We have compared a new enzyme immunoassay (EIA) for estrogen receptors (ER) with our conventional radioligand binding assays (multipoint dextran-coated charcoal assay for cytoplasmic ER and hydroxylapatite exchange assay for nuclear ER). Cytoplasmic ERs were measured in 76 human breast cancer specimens by EIA and by five-point Scatchard analysis. The correlation between the two assays yielded a...

Sulfonylurea and particularly glibenclamide are potent blockers of ATP-regulated K+ channels in insulin-secreting cells. A very good correlation exists between binding of sulfonylurea to brain and insulinoma cell membranes. The [3H]glibenclamide-binding component from pig brain microsomes was solubilized with digitonin with a complete retention of its properties of interaction with glibenclamid...

Strains of Streptococcus mutans (serotypes c, e and f) were found to possess high levels of glucosyltransferase (GTase) activity, both cell-associated and in the culture medium, when grown in either sucrose-free or sucrose-containing broth media. The cell-associated GTase of S. mutans MT8148 (serotype c) was effectively extracted by treatment with 8 M-urea at 25 degrees C for 1 h. Approximately...

The composition and dental properties of eight different soft drinks, representing some of the most popular types used in the UK, were examined. Demineralization experiments were conducted on hydroxylapatite, the basic component of dental enamel, determining calcium dissolving by atomic absorption spectroscopy and phosphorus by u.v. visual spectrophotometry. The titratable acid content of the d...

Protein kinases were separated from rat kidney nuclear extract by hydroxylapatite column chromatography. Five (I-V) different protein kinases were isolated when histone was used as a substrate. Two (I and III) of them stimulated phosphorylation of c-erb A-beta protein (50 kDa) expressed in Escherichia coli. The c-erb A product has an activity of high affinity T3 binding. One (I) of the kinases ...

OBJECTIVES/HYPOTHESIS Studies have shown excellent results for 12-month post-injection augmentation data for calcium hydroxylapatite (CaHA) for glottal incompetence; however, the longevity of the material past one year was unknown. Our objective was to report the long-term effectiveness of CaHA as a vocal fold injectable by assessing data from a cohort of patients who underwent injection for gl...

Several aspects of the study of the rate of dissolution of calcium hydroxylapatite in aqueous solution are discussed. From a chemical point of view, this system provides the possibility to study the chemical processes taking place at the crystal surface during the dissolution process, both in the pure system and in systems containing foreign substances. From a biological point of view, the stud...