Search results for "DAS"
showing 10 items of 4164 documents
Giant liposomes as model membranes for immunological studies: spontaneous insertion of purified K1-antigen (poly-alpha-2,8-NeuAc) of Escherichia coli.
1990
A flow chamber has been constructed to use giant liposomes (diameter 5-50 microns) as model membranes for immunological studies and other experiments involving the interaction with water-soluble compounds. As an example of immunological importance, the insertion of purified K-antigen from Escherichia coli K1 has been studied. Despite its large hydrophilic part (poly-alpha-2,8-NeuAc), which is capped at its potential reducing end with phosphatidic acid acting as a lipid anchor group, this water-soluble material is readily incorporated into liposomal membranes of dimyristoylphosphatidylcholine (DMPC). The incorporation has been proven by immunofluorescence using a FITC-labeled monoclonal anti…
Mucolipidosis I: increased sialic acid content and deficiency of an alpha-N-acetylneuraminidase in cultured fibroblasts.
1977
Abstract Extracts of fibroblasts derived from a patient with mucolipidosis I exhibited a fivefold increase in sialic acid content as compared to those of normal cells. About 80% of this sialic acid was linked to other molecules. Using neuraminlactose as a substrate, mucolipidosis I fibroblasts were found to be severely deficient in an “acid” α-N-acetylneuraminidase. Since other lysosomal hydrolase activities were normal, we hypothesize that the basic metabolic lesion in mucolipidosis I lies in a defective degradation of sialic acid-containing compounds due to the genetic deficiency of a neuraminidase.
Mutation of the important Tyr-33 residue of chicken avidin: functional and structural consequences
2002
The strong interaction between avidin and biotin is so tight (dissociation constant 10-15M) that conditions usually sufficient for protein denaturing fail to dislodge biotin from the avidin—biotin complex. This kind of irreversible binding hinders the use of avidin in applications such as affinity purification or protein immobilization. To address this concern, we have constructed a series of mutants of the strategically positioned Tyr-33 in order to study the role of this residue in biotin binding, and to create avidin variants with more reversible ligand-binding properties. Unexpectedly, an avidin mutant in which Tyr-33 was replaced with phenylalanine (Avm-Y33F) displayed similar biotin-b…
Bis(hydroxyphenyl)methane-bisphenol F-metabolism by the HepG2 human hepatoma cell line and cryopreserved human hepatocytes
2011
author cannot archive publisher's version/PDF; International audience; Bisphenol F (BPF) is present in the environment and as a contaminant of food. Humans may, therefore, be exposed to BPF, and an assessment of this risk is required. BPF has been shown to have genotoxic and endocrine-disruptor properties in a human hepatoma cell line (HepG2), which is a model system for studies of xenobiotic toxicity. In this study, we investigated the ability of HepG2 cells to biotransform BPF, because metabolism may affect the observed effects of BPF, and we compared this metabolic capacity with that of human hepatocytes. Cells were incubated for 24 hours with [(3)H]-BPF. The culture medium was then conc…
EVOO's Effects on Incretin Production: Is There a Rationale for a Combination in T2DM Therapy?
2022
Type 2 diabetes mellitus (T2DM) is a serious public health concern as it is one of the most common chronic diseases worldwide due to social and economic developments that have led to unhealthy lifestyles, with a considerable impact both in terms of morbidity and mortality. The management of T2DM, before starting specific therapies, includes cornerstones such as healthy eating, regular exercise and weight loss. Strict adherence to the Mediterranean diet (MedDiet) has been related to an inverse association with the risk of T2DM onset, as well as an improvement in glycaemic control; in particular, thanks to the consumption of extra virgin olive oil (EVOO). Agonists of gut-derived glucagon-like…
Basic knowledge of social hierarchies and physiological profile of reared sea bass Dicentrarchus labrax (L.).
2019
The effects of social hierarchies (dominant/subordinate individuals), such as aggressiveness, feeding order, and territoriality, are some of the characteristics used for describing fish behaviour. Social hierarchy patterns are still poorly understood in European-reared sea bass (Dicentrarchus labrax). In this work, we examine the social interactions among captive fish integrating behavioural and physiological profiles. Groups of three fish with EMG (electromyogram) radio transmitters were monitored for two weeks via video recording. Plasma levels of cortisol, glucose, lactate and lysozyme as well as haematological parameters such as haemoglobin, haematocrit and RBCC (red blood cell count) w…
Beneficial Effect of Docosahexanoic Acid and Lutein on Retinal Structural, Metabolic, and Functional Abnormalities in Diabetic Rats
2009
To assess the effect of docosahexanoic acid (DHA) and lutein (both compounds with anti-inflammatory and antioxidant properties) on experimental diabetic retinopathy.Male Wistar rats were studied: non-diabetic controls, untreated diabetic controls, and diabetic rats were treated with DHA and lutein or the combination of DHA + insulin and lutein + insulin for 12 weeks. Oxidative stress and inflammatory markers, apoptosis, and functional tests were studied to confirm biochemical and functional changes in the retina of diabetic rats. Malondialdehyde (MDA), glutathione concentrations (GSH), and glutathione peroxidase activity (GPx) were measured as oxidative stress markers. TUNEL assay and caspa…
Hypothalamic reactive oxygen species are required for insulin-induced food intake inhibition: an NADPH oxidase-dependent mechanism
2009
1939-327X (Electronic) Journal Article Research Support, Non-U.S. Gov't; OBJECTIVE: Insulin plays an important role in the hypothalamic control of energy balance, especially by reducing food intake. Emerging data point to a pivotal role of reactive oxygen species (ROS) in energy homeostasis regulation, but their involvement in the anorexigenic effect of insulin is unknown. Furthermore, ROS signal derived from NADPH oxidase activation is required for physiological insulin effects in peripheral cells. In this study, we investigated the involvement of hypothalamic ROS and NADPH oxidase in the feeding behavior regulation by insulin. RESEARCH DESIGN AND METHODS: We first measured hypothalamic RO…
POSTPRANDIAL HYPERGLYCEMIA IS A DETERMINANT OF PLATELET ACTIVATION IN EARLY 2 DIABETES MELLITUS
2010
BACKGROUND: Chronic hyperglycemia is a major contributor to in vivo platelet activation in diabetes mellitus. OBJECTIVES: To evaluate the effects of acarbose, an alpha-glucosidase inhibitor, on platelet activation and its determinants in newly diagnosed type 2 diabetic patients. METHODS: Forty-eight subjects (26 males, aged 61 +/- 8 years) with early type 2 diabetes (baseline hemoglobin A(1c) < or = 7% and no previous hypoglycemic treatment) were randomly assigned to acarbose up to 100 mg three times a day or placebo, and evaluated every 4 weeks for 20 weeks. The main outcome measures were urinary 11-dehydro-thromboxane (TX)B(2) (marker of in vivo platelet activation) and 8-iso-prostaglandi…
Time course of asymmetric dimethylarginine (ADMA) and oxidative stress in fructose-hypertensive rats: A model related to metabolic syndrome
2011
Asymmetric dimethylarginine (ADMA) is an endogenous modulator of endothelial function and oxidative stress, and increased levels of this molecule have been reported in some metabolic disorders and cardiovascular diseases. The aim of this work was to analyze the time course of dimethylarginine compounds and oxidative stress levels and the relationship between these and cardiovascular function in fructose-hypertensive rats.90 male Sprague-Dawley rats were randomized into 2 groups, fed for 3 months with standard (C) chow supplemented or not with fructose (F, 60%). After sacrifice at different weeks (W), the aorta and plasma were harvested to assess the vascular and biochemical parameters. Our …