Glucocorticoids induced down-regulation of glucocorticoid receptor mRNA expression in asthma.

Although their precise mechanism of action remains to be elucidated, glucocorticoids represent the most effective therapy in the treatment of asthma. Interactions between the glucocorticoid receptor and the AP-1 complex have been shown to regulate the transcription of some genes, including glucocorticoid receptor itself. The aim of the present study was to compare the expression of mRNA for glucocorticoid receptor in human blood monocytes obtained from seven unstable untreated asthmatic patients who were subsequently treated with high doses of parenteral corticosteroid (methyl prednisolone 120 mg/day) for 10 days.

Nonradioactive quantification of glucocorticoid receptor expression during differentiation of human monocytic cells (U937).

We describe a method for relative quantification of specific mRNA using a nonradioactive assay based on DNA strand competition between identical sequences of biotin- and fluorescein-labeled amplicon (probe) and unlabeled amplicon (target) during hybridization. As the target quantity increased, that of the double-labeled probe decreased in accordance with the mass action law. This technique was successfully applied to evaluate differences in glucocorticoid receptor expression in U937 cells before and after the addition of potent differentiation inducers: 12-O-tetradecanoylphorbol 13-acetate (TPA) and a combination of all-trans retinoic acid (RA) and 1,25-dihydroxyvitamin D2 (VD).

Imaging reactive oxygen species in asthma.

Inflammatory processes in asthma are characterized by an infiltration of inflammatory cells including mononuclear phagocytes. It has been observed that mononuclear phagocytes, alveolar macrophages and blood monocytes, release higher quantities of reactive oxygen species in asthmatic patients than in healthy subjects. Chemiluminescence assays were developed to measure the superoxide anion and the other reactive oxygen species.

Reciprocal effects between opioid peptides and human polymorphonuclear leukocytes--II. Enhancement of phorbol myristate acetate-induced respiratory burst in human polymorphonuclear leukocyte by opioid peptides previously exposed to activated oxygen species.

Activated oxygen species (AOS) have often been shown to promote strong modifications in peptide structures and thus in their biological functions. In the present study, the immunomodulatory effects of Leu-enkephalin, beta-endorphin, dynorphin and some fragments are evaluated, before and after exposure of peptides to AOS, by studying their influence on human polymorphonuclear leukocyte (PMN) respiratory burst. None of the tested opioid peptides (modified or not) were shown to affect resting oxidative metabolism in the PMNs.

Correlation in inflammatory fibroblasts between the number of glucocorticoid receptors and PGE2 release.

The anti-inflammatory effects of glucocorticoids are mediated through steroid receptor occupancy and there is a significant correlation between the extent of receptor saturation and the extent of the biological effects. In a previously published study, we found that the number of these receptors was higher in inflammatory fibroblasts than in quiescent ones. PGE2 release, measured at the same time as the number of steroid receptors, was higher when the cells were from inflammatory tissue.

Glucocorticoid receptors in fibroblasts from synovial tissue. Changes during the inflammatory process. Preliminary results.

There is known to be a significant correlation between the number of glucocorticoid receptors in tissues and their anti-inflammatory effect. In this work, the specific binding of glucocorticoids was studied in inflammatory fibroblasts. Human fibroblasts were obtained from the knee joint of a rheumatoid patient undergoing surgery; experimental fibroblasts were from rat granulomas.

[New derivatives of benzopyran-4-one with analgesic, anti-inflammatory and antiplatelet clumping activity].

A series of 35 new derivatives of 3-benzylidene benzopyran-4-one carboxylic acid was synthesized; their antiinflammatory and analgesic activities were investigated and compared with those of acetylsalicylic acid, phenylbutazone, ketoprofene and glafenine. Among these compounds, four were found to be more potent than the references compounds in tests of antiinflammatory and analgesic activity. Seven compounds were tested on rat blood platelet aggregation induced by ADP.