Search results for "ascorbic acid"
showing 10 items of 295 documents
Effects of maternal ageing and dietary antioxidant supplementation on ovulation, fertilisation and embryo development in vitro in the mouse.
1999
The present study aims to ascertain whether dietary supplementation with a mixture of vitamins C and E may prevent the maternal-age-associated decrease in both the number of ovulated oocytes after exogenous ovarian stimulation and embryo development in vitro in the mouse. Experimental females were fed a standard diet supplemented with i) high doses of vitamins C and E from the first day of weaning until 12 or 40 weeks of age; or ii) moderate doses of vitamins C and E from the first day of weaning until 12 weeks of age or from 22 to 33 weeks of age. The age-related reduction in ovulation rate was partially prevented by supplementing diet with high doses of vitamins C and E from the first day…
Ascorbic acid decomposition into oxalate ions: a simple synthetic route towards oxalato-bridged heterometallic 3d-4f clusters.
2015
Two types of oxalato-bridged heterometallic 3d–4f dodeca- and hexanuclear compounds have been obtained by connecting six bi- and, respectively, trinuclear moieties through oxalato bridges arising from the slow decomposition of the L-ascorbic acid.
Oxidative DNA damage induced by visible light in mammalian cells: extent, inhibition by antioxidants and genotoxic effects
1998
The extent of the indirect DNA damage generated in mammalian cells by visible light because of the presence of endogenous photosensitizers was studied by means of repair endonucleases. In immortalized human keratinocytes (HaCaT cells) exposed to low doses of natural sunlight, the yield of oxidative DNA base modifications sensitive to the repair endonuclease formamidopyrimidine-DNA glycosylase (Fpg protein) generated by this indirect mechanism was 10% of that of pyrimidine dimers (generated by direct DNA excitation). A similar yield of Fpg-sensitive modifications, which include 8-hydroxyguanine, was observed in primary keratinocytes. The relative yield of oxidative base modifications decreas…
Effect of nitrogen fertilizer level on quality and shelf-life of fresh cut Swiss chard
2018
Swiss chard (Beta vulgaris L. var. cicla L.) is a leafy vegetable highly appreciated in some areas for its nutritional properties and year round supply. Its production area is not commercially important, but this minor vegetable offers an interesting enlargement of the current vegetable assortment by using its stalks and leaves. Swiss chard is a very nutritive demanding species. The content of mineral elements, total quality and yield are influenced by the amount, frequency and method of fertilization. The aim of this study was to evaluate the effect of high or low levels of nitrogen fertilization on the quality and shelf-life of minimally processed Swiss chard. Plants grown with a high (18…
Supplementary Ultraviolet-B Radiation Induces a Rapid Reversal of the Diadinoxanthin Cycle in the Strong Light-Exposed DiatomPhaeodactylum tricornutu…
2002
AbstractA treatment of the diatom Phaeodactylum tricornutum with high light (HL) in the visible range led to the conversion of diadinoxanthin (Dd) to diatoxanthin (Dt). In a following treatment with HL plus supplementary ultraviolet (UV)-B, the Dt was rapidly epoxidized to Dd. Photosynthesis of the cells was inhibited under HL + UV-B. This is accounted for by direct damage by UV-B and damage because of the UV-B-induced reversal of the Dd cycle and the associated loss of photoprotection. The reversal of the Dd cycle by UV-B was faster in the presence of dithiothreitol, an inhibitor of the Dd de-epoxidase. Our results imply that the reversal of the Dd cycle by HL + UV-B was caused by an incre…
Change in Taste-altering Non-volatile Components of Blood and Common Orange Fruit during Cold Storage
2020
Abstract Cold storage may cause changes in the volatile and non-volatile components of orange fruit, in association with the decrement of the characteristic fruit flavour and sensory acceptability. The aim of this work was to evaluate the changes of some non-volatile taste-altering components (total and individual sugars, acids, anthocyanins, putrescine and limonin) that may affect the organoleptic perception of cold-stored orange fruit. Three blood orange varieties ('Tarocco TDV', 'Tarocco Gallo', and 'Moro') and a common variety ('Washington navel') were stored at 6 ± 1 °C and 90–95% Relative Humidity (RH) for 60 d. Chemical and sensory assessments were performed during fruit storage at 1…
Hemostatic, inflammatory, and oxidative markers in pesticide user farmers
2016
Research Article; International audience; The aim of this work was to investigate inflammatory, oxidative, and thrombotic parameters as biomarkers in farmers exposed to pesticides. Fifty farmers using chemical pesticides and 60 unexposed control men participated in this study. The Mediterranean diet compliance, the duration of pesticide use, and personal protection for pesticides handling were recorded using self-administered questionnaires. Serum biochemical parameters, oxidant/antioxidant, inflammatory, and thrombosis markers were determined. Our findings showed oxidative stress reflected by an increase in malondialdehyde, carbonyl proteins and superoxide anion levels and a decrease in vi…
A Multi-Locus Genetic Risk Score for Primary Open-Angle Glaucoma (POAG) Variants Is Associated with POAG Risk in a Mediterranean Population: Inverse …
2017
Primary open-angle glaucoma (POAG) is a leading cause of blindness worldwide. The genetics of POAG are complex, and population-specific effects have been reported. Although many polymorphisms associated with POAG risk have been reported, few studies have analyzed their additive effects. We investigated, in a southern European Mediterranean population, the association between relevant POAG polymorphisms, identified by initial genome-wide association studies (GWASs) and POAG risk, both separately and as an aggregated multi-locus genetic risk score (GRS). Also, bearing in mind that oxidative stress is a factor increasingly recognized in the pathogenesis of POAG, we analyzed the potential assoc…
Gender- and age-related distinctions for the in vivo prooxidant state in Fanconi anaemia patients.
2004
Abstract Some selected oxidative stress parameters were measured in 56 Fanconi anaemia (FA) patients (42 untransplanted and 14 transplanted), 54 FA heterozygotes (parents) and 173 controls. Untransplanted FA patients showed a highly significant increase in leukocyte 8-hydroxy-2’-deoxyguanosine (8-OHdG) (p = 0.00003) and a borderline increase (p = 0.076) in urinary levels of 8-OHdG vs. child controls. These increases were more pronounced in female FA patients (p = 0.00005 for leukocyte 8-OHdG, and p = 0.021 for urinary 8-OHdG). Female FA patients also displayed a highly significant excess of spontaneous chromosomal breaks vs. male patients (p = 0.00026), in the same female:male ratio (≅ 1.4)…
Dppa3 expression is critical for generation of fully reprogrammed iPS cells and maintenance of Dlk1-Dio3 imprinting.
2014
Reprogramming of mouse somatic cells into induced pluripotent stem cells (iPSCs) often generates partially reprogrammed iPSCs (pre-iPSCs), low-grade chimera forming iPSCs (lg-iPSCs) and fully reprogrammed, high-grade chimera production competent iPSCs (hg-iPSCs). Lg-iPSC transcriptome analysis revealed misregulated Dlk1-Dio3 cluster gene expression and subsequently the imprinting defect at the Dlk1-Dio3 locus. Here, we show that germ-cell marker Dppa3 is present only in lg-iPSCs and hg-iPSCs, and that induction with exogenous Dppa3 enhances reprogramming kinetics, generating all hg-iPSCs, similar to vitamin C (Vc). Conversely, Dppa3-null fibroblasts show reprogramming block at pre-iPSCs sta…