Biomedical subjects

D S Ng

Publications and source records attributed to D S Ng.

22 records · Page 2Linked to original sources

PubMed1984

Binding of antimorphine anti-idiotypic antibodies to opiate receptors.

Antibodies that specifically recognize and bind opiate receptors were developed by the anti-idiotypic method. Antimorphine antibodies were generated in rabbits and showed selective binding to various opiate ligands. Guinea pigs were immunized with antimorphine antibodies to produce anti-idiotypic antibodies that cross-reacted with opiate receptors. Guinea pig antiserum inhibited binding of naloxone (0.6 nmol) to mouse brain homogenate. In isolated mouse vas deferens, contraction of electrically stimulated tissue was inhibited by the antiserum. The results indicate that anti-idiotypic antibodies which interact with opiate receptors were developed without isolating receptors.

Animals↗

PubMed1982

Subcellular distribution of weak acids and bases in adrenal medulla.

1. Studies of the subcellular distribution of two acids and three bases in adrenal medulla support the hypothesis that the charge on a drug molecule is an important factor determining its subcellular distribution in this tissue. 2. Acidic drugs carrying a negative charge do not bind well to adrenomedullary subcellular particles and accumulate predominantly in cell supernatant. 3. Basic drugs tend to bind more extensively to adrenomedullary intracellular organelles and distribute more uniformly over all subcellular fractions.

Acids↗

PubMed1980

Miniature two-dimensional thin-layer chromatographic separation of lecithin and sphingomyelin.

A miniature two-dimensional thin-layer chromatographic procedure employing silica gel impregnated glass-microfiber chromatography sheets (commercial product, ITLC-type SG sheets) has been developed for the separation of lecithin (L) and sphingomyelin (S) from a standard lipid mixture containing L, S, lysolecithin, phosphatidyl inositol (PI), phosphatidyl serine (PS), phosphatidyl ethanolamine, phosphatidyl glycerol, and diphosphatidyl glycerol. The newly developed procedure eliminates possible interference from PI and PS. Complete separation of L and S was easily achieved with chromatographic solvent migration times of approximately 3 and 2 min for the first and second dimensions, respectively. The lipids were visualized by charring and fluorescent staining techniques. The procedure has been adapted for the separation of L and S from amniotic fluid samples.

Amniotic Fluid↗

PubMed1979

A rapid, sensitive method for accurate determination of the lecithin/sphingomyelin ratio by thin-layer chromatography and reflectance spectrofluorometry.

A highly reproducible thin-layer chromatographic procedure has been developed for accurate determination of the lecithin/sphingomyelin ratio. Two interfering compounds, phosphatidyl inositol and phosphatidyl serine, have been investigated and eliminated by adsorption onto DEAE-cellulose. A uniform fluorescence staining procedure employing 2',7'-dichlorofluorescein has been developed. Accurate quantitation was performed by direct measurement of the reflected fluorescence intensity of the lecithin and sphingomyelin fluorophore spots with a spectrofluorometer equipped with a thin-layer scanning attachment. Stability and reproducibility studies are reported.

Chromatography, Thin Layer↗