Search results for "Steroid"
showing 10 items of 1005 documents
Anti-inflammatory actions of the heme oxygenase-1 pathway.
2003
Heme oxygenase 1 (HO-1) is induced by oxidative or nitrosative stress, cytokines and other mediators produced during inflammatory processes, likely as part of a defence system in cells exposed to stress to provide a negative feedback for cell activation and the production of mediators, which could modulate the inflammatory response. HO-1 activity results in the inhibition of oxidative damage and apoptosis, with significant reductions in inflammatory events including edema, leukocyte adhesion and migration, and production of inflammatory cytokines. HO-1 is induced by nitric oxide (NO) in different biological systems and can control the increased production of this mediator observed in many i…
Bone damage after chemotherapy for lymphoma: a real-world experience
2021
AbstractBackgroundDespite recent improvements in survival due to advances in treatment, the quality of life of patients with lymphoma may be compromised by the long-term complications of chemotherapy and steroid therapy. Among these, a potentially relevant problem is bone loss and the development of fragility fractures.AimTo provide further evidence of clinical or subclinical skeletal complications in correlation with biological variables and markers of bone disease in patients with complete response to therapy.MethodA cross-sectional observational study was conducted on subjects diagnosed with lymphoma with subsequent antineoplastic treatment, disease status after therapy defined as comple…
Cholesterol–Protein Interaction: Methods and Cholesterol Reporter Molecules
2010
Cholesterol is a major constituent of the plasma membrane in eukaryotic cells. It regulates the physical state of the phospholipid bilayer and is crucially involved in the formation of membrane microdomains. Cholesterol also affects the activity of several membrane proteins, and is the precursor for steroid hormones and bile acids. Here, methods are described that are used to explore the binding and/or interaction of proteins to cholesterol. For this purpose, a variety of cholesterol probes bearing radio-, spin-, photoaffinity- or fluorescent labels are currently available. Examples of proven cholesterol binding molecules are polyene compounds, cholesterol-dependent cytolysins, enzymes acce…
Pyrolytic formation of polyaromatic hydrocarbons from steroid hormones
2011
Author's version of an article published in Food Chemisty, 124 (4), 1466-1472. Also available from the publisher: hhtp://dx.doi.org/10.1016/j.foodchem.2010.07.109 Four steroid hormones, namely androsterone, cholesterol, estrone and estradiol, have been pyrolysed at 300, 400 and 500 °C and the pyrolysates from these have been analysed by GC-MS. The results indicate that these formed different products under the pyrolysis and most of them evolved into polycyclic aromatic hydrocarbons during their residence in the pyrolysis chamber at high temperatures. The products from the pyrolysates, at all temperatures, were analysed for similarities and differences using multivariate data analysis. The p…
Metabolites of the aquatic pollutant diclofenac in fish bile.
2010
The uptake and metabolism of anti-inflammatory drug diclofenac (DCF) was studied by exposing rainbow trout (Oncorhynchus mykiss) to DCF intraperitoneally, and via water at concentration of 1.7 μg L(-1). The bile was collected and the formed metabolites were identified. The identification was based on the exact mass determinations by a time-of-flight mass analyzer and on the studies of fragments and fragmentation patterns of precursor ions by an ion trap mass analyzer. The main metabolites found were acyl glucuronides of hydroxylated DCFs. In addition, one ether glucuronide of hydroxylated DCF was found. Also, unmetabolized DCF was detected in the bile. The total bioconcentration factors (BC…
Development of predictive retention-activity relationship models of non-steroidal anti-inflammatory drugs by micellar liquid chromatography: comparis…
2000
The predictive and interpretative capability of quantitative chromatographic retention-biological activity models is supported by the fact that under adequate experimental conditions the solute partitioning into chromatographic system can emulate the solute partitioning into lipid bilayers of biological membranes, which is the basis for drug and metabolite uptake, passive transport across membranes and bioaccumulation. The use of micellar solutions of Brij35 as mobile phases in reversed-phase liquid chromatography has proven to be valid to predict some biological activities of different kinds of drugs. In this study, quantitative retention-activity relationship (QRAR) models to describe som…
Quantification of ecdysteroids by immunoassay: comparison of enzyme immunoassay and radioimmunoassay.
1995
Abstract The performance of enzyme immunoassay (EIA) and radioimmunoassay (RIA) in the quantitative analysis of ecdysteroids was compared. The EIA was found to be at least equivalent to the RIA with respect to analytical range and sensitivity and to be more comfortable with respect to safety and time saving. When biological samples were analyzed by both assays a good correlation (r = 0.83) was found. Since the EIA has certain advantages over the RIA, we now recommend the use of the former assay for the quantification of ecdysteroids.
Radioactively labelled epoxides. Part III. Tritium labelled steroid 16α, 17α-epoxides
1980
Tritium labelled (17-3H) 16α, 17α-epoxy-androst-4-en-3-one and 16α, 17α-epoxy-estra-1,3,5(10)-trien-3-ol have been prepared on a large scale (200-300 mg amounts) with efficient (i.e. activity of product exactly predictable) introduction of label. The preparative method is very inexpensive, since the tritium derives from tritiated water, the steroid starting materials are readily available, and high yields are obtained in all steps.
Application of Liquid-Liquid Partition Chromatography (LLPC) in the Preparation of Steroid Binding Proteins
1989
Two human serum proteins, i.e. sex hormone binding globulin (h-SHBG) and corticosteroid binding globulin (h-CBG), rat corticosteroid binding globulin (r-CBG), and progesterone binding globulin (PBG) from new guinea pig were purified by the application of three different modes of chromatography. The proteins were purified by affinity chromatography and anion exchange chromatography. Fractions containing the steroid binding proteins were finally purified by liquid-liquid partition chromatography on LiParGel 750 (Merck, Darmstadt, FRG). This Chromatographic sequence clearly separated the steroid binding proteins from other proteins, mainly from serum albumin without a loss of protein and compl…
Quinone reduction and redox cycling catalysed by purified rat liver dihydrodiol/3 alpha-hydroxysteroid dehydrogenase.
1992
A highly active preparation of rat liver dihydrodiol/3 alpha-hydroxysteroid dehydrogenase was obtained using a newly developed, rapid purification scheme involving affinity chromatography on Red Sepharose. Depending on the coenzyme present, the purified enzyme was found to catalyse the oxidation of dihydrodiols and steroids or the reduction of substrates with carbonyl or quinone moieties. Using a wide range of synthetic quinones derived from polycyclic aromatic hydrocarbons (PAHs), we observed a pronounced regioselectivity of the quinone reductase activity. Good substrates were the o-quinones of phenanthrene, benz(a)anthracene, chrysene and benzo(a)pyrene with the quinonoid moiety in the K-…