Search results for "O-2"
showing 10 items of 854 documents
Bioaccesibility of Cylindrospermopsin from cooked fish muscle after the application of an in vitro digestion model and its bioavailability.
2017
Humans can be exposed to cyanotoxins through the ingestion of contaminated water, food or beverages. In the present work, the bioaccesibility of Cylindrospermopsin (CYN), one of the most relevant cyanotoxins, was evaluated in a pure CYN solution and cooked CYN-contaminated fish muscles (20 μg/mL). An in vitro digestion model including the salivar, gastric, duodenal and colonic phases was performed, being each fraction analyzed by HPLC-MS-MS to evaluate CYN degradation. Moreover, Caco-2/TC7 cells were exposed to the digested duodenal and colonic phases to elucidate the final bioavailability of CYN in an approximation to the real human exposure scenario. The results revealed that CYN bioacces…
Bioavailability of calcium from milk-based formulas and fruit juices containing milk and cereals estimated by in vitro methods (solubility, dialyzabi…
2005
An adequate calcium intake during the first years of life is needed for normal growth and development and to prevent rickets. The bioavailability of calcium from infant foods (milk-based formulas and fruit juices containing milk and cereals, FMC), the dietary sources of calcium in these stages of life, has been estimated on the basis of simulated gastrointestinal digestion and calcium solubility and dialyzability values and on the efficiency of transport and uptake by Caco-2 cells. The ranking of samples according to calcium bioavailability depends on the use of solubility or dialyzability as criterion. On the basis of the former, the highest value corresponded to adapted formulas and the l…
Sensitivity to acetic acid, ability to colonize abiotic surfaces and virulence potential of Listeria monocytogenes EGD-e after incubation on parsley …
2010
International audience; Abstract Aim: To investigate how the survival of Listeria monocytogenes on parsley leaves may affect its ability to sustain process-related harsh conditions and its virulence. Methods and Results: Parsley seedlings were spot inoculated with stationary phase cells of L. monocytogenes EGD-e and incubated for 15 days. Each day, bacterial cells were harvested and enumerated, and their ability to survive acetic acid challenge (90 min, pH 4.0), to colonize abiotic surfaces and to grow as biofilms was assessed. After a 3-log decrease over the first 48 h, the population stabilized to about 10(6) CFU g(-1) until the sixth day. After the sixth day, L. monocytogenes was no long…
Bioavailability of inorganic arsenic in cooked rice: practical aspects for human health risk assessments.
2005
Arsenic is present in rice grain mainly as inorganic arsenic. Little is known about the effect of cooking on inorganic arsenic content in rice and its bioavailability. This study evaluated total arsenic and inorganic arsenic in rice cooked with arsenic-contaminated water, the bioaccessibility of As(III) and As(V) after simulated gastrointestinal digestion, and the extent of arsenic retention and transport by Caco-2 cells used as a model of intestinal epithelia. After cooking, inorganic arsenic contents increase significantly. After simulated gastrointestinal digestion, the bioaccessibility of inorganic arsenic reached 63-99%; As(V) was the main species found. In Caco-2 cells, arsenic retent…
Iron Oxide/Hydroxide Nanoparticles with Negatively Charged Shells Show Increased Uptake in Caco-2 Cells
2012
The absorption of commonly used ferrous iron salts from intestinal segments at neutral to slightly alkaline pH is low, mainly because soluble ferrous iron is easily oxidized to poorly soluble ferric iron and because ferrous iron, but not ferric iron, is carried by the divalent metal transporter DMT-1. Moreover, ferrous iron frequently causes gastrointestinal side effects. Iron hydroxide nanoparticles with neutral and hydrophilic carbohydrate shells are alternatively used to ferrous salts. In these formulations gastrointestinal side effects are rare because hundreds of ferric iron atoms are safely packed in nanoscaled cores surrounded by the solubilizing shell; nevertheless, iron bioavailabi…
6-Amino-2-(pivaloylamino)pyridinium benzoate
2013
In the crystal structure of the title salt, C10H16N3O+·C7H5O2−, the cations and anions are linked to each other via N—H⋯O hydrogen bonds, forming infinite chains running along [010]. The crystal structure also features C—H⋯O and π–π stacking interactions, which assemble the chains into supramolecular layers parallel to (100). The π–π stacking interactions are observed between the pyridine rings of inversion-related cations with a centroid–centroid distance of 3.867 (2) Å. Financial support from the National Science Centre in Kraków (grant No. NCN204 356840) is gratefully acknowledged. Academy Professor Kari Rissanen (Academy of Finland grant Nos. 122350, 140718, 265328 and 263256) and th…
Relative expression of cholesterol transport-related proteins and inflammation markers through the induction of 7-ketosterol-mediated stress in Caco-…
2013
Human diets contain sterol oxidation products that can induce cytotoxic effects, mainly caused by cholesterol oxides. However, phytosterol oxides effects have been less extensively investigated. This study evaluates the production of inflammatory biomarkers (IL-1β, IL-8, IL-10, TNFα) and the influence of gene expression transporters and enzymes related to cholesterol absorption and metabolism (NPC1L1, ABCG5/8, HMGCoA, ACAT) produced by 7-ketosterols (stigmasterol/cholesterol) in Caco-2 cells. These effects were linked to intracellular signaling pathways by using several inhibitors. Results showed 7-ketostigmasterol to have a greater proinflammatory potential than 7-ketocholesterol. In non-p…
Comparison of the contractile effects of endothelin-1 and sarafotoxin S6b in goat isolated cerebral arteries
1992
1. The effects of endothelium-derived endothelin-1 and snake venom-derived sarafotoxin S6b, peptides with striking structural and functional similarities, were examined and compared in isolated middle cerebral arteries of goats. 2. Endothelin-1 and sarafotoxin S6b contracted cerebral arteries in a concentration-dependent manner. The potency of endothelin-1 (EC50 = 4.9 (3.9-6.2) x 10(-10) M) was about ten times higher than that of sarafotoxin S6b (EC50 = 5.5 (4.4-6.9) x 10(-9) M). The tension returned to basal values after repeated washings and contraction with endothelin-1 could be reproduced. Endothelin-1 and sarafotoxin S6b induced further contraction in arteries precontracted with prosta…
Effects of endothelin-1 on the cerebrovascular bed of the goat.
1991
Abstract The aim of the present study was to analyze the effects of endothelin-1 (ET-1) in the cerebrovascular bed of the goat, the importance of endothelial integrity and the contribution of extracellular Ca2+ to these responses. We measured isometric tension and 45Ca2+ uptake in isolated middle cerebral arteries, and cerebral blood flow (CBF) in unanesthetized animals. ET-1 elicited concentration-dependent contractions which were potentiated in arteries without endothelium. Ca2+-free medium and nicardipine inhibited, and Bay K 8644 potentiated the ET-1-induced contractions. ET-1 enhanced 45Ca2+ uptake in isolated arteries. Injections of ET-1 directly into the cerebral circulation decrease…
An exploratory study of two Caco-2 cell models for oral absorption: A report on their within-laboratory and between-laboratory variability, and their…
2010
In 2005, the European Centre for the Validation of Alternative Methods (ECVAM) sponsored a study aimed at evaluating the reproducibility (between-laboratory and within-laboratory variability) and the predictive capacity of two in vitro cellular systems — the Caco-2/ATCC parental cell line and the Caco-2/TC7 clone — for estimating the oral fraction absorbed (Fa) in humans. Two laboratories, both of which had experience with Caco-2 cultures, participated in the study. Ten test chemicals with documented in vivo oral absorption data were selected. Atenolol, cimetidine and propranolol were included as reference compounds for low, medium and high intestinal absorption, respectively. Transport ex…