首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The biomass production and antioxidant accumulation of the aerial microalga Trentepohlia aurea were examined. Using ammonium chloride as nitrogen source for growth in liquid medium, the growth rate was exponential and accompanied by a marked fall in the pH of the medium. The highest growth rate of 152 mg L-1 day-1 (logarithmic phase) was attained when T. aurea was cultured with aeration of 5% CO2-enriched air in medium buffered with HEPES. The growth rate and antioxidant content were enhanced under 5% CO2 by switching the light intensity from 43 to 143 μmol photon m-2 s-1 for the two-stage culture. As a result, T. aurea cells accumulated 2.1 mg β-carotene, 0.3 mg L-ascorbic acid and 2.4 mg tocopherols, respectively, per g dry cell. The simultaneous production of useful materials, such as β-carotene, vitamin E and vitamin C, was demonstrated. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

2.
It has been suggested that the major source of vitamin D should come from dietary sources and not sun exposure. However, the major fortified dietary source of vitamin D is milk which often does not contain at least 80% of what is stated on the label. Fish has been touted as an excellent source of vitamin D especially oily fish including salmon and mackerel. Little is known about the effect of various cooking conditions on the vitamin D content in fish. We initiated a study and evaluated the vitamin D content in several species of fish and also evaluated the effect of baking and frying on the vitamin D content. Surprisingly, farmed salmon had approximately 25% of the vitamin D content as wild salmon had. The vitamin D content in fish varied widely even within species. These data suggest that the tables that list the vitamin D content are out-of-date and need to be re-evaluated.  相似文献   

3.
In addition to epidemiologic studies that suggest a benefit for high intakes of alpha-tocopherol, studies of supplementation in humans have clearly shown that alpha-tocopherol decreases lipid peroxidation, platelet aggregation, and functions as a potent anti-inflammatory agent. In the five large prospective clinical trials with alpha-tocopherol therapy, four have shown a beneficial effect on cardiovascular end-points (two studies on a primary end-point and two studies on other cardiovascular end-points). Thus, the totality of evidence based on the epidemiologic data, in-vitro studies and animal models, and the clinical trials appears to support a benefit for alpha-tocopherol supplementation in patients with pre-existing cardiovascular disease. However, definitive recommendations must await ongoing clinical trials.  相似文献   

4.
The vitamin D receptor (VDR) is a member of the nuclear receptor superfamily and plays a central role in the biological actions of vitamin D. VDR regulates the expression of numerous genes involved in calcium/phosphate homeostasis, cellular proliferation and differentiation, and immune response, largely in a ligand-dependent manner. To understand the global function of the vitamin D system in physiopathological processes, great effort has been devoted to the detection of VDR in various tissues and cells, many of which have been identified as vitamin D targets. This review focuses on the tissue- and cell type-specific distribution of VDR throughout the body.  相似文献   

5.
6.
It has been suggested that the major source of vitamin D should come from dietary sources and not sun exposure. However, the major fortified dietary source of vitamin D is milk which often does not contain at least 80% of what is stated on the label. Fish has been touted as an excellent source of vitamin D especially oily fish including salmon and mackerel. Little is known about the effect of various cooking conditions on the vitamin D content in fish. We initiated a study and evaluated the vitamin D content in several species of fish and also evaluated the effect of baking and frying on the vitamin D content. Surprisingly, farmed salmon had approximately 25% of the vitamin D content as wild salmon had. The vitamin D content in fish varied widely even within species. These data suggest that the tables that list the vitamin D content are out-of-date and need to be re-evaluated.  相似文献   

7.
Vitamin D is a secosteroid best known for its role in maintaining bone and muscle health. Adequate levels of vitamin D may also be beneficial in maintaining DNA integrity. This role of vitamin D can be divided into a primary function that prevents damage from DNA and a secondary function that regulates the growth rate of cells. The potential for vitamin D to reduce oxidative damage to DNA in a human has been suggested by clinical trial where vitamin D supplementation reduced 8-hydroxy-2'-deoxyguanosine, a marker of oxidative damage, in colorectal epithelial crypt cells. Studies in animal models and in different cell types have also shown marked reduction in oxidative stress damage and chromosomal aberrations, prevention of telomere shortening and inhibition of telomerase activity following treatment with vitamin D. The secondary function of vitamin D in preventing DNA damage includes regulation of the poly-ADP-ribose polymerase activity in the DNA damage response pathway involved in the detection of DNA lesions. It is also able to regulate the cell cycle to prevent the propagation of damaged DNA, and to regulate apoptosis to promote cell death. Vitamin D may contribute to prevention of human colorectal cancer, though there is little evidence to suggest that prevention of DNA damage mediates this effect, if real. Very limited human data mean that the intake of vitamin D required to minimise DNA damage remains uncertain.  相似文献   

8.
Magnetic resonance studies reveal a marked difference between the binding of α-tocopherol and that of the corresponding acetate (vitamin E acetate) with dipalmitoylphosphatidylcholine (DPPC) vesicles. This is reflected in differences in the phase-transition curves of the DPPC vesicles incorporated with the two compounds, as well as in the 13C relaxation times and line widths. A model for the incorporation of these molecules in lipid bilayers has been suggested. α-Tocopherol binds strongly with the lipids, possibly through a hydrogen bond formation between the hydroxyl group of the former and one of the oxygen atoms of the latter. The possibility of such a hydrogen bond formation is excluded in vitamin E acetate, which binds loosely through the normal hydrophobic interaction. The model for lipid-vitamin interaction explains the in vitro decomposition of H2O2 by α-tocopherol. α-Tocopherol in conjuction with H2O2 can also act as a free-radical scavenger in the lipid phase. The incorporation of α-tocopherol and vitamin E acetate in DPPC vesicles enhances the permeability of lipid bilayers for small molecules such as sodium ascorbate.  相似文献   

9.
10.
11.
K Pehr  R R Forsey 《CMAJ》1993,149(9):1247-1253
OBJECTIVE: To review the possible uses of topical and systemic tocopherols as therapy for skin conditions in light of the widespread use of vitamin E by patients. DATA SOURCES: Index Medicus was searched for articles published from 1922 (when vitamin E was discovered) to 1966 (the beginning of MEDLINE). MEDLINE was searched for articles in English and French on vitamin E or tocopherol in relation to dermatology. Additional original articles were identified from the reference lists of the review articles. STUDY SELECTION: Only well-designed controlled studies were accepted; anecdotes and open studies are cited for completeness and as direction for future research. DATA SYNTHESIS: There was some weak or conflicting evidence that vitamin E is of value in yellow nail syndrome, vibration disease, epidermolysis bullosa, cancer prevention, claudication, cutaneous ulcers, and collagen synthesis and wound healing. It was of no use in atopic dermatitis, dermatitis herpetiformis, psoriasis, subcorneal pustular dermatosis, porphyrias and skin damage induced by ultraviolet light. CONCLUSIONS: After 44 years of research there is still scant proof of vitamin E''s effectiveness in treating certain dermatologic conditions. Further research in well-designed controlled trials is needed to clarify vitamin E''s role.  相似文献   

12.
Summary We have determined the various haplotypic combinations between alleles as well as restriction fragment length polymorphisms of two linked genetic markers, albumin and vitamin D-binding protein or group-specific component, in a number of Asian-Pacific populations. Using the partial maximum likelihood method, we constructed a phylogenetic network from the haplotype frequencies to assess relationships among the populations sampled. No systematic linkage disequilibrium was detected between most of the combinations, suggesting a lack of operation of any selection pressure at the two loci. The phylogenetic analysis confirmed the known interrelationships among various populations in the Asian-Pacific region. The Australian aborigines clustered closely with the non-Austronesian-speaking highlanders from Papua New Guinea, as expected. Similarly, the Austronesian-speaking Polynesians, Micronesians, and the Southeast Asians branched off together as a separate group. The position of the Austronesian-speaking Tolais from New Britain with respect to other populations from the Southwest Pacific was anomalous. The Tolais revealed a strong affinity with the Australian aborigines, which is inexplicable. The populations from China formed a tight cluster with other populations from the Asian-Pacific region. Genetic interrelationships of these populations with the white Australians were remote, which is in accordance with the known affinities of various human racial groups.  相似文献   

13.
14.
Lipase-catalyzed synthesis of vitamin C fatty acid esters   总被引:8,自引:0,他引:8  
Fatty acid esters of vitamin C (ascorbic acid) where synthesized in a mainly solid-phase system in the presence of small amounts of organic solvent (acetone or t-butanol) catalyzed by immobilized lipase B from Candida antarctica.Highest reaction rates and yields of isolated products were obtained using fatty acid vinyl esters, e.g., 6-O-palmitoyl-l-ascorbic acid was obtained in 91% isolated yield after 48 h. As vitamin C and its esters are very sensitive to oxidation, a mild extraction method for the isolation of reaction products was developed.  相似文献   

15.
16.
IntroductionThe introduction of tumor necrosis factor-alpha (TNF-α) antagonists has substantially improved patient’s clinical outcome in rheumatoid arthritis (RA). However, nearly 20% to 40% of RA patients do not respond to anti-TNF-α treatment strategies. To identify valid predictors of TNF-α antagonist response in RA, serum proteome profiles from responders (R) and non-responders (NR) to etanercept, a soluble recombinant TNF-α receptor/IgG Fc fusion protein receptor, were compared in a prospective cohort study.MethodsIn this clinical study 50 RA patients with inadequate response to conventional DMARDs were included and treated with etanercept. The primary efficacy endpoint was response according to the European League against Rheumatism (EULAR) improvement criteria. Serum samples collected prior to initiation and after six months of etanercept therapy were cleared of the most abundant major proteins by immunoaffinity chromatography. After separation by two-dimensional differential gel electrophoresis (2D-DIGE) and identification by mass spectrometry (MS) data were validated by Western blot analysis.ResultsAfter six months of etanercept treatment 62% (n = 31) of RA patients achieved response. Haptoglobin-α1 (Hp-α1) and -α2 (Hp-α2) and vitamin D-binding protein (VDBP) were found to be significantly upregulated in responder sera (P ≤0.02) at study entry. In contrast, apolipoprotein C-III (ApoC-III) showed significantly higher levels in non-responders (P = 0.0162). At study end ApoA-II, Hp-α1, Hp-α2 and VDBP were identified to be expressed at significantly higher levels (P <0.05) in responder sera.ConclusionsBy application of clinical proteomics in immunodepleted sera we could identify and validate for the first time Hp-α1, -α2, VDBP and ApoC-III as potential biomarkers for prediction of etanercept drug response in RA.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0553-1) contains supplementary material, which is available to authorized users.  相似文献   

17.
In this study, fatty acids compositions, fat-soluble vitamins (D, E, and K) and cholesterol in the gonads, hepatopancreas, and abdomen muscle of male and female Astacus leptodactylus caught from wild were determined in their prior of reproduction period. The results showed that in female A. leptodactylus, compared with hepatopancreas, the ovaries contained a significantly high level of C16:0, C16:1n-7, C18:1n-9, C22:6n-3, the ratio of n-3 to n-6 (p < 0.05). In females, the values of δ-tocopherol, α-tocopherol, K2 and D2 vitamins, and cholesterol obtained in ovaries were significantly higher than those of obtained in abdomen muscle and hepatopancreas (p < 0.05). In male A. leptodactylus δ-tocopherol was found to be 1.91 μg/g in testes, which is significantly higher than that of abdomen muscle, hepatopancreas, and vasa deferentia (p < 0.05). In conclusion, the findings of present study are especially constructive for both crayfish biologists and farmers for preparing broodstock diets for crayfish at reproduction units.  相似文献   

18.
19.
20.
Epidemiological studies have shown that regular consumption of fruits and vegetables is associated with reduced risk of chronic diseases. Vegetables can provide vitamins, phenolics, flavonoids, minerals and dietary fibers for optimal health benefits. However, some nutrients contained in many fruits and vegetables cannot meet of the complete nutrition need in the human body. Biotechnology has the potential to improve the nutritional value of crops. Considering the high consumption of romaine lettuce in human diet worldwide, the objective of study is to enhance the contents of vitamin C, phenolics and antioxidant activity in lettuce leaves by genetic engineering techniques. The gene expression level, vitamin C content, total phenolics, as well as total and cellular antioxidant activities were analyzed by real-time PCR, HPLC, Folin–Ciocalteu, Hydro-PSC and CAA methods, respectively. The bio-fortification of genetically engineered lettuce increased vitamin C up to 48.94 ± 1.34 mg/100 g FW following the increased over-expression of At GLDH. This is almost a 3.2-fold increase as the content when compared with wild type lettuce (p < 0.05). In addition, phenolic compounds in transgenic lettuce contained 120.4 ± 1.62 mg GA equiv./100 g FW, almost double the phenolic content of the wild type. Total antioxidant activities were 735.4 ± 47.7 μmol vitamin C equiv./100 g FW, cellular antioxidant activities were 7.33 ± 0.86 μmol quercetin equiv./100 g FW (PBS wash) and 18.14 ± 0.68 μmol quercetin equiv./100 g FW (No PBS wash) in transgenic lettuce, respectively, 1.5, 4 and twofold increases when compared with the wild type. This study suggests that bio-fortification by genetic engineering has great potential to improve vitamin C, phenolic contents and antioxidant activity in lettuce.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号