Sixty samples of amniotic fluid were analyzed for their surfactant level by measuring the lecithin-spingomyelin ratio and performing the "shake" test. Cytologic examination of the sediment was also performed using Nile blue sulfate staining. The lecithin-sphingomyelin ratio was found to be the best method to predict fetal maturity and assess ...

The amniotic fluid lecithin/sphingomyelin (L/S) ratio was determined in 182 pregnancies complicated by Classes B and C diabetes and in 28 patients with Classes D, F, and R diabetes. These data were retrospectively correlated with the occurrence of the respiratory distress syndrome (RDS) or hyaline membrane disease (HMD). Only four ...

The surface tension (ST)-lowering properties of an amniotic fluid lipid extract can provide a rapid and reliable means of predicting pulmonary maturity. One hundred and eleven samples from 91 patients were analyzed. A surface tension of less than 56 dynes per centimeter at 120 microliter of extract and less than ...

Serial samples of amniotic fluid were taken from 48 patients during labour. The lecithin/sphingomyelin (L/S) ratio was estimated and found to rise in 52 per cent, remain almost unchanged in 33 per cent and fall in 15 per cent. The rate of rise in the L/S ratio seemed inversely related ...

Transabdominal amniocenteses were performed on both sacs of 14 sets of twins. In each instance one sac was marked with methylene blue to correctly identify the fluids. The lecithin/sphingomyelin ratio was determined on each fluid, and the correlation coefficient between the two sets of fluids was 0.86. There was no ...

THe thromboplastic activity of amniotic fluid was correlated with the lecithin sphingomyelin (L/S) ratio in 59 pregnancies. It was shown that the thromboplastic activity and the L/S ratio in amniotic fluid had a coefficient of correlation of r = --0-73 (P less than 0-004). The thromboplastic activity was estimated by ...

Amniotic fluid cortisol (AFC) levels were measured in 76 normal and 67 high-risk human pregnancies. When compared to normal gestations, diabetic pregnancies were found to be associated with lower AFC levels, while toxemic, early Rh-sensitized, and other stressed pregnancies had higher mean cortisol values. Serially followed normal and high-risk pregnancies ...

Amniotic fluid cortisol concentration was compared with lecithin/sphingomyelin ratio, gestational age, and eventual birth-weight in a large series of normal and high-risk human pregnancies in an effort to determine whether cortisol could be used as a reliable indicator of fetal maturity. It appears that when used alone amniotic fluid cortisol ...

Betamethasone was administered to six rhesus-sensitized pregnant women carrying seven fetuses in an attempt to accelerate fetal pulmonary maturation. A reduction in optical density of amniotic fluid at 450 mmu was observed in all cases following steroid therapy; however, only minimal changes were noted in the lecithin-sphingomyelin ratio. The implications ...

The efficacy of correlating the L/S ratio in the amniotic fluid with fetal lung maturity has been substantiated in normal pregnancies. In gestations complicated by fetomaternal diseases, however, the assay is less reliable. This study involves 555 pregnancies in which there was a significant maternal, fetal, or placental disorder. The ...

The reliability of eight methods for estimating gestational age in the third trimester of pregnancy has been assessed in patients with fetuses of known maturity. Late ultrasound cephalometry, amniotic fluid creatinine estimations and lecithin/sphingomyelin ratio were found to be significantly more reliable than the other five methods. The mean of ...

In a material of 144 samples of amniotic fluid from the last trimester, creatinine concentration, lecithin/sphingomyelin (L/S) ration and their correlation, have been examined. Amniotic fluid creatinine concentration (a.f.c.) increased gradually through the last trimester up to 39 weeks (273-279 days p.m.) with median values of 2 mg/100 ml at ...

The amniotic fluid study of 80 samples from 40 patients, obtained by amniocentesis between 28 and 40 weeks of pregnancy, was carried out. It was noted that L/S (Lecithin/Sphingomyelin) ratio was significantly different at 36-38 weeks of pregnancy when compared with values in pregnancies of less than 36 weeks gestation ...

The lecithin-sphingomyelin (L/S) ratio is acknowledged to be superior to most procedures for predictinf fetal lung maturity in normal pregnancy. In complicated gestations, however, errors have been reported. This study involves 686 normal gestations and 389 pregnancies complicated by fetomaternal diseases. The L/S ratio, creatinine level, and percent of fat-staining ...

The ultrastructure of neuroglial fatty metamorphosis (GFM) has been investigated in the telencephalic white matter of 12 premature and mature infants (gestational age 22-40 weeks; survival 0-96 days). GFM was found in all cases apart from a 22-week-old fetus, and involves predominantly astrocytic cells (68.8%), then glioblasts (43.5%), but only ...

In various organs in fetal animals, maturation is inducible by corticosteroids and delayed by hypophysectomy. A surge of corticosteroid in the fetal circulation preceding parturition may cause rapid organ maturation and enhanced viability. Since this phase of accelerated maturation is linked to the parturitional mechanisms, the changes can be termed ...

The chief obstetrical problems encountered today in the prenatal evaluation of the high-risk fetus are presented. Advantages and pitfalls or recent techniques utilized in the management of the high-risk pregnancy are discussed. They include: a prenatal scoring system for identifying the high-risk population; examination of the karyotype of cells in ...

The action of Taka-amylase A from Asp. oryzae was studied quantitatively by the product analysis method using unlabeled maltotriose and maltotriose labeled at the reducing end as substrates. It was found that the ratio of the unlabeled products, maltose (G2) and glucose (G1) exceeded unity, and that the ratio of ...

A specific and thoroughly validated competitive protein binding radioassay has been developed for the measurement of unconjugated cortisol in human amniotic fluid. Cortisol levels rose throughout normal gestation from 8.6 +/- 0.8 ng/ml at less than 20 weeks to 19.8 +/- 1.5 ng/ml at 30-40 weeks. Levels were significantly higher ...

The minor phospholipids in amniotic fluid from normal pregnancies were correlated with the well-established index of lung maturity, the lecithin/sphingomyelin (L/S) ratio. When the L/S ratio was less than 1.0, the acidic phospholippids phosphatidylglycerol (PG) and phosphatidylinositol (PI) were absent or low in concentration (0.0 to 2.5 per cent of ...

Amniotic fluid creatinine, percentage of lipid-positive cells, and L/S ratio were determined on 285 samples from normal pregnancies and 222 samples from abnormal pregnancy states (Rh isoimmunization, diabetes, hypertensive disorders, intrauterine growth retardation, and hydramnios). In normal pregnancy the coefficient of correlation between true gestational age and estimated period of ...

Mixed dispersions of the nonionic detergent Triton X-100 and sphingomyelin were used as substrate for sphingomyelinase of rat brain. The dependence of the rate of hydrolysis on the concentration of sphingomyelin was measured in two ways: at a fixed concentration of Triton X-100 or at varying concentrations of this detergent, ...

The amniotic fluid lecithin/sphingomyelin (L/S) ratio in normal rhesus monkey pregnancies exhibits a distribution through the latter half of gestation similar to that seen in human pregnancies. Changes in the synthesis and concentration of lecithin in the fetal lung, measured both in vitro and in vivo, are paralleled by changes ...

The lecithin/sphingomyelin (L/S) ratio has been estimated in the amniotic fluid from 20 patients with a twin pregnancy. The values in each pair of amniotic fluids were closely related. If amniotic fluid from one sac only is available, it is suggested that a ratio of 2-5:1 is taken as the ...

118 samples of amniotic fluid were taken from 102 patients in the 25th to the 43th week of pregnancy by amniotomy or by transabdominal amniocentesis. 76 samples were obtained from patients with normal pregnancies without evidence for either induction or retardation of lung maturity; they served to establish normal values. ...

176 samples of amniotic fluid were obtained by abdominal amniocentesis from 69 women with complicated pregnancies (toxemia, diabetes mellitus or rhesus isoimmunization) in the 27th-43rd week of pregnancy. The concentration of creatinine (172 cases), the ratio of lecithin/sphingomyelin (L/S-ratio, 155 cases) and phospholipid phosphorus (155 cases) were determined and related ...

Lecithin/sphingomyelin (L/S) ratio was measured and rapid surfactant test (RST) was performed on amniotic fluid samples drawn from 60 normal and 18 diabetic pregnancies, for determination of fetal lung maturity. The results were compared to the neonatal outcome. Comparison of L/S ratio and RST demonstrates a good correlation (95%) between ...

A patient with an unsuspected placenta percreta presented with intraperitoneal bleeding at 33 weeks' gestation. Because of the clinical picture and a lecithin/sphingomyelin ratio of 1:1, this patient was treated conservatively until 38 weeks' gestation when an L/S ratio test indicated fetal maturity. The pregnancy was successfully terminated by cesarean ...

Amniotic fluid was obtained by transabdominal amniocentesis in 51 women in the 29th-36th week of pregnancy. The lecithin/sphingomyelin ratio was determined. In 28 patients,the ratio was less than 2.2. Beta-methasone was given for three days to 14 of them; the rest served as controls. On the fourth day, a second ...

The lecithin/sphingomyelin ratio in amniotic fluid is a method of predicting fetal lung maturity. The L/H ratios in certain high risk pregnancies are poorly correlated with the shake test. The L/S ratios in drug addiction methadone pregnancies and diabetic pregnancies do not have a high degree of correlation with normal ...

246 samples of amniotic fluid were obtained from 245 women with normal or complicated pregnancy near or at parturition. The lecithin/sphingomyelin (L/S) ratio was determined and retrospectively correlated with the clinical course of the neonate. Ten neonates developed hyaline membrane disease (HMD). The highest L/S-ratio in this group was 1.82. ...

Fetal pulmonary maturity based on visualization of one or both fetal knee secondary centers of ossification was assessed in 84 gravidas. Amniotic fluid lecithin/sphingomyelin ration of 2:1 or greater was the criterion of fetal lung maturity. It was concluded that when antenatal radiographs reveal the presence of both centers of ...

We have found the lecithin/sphingomyelin ratio of Gluck (L/S ratio) to be very useful for predicting respiratory distress. It correlated reasonably well with three other phospholipid values: the total lecithin content, the acetone-insoluble lecithin content, and the total lecithin/total phospholipids ratio. When the L/S ratio of amniotic fluid was greater ...

Amniotic fluid (AF) lecithin/sphingomyelin (L/S) rations were obtained in 223 pregnancies. Gestations complicated by maternal diabetes (71), vascular disease (50), and fetal growth retardation (47) were included. Elevated L/S ratios at 34 to 36 weeks' gestation were observed to accompany maternal vascular disease; higher rat;os were also related to fetal ...

During the prenatal period of development of the rabbit skeleton (days 21-30) the successive phases of fetal maturity can be distinguished by reference to the progress of ossification, particularly in the distal limbs and sternum. In the present study absent or incomplete ossification of sternebra 5 occurred in 8% of ...

The effect of dexamethasone on amniotic fluid lecithin-sphingomyelin (L/S) ratio was measured in 15 fetuses of 34 weeks or less of gestation. Six of the patients presented with premature rupture of the membranes. A rise in the L/S ratio is mature levels (two or more) was observed 24 hours to ...

The frequent necessity for termination of pregnancy before the spontaneous onset of labor requires that we be able to accurately predict fetal lung maturity. We have used amniotic fluid studies for evaluation of fetal lung maturity and have found that (1) a "fat" cell concentration of 30% or more, or ...

198 amniotic fluid samples, obtained from 14-42 weeks of 158 patients were assessed for amniotic fluid phospholipids (total phospholipids, lecithin, sphingomyelin, lecithin/sphingomyelin ratio). The TPLP and Lec-concentrations show significant rises in concentration after 34th week whereas the sphingomyelin concentration remains virtually constant during pregnancy. L/S ratio remains relatively constant smaller ...

One hundred and three samples of amniotic fluid from 21 normal and 64 medically complicated pregnancies were used for evaluating fetal maturity by measuring one or more of the following: the lecithin-sphingomyelin ratio (L/S), bilirubin concentration, creatinine concentration, and percentage of fetal fat cells. The rapid foam test for surfactant ...

Subcommissural organs of young and mature rabbits were analyzed for their content of arginine vasotocin by radioimmunoassay. Younger animals had significantly greater quantities of this peptide. There was no detectable arginine vasopressin or oxytocin in subcommissural organ extracts. It is concluded that the subcommissural organ represents, in addition to the ...

Lecithin has been measured in amniotic fluid, pharyngeal aspirate, fetal and maternal plasma and fetal membranes from the same pregnancy. In the amniotic fluid from a term pregnancy 79 per cent of the lecithin is found in the reconstituted precipitate of centrifuged fluid. It is suggested that the lecithin of ...

Development of parasympathetic and sympathetic reflexes controlling heart rate, vascular pressures, and blood flows was investigated in fetal lambs weighing 300-5,800 g (65-165 days' gestation). Cardiovascular responses to veratridine injections, atrial stretching, bilateral cervical vagotomy, and cholinergic blockade with atropine were used to test parasympathetic activities. Responses to propranolol and ...

In recent years fetal lung maturity has been assessed by chemical determination of lung surfactant components in the amniotic fluid. The variation in the results, however, limits the clinical usefulness of these methods. To establish reliable criteria for fetal lung maturity 98 specimens of amniotic fluid were obtained in the ...

The validity of the assessment of the fetal age and pulmonary maturity was evaluated on 369 patients at various stages of normal pregnancy and complicated by diabetes, toxemia and fetal anencephaly. Gestational maturity was assessed by ultrasonic measurement of the fetal biparietal diameter and by analysing constituents of amniotic fluid ...

185 samples of amniotic fluid were obtained from 174 healthy women with uncomplicated pregnancies in the 15th-43rd week of pregnancy by abdominal amniocentesis or by puncture of the amniotic sac via an amnioscope. The concentrations of creatinine (183 cases), phospholipid phosphorus and the ratio of lecithin/sphingomyelin (L/S-ratio, 130 cases) were ...

Maturation of female Cediopsylla simplex takes place on the pregnant rabbit and nestlings but not on the estrous doe. If matured fleas are transferred to the estrous doe their ovaries are resorbed.

The normal range and trends of the ratio between lecithin and sphingomyelin in the amniotic fluid, estimated on thin-layer chromatograms, have been established for the last trimester. The accuracy of the ratio as an index of fetal lung development and of the risk of neonatal respiratory distress has been confirmed. ...

Renal p-aminohippurate transport in rabbits increased rapidly from birth to 4 weeks of age and then declined to that observed in adults. Penicillin administration to pregnant does or newborn rabbits stimulated the developing transport system, but did not increase the peak observed at 4 weeks. Therefore the continued presence of ...