Variability in the fatty acid composition of wax esters from vernix caseosa and its possible relation to sebaceous gland activity.

Wax ester/sterol ester (WE/SE) ratios were measured in samples of vernix caseosa lipid obtained from 21 full-term infants. The mean WE/SE ratio was twice as high in males as in females, suggesting higher average fetal sebum production rates in males, but individual values varied widely and there was considerable overlap between the sexes. Wax esters (a class of lipid produced only by the sebaceous glands) were isolated from 6 of the 21 samples of vernix caseosa lipid and analyzed for fatty acid composition. The percentages of iso and anteiso branched saturated fatty acids and of delta 9-type monounsaturated fatty acids were found to be correlated negatively with the WE/SE ratios of the original lipid samples. Values for the percentages of the major delta 9-type monounsaturates, plotted as a function of WE/SE ratios, fell near a curve of the shape which would be expected if a limited quantity of delta 9-type monounsaturates were available for sebum synthesis, and were diluted with varying amounts of delta 6-type monounsaturates, the amount of the delta 6-type monounsaturates being proportional to the amount of wax esters synthesized by the sebaceous glands. The results suggested that the rate of sebum production may be the sole determinant of the percentage of delta 9-type monounsaturates in sebaceous wax esters and a partial determinant of the percentage of iso and anteiso branched saturates.

Rapid diagnosis of amniotic fluid embolism.

Acute respiratory failure developed in a 19-year-old primigravida 7 hours after undergoing cesarean section. The diagnosis of amniotic fluid embolism was established by viewing fragments of vernix caseosa in a pulmonary artery blood sample. Forty-eight hours after the cytologic diagnosis had been made, amniotic fluid material was no longer present in pulmonary arterial blood. The patient underwent supportive care in an intensive care setting and recovered completely.

Further studies of the saturated methyl branched fatty acids of vernix caseosa lipid.

By the method of capillary gas chromatography-mass spectrometry, we have identified 35 monomethyl and 46 dimethyl branched acids in the saturated acids of vernix caseosa lipid with chain lengths ranging from C11 to C18. Many other mono-, di-, and trimethyl branched acids have been partially identified. All methyl branches were found to be on the even numbered C-atoms except for some terminal iso methyl groups. Three types of dimethyl branched acids were found: those with a terminal iso structure, those with a terminal anteiso structure, and those with neither iso nor anteiso structures. The 4-methyl branch predominated for all types of branched acids. Equivalent chain length data for di- and trimethyl branched acids were determined on a Pentasil (nonpopolar) wall coated capillary column and checked by calculation from monomethyl branched acid data. Mass spectral identification was performed with and without the aid of a data system. A possible mode of formation of these acids is discussed.

Analysis of fatty acid and alcoholic components of sebaceous lipid types.

Lipids were extracted from hair, scalp wipings, ovarian dermoid cysts, and vernix caseosa and submitted to alkaline hydrolysis. Alumina chromatography applied to the unsaponifiable portions allowed for the separation of hydrocarbons, alcohols, and sterols. The fatty acids from the saponifiable mixtures were converted to the methyl esters and analyzed by gas chromatography in conjunction with mass spectrometry. This technique permitted the identification of the even, odd, iso, and anteiso fatty acid levels of the various pools. Analysis of the alcohols was afforded by gas chromatography of the acetates. Ratios were determined among the acidic and alcoholic components of each lipid class and the alcoholic constituents of each pool appeared to be increased by two C2-fragments over the average carbon number of the corresponding acid fraction. Branched components ranged higher in all alcohol mixtures as compared to the respective acids and thus, indicative of a specificity for the synthesis of a specificity for the synthesis of alcohols.

Lipids in forehead vernix from newborn infants.

Neutral lipids in forehead vernix from newborn infants of various gestations were analysed by gas chromatography. Vernix collected from pre-term (less than 37 weeks) infants differed markedly from that collected from near-term (less than or equal to 37 weeks) infants. The principle difference was a increase in the content of squalene relative to other lipids in vernix from near-term infants. This change indicated a surge in fetal sebaceous gland function at about 37 weeks gestation.

Vernix in amniotic fluid: sonographic detection.

We investigated the possibility of using sonography to detect vernix caseosa, a complex fatty substance derived from desquamated epithelial cells and sebaceous material. In one of our cases, the sonographic appearance of vernix was dramatic, and its presence was confirmed at amniocentesis.

[Fetal lung maturity and skin maturity: 2 distinct concepts and the clinical significance of their differences]. / Lungenreife und Hautreife des Feten: zwei unterschiedliche Begriffe und die klinische Bedeutung ihrer Differenzierung.

The maturation of the fetal lungs, that is to say the adequate production of surfactant in the fetal alveoli, as it is well known reaches to its end about the 35.-36th week of gestation. Even more closely to the date of delivery, about the 37.-38th week of gestation, the maturation of the fetal skin takes place, so to say the detachment of the Vernix caseosa from the fetal skin into the amniotic fluid. The above mentioned means that the children with "mature skin" should have mature lungs too, so that those children have about nothing to fear from the RDS. That can be proved by the comparison of the values which were measured in 38 cases of the L/S Ratio (as a criterion of the lung-maturity), to those of the turbidity of the amniotic fluid and average quantities of the keratinocytes of the amniotic fluid cell population (as a criterion of the skin-maturity); that observation becomes stronger with the comparison of all those values to a Vernix-Score, which can be completed after delivery.