Biomedical subjects

J E Goral

Publications and source records attributed to J E Goral.

4 recordsLinked to original sources

PubMed1998

Paediatric preoperative teaching: effects at induction and postoperatively.

In a randomized controlled trial at Duke University and University of North Carolina Hospitals, 143 two to six year old children undergoing elective ambulatory surgery were randomized into a control group who received routine preoperative teaching or an intervention group who received an interactive teaching book. Changes in behaviour were measured by a Vernon behavioural questionnaire preoperatively and again two weeks postoperatively. A Global Mood Score was assessed in the preoperative holding area, at arrival into the operating room, and at the time of mask induction. The children in the control group were significantly more aggressive postoperatively than the intervention group (P < 0.05). Children who received the interactive teaching book exhibited higher levels of anxiety on the day of surgery, but fewer behavioural changes two weeks following surgery. Parents in the intervention group reported that preoperative teaching helped their child (87%) and themselves (83%).

Affect↗

PubMed1976

Characteristics of progesterone-binding components in neoplastic mammary tissues of the rat.

Characteristics of [3H]progesterone-binding components were studied in cell-free preparations of two hormonally responsive tumors: the R3230AC mammary adenocarcinoma and 9,10-dimethyl-1,2-benzanthracene-induced mammary tumor of the rat. Progesterone-binding macromolecules from cytosols of both mammary neoplasms exhibited sedimentation coefficients of 3.5 to 4.0 S on sucrose gradients of either low or high ionic strength. From Scatchard analyses of titration data, apparent dissociation constants of 4 to 6 X 10(-8) M were determined for ligand-binding protein complexes from either tumor. Specific progesterone-binding capacities varied considerably, ranging from 150 to 650 fmoles/mg of cytosol protein. Optimal binding of [3H]progesterone was reached by 2 to 3 hr at 3 degrees, pH 7.4, and then decreased rapidly. Specificity studies indicated that cortisol, corticosterone, and triamcinolone acetonide competed effectively for [3H]progesterone-binding. This suggested that [3H] progesterone was bound largely to a macromolecule distinct from transcortin, which does not bind glucocorticoids containing 9alpha-fluoro groups. Aldosterone, as well as several androgens and estrogens, were weak competitors of binding except at high concentrations. The nature of the inhibition of progesterone-binding sites by triamcinolone acetonide and corticosterone was competitive. Concurrent titrations of [3H]progesterone and [3H]triamcinolone acetonide-binding sites demonstrated that their binding capacities were similar, considering the relative stabilities of the complexes. These results, which indicated that progesterone and glucocorticoids compete for the same binding site, suggest that these hormones may influence mammary gland differentiation and development by a common mechanism.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1976

Steroid-binding proteins of the mammary gland and their clinical significance in breast cancer.

Differentiation and development of the mammary gland are influenced by estrogens, glucocorticoids, and progesterone. Specific binding sites for each of these classes of steroid hormones have been characterized in vivo and in cell-free preparations of lactating mammary gland of the rat. These properties were compared with those of steroid-binding proteins in the R3230AC and dimethylbenz[a]anthracene-induced mammary tumors of the rat and of human breast carcinomas. The binding components that were protein in nature were more concentrated in tissue from lactating than from virgin or pregnant rats. The steroid-binding capacities of mammary tumors were highly variable. Using a dextran-coated charcoal procedure, the rate constants of 3H-ligand association with specific binding sites were temperature dependent. Ligand specificity indicated that [3H]estradoil-17beta(3H-E) binding was inhibited only by estrogens, whereas [3H]triamcinolone acetonide (3 H-TA) was blocked by glucocorticoid/s and progesterone. Likewise, [3H]progesterone (3H-P) binding was inhibited by progestins and certain glucocorticoids. Incubation of minced mammary gland with 3H-steroid in the presence and absence of unlabeled competitor demonstrated specific binding sites in cytoplasm that were translocated to nuclei in a tempreature-dependent fashion. Using a steroid-exchange procedure both DEX and TA inhibited 3H-P binding to exchangeable sites that were loaded previously with unlabeled progesterone. These data suggest that certain glucocorticoid and progesterone binding sites were translocated simultaneously to nuclei. Administration in vivo of either 3H-E or 3H-TA indicated binding in cytoplasm and subsequent translocation to nuclei.

Animals↗

PubMed1975

Comparison of glucocorticoid-binding proteins in normal and neoplastic mammary tissues of the rat.

Kinetic and molecular properties of components binding [3H]triamcinolone acetonide were studied using 105,000g supernatants of lactating mammary gland, R3230AC, and dimethylbenz[a]anthracene (DMBA) induced mammary tumors of the rat. Using a dextran-coated charcoal adsorption procedure, the relationship between specific glucocorticoid binding and protein concentration was linear in the range of 0.5-4.0 mg/reaction. These cytoplasmic macromolecules bound [3H]triamcinolone acetonide with limited capacity (50-400 fmol/mg of cytosol protein) and high affinity, Kd approximately 10(-8)-10(-9) M. Optimal binding was obtained when homogenizations were made in Tris buffers, at pH 7.4, containing monothioglycerol. Time course of association of [3H]triamcinolone acetonide and its binding sites showed maximal binding by 6-8 hr at 3 degrees which remained unchanged up to 24 hr. The rate constant of association at 3 degrees was in the range of 2-4 x 10(5) M-1 min-1. The rate constant of dissociation of bound [3H]triamcinolone acetonide could not be calculated accurately since the reaction was essentially irreversible for 5 hr at 3 degrees. Estimation of the half-life of the steroid-binding protein complexes from the Kd and the rate constant for association gave a value of 11-12 hr. From ligand specificity studies, the glucocorticoids, triamcinolone acetonide, corticosterone, cortisol, and dexamethasone competed well for [3H]triamcinolone acetonide binding sites. Progesterone, aldosterone, and the anti-glucocorticoid, cortexolone, were also good competitors while androgens and estrogens were weak inhibitors of binding. The binding compenents sedimented at 7-8 S in sucrose gradients of low ionic strength and dissociated into lower molecular weight components sedimenting at 4-5S in high ionic strength gradients. Studies in vivo using animals bearing the DMBA-induced tumor demonstrated that [3H]triamcinolone acetonide binding complexes were present in cytoplasmic and nuclear compartments. Sedimentation coefficients of the cytoplasmic and nuclear forms of these receptors labeled in vivo were 7-8S and 4-5S, respectively. These studies suggest that the molecular and kinetic binding properties of glucocorticoid receptors in neoplastic mammary tissues are similar to those of the normal mammary gland.

9,10-Dimethyl-1,2-benzanthracene↗