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S C Lynn

Publications and source records attributed to S C Lynn.

7 recordsLinked to original sources
PubMed1984

Removal of a component interfering with phosphatidylglycerol estimation in the "Helena" system for amniotic fluid phospholipids.

A simple " prechromatography " step removes a component of amniotic fluid ("pseudo PG") that otherwise co-chromatographs with phosphatidylglycerol in the system for amniotic fluid analysis developed by Touchstone et al. (Lipids 15: 61-62, 1980) and incorporated into the Helena "Fetal-Tek" kit. The final positions of the major phospholipids are practically unchanged but the faster migrating, more neutral components are swept into a tight band near the solvent front, providing improved general resolution. The resulting change in the ratio of "phosphatidylglycerol" to sphingomyelin ("PG"/S) is as much as 0.5 for some specimens, but no change is seen for others. In 20% of the 73 cases examined, including four of the six fluids associated with respiratory distress syndrome, the PG initially reported was found to be "pseudo PG" and was completely removed by the prechromatography step. This step produces a negligible decrease in the lecithin to sphingomyelin (L/S) ratio in amniotic fluid.

Amniotic Fluid↗
PubMed1983

Influence of phospholipid saturation on classical thin-layer chromatographic detection methods and its effect on amniotic fluid lecithin/sphingomyelin ratio determinations.

We compared seven techniques, commonly used for detection of amniotic fluid phospholipids in thin-layer chromatography, with respect to their sensitivity to saturation of the fatty acid carbon-chain of lecithin. The techniques fell into two classes: sensitive and insensitive; those classed as saturation sensitive were less than or equal to 10% as sensitive to fully saturated lecithin as to lecithin with singly unsaturated acid moieties. Color development increased with the number of carbon-carbon double bonds per molecule but required only a single unsaturated acid ester in either the alpha or the beta position. Mixtures of lecithins with defined saturation, when detected by saturation-sensitive methods, mimicked the uneven coloration of amniotic fluid lecithin bands, supporting the hypothesis that this uneven coloration results from natural saturation heterogeneity. Detection techniques representative of these classes are shown to give widely differing values for the lecithin/sphingomyelin ratio for actual specimens of amniotic fluid.

Amniotic Fluid↗
PubMed1976

Effects of chronic morphinization on calcium membrane interaction.

Tolerance to morphine proceeds with an adaptation in the nerve membrane causing an increase in endogenously bound calcium. Our data on calcium binding is compatible with Collier's hypothesis (10) for drug induced changes in number and/or types of receptors. The results demonstrating naloxone reversal of this membrane adaptation suggest that opiate antagonist action may be to maintain the opiate macromolecule portion of the membrane in a Ca++ associated homeostatic state. Lack of effects of Na+ on opiate treated SPM suggest that cellular adaptation to morphine proceeds in vivo through a change in membrane binding of calcium.

Animals↗