Search results for "Ethylamines"
showing 10 items of 47 documents
A bacterial metabolite, trimethylamine N-oxide, disrupts the hemostasis balance in human primary endothelial cells but no coagulopathy in mice
2019
: The gut microbial metabolite, trimethylamine N-oxide (TMAO), was previously reported to induce platelet hypersensitivity, which leads to thrombotic risk. However, the molecular mechanism underlying the effects of TMAO on endothelial cells (EC), which is the primary vessel wall contact with the lumen, remains unclear. Here, we investigated the impact of TMAO on procoagulant activity (PCA) in EC and mice, for a possible link between microbiota and coagulation. To test the PCA of TMAO in EC, we performed one-stage clotting assays and converted into PCA. Antitissue factor (TF) antibody was used to test the TF role in PCA. Quantitative PCR was performed to measure the TF, thrombomodulin, IL-6,…
Selective determination of trimethylamine in air by liquid chromatography using solid phase extraction cartridges for sampling.
2004
Abstract The selective determination of trimethylamine (TMA) in air by liquid chromatography is reported. Sampling is effected by flushing air through C18-packed solid-phase extraction (SPE) cartridges at a flow rate of 15 mL/min for 15 min. Next, TMA is desorbed from the cartridges and injected into the chromatographic system. The analyte is then selectively retained on a precolumn ( 20 mm ×2.1 mm i.d., packed with 30 μm, Hypersil C18 phase), and derivatized on-line by injecting 9-fluorenylmethyl chloroformate (FMOC). Finally, the TMA-FMOC derivative is transferred to the analytical column ( 125 mm ×4 mm i.d., LiChrospher 100 RP18, 5 μm), and monitored at 262 nm. The method was applied to …
Calculation of the relative basicities of methylamines in solution
1990
Abstract The relative basicities in solution of the methylamines have been calculated using the model of Miertus, Scrocco and Tomasi to describe the solvent effect. The surface of the cavity is defined with the GEPOL method. The ab initio calculations have been performed using a 4-31G basis set. The relative order is reproduced using a combination of the gas-phase proton affinities obtained with quantum-mechanical methods by Eades, Weil, Dixon and Douglass and the solvation values obtained by us. The results seem to point out that the irregular order is not due to solvent but to basis-set effects.
Synthesis and inhibitory activity of dimethylamino-chalcone derivatives on the induction of nitric oxide synthase.
2002
A series of nine dimethylamino-chalcone derivatives (1,3-diaryl-propenones) was synthesized and screened as potential inhibitors of NO and PGE(2) production in the RAW 264.7 macrophage cell line. 4-Dimethylamino-2',5'-dimethoxychalcone (6) was found to be the most potent and dual inhibitor (IC(50s) in the submicromolar range) of NO and PGE(2) production. 2',6'-Dimethoxylation appeared to be an effective requirement for selective and potent inhibition of nitric oxide synthase induction as it was confirmed by Western blot analysis. Chalcone (6) at 25 mg kg(-1) by oral route, inhibited significantly the formation of oedema in the carrageenan-induced model of inflammation in mice.
Detection of the synthetic drug 4-fluoroamphetamine (4-FA) in serum and urine.
2010
Abstract 4-Fluoroamphetamine (4-FA) was detected in the blood and urine of two individuals suspected for driving under the influence (DUI). The test for amphetamines in urine subjected to immunoassay screening using the CEDIA DAU assay proved positive. Further investigations revealed a 4-FA cross-reactivity of about 6% in the CEDIA amphetamine assay. 4-FA was qualitatively detected in a general unknown screening for drugs using GC/MS in full scan mode. No other drugs or fluorinated phenethylamines were detected. A validated GC/MS method was established in SIM mode for serum analysis of 4-FA with a limit of detection (LOD) of 1 ng/mL and a lower limit of quantification (LLOQ) of 5 ng/mL. Int…
Plasma Metabolites From Choline Pathway and Risk of Cardiovascular Disease in the PREDIMED (Prevention With Mediterranean Diet) Study.
2017
Background-The relationship between plasma concentrations of betaine and choline metabolism and major cardiovascular disease (CVD) end points remains unclear. We have evaluated the association between metabolites from the choline pathway and risk of incident CVD and the potential modifying effect of Mediterranean diet interventions. Methods and Results-We designed a case-cohort study nested within the PREDIMED (Prevention With Mediterranean Diet) trial, including 229 incident CVD cases and 751 randomly selected participants at baseline, followed up for 4.8 years. We used liquid chromatography-tandem mass spectrometry to measure, at baseline and at 1 year of follow-up, plasma concentrations …
Choline is a Selective Agonist of α7 Nicotinic Acetylcholine Receptors in the Rat Brain Neurons
1998
In the present study, we demonstrate that choline, a precursor of acetylcholine (ACh) and a product of acetylcholine hydrolysis by acetylcholinesterase (AChE), acts as an efficient and relatively selective agonist of alpha7-containing nicotinic acetylcholine receptors (nAChR) in neurons cultured from the rat hippocampus, olfactory bulb and thalamus as well as in PC12 cells. Choline was able to activate postsynaptic and presynaptic alpha7 nAChRs, with the latter action resulting in the release of other neurotransmitters. Although choline was approximately one order of magnitude less potent than ACh (EC50 of 1.6 mM for choline and 0.13 mM for ACh), it acted as a full agonist at alpha7 nAChRs.…
The amelioration of olfactory acuity upon sexual maturation might affect food preferences.
2009
Upon sexual maturation, olfactory acuity in women ameliorates and starts oscillating across the cycle. During ovulation, mean olfactory threshold is 30 times lower than during bleeding. Interestingly, menstruated women undergo maleodorant trimethylaminuria. We argued that olfactory amelioration during ovulation might concur to a mating strategy, whereas olfactory impairment during bleeding might protect women against self-refusal. Testosterone and its 17β-estradiol derivative might be responsible for the synchronization of these menstrual events. Furthermore, we posed the question whether olfactory detection amelioration upon sexual maturation might provoke a change in food preferences, for…
Plasma trimethylamine-N-oxide and related metabolites are associated with type 2 diabetes risk in the Prevención con Dieta Mediterránea (PREDIMED) tr…
2018
Background The role of trimethylamine-N-oxide (TMAO) in type 2 diabetes (T2D) is currently partially understood and controversial. Objective The aim of this study was to investigate associations between TMAO and related metabolites with T2D risk in subjects at high risk of cardiovascular disease. Design This is a case-cohort design study within the Prevencion con Dieta Mediterranea (PREDIMED) study, with 251 incident T2D cases and a random sample of 694 participants (641 noncases and 53 overlapping cases) without T2D at baseline (median follow-up: 3.8 y). We used liquid chromatography-tandem mass spectrometry to measure plasma TMAO, l-carnitine, betaine, lyso-phosphatidylcholine (LPC) and l…
Histamine-sensitive adenylate cyclase of human gastric mucosa: a model for H2-receptor excitation.
1978
Recent studies revealed that human gastric mucosa contains a histamine-sensitive adenylate cyclase which is almost completely localized within the acid-secreting area of the stomach. In an attempt to further characterize the effector system of histamine’s action, we compared the effects of H 1 — and H 2-receptor agonists upon the adenylate cyclase in human fundic gastric mucosa.