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Biomedical subjects

J Lempert

Publications and source records attributed to J Lempert.

At least 19 recordsLinked to original sources
PubMed1977

[Surface tension properties of the amniotic fluid obtained by serial puncture in normal pregnancies (author's transl)].

Serial amniotic fluid samples were obtained in the last trimester of pregnancy during the course of 12 uneventful pregnancies. The surface tension properties of the amniotic fluid samples were measured in the surface (Wilhelmy) balance. Eight pregnancies showed a normal pattern of surface activity parameters, whereas in four pregnancies the pattern was abnormal. The pattern of surface activity parameters is shown individually for each of the 12 pregnancies and the possible reasons for individual variations are discussed.

Amniocentesis↗
PubMed1976

Surface properties of amniotic fluid and fetal lung maturity.

Surface activity of 75 amniotic fluid samples from pregnancies which ended before term or at term with small-for-date newborns was measured in the surface balance. The results were correlated with the clinical symptomatology and the birth weight of the newborn. The surface properties of the lungs of those infants who had died were assessed by the buble stability method (Pattle), by recording of pressure-volume diagram and by measurements of surface activity of lung extracts. The results indicate that gamma-min is the essential parameter in determining the degree of fetal lung maturity. In cases with gamma-min values of amniotic fluid above 27 dyn/cm, a 100% respiratory distress syndrome (RDS) incidence is to be expected; values between 23 and 27 dyn/cm have a 70% values between 17 and 23 dyn/cm have a 30% incidence of RDS and in all cases with values below 17 dyn/cm, RDS may be rules out. When induced delivery before term is considered, this method of determining the degree of fetal lung maturity is, therefore, of significant prognostic reliability.

Amniotic Fluid↗
PubMed1975

Surface properties of the amniotic fluid in normal pregnancy.

The surface properties of the amniotic fluid were determined in 96 normal pregnancies between weeks 23 and 41. The y-max, y-min, hysteresis areaa, and stability index were used as parameters for evaluation of the surface tension are diagrams. These results were plotted against the gestation week and a curve for the normal course of surface tension of the amniotic fluid during the second half of gestation was obtained. The influence of addition of blood, vernix, and meconium to amniotic fluid as well as that of changes in the pH and dilution were examined. The results were unaffected by either blood, vernix, or pH changes. The slight scatter of the y-min values makes this parameter particularly suitable for determining fetal lung maturity.

Amniotic Fluid↗
PubMed1975

[Placental function and foetal lung maturity (author's transl)].

The placental function and foetal lung maturity were simultaneously assessed before delivery in 48 high-risk pregnancies, the actual time varying from case to case. A statistically significant correlation was found between placental function and foetal lung maturity. Since the actual time of investigation often lay back several weeks before delivery, no significant connection was detected between the state of foetal lung maturity at the time of amniocentesis and the clinical picture in respect to lung maturity of the infant at birth. The discrepancy is tabulated and possible causative factors are discussed.

Female↗
PubMed1975

The prediction of fetal lung maturity from the surface tension characteristics of amniotic fluid.

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 23rd to 41st week of gestation and their surface properties measured in the surface balance (Fig 1). A continuous rise in surface activity of amniotic fluid was observed during this period (Fig. 2). In the evaluation of the surface activity of amniotic fluid y-min appears to be the most suitable parameter because it shows a considerable change during the course of pregnancy and has low variations (Fig. 3). In 64 prematures amniotic fluid was obtained during delivery and its surface properties measured. The correlation of clinical symptoms of the premature with y-min of the amniotic fluid makes it possible to predict the fetal lung maturity at a given y-min value (Fig. 4). When the results are arranged according to the incidence of RDS (lethal RDS, recovered from RDS and without RDS) three y-min-ranges can be clearly distinguished. When y-min of the amniotic fluid is over 27 dyn/cm the probability of lethal RDS is 100%, whereas when y-min is under 17 dyn/cm a mature lung can be expected. In the range between 27 to 17 dyn/cm any degree of lung maturity can be encountered. By division of this range in two additional ones a more accurate prediction of fetal lung maturity is possible: In the y-min-range 27-23 dyn/cm RDS-probability is approximately 70%, in the range 23-17 dyn/cm it is only 30% (Fig. 4). Measurements of surface activity of the amniotic fluid make it possible to predict fetal lung maturity and estimate RDS-probability.

Amniotic Fluid↗