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Results 201 - 250 of 2384
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Paulikova H - - 2008
Cytotoxic/cytostatic activity of N-salicylidene-L-glutamato diaqua copper(II) complex (CuC) against mice leukemia cells L1210 has been estimated and their bioactivity was enhanced by addition of ascorbic acid. The Cu-complex with isoquinoline ligand (IQ-CuC) had stronger cytostatic effect (IC50 =15.6 microM) than parental complex (CuC) and its cytotoxicity several times increased in ...
Koc Murat - - 2008
Reactive oxygen species (ROS) have been implicated in the etiology of indomethacin-induced gastric mucosal damage. This study investigated ascorbic acid (vitamin C)'s protective effects against oxidative gastric mucosal damage induced by indomethacin. Ascorbic acid is a powerful antioxidant because it can donate a hydrogen atom and form a relatively stable ...
Tikare Swati N - - 2008
Nickel-induced hyperglycemia in rats under both acute and subchronic exposure conditions could be due to increased hepatic glycogenolysis, increased pancreatic release of glucagon, decreased peripheral utilization of glucose, or gluconeogenesis. We studied the effect of acute and subchronic nickel sulfate treatment on Wister strain male albino rats simultaneously treated with ...
Retana-Ugalde Raquel - - 2008
AIM: To determine the useful dosage of ascorbic acid and alpha-tocopherol against oxidative stress and DNA damage in the elderly. METHODS: A double-blind controlled clinical assay carried out in a sample of 66 healthy subjects divided into three age-paired random groups with 22 subjects in each group. Group A received ...
Rossi Silvia - - 2008
The aim of the present work was to investigate if chitosan salification with ascorbic acid could produce an increase in chitosan penetration enhancement properties towards buccal mucosa and intestinal Caco-2 cell monolayer. Three different chitosan grades were considered. Chitosan hydrochloride and lactate were used as references. Fluorescein isothiocyanate-dextran (FD4), a ...
Leclerc Patrice C - - 2008
BACKGROUND: Ascorbic acid is an essential vitamin and a powerful antioxidant. Many studies have highlighted the benefits of ascorbic acid for chronic cardiovascular diseases such as hypertension in which angiotensin II (Ang II) plays an significant role. We therefore hypothesized that ascorbic acid could modify the pharmacological properties of the ...
Yillar D O - - 2008
The stability of choline ascorbate was studied considering concentration, temperature, and pH of the drug solution. Our results revealed that choline ascorbate is almost fully stable with respect to these parameters. Practically no loss was observed when 3 x l0(-1) (50%) drug solution is preserved in the refrigerator, at ambient ...
Robaszkiewicz A - - 2008
Amino acids present in blood plasma may be targets for oxidation and chlorination by HOCl/OCl(-). N-Chloroamino acids have been reported to be less reactive, but more selective than HOCl/OCl(-) in their reactions; therefore, they may act as secondary mediators of HOCl/OCl(-)-induced injury. This study compared the effects of five N-chloroamino ...
Bagga V V Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, - - 2008
The inadequate survival of dopamine neurons following intracerebral transplantation is in part attributed to the generation of reactive oxygen species and subsequent oxidative stress. To address this, we investigated whether the antioxidant ascorbic acid (vitamin C) had any effect on the yields of dopamine neurons derived from E14 rat ventral ...
Lu Xin-Liang - - 2007
PURPOSE: Because previous studies have reported depleted antioxidant capacity in patients with chronic pancreatitis (CP), prevention of free radical production has gained importance in antifibrotic treatment strategies for CP. The aim of this study was to investigate the effects of ascorbic acid on oxidative capacity and pancreatic damage in experimental ...
Ambrosi Adriano - - 2008
An ascorbic acid sensor was fabricated via the drop-casting of dodecylbenzene sulphonic acid (DBSA)-doped polyaniline nanoparticles onto a screen-printed carbon-paste electrode. The modified electrode was characterised with respect to the numbers of drop cast layers, optimum potential and operating pH. The sensor was found to be optimal at neutral pH ...
Furnus C C - - 2008
Glutathione (GSH) concentration increases in bovine oocytes during in vitro maturation (IVM). The constitutive amino acids involved in GSH synthesis are glycine (Gly), glutamate (Glu) and cysteine (Cys). The present study was conducted to investigate the effect of the availability of glucose, Cys, Gly and Glu on GSH synthesis during ...
Mackenzie Bryan - - 2008
Vitamin C (L-ascorbic acid) is an essential micronutrient that serves as an antioxidant and as a cofactor in many enzymatic reactions. Intestinal absorption and renal reabsorption of the vitamin is mediated by the epithelial apical L-ascorbic acid cotransporter SVCT1 (SLC23A1). We explored the molecular mechanisms of SVCT1-mediated L-ascorbic acid transport ...
Kato Hiroharu - - 2007
As part of our program to develop potential imaging agents for ascorbate bioactivity in the brain, 5-O-(4'-iodobenzyl)-L-ascorbic acid was prepared through a seven-step sequence which involved C5-O-alkylation with p-iodobenzyl bromide in the presence of Ag2O and CaSO4 as the key step, starting from L-ascorbic acid. The scavenging activity of the ...
Muzíková J - - 2007
The paper evaluates the differences between the properties of tablets from two coprocessed dry binders based on alpha-lactose monohydrate and cellulose, MicroceLac 100 and Cellactose 80. The substances differ in the type of contained cellulose; MicroceLac 100 contains 25% of microcrystalline cellulose, Cellactose 80, 25% of powdered cellulose. The properties ...
López Martha L - - 2007
This manuscript describes the toxicity of lead in alfalfa plants treated with ethylenediaminetetraacetic acid (EDTA) and the phytohormones indole-3-acetic-acid (IAA), gibberellic acid (GA), and kinetin (KN), on catalase (CAT), ascorbate peroxidase (APOX), and total amylase activity (TAA). In all cases Pb was used at 40 mg/L; EDTA at 0.2 mM ...
Yu Fei - - 2008
To examine the effects of meso-2,3-dimercaptosuccinic acid (DMSA) on developmental toxicity resulting from exposure to lead in utero, female albino mice were exposed to lead by drinking water contaminated with lead acetate for 4 weeks. After the cessation of lead exposure, female mice were supplemented by gavage with saline solution, ...
Park Sang-Won - - 2008
Oxidative stress, which has been generated during reperfusion after a liver transplant, has been implicated in the higher rates of postoperative organ dysfunction. The aim of this study was to examine the effect of ascorbic acid on reperfusion injury after hepatic cold preservation. Isolated perfused rat livers were preserved in ...
Paixão Thiago R L C - - 2008
The anodic oxidation of ascorbic acid on a ruthenium oxide hexacyanoferrate modified electrode was characterized by cyclic voltammetry. On this modified surface, the electrocatalytic process allows the determination of ascorbic acid to be performed at 0.0 V and pH 6.9 with a limit of detection of 2.2 microM in a ...
Barril Célia - - 2008
The present study investigated the contribution of ascorbic acid to the formation of coloured species in model white wine systems containing (+)-catechin as the oxidisable phenolic substrate. Reactions were carried out in the presence or absence of ascorbic acid in model wine systems buffered with either tartaric acid or formic ...
Lykkesfeldt Jens - - 2007
Lack of post-sampling stability of ascorbate and dehydroascorbic acid and failure to block their in vivo equilibrium have lowered their value as biomarkers of oxidative stress and limited the ability to further investigate their possible role in disease prevention. In the present article, analytic reproducibility was tested by repeated analysis ...
Barrett D M - - 2007
Organically grown products experienced a doubling in percent penetration of organic sales into retail markets during the period from 1997 to 2003; however, there is still a debate over the perceived quality advantage of organically grown fruits and vegetables. In a study focusing on commercial production of processing tomatoes, samples ...
Muraguchi Koichi - - 2007
The purposes of this study were twofold: (1) to examine the effects of bleaching on the bond strength of an adhesive to bovine tooth surfaces; and (2) to explore the effectiveness of an ascorbic acid application in preventing the deterioration of bonding ability due to bleaching. In the experimental groups, ...
Liao Hui-Ling - - 2008
Elsinochromes are the red/orange pigments produced by many Elsinoë fungal species and are structurally similar to the phytotoxin, cercosporin. Here, pigments were extracted from cultures of a citrus pathogen, Elsinoë fawcettii and tested for cellular toxicity. On irradiation with light, elsinochromes rapidly killed suspension cultured citrus and tobacco cells. The ...
Sannaveerappa Thippeswamy - - 2007
The antioxidative effect of herring (Clupea harengus) light muscle press juice (PJ) against hemoglobin-(Hb-) mediated oxidation of washed cod mince during ice storage was tested. The PJ was fractionated into low-molecular-weight (LMW; <1 [corrected] kDa) and high-molecular-weight (HMW; >1, >3.5, and > 50 kDa) fractions; it was preheated (10 min, ...
Ali Shah R - - 2007
The electrochemistry of a poly(anilineboronic acid)/carbon nanotube composite was studied in the presence of dopamine and ascorbic acid. To understand the binding affinity of dopamine and ascorbic acid to the boronic acid functional groups in the composite, the association constants between the diol groups in dopamine and ascorbic acid and ...
Campos Evangelina - - 2007
The anaerobic utilization of L-ascorbate by gene products of the ula regulon in Escherichia coli has been widely documented. Under aerobic conditions, we have shown that this metabolism is only functional in the presence of casein acid hydrolysate. Transcriptional fusions and proteomic analysis indicated that both the ula regulon and ...
Maneshl Kalayil Manian - - 2007
A modified electrode based on gold nanoparticles decorated multiwall carbon nanotubes (MWNTs), MWNT-Au(nano)-ME is fabricated. MWNTs are functionalized with 4-aminothiophenol and coated over the glassy carbon electrode. Further, Au nanoparticles are deposited into MWNTs coated GC electrode by electrochemical reduction of HAuCl4. Field emission transmission electron microscope (FETEM) image shows ...
Hatano Tsutomu - - 2008
Although plant polyphenols such as (-)-epigallocatechin gallate (EGCG) have antibacterial activity towards methicillin-resistant Staphylococcus aureus (MRSA), such polyphenols are unstable in solution. Because the instability of polyphenols is attributable to their oxidation, we examined the effects of antioxidants and inhibitors of polyphenol oxidation on the maintenance of polyphenol antibacterial activity. ...
Bergquist Sara A M - - 2007
Baby spinach ( Spinacia oleracea L.) was grown under three types of shade netting (high transmittance, spectrum-altering, and low transmittance) to study the effect on the concentrations of vitamin C (ascorbic acid and dehydroascorbic acid), carotenoids, and chlorophyll and on the visual quality of the leaves. The spinach was sown ...
Wang Xiuyun - - 2008
Ascorbate oxidase (ASOD) bound to polymaleimidostyrene (PMS) forms stable ASOD micelle structure in polystyrene (PS) membrane. The oxygen permeable hydrophobic ASOD micelle membrane were coated on both aminated glassy carbon electrode (AGCE) and gold electrode (AuE) for the amperometric detections of l-ascorbic acid (AsA) based on the consumption of oxygen. ...
Nostro Pierandrea Lo - - 2007
A new double chained surfactant, 2-octyl-dodecanoyl-6-O-ascorbic acid (8ASC10), with a L-ascorbic acid unit as the polar headgroup was synthesized for the first time. The behavior of the compound in the dry solid state has been characterized through DSC, XRD, and SAXS measurements. The surfactant forms stable viscous organogels in the ...
Bahçeci K SavaƟ - - 2007
In this study, thermal inactivation parameters (D- and z-values) of Alicyclobacillus acidoterrestris spores in McIlvaine buffers at different pH, apple juice and apple nectar produced with and without ascorbic acid addition were determined. The effects of pH, temperature and ascorbic acid concentration on D-values of A. acidoterrestris spores were also ...
Hsieh Hsin-Ju - - 2007
The mycelia of Aspergillus niger, cultivated in a medium containing 45 g l(-1) maltose, 66 g l(-1) yeast extract, and 5 g l(-1) K(2)HPO(4) at 30 degrees C and 200 rpm, were used as a biocatalyst in the glucosylation of ascorbic acid. Free mycelia from 3-day-old culture, when used in ...
Biffinger Justin C - - 2008
Miniature microbial fuel cells (mini-MFCs) were used to monitor the current generated by Shewanella oneidensis DSP10 under both anaerobic and aerobic conditions when exposed to glucose as a potential electron donor. In addition to glucose, other carbon fuels including fructose, sucrose, acetate, and ascorbic acid were also tested. When the ...
Kaehler Jan - - 2008
Elevated levels of fibrinogen, C-reactive protein, and increased platelet aggregation are known to be increased by cigarette smoking, but the underlying mechanisms of the prothrombotic state in smokers are not completely understood. Since cigarette smoke contains several oxidants, we investigated the effect of the antioxidant ascorbic acid on stimulated fibrinolytic ...
Bhakta Mehul N - - 2008
Heme oxygenase (HO) catalyzes the NADPH dependent conversion of heme to biliverdin with the release of iron and CO via three successive oxygenation steps. The oxidation of heme in the presence of alternate reductants, such as ascorbic acid, has been used extensively to characterize the mechanism of oxygen activation in ...
Combet E - - 2007
The major potential site of acid nitrosation is the proximal stomach, an anatomical site prone to a rising incidence of metaplasia and adenocarcinoma. Nitrite, a pre-carcinogen present in saliva, can be converted to nitrosating species and N-nitroso compounds by acidification at low gastric pH in the presence of thiocyanate. To ...
Liao Yingjun - - 2008
The objective of this study was to explore the optimum combination of micronutrients used with 2,3-dimercaptosuccinic acid (DMSA) in the treatment of moderately lead-intoxicated mice. Experiment was carried out based on the orthogonal design L(8)(2(7)) setting six factors with two different levels of each, and eight groups of mice were ...
van der Meer P F - - 2007
BACKGROUND: For hygienic purposes, plastic overwraps can be used for storage of leucoreduced red cell concentrates (LR-RCC). However, the effect of the use of such overwrapping on in vitro parameters during 42 days of storage was unknown. METHODS: In paired experiments, LR-RCCs in SAGM (saline, adenine, glucose, mannitol) were packed ...
Ikeuci Sayaka - - 2007
The influence of L-ascorbic acid at 40 degrees C incubation on the subfragment-1 and rod regions, prepared by chymotryptic digestion of myosin, and myosin was investigated by SDS-polyacrylamide gel electrophoresis and transmission electron microscopy respectively. It was observed that L-ascorbic acid acted more readily on the subfragment-1 region of myosin. ...
Fan Xuetong - - 2007
The effects of irradiation (0, 1.8, and 4.5 kGy) on the quality of frozen corn and peas were investigated during a 12month period of postirradiation storage at -18 degrees C. Irradiation of frozen corn and peas caused a reduction in ascorbic acid content of both vegetables and a loss of ...
Maurice D V - - 2007
1. An experiment was conducted with commercial White Leghorn type chickens to determine the effect of gender on tissue ascorbic acid concentration, antioxidant capacity and ascorbic acid synthesis. 2. Birds reared and maintained on litter were given a standard layer diet, without supplemental ascorbic acid, from 18 weeks of age. ...
Takarada Takeshi - - 2007
The view that ascorbic acid indirectly benefits osteoclastogenesis through expression of receptor activator of nuclear factor-kappaB (NF-kappaB) ligand (RANKL) by osteoblasts is prevailing. In this study, we have examined the direct effect of ascorbic acid on osteoclastogenesis in cultured mouse osteoclasts differentiated from bone marrow precursors. The absence of alkaline ...
Ito Atsuo - - 2007
An ascorbate-apatite composite layer was successfully formed on NaOH- and heat-treated titanium by coprecipitating L-ascorbic acid phosphate and low-crystalline apatite in a supersaturated calcium phosphate solution at 37 degrees C for 48 h. The supersaturated calcium phosphate solutions used have chemical compositions attainable by mixing infusion fluids officially approved for ...
Yan Wei - - 2008
Silver chloride@polyaniline (PANI) core-shell (AgCl@PANI) nanocomposites were synthesized in the presence of polyvinylpyrrolidone (PVP). The obtained AgCl@PANI nanocomposites could be easily dispersed in aqueous media, which overcame the processible issues of PANI. Moreover, the nanocomposites showed excellent electrochemical behavior at pH neutral environment, and had inhibitive effect on oxidation of ...
Takebayashi Jun - - 2007
Inhibitory effects of 2-O-substituted ascorbic acid derivatives, ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S), on 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of sheep erythrocytes were studied and were compared with those of ascorbic acid (AA) and other antioxidants. The order of the inhibition efficiency was ...
Vermeir S - - 2007
In this paper we report on the development of a label-free low-volume (12.5 microL), high-throughput microplate calorimetric biosensor for fast ascorbic acid quantification in food and pharmaceutical products. The sensor is based on microplate differential calorimetry (MiDiCal) technology in which the heat generation, due to the exothermic reaction between ascorbic ...
Murata Masatsune - - 2007
Furfural is an important intermediate compound of the Maillard reaction of pentose or ascorbic acid. We examined the browning of furfural and lysine by heating and found a yellow compound, called furpipate, (E)-3-(2-furylmethylidene)-3H, 4H, 5H, 6H-pyridine-2-carboxylic acid. Furpipate is a novel pipecolic acid derivative and shows absorption maxima at 375 ...
Muzíková Jitka - - 2007
The paper deals with a study of tensile strength and disintegration time of compacts made from silicified microcrystalline celluloses, Prosolv SMCC 90, and Prosolv HD 90, in dependence on compression force, addition of two types of lubricants, and two active ingredients. The lubricants were magnesium stearate and sodium stearyl fumarate ...
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