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Biomedical subjects

S S Butler

Publications and source records attributed to S S Butler.

8 recordsLinked to original sources
PubMed1992

Factors related to substance use by pregnant, school-age adolescents.

This study provides information on substance use among pregnant adolescents, and examines social influence, intrapersonal, and environmental factors associated with substance use during pregnancy in adolescence. The sample consists of premaritally pregnant adolescents (N = 241), who were interviewed as part of a longitudinal study of patterns of drug use among pregnant and parenting school-age adolescents. The findings indicate that, although the sample demonstrated a high rate of prepregnancy substance use, a significant drop in use occurred during pregnancy. Logistic regression analysis indicated that perceived harm of using substances while pregnant, best friend's substance use, boyfriend's substance use, and school status were related to substance use during pregnancy, even after controlling for the effects of prepregnancy substance use. The findings have implications for substance use prevention and intervention programs for pregnant and parenting adolescents.

Adolescent↗
PubMed1984

Biologic activity of human chorionic gonadotropin following reversed-phase high-performance liquid chromatography.

Human chorionic gonadotropin (hCG) was analyzed by reversed-phase high-performance liquid chromatography (HPLC) using mobile phases previously described in the literature, as well as newly developed solvent systems. Fractions of hCG collected following reversed-phase HPLC were bioassayed by activation of adenylate cyclase to determine their biologic potencies. hCG retained only 10-60% of its biologic activity following reversed-phase HPLC, depending on the chromatographic conditions employed. A portion of the reduced biologic activity was attributed to dissociation of the alpha- and beta-subunits of hCG at the low pH of the mobile phases, since neutralization of the pH prior to lyophilization and bioassay increased the biologic potency of the chromatographed hormone. The remaining loss in biologic activity is presumably due to organic solvent denaturation.

Adenylyl Cyclases↗
PubMed1981

Transport of prostaglandins through silicone rubber.

The in vitro release profiles of the F-series of prostaglandins were determined from a silicone rubber matrix of constant surface area. Silicone rubber was selective toward prostaglandin transport and offers potential as a controlled-release delivery system. Drug release patterns were dependent on the lipophilicity of the prostaglandin molecule. For dinoprost (prostaglandin F2 alpha), the following sequences was observed: methyl ester greater than free acid greater than tromethamine salt. The biologically potent carboprost methyl [(15S)-15-methylprostaglandin F2 alpha methyl ester] was release considerably faster than the methyl ester of the parent dinoprost molecule, while release of the tromethamine salt of the two prostaglandins was similar. Permeability rates of the salts were depressed substantially when compared to their respective C-1 methyl esters. Results from independent membrane transport studies supported the observed dependence of steady-state flux on the chemical structure of the prostaglandin molecule. Plots of the amount released per unit area versus the square root of time were linear except for the initial drug release phase, and the total amount of prostaglandin released increased as the initial loading dose was raised. The data were analyzed according to a physical model describing drug release from inert matrix systems. The observed concentration dependence was consistent with the predictions of the model.

Diffusion↗
PubMed1981

Continuous flow bead-bed dissolution apparatus for suppositories.

A bead-bed dissolution apparatus for suppositories was evaluated by measuring the release of benzocaine from various vehicles. During dissolution, suppositories soften, deform, disintegrate, and eventually pass through a phase change from a solid to an oil. The control of the interfacial area during dissolution is a key factor in obtaining experimentally reproducible release data. The proposed suppository dissolution apparatus was designed to provide greater constancy of the exposed suppository area for dissolution. The apparatus consisted of a glass bead-bed containing the suppository. A continuous flow of liquid was passed through the bead-bed at a constant rate. Direct contact of the suppository was maintained with the dissolution medium, confining the suppository within the beads.

Benzocaine↗
PubMed1976

High-pressure liquid chromatographic determination of the 15-epimer of dinoprost in bulk drug.

The p-nitrophenacyl esters of dinoprost and its 15-epimer are well resolved using high-pressure liquid chromatography. Quantitation was achieved using the internal standard technique. The specially synthesized diphenylurea ester of cholic acid was found to be a model internal standard. Graphs of peak height ratios of the prostaglandin to the internal standard were linear with respect to the amount of prostaglandin injected, with the lower detection limit of the 15-epimer being about 0.5%. Data are presented that demonstrate the usefulness of this analytical technique in determining the concentration of the 15-epimer present during studies on the kinetics of decomposition of dinoprost.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Substance use and other factors associated with risky sexual behavior among pregnant adolescents.

A study of the relationship between substance use and risky sexual behavior was conducted among 241 unmarried pregnant adolescents aged 17 and younger who lived in a metropolitan area in the Northwest. The respondents had comparable or higher lifetime use rates for all substances than did women in a national sample of high school seniors, even though the pregnant adolescents were younger. Ninety-four percent had used alcohol, 78% marijuana, 30% cocaine and 30% stimulants, compared with 92%, 48%, 14% and 23%, respectively, among women in the national sample. Among the pregnant adolescents, 84% had had more than one sexual partner, 39% had had a sexually transmitted disease and 60% had used contraceptives during less than half of their sexual encounters. At the bivariate level, use of cigarettes and alcohol in general and use of alcohol and drugs during sex were positively associated with risky sexual behavior. However, when other characteristics associated with risky sexual behavior--family bonding, parental monitoring, commitment to conventional values, peer associations, self-esteem and delinquent activities--were included in the multivariate analysis, the effect of substance use disappeared.

Adolescent↗