[Detecting a peak in fraction beta by capillary electrophoresis: interference due to iomeprol].

Capillary zone electrophoresis for analysis of serum proteins, is a technic more and more used in laboratory medicine. We report the case of an interference of iomeprol, radioopaque agent, in a context of acute renal failure and aregenerative anemia in a 53 year-old patient.

Enteral delivery of proteins stimulates protein synthesis in human duodenal mucosa in the fed state through a mammalian target of rapamycin-independent pathway.

Background: Glutamine modulates duodenal protein metabolism in fasted healthy humans, but its effects in a fed state remain unknown.

Objective: We aimed to assess the effects of either glutamine or an isonitrogenous protein mixture on duodenal protein metabolism in humans in the fed state.

Design: Twenty-four healthy volunteers were randomly included in 2 groups.

Glutamine induces nuclear degradation of the NF-κB p65 subunit in Caco-2/TC7 cells.

In the intestine, NF-κB is the main transcription factor involved in the anti-inflammatory effect of glutamine and we previously demonstrated that glutamine via its conversion to glutamate diminished the p65 protein content in Caco-2/TC7 cell nuclei without affecting the stimulating effect of IL-1β on NF-κB [21]. However, the molecular mechanism by which glutamine acts is not established. We therefore tried to identify such a mechanism.

Effects of an enteral glucose supply on protein synthesis, proteolytic pathways, and proteome in human duodenal mucosa.

Background: Previous studies have shown that the glucose supply reduces postoperative insulin resistance and improves patient outcomes. However, the effects of luminal glucose on intestinal mucosal proteins remain unknown.

Objective: We aimed to assess the effects of an enteral glucose supply on protein synthesis, proteolytic pathways, and proteome in human duodenal mucosa.

Influence of leucine on protein metabolism, phosphokinase expression, and cell proliferation in human duodenum1,3.

Background: Although leucine increases protein anabolism through the mammalian target of rapamycin (mTOR) pathway in human muscles, its effects on intestinal mucosal proteins remain unknown.

Objective: We aimed to assess the effects of leucine on duodenal protein metabolism in healthy humans and to elucidate the signaling pathways involved.

Design: Eleven healthy volunteers received for 5 h, on 2 occasions and in random order, an enteral supply of maltodextrins (0.

Effects of essential amino acids or glutamine deprivation on intestinal permeability and protein synthesis in HCT-8 cells: involvement of GCN2 and mTOR pathways.

GCN2 and mTOR pathways are involved in the regulation of protein metabolism in response to amino acid availability in different tissues. However, regulation at intestinal level is poorly documented. The aim of the study was to evaluate the effects of a deprivation of essential amino acids (EAA) or glutamine (Gln) on these pathways in intestinal epithelial cells.

Immunoassay for human serum hemojuvelin.

Background: Hemojuvelin, a critical regulator of iron homeostasis, is involved in the regulation of hepcidin expression and iron homeostasis. It is expressed both as a membrane-bound form and as a soluble one. Serum hemojuvelin can be produced by secretion following furin cleavage or by proteolytic cleavage of the membrane-bound form by matriptase 2 (TMPRSS6).

Amino acid regulation of mammalian gene expression in the intestine.

Some amino acids exert a wide range of regulatory effects on gene expression via the activation of different signalling pathways and transcription factors, and a number of cis elements were shown to respond to changes in amino acid concentration. Particular attention has been paid to the effects of glutamine and arginine, which modulate a number of cell functions through the activation of various pathways in different tissues. In the intestine, appropriate concentrations of both arginine and/or glutamine contribute to facilitate cell proliferation, to limit the inflammatory response and apoptosis, and to modulate intermediary metabolism through specific transcription factors.

Is heparin plasma suitable for the determination of B-type natriuretic peptide on the Beckman-Coulter Access 2?

Background: The use of heparin as an alternative to EDTA in the production of plasma samples is of particular interest for B-type natriuretic peptide (BNP) measurements. Lithium heparin is now widely used for the determination of biochemical parameters, including cardiac markers. The goal of this study was to determine the feasibility of measuring BNP using heparin plasma instead of EDTA plasma with the Access 2 system (Beckman-Coulter).

A diet containing whey protein, glutamine, and TGFbeta modulates gut protein metabolism during chemotherapy-induced mucositis in rats.

Background: Mucositis, a common side effect of chemotherapy, is characterized by compromised digestive function, barrier integrity and immune competence.

Aims: Our aim was to evaluate the impact of a specifically designed diet Clinutren Protect (CP), which contains whey proteins, TGFbeta-rich casein, and free glutamine, on mucositis in rats.

Methods: Mucositis was induced by three consecutive injections (day 0, day 1, day 2) of methotrexate (2.

Control of mammalian gene expression by amino acids, especially glutamine.

Molecular data rapidly accumulating on the regulation of gene expression by amino acids in mammalian cells highlight the large variety of mechanisms that are involved. Transcription factors, such as the basic-leucine zipper factors, activating transcription factors and CCAAT/enhancer-binding protein, as well as specific regulatory sequences, such as amino acid response element and nutrient-sensing response element, have been shown to mediate the inhibitory effect of some amino acids. Moreover, amino acids exert a wide range of effects via the activation of different signalling pathways and various transcription factors, and a number of cis elements distinct from amino acid response element/nutrient-sensing response element sequences were shown to respond to changes in amino acid concentration.

Combined enteral infusion of glutamine, carbohydrates, and antioxidants modulates gut protein metabolism in humans.

Background: Available data suggest that nutrients can affect intestinal protein metabolism, which contributes to the regulation of gut barrier function.

Objective: We aimed to assess whether an oral nutritional supplement (ONS) containing glutamine (as the dipeptide Ala-Gln), carbohydrates, and antioxidants would modulate duodenal protein metabolism in healthy humans.

Design: Thirty healthy control subjects were included and, over a period of 5 h, received by nasogastric tube either saline or ONS providing 11.

Methotrexate induces intestinal mucositis and alters gut protein metabolism independently of reduced food intake.

One of the main secondary toxic side effects of antimitotic agents used to treat cancer patients is intestinal mucositis. This one is characterized by compromised digestive and absorptive functions, barrier integrity, and immune competence. At the same time, food intake is decreased, which may induce intestinal damages per se.

Glutamine and interleukin-1beta interact at the level of Sp1 and nuclear factor-kappaB to regulate argininosuccinate synthetase gene expression.

We previously demonstrated that the expression of the argininosuccinate synthetase (ASS) gene, a key step in nitric oxide production, is stimulated either by interleukin-1beta[Brasse-Lagnel et al. (2005) Biochimie 87, 403-9] or by glutamine in Caco-2 cells [Brasse-Lagnel et al. (2003) J.

Lack of effect of acute enteral arginine infusion on whole-body and intestinal protein metabolism in humans.

Arginine is a conditionally essential amino acid and exerts anabolic effects. We studied the effects of enteral arginine on whole-body and duodenal protein metabolism. Eight healthy fasted volunteers received randomly a 5-hr enteral infusion of either arginine (Arg; 20 g) or an isonitrogenous amino acid mixture (AA) and an IV infusion of [13C]leucine.

Biphasic effect of IL-1beta on the activity of argininosuccinate synthetase in Caco-2 cells. Involvement of nitric oxide production.

The expression of the argininosuccinate synthetase gene (ASS), the limiting enzyme of arginine synthesis, was previously shown to be rapidly induced by a short-term (4 h) exposure to IL-1beta in Caco-2 cells [Biochimie, 2005, 403-409]. The present report shows that, by contrast, a long-term (24 h) exposure to IL-1beta inhibited the ASS activity despite an increase in both specific mRNA level and protein amount, demonstrating a post-translational effect. Concerning the mechanism involved, we demonstrate that the inhibiting effect is linked to the production of nitric oxide (NO) induced by IL-1beta.

IL-1beta stimulates argininosuccinate synthetase gene expression through NF-kappaB in Caco-2 cells.

Argininosuccinate synthetase (ASS) is limiting the arginine synthesis and can be stimulated by immunostimulants. We previously identified a putative NF-kappaB element in the human ASS gene promoter but its functionality was unknown (Husson et al., Eur.

Osmotic stress, a proinflammatory signal in Caco-2 cells.

Hyper- (450 mOsm/l) and hypoosmotic exposure (150 mOsm/l) of Caco-2 cells, a human intestinal epithelial cell line, induced a twofold- and a fivefold increase in the production of IL-8, a constitutively expressed cytokine, respectively. This was observed both in the presence or in the absence of added proinflammatory cytokines and the stimulatory effect of osmotic stress was additive to that induced by the cytokines. Thus, IL-8 production appeared minimal around isoosmolarity, i.

Glutamine stimulates argininosuccinate synthetase gene expression through cytosolic O-glycosylation of Sp1 in Caco-2 cells.

Glutamine stimulates the expression of the argininosuccinate synthetase (ASS) gene at both the level of enzyme activity and mRNA in Caco-2 cells. Searching to identify the pathway involved, we observed that (i) the stimulating effect of glutamine was totally mimicked by glucosamine addition, and (ii) its effect but not that of glucosamine was totally blocked by 6-diazo-5-oxo-l-norleucine (DON), an inhibitor of amidotransferases, suggesting that the metabolism of glutamine to glucosamine 6-phosphate was required. Moreover, run-on assays revealed that glucosamine was acting at a transcriptional level.

Amino acid control of the human glyceraldehyde 3-phosphate dehydrogenase gene transcription in hepatocyte.

Glutamine (Gln) is the most potent of the amino acids (AAs) that regulate liver anabolism, and its effect is similar to that of insulin in peripheral tissues. However, the influence of AAs on regulation of metabolic enzyme-encoding genes is not known at the molecular level in liver. We now report that Gln and some essential AAs activate the human GAPDH gene that codes for GAPDH, a central enzyme of glycolysis and a target for insulin regulation.

Argininosuccinate synthetase from the urea cycle to the citrulline-NO cycle.

Argininosuccinate synthetase (ASS, EC 6.3.4.

Enteral glutamine stimulates protein synthesis and decreases ubiquitin mRNA level in human gut mucosa.

Effects of glutamine on whole body and intestinal protein synthesis and on intestinal proteolysis were assessed in humans. Two groups of healthy volunteers received in a random order enteral glutamine (0.8 mmol.