Search PubMed⌕ Search

Biomedical subjects

J R Edwards

Publications and source records attributed to J R Edwards.

At least 127 records · Page 7Linked to original sources
PubMed1979

Improved purification procedure for the extracellular D-glucosyltransferase from Streptococcus mutans 6715.

The exocellular D-glucosyltransferase from Streptococcus mutans 6715 has been highly purified with minimal loss of enzymic activity. The organisms were cultured in trypticase soy-broth that had been treated with invertase and filtered through an ultrafilter fitted with a membrane having a cut-off molecular weight at 10,000. To the growth medium was added Tween 80, which prevented the enzyme from aggregating. The final step in the purification employed insoluble, streptococcal dextran as an affinity support. Two D-glucosyltransferase activities were detected, viz., one that did not adsorb to the insoluble dextran and one that did. The enzymic fraction that had adsorbed to the insoluble dextran in the affinity column was strongly inhibited by added insoluble dextran.

Glucosyltransferases↗
PubMed1977

Development of sex-trait stereotypes among young children in the United Staes, England, and Ireland.

The Sex Stereotype Measure II (SSM II), a 32-item revision of the Williams, Bennett, and Best Sex Stereotype Measure, was developed to assess children's knowledge of conventional, sex-trait stereotypes defined by American university students. The procedure employed brief stories and human figure silhouettes which were individually administered to 5- and 8-year-old children in the United States, England, and Ireland and group administered to 11-year-olds in the United States. In the United States, knowledge of sex-trait stereotypes was found to develop in a linear fashion between the ages of 5 and 11, with more male traits than female traits being known at each age level. Cross-nationally, there was a high degree of similarity in the nature of the sex stereotypes being learned by the children in the 3 countries, although the rate of learning appeared slower among the Irish children. In all countries there was a clear progression in sex-stereotype learning from age 5 to age 8. English boys had greater knowledge of stereotypes than English girls, but this was not true in Ireland and the United States. Generally, knowledge of male stereotype traits appeared to develop earlier while knowledge of the female traits increased more rapidly between ages 5 and 8. The similarity in sex-stereotype learning in the 3 countries is discussed, and studies in progress in other countries of greater cultural diversity are noted.

Behavior↗
PubMed1976

alpha-D-Glucopyranosyl fluoride as a D-glucopyranosyl donor for a glycosyltransferase complex from Streptococcus mutans FA1.

alpha-D-glucopyranosyl fluoride can serve as the D-glucopyranosyl donor for the glycosyltransferase from Streptococcus mutans. The products of the reaction are a D-glucan of high molecular weight and fluoride ion. The rate of reaction was measured by an electrode specific for the fluoride ion. The reaction was inhibited by the substrate at concentrations greater than 30 mM, but was not affected by fluoride ion. There was little inhibition of the reaction by a series of monosaccharides, except for 2-amino-2-deoxy-D-glucose, D-mannitol, and 3-deoxy-D-ribo-hexose. Maltose, isomaltose, isomaltotriose, and D-fructose all stimulated the release of fluoride from alpha-D-glucopyranosyl fluoride.

Fluorides↗
PubMed1976

Orthodontically induced eruption of the permanent canine combined with alveolar cleft osteoplasty: a new procedure illustrated by a case with stereophotogrammetric reconstructions.

A new technique is suggested which will allow secondary bone grafting to be carried out at approximately 10 years of age when some potential of active tooth eruption and maxillary alveolar growth remains. Surgery is followed during the healing phase by orthodontic traction of the unerupted canine through the bone graft. This allows the reconstruction of the dental arch, while the bone graft is maintained by the osteogenic influence of the canine root. The technique is detailed and illustrated and a case report presented. A stereophotogrammetric reconstruction demonstrates the improvement in integumental contour following the technique described.

Activator Appliances↗
PubMed1975

Purification and characterization of a glycosyltransferase complex from the culture broth of Streptococcus mutans FA1.

The extracellular glycosyltransferases from Streptococcus mutans FA1 were purified by using the following procedures: ammonium sulfate precipitation, poly-(acrylamide) gel filtration, DEAE-cellulose chromatography, and agarose-gel filtration. The dextransucrase and levansucrase activities were purified 350- and 500-fold, repsectively, and the ratio of the two activities remained almost constant throughout the purification. Both enzymes have a pH optimum of 6.0, a Km for sucrose of 55mM, and isoelectric points of 3.7 and 4.6. The enzymes are inactivated by repeated freezing and thawing, but retain partial activity even after heating at 100 degrees. The enzyme preparation contains a carbohydrate moiety which does not appear to be either bound levan or dextran.

Chromatography, DEAE-Cellulose↗
PubMed1973

Laboratory prices.

Explore the source record for details and available documents.

Fees and Charges↗