Search results for "cyclic"
showing 10 items of 2439 documents
Beta-MSH inhibits brain inflammation via MC(3)/(4) receptors and impaired NF-kappaB signaling.
2005
The anti-inflammatory effects of melanocortin peptides have been demonstrated in different inflammation models. This is the first report describing the molecular mechanisms for the beta-MSH-induced suppression of bacterial lipopolisaccharide (LPS)-caused brain inflammation. We found that beta-MSH suppresses LPS-induced nuclear translocation of the transcription factor NF-kappaB, and inhibits the expression of inducible nitric oxide synthase, and the following nitric oxide overproduction in the brain, in vivo. Moreover, administering the preferentially MC(4) receptor selective antagonist HS014 blocked completely these effects, suggesting a tentative MC(4) receptor mediated mechanism of actio…
Conversion of biliverdin to bilirubin by biliverdin reductase contributes to endothelial cell protection by heme oxygenase-1—evidence for direct and …
2009
Heme oxygenase-1 (HO-1) is highly protective in various pathophysiological states such as cardiovascular and neurodegenerative diseases. HO-1-derived bilirubin is an efficient scavenger of reactive oxygen and nitrogen species (RONS). It remains to determine whether conversion of biliverdin to bilirubin is an essential step for HO-1-conferred protection of endothelial cells. RONS scavenging activities of biliverdin versus bilirubin were assessed by different RONS generating systems and detection techniques. We also silenced the biliverdin reductase (BVR) or HO-1 gene in cultured primary human endothelial cells (HUVECs) and measured the effect on RONS formation upon stimulation with lipopolys…
Membrane fluidity and the surface properties of the lipid bilayer: ESR experiment and computer simulation
2009
Penetration of the liposome membranes formed in the gel phase from DPPC (DPPC liposomes) and in the liquid-crystalline phase from egg yolk lecithin (EYL liposomes) by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) and 16 DOXYL (2-ethyl-2-(15-methoxy-oxopentadecyl)-4,4-dimethyl-3-oxazolidinyloxy) spin probes has been investigated. The penetration process was followed by 120 hours at 24(0)C, using the electron spin resonance (ESR) method. The investigation of the kinetics of the TEMPO probe building into the membranes of both types of liposomes revealed differences appearing 30 minutes after the start of the experiment. The number of TEMPO particles built into the EYL liposome membranes beg…
Enantioselective α-alkylation of unsaturated carboxylic acids using a chiral lithium amide
2001
Abstract The regio- and stereochemistry of the alkylation of dienediolates from unsaturated carboxylic acids with benzylic halides, which often results in mixtures of isomers, can be controlled by means of changes in the lithium amide, allowing the α-regioisomer to be obtained as the major diastereoisomer. In addition, when chiral amines are used, moderate enantiomeric excesses can be attained.
ChemInform Abstract: Enantioselective α-Alkylation of Unsaturated Carboxylic Acids Using a Chiral Lithium Amide.
2010
Abstract The regio- and stereochemistry of the alkylation of dienediolates from unsaturated carboxylic acids with benzylic halides, which often results in mixtures of isomers, can be controlled by means of changes in the lithium amide, allowing the α-regioisomer to be obtained as the major diastereoisomer. In addition, when chiral amines are used, moderate enantiomeric excesses can be attained.
Non invasive blood flow measurement in cerebellum detects minimal hepatic encephalopathy earlier than psychometric tests
2013
AIM: To assess whether non invasive blood flow measurement by arterial spin labeling in several brain regions detects minimal hepatic encephalopathy. METHODS: Blood flow (BF) was analyzed by arterial spin labeling (ASL) in different brain areas of 14 controls, 24 cirrhotic patients without and 16 cirrhotic patients with minimal hepatic encephalopathy (MHE). Images were collected using a 3 Tesla MR scanner (Achieva 3T-TX, Philips, Netherlands). Pulsed ASL was performed. Patients showing MHE were detected using the battery Psychometric Hepatic Encephalopathy Score (PHES) consisting of five tests. Different cognitive and motor functions were also assessed: alterations in selective attention we…
The lipid lowering drug lovastatin protects against doxorubicin-induced hepatotoxicity.
2012
Liver is the main detoxifying organ and therefore the target of high concentrations of genotoxic compounds, such as environmental carcinogens and anticancer drugs. Here, we investigated the usefulness of lovastatin, which is nowadays widely used for lipid lowering purpose, as a hepatoprotective drug following the administration of the anthracycline derivative doxorubicin in vivo. To this end, BALB/c mice were exposed to either a single high dose or three consecutive low doses of doxorubicin. Acute and subacute hepatotoxicities were analyzed with or without lovastatin co-treatment. Lovastatin protected the liver against doxorubicin-induced acute pro-inflammatory and pro-fibrotic stress respo…
Flexural behavior of external beam-column reinforced concrete assemblages externally strengthened with steel cages
2016
In this paper, an experimental study referring to the flexural behavior of full-scale external beam-column joints externally strengthened with steel angles and strips and subjected to cyclic reversal loading is presented. One control specimen and five other specimens having the same characteristics as the control specimen but strengthened with steel angles and strips along beams and columns, and characterized by different configurations of strengthening in the critical regions, were tested. The control specimen was designed with a weak column and strong beam to reproduce the most common cases of old frame structures in the Mediterranean area, which were designed only for gravity loads and a…
Local nearrings with dihedral multiplicative group
2004
AbstractA not necessarily zero-symmetric nearring R with a unit element is called local if the set of all non-invertible elements of R forms a subgroup of the additive group of R. It is proved that every local nearring whose multiplicative group is dihedral is finite and its additive group is either a 3-group of order at most 9 or a 2-group of order at most 32.
Predicting the bioaccumulation of polyaromatic hydrocarbons and polychlorinated biphenyls in benthic animals in sediments
2016
There were two main objectives in this study. The first was to compare the accuracy of different prediction methods for the chemical concentrations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the organism, based on the measured chemical concentrations existing in sediment dry matter or pore water. The predicted tissue concentrations were compared to the measured ones after 28-day laboratory test using oligochaeta worms (Lumbriculus variegatus). The second objective was to compare the bioaccumulation of PAHs and PCBs in the laboratory test with the in situ bioaccumulation of these compounds. Using the traditional organic carbon-water partitioning model, tissue…