greater than 0.5 mumol/l) and all but three of these exhibited PC concentrations in excess of 10 mumol/l. One case of respiratory distress occurred in an infant of 29 wk gestation with severe intrauterine growth retardation. Of the remaining 17 fluids in which PG was undetected enzymatically (less than or equal to 0.5 mumol/l), 14 also contained PC concentrations less than or equal to 10 mumol/l and all six cases of true respiratory distress syndrome came from within this sub-group. Strong correlations between the PC concentration and the lecithin:sphingomyelin ratio, r = 0.85 (p less than 0.001) and the PC and PG concentrations, r = 0.96 (p less than 0.001) were also found.

Assessment of the AmnioStat-FLM immunoagglutination test for phosphatidylglycerol in amniotic fluid

One hundred and eight amniotic fluids were assayed by the AmnioStat-FLM (A-FLM) immunological agglutination test for phosphatidylglycerol (PG) and simultaneously measured enzymatically for PG content. Of 52 amniotic fluids found to be PG negative by the A-FLM method, all had enzymatic PG concentrations less than or equal to 1.5 mumol/l. Conversely, of 56 amniotic fluids judged to be either PG positive or weak positive, all but five had enzymatic PG concentrations greater than 1.5 mumol/l. The sensitivity of the A-FLM assay employed clinically for predicting foetal lung maturity was 89% and the specificity was 100%. The overall predictive accuracy of the test could be improved by providing controls at lower, more appropriate PG concentrations. Ninety-one fluids analysed by the A-FLM kit were subsequently tested for the presence of PG by two-dimensional thin-layer chromatography (2D TLC). A 94%-concordance between the methods was found.