Delta Hemolysin and Phenol-Soluble Modulins, but Not Alpha Hemolysin or Panton-Valentine Leukocidin, Induce Mast Cell Activation.

Mast cells are located at host interfaces, such as the skin, and contribute to the first-line defense against pathogens by releasing soluble mediators, including those that induce itching and scratching behavior. Here, we show that delta-hemolysin (Hld) and phenol soluble modulins (PSMs) PSMα1 and PSMα3, but not alpha-hemolysin (Hla) or Panton-Valentine leukocidin (PVL), induce dose-dependent tryptase, and lactate dehydrogenase (LDH) release by the HMC-1 human mast cell line. Using supernatants from isogenic strains, we verified that tryptase and LDH release was Hld- and PSMα-dependent.

Dietary polyunsaturated fatty acids and heme iron induce oxidative stress biomarkers and a cancer promoting environment in the colon of rats.

The end products of polyunsaturated fatty acid (PUFA) peroxidation, such as malondialdehyde (MDA), 4-hydroxynonenal (HNE), and isoprostanes (8-iso-PGF2α), are widely used as systemic lipid oxidation/oxidative stress biomarkers. However, some of these compounds have also a dietary origin. Thus, replacing dietary saturated fat by PUFAs would improve health but could also increase the formation of such compounds, especially in the case of a pro-oxidant/antioxidant imbalanced diet.

Phenol-soluble modulin α induces G2/M phase transition delay in eukaryotic HeLa cells.

Staphylococcus aureus is a gram-positive bacterium responsible for a wide range of infections. Host cell cycle alteration is a sophisticated mechanism used by pathogens to hijack the defense functions of host cells. We previously demonstrated that S.

Malondialdehyde adduct to hemoglobin: a new marker of oxidative stress suitable for full-term and preterm neonates.

Oxidative stress may play a central role in the onset of many diseases during the neonatal period. Malondialdehyde (MDA) is a marker of lipid peroxidation. The aim of this study was to evaluate a new marker, the malondialdehyde adduct to hemoglobin (MDA-Hb), which is measured in red blood cells (RBCs) and thus does not require that an additional blood sample be drawn.

Adduct of malondialdehyde to hemoglobin: a new marker of oxidative stress that is associated with significant morbidity in preterm infants.

Preterm infants (PT) are particularly exposed to oxidative stress (OS), and a blood-sparing marker, the malondialdehyde adduct to hemoglobin (MDA-Hb), may be useful to accurately assess OS-related neonatal morbidity. In a prospective study, MDA-Hb concentrations were assessed in two groups of PT, one with and one without severe neonatal morbidity as estimated by a composite index of severe morbidity (ISM). All PT born in a single tertiary care NICU (<32 weeks and birth weight <1500 g) were consecutively included.

Estimating glomerular filtration rate in kidney transplant recipients: performance over time of four creatinine-based formulas.

Background: The management of kidney transplant recipients requires accurate estimate of glomerular filtration rate (GFR). This study aims at evaluating the performance of four creatinine-based formulas for estimating the GFR (estimated GFR) in this population.

Methods: Performances of Cockcroft and Gault formula, Modification of Diet in Renal Disease (MDRD) simplified formula, Chronic Kidney Disease Epidemiology Collaboration formula, and Nankivell formula were assessed compared with inulin clearance taken as the gold standard for measuring GFR (measured GFR).

Influence of vitamins, trace elements, and iron on lipid peroxidation reactions in all-in-one admixtures for neonatal parenteral nutrition.

Background: The purpose of this study was to evaluate the effect of vitamins, trace elements, or iron on lipid peroxidation in all-in-one parenteral nutrition (PN) admixtures for preterm neonates.

Methods: Malondialdehyde (MDA) concentrations were analyzed over a 24-hour period (H1-H24) in lipid-containing PN solutions that have a composition identical to that used in the routine clinical care of preterm infants. Six different solutions were prepared and evaluated when exposed to ambient light and light-protected conditions as follows: control (without vitamins [Vit], trace elements [TE], or iron [Fe] [Vit-TE-Fe-]), solution 1 (Vit+TE+Fe-), solution 2 (Vit+TE-Fe-), solution 3 (Vit-TE+Fe-), solution 4 (Vit-TE-Fe+), and solution 5 (Vit+TE+Fe+).

Lipid peroxidation in all-in-one admixtures for preterm neonates: impact of amount of lipid, type of lipid emulsion and delivery condition.

Aim: To evaluate the effect of lipid emulsion composition and delivery condition on lipid peroxidation in typical all-in-one parenteral admixtures for preterm neonates.

Methods: Malonedialdehyde (MDA) concentrations were assessed in different all-in-one admixtures. We evaluated the effects of fat blend (three lipid emulsions) and the amount of lipids, as well as the effects of protecting bags and/or tubing from ambient light and storage for 72 h.

Preserved residual renal function is associated with lower oxidative stress in peritoneal dialysis patients.

Background: Residual renal function (RRF) correlates with survival in peritoneal dialysis (PD). We investigated the association between oxidative stress and RRF in PD.

Methods: Adequacy of dialysis, total and free malondialdehydes (MDA), and lipid hydroperoxides (LHP) were obtained from 23 stable PD patients.

Structural equations to model relationships between pulmonary function, fatty acids and oxidation in cystic fibrosis.

Objective: To illustrate the advantages of structural equation models in biomedical research using the complex example of cystic fibrosis.

Material And Methods: 595 blood samples from 312 patients were tested. The model studied the effects of age, BMI and clinical condition on seven major latent variables: pulmonary function, lipid oxidation status, vitamins A and E, glutathione, carotenoids, two essential fatty acids and arachidonic acid.

Sensitization by docosahexaenoic acid (DHA) of breast cancer cells to anthracyclines through loss of glutathione peroxidase (GPx1) response.

Docosahexaenoic acid (DHA, a lipid of marine origin) has been found to enhance the activity of several anticancer drugs through an oxidative mechanism. To examine the relation between chemosensitization by DHA and tumor cells antioxidant status, we used two breast cancer cell lines: MDA-MB-231, in which DHA increases sensitivity to doxorubicin, and MCF-7, which does not respond to DHA. Under these conditions, reactive oxygen species (ROS) level increased on anthracycline treatment only in MDA-MB-231.

Bacterial adhesion to conventional hydrogel and new silicone-hydrogel contact lens materials.

Background: As bacterial adhesion to contact lenses may contribute to the pathogenesis of keratitis, the aim of our study was to investigate in vitro adhesion of clinically relevant bacteria to conventional hydrogel (standard HEMA) and silicone-hydrogel contact lenses using a bioluminescent ATP assay.

Methods: Four types of unworn contact lenses (Etafilcon A, Galyfilcon A, Balafilcon A, Lotrafilcon B) were incubated with Staphylococcus epidermidis (two different strains) and Pseudomonas aeruginosa suspended in phosphate buffered saline (PBS). Lenses were placed with the posterior surface facing up and were incubated in the bacterial suspension for 4 hours at 37 degrees C.

Polyunsaturated fatty acids modulate NOX 4 anion superoxide production in human fibroblasts.

The strong ROS (reactive oxygen species) production, part of an antioxidant response of human fibroblasts triggered by DHA (docosahexaenoic acid; C(22:6,n-3), served as a model for deciphering the relative contribution of NOX (NADPH oxidase) to ROS production, as the role of this enzymatic system remains controversial. Using hydroxyethidium fluorescence for fibroblast ROS production, RT (reverse transcriptase)-PCR for NOX 4 mRNA quantification and mRNA silencing, we show that ROS production evolves in parallel with the catalytic activity of NOX and is suppressed by siNOX 4 (small interference oligonucleotide RNA directed against NOX 4) silencing. Apocynin and plumbagin, specific inhibitors of NOX, prevent ROS production in this cellular model and confirm the role of NOX 4 for this production.

Fatty acids platelets and oxidative markers following intravenous n-3 fatty acids administration in cystic fibrosis: An open pilot observational study.

Background: An imbalance in the ratio of arachidonic acid and docosahexaenoic acid (DHA) was found in cystic fibrosis (CF) affected tissues and was suggested to promote inflammation. Several studies have shown that the long chain n-3 fatty acids reduced inflammatory activity while others have highlighted prooxidant activity of DHA at high concentrations. The aim of our study was to evaluate the effects of an intravenous fish-oil emulsion enriched with n-3 FA in patients with CF on plasma and platelet FA composition and peroxidation markers.

Conjugated linoleic acid, unlike other unsaturated fatty acids, strongly induces glutathione synthesis without any lipoperoxidation.

Enhancement of the redox status of cells is a cytoprotective strategy against oxidative damage. We recently showed that DHA upregulates glutathione (GSH) content via an induction of its related enzymes gamma-glutamylcysteine ligase and glutathione reductase. In the present study, we investigated the effects of eight other fatty acids on the redox status and lipid peroxidation of human fibroblasts.

Evaluation of IGL-1 preservation solution using an orthotopic liver transplantation model.

Aim: To compare, in a pig liver transplantation model, the protective effect of UW with that of IGL-1, a high-sodium preservation solution containing polyethylene glycol (PEG) as an oncotic supply.

Methods: All livers were harvested and grafted orthotopically according to standard techniques. The livers were washed out and preserved for 7 h in IGL-1 (n = 6) or in UW solution (n = 7) at 4 degree centigrade.

Systemic markers of the redox balance and apolipoprotein E polymorphism in atherosclerosis: the relevance for an integrated study.

Prospective studies have demonstrated that an imbalance between oxidative damage and antioxidative protection can play a role in the development and progression of atherosclerosis. Also, genotypes with the apolipoprotein E epsilon4 allele have been associated with an increase risk for this pathology. Based on this knowledge, the aim of this study was to evaluate indicators of the redox balance, trace elements, and apolipoprotein E allelic profile in subjects from the Lisbon population with clinically stable atherosclerosis, at risk for atherosclerotic events, and in healthy subjects for comparison.

[Influence of hemodialysis on total and free malondialdehyde measured by a new HPLC method].

Accurate evaluation of oxidative stress is needed for patients on chronic hemodialysis (HD), as cardiovascular risk level seems related to it. Oxidative stress is often evaluated by measuring an end product of lipoperoxidation named malondialdehyde (MDA). However, the most common technique for measuring MDA, the Thio Barbituric Acid Reactive Substances method (TBARS), is known to be sensitive but poorly specific.

Docosahexaenoic acid enhances the antioxidant response of human fibroblasts by upregulating gamma-glutamyl-cysteinyl ligase and glutathione reductase.

The chemopreventive effects of dietary n-3 PUFA in various pathologies has so far remained controversial, and we were interested in studying their potential influence on cell redox status. DHA (22 : 6n-3), a typical highly unsaturated n-3 PUFA, was used at 30 micromol/l in a model of human fibroblast cell culture. A dose-response effect, roughly linear, was checked for DHA between 0 and 60 micromol/l, and was accompanied by a large increase in intracellular GSH content.

Dihydroxynonene mercapturic acid, a urinary metabolite of 4-hydroxynonenal, as a biomarker of lipid peroxidation.

The objective of our study was to compare the information obtained through the use of three different urinary biomarkers of lipoperoxidation during the time course of a bromotrichloromethane (BrCCl3) induced oxidative stress in rats. These biomarkers were malondialdehyde (MDA) measured by LC/MS after derivatization, the isoprostane 8-iso-PGF2alpha measured by enzyme immunoassay and 1,4-dihydroxynonene mercapturic acid (DHN-MA), the major 4-hydroxynonenal urinary metabolite [1], measured by LC-MS. Male Wistar rats received a single dose of 100 microL/kg BrCCl3 per os and lipid peroxidation was estimated every day for a 4-day-period after treatment.

Differential sensitization of cancer cells to doxorubicin by DHA: a role for lipoperoxidation.

Polyunsaturated fatty acids have been reported to enhance the cytotoxic activity of several anticancer drugs. In the present study, we observed that doxorubicin chemosensitization of breast cancer cell lines by docosahexaenoic acid (DHA, a long-chain omega-3 polyunsaturated fatty acid) was cell-line selective, affecting MDA-MB-231 and MCF-7 dox (a doxorubicin-resistant cell line) but not the parental MCF-7 cell line. DHA supplementation led to an increase in membrane phospholipid DHA level, but did not induce changes in intracellular [(14)C]doxorubicin accumulation.

[Evaluation of IGL-1, a new organ preservation solution: preclinical results in renal transplantation].

Introduction: Renal ischaemia and reperfusion lesions partly determine short-term and long-term graft survival. Organ preservation conditions appear to play a decisive role. This article presents the preclinical experimental results obtained in renal transplantation with an extracellular organ preservation solution, in which polyethylene glycol (PEG) is used as colloid.

Ion-pairing reversed-phase liquid chromatography/electrospray ionization mass spectrometric analysis of 76 underivatized amino acids of biological interest: a new tool for the diagnosis of inherited disorders of amino acid metabolism.

Seventy-six molecules of biological interest for the diagnosis of inherited disorders of amino acids (AA) metabolism have previously been demonstrated to be detectable in electrospray ionization tandem mass spectrometry (ESI-MS/MS) positive mode without derivatization. Reversed-phase liquid chromatography (RPLC) separation on different C18 columns using various perfluorinated carboxylic acids as ion-pairing agents has been found suitable for coupling with MS/MS, and for the separation of AA. A new procedure was optimized in order to replace the usual ion-exchange chromatographic, post-column ninhydrin derivatization, time-consuming routine method.

Kinetic measurement by LC/MS of gamma-glutamylcysteine ligase activity.

gamma-Glutamylcysteine ligase (GCL) combines cysteine and glutamate through its gamma carboxyl moiety as the first step for glutathione (GSH) synthesis and is considered to be the rate-limiting enzyme in this pathway. The enzyme is a heterodimer, with a heavy catalytic and a light regulatory subunit, which plays a critical role in the anti-oxidant response. Besides the original method of Seelig designed for the measurement of a purified enzyme, few endpoint methods, often unrefined, are available for measuring it in complex biological samples.

Effect of IGL-1, a new preservation solution, on kidney grafts (a pre-clinical study).

Ischemia-reperfusion injury conditions short-term and long-term graft function. The effects of the inversion of K+ and Na+ concentrations and substitution with polyethylene glycol for hydroxyethyl starch in University of Wisconsin (K-UW) solution were evaluated in isolated perfused rat kidneys and in autotransplanted pig kidneys. In the rat model kidneys were cold-stored for 24 h in K-UW or Na-UW or Na-PEG UW solutions (IGL-1 solution).