Search results for "Acetates"

The construction of open GdIII metal–organic frameworks based on methanetriacetic acid: New objects with an old ligand

2010

11 páginas, 11 figuras, 2 esquemas.-- et al.

Coupling of Contact Sensitizers to Thiol Groups is a Key Event for the Activation of Monocytes and Monocyte-Derived Dendritic Cells

2003

Strong contact sensitizers are able to induce distinct signal transduction mechanisms in antigen-presenting cells by coupling to cell proteins. The predominant target structures of haptens are thought to be thiol and amino groups in cysteine and lysine residues. We studied whether coupling of small reactive chemicals to thiol or amino groups might be responsible for the activation of monocytes and mature monocyte-derived dendritic cells. Human peripheral blood mononuclear cells were stimulated in vitro with subtoxic concentrations of the strong haptens 5-chloro-2-methylisothiazolinone plus 2-methylisothiazolinone and 2, 4, 6-trinitrochlorobenzene, the thiol-reactive reagents N-hydroxymaleim…

Extracellular oxidoreduction potential modifies carbon and electron flow in Escherichia coli.

2000

ABSTRACT Wild-type Escherichia coli K-12 ferments glucose to a mixture of ethanol and acetic, lactic, formic, and succinic acids. In anoxic chemostat culture at four dilution rates and two different oxidoreduction potentials (ORP), this strain generated a spectrum of products which depended on ORP. Whatever the dilution rate tested, in low reducing conditions (−100 mV), the production of formate, acetate, ethanol, and lactate was in molar proportions of approximately 2.5:1:1:0.3, and in high reducing conditions (−320 mV), the production was in molar proportions of 2:0.6:1:2. The modification of metabolic fluxes was due to an ORP effect on the synthesis or stability of some fermentation enzy…

Effects of peroxisome proliferator-activated receptor alpha activation on pathways contributing to cholesterol homeostasis in rat hepatocytes

2004

International audience; Peroxisome proliferator-activated receptor alpha (PPARa) activation by fibrates controls expression of several genes involved in hepatic cholesterol metabolism. Other genes could be indirectly controlled in response to changes in cellular cholesterol availability. To further understand how fibrates may affect cholesterol synthesis, we investigated in parallel the changes in the metabolic pathways contributing to cholesterol homeostasis in liver. Ciprofibrate increased HMG-CoA reductase and FPP synthase mRNA levels in rat hepatocytes, together with cholesterogenesis from [14C] acetate and [3H] mevalonate. The up-regulation observed in fenofibrate- and WY-14,643-treate…

l-[3H]lysine binding to rat retinal membrane: II. effect of kainic acid,d,l-?-aminoadipic acid, iodoacetic acid, and modification by dark-exposure

1986

The rat retina and the different brain regions contain membranes sites that bindl-lysine in the nanomolar range. These binding sites undergo changes in different experimental conditions, thus: I) intraocular injection of kainic acid induces a reduction of the density ofl-lysine binding sites, II)d,l-α-aminoadipic acid injected into the eye enhances both kinetic parameters (Bmax andKd) ofl-[3H]lysine binding sites, III) the intraperitoneal injection of iodoacetic acid decreases the sensitivity for its ligand binding sites, and IV) the exposure to darkness of the rats reducesl-[3H]lysine binding in the retina, thalamus, hypothalamus and superior colliculus, but not in the occipital cortex; su…

Early colon cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

2013

An olfactory receptor for food-derived odours promotes male courtship in Drosophila.

2011

International audience; Many animals attract mating partners through the release of volatile sex pheromones, which can convey information on the species, gender and receptivity of the sender to induce innate courtship and mating behaviours by the receiver. Male Drosophila melanogaster fruitflies display stereotyped reproductive behaviours towards females, and these behaviours are controlled by the neural circuitry expressing male-specific isoforms of the transcription factor Fruitless (FRU(M)). However, the volatile pheromone ligands, receptors and olfactory sensory neurons (OSNs) that promote male courtship have not been identified in this important model organism. Here we describe a novel…

Staphylococcal α-toxin provokes coronary vasoconstriction and loss in myocardial contractility in perfused rat hearts: Role of thromboxane generation

2000

Background —Cardiac performance is severely depressed in septic shock. Endotoxin has been implicated as the causative agent in Gram-negative sepsis, but similar abnormalities are encountered in Gram-positive sepsis. We investigated the influence of the major exotoxin of Staphylococcus aureus, staphylococcal α-toxin, in isolated perfused rat hearts. Methods and Results —α-Toxin 0.25 to 1 μg/mL caused a dose-dependent increase in coronary perfusion pressure that more than doubled. In parallel, we noted a decrease in left ventricular developed pressure and the maximum rate of left ventricular pressure rise (dP/dt max ), dropping to a minimum of <60% of control. These changes were accompani…

Chronic Moderate Hyperammonemia Impairs Active and Passive Avoidance Behavior and Conditional Discrimination Learning in Rats

2000

Abstract The cerebral dysfunction associated with hepatic encephalopathy is generally considered to have hyperammonemia as one of its main causes. Hyperammonemia impairs the neuronal glutamate–nitric oxide–cyclic GMP pathway and the induction of NMDA receptor-dependent long-term potentiation in the hippocampus. We studied the performance of pre/neonatally and postnatally exposed rats to hyperammonemia on active avoidance, passive avoidance, and conditional discrimination tasks. Pre/neonatal hyperammonemia slowed learning of active avoidance behaviors and impaired memory for the passive avoidance task while postnatal hyperammonemia impaired learning on the conditional discrimination task. Hy…

Antiulcer activity of Cyperus alternifolius in relation to its UPLC-MS metabolite fingerprint: A mechanistic study

2019

Abstract Background Gastric ulcer is one of the main prevalent gastrointestinal multi-etiological disorders with many associated complications and adverse effects. Our aim was to develop safer antiulcer therapies based on methanol or ethyl acetate extracts of tubers and aerial parts from Cyperus alternifolius. Methods Gastric ulceration was experimentally generated by administration of single oral doses of indomethacin (30 mg/kg) to fasted rats. The animals received methanol or ethyl acetate extracts of C. alternifolius tuber and methanol or ethyl acetate extracts of aerial parts at two dose levels (50 or 100 mg/kg). Ranitidine (50 mg/kg) was used as standard anti-ulcer drug. After 4 h, the…