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Biomedical subjects

M H Gordon

Publications and source records attributed to M H Gordon.

15 recordsLinked to original sources
PubMed2003

Dietary supplementation with a natural carotenoid mixture decreases oxidative stress.

OBJECTIVE: To determine whether dietary supplementation with a natural carotenoid mixture counteracts the enhancement of oxidative stress induced by consumption of fish oil. DESIGN: A randomised double-blind crossover dietary intervention. SETTING: Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, The University of Reading, Whiteknights PO Box 226, Reading RG6 6AP, UK. SUBJECTS AND INTERVENTION: A total of 32 free-living healthy nonsmoking volunteers were recruited by posters and e-mails in The University of Reading. One volunteer withdrew during the study. The volunteers consumed a daily supplement comprising capsules containing fish oil (4 x 1 g) or fish oil (4 x 1 g) containing a natural carotenoid mixture (4 x 7.6 mg) for 3 weeks in a randomised crossover design separated by a 12 week washout phase. The carotenoid mixture provided a daily intake of beta-carotene (6.0 mg), alpha-carotene (1.4 mg), lycopene (4.5 mg), bixin (11.7 mg), lutein (4.4 mg) and paprika carotenoids (2.2 mg). Blood and urine samples were collected on days 0 and 21 of each dietary period. RESULTS: The carotenoid mixture reduced the fall in ex vivo oxidative stability of low-density lipoprotein (LDL) induced by the fish oil (P=0.045) and it reduced the extent of DNA damage assessed by the concentration of 8-hydroxy-2'-deoxyguanosine in urine (P=0.005). There was no effect on the oxidative stability of plasma ex vivo assessed by the oxygen radical absorbance capacity test. beta-Carotene, alpha-carotene, lycopene and lutein were increased in the plasma of subjects consuming the carotenoid mixture. Plasma triglyceride levels were reduced significantly more than the reduction for the fish oil control (P=0.035), but total cholesterol, HDL and LDL levels were not significantly changed by the consumption of the carotenoid mixture. CONCLUSIONS: Consumption of the natural carotenoid mixture lowered the increase in oxidative stress induced by the fish oil as assessed by ex vivo oxidative stability of LDL and DNA degradation product in urine. The carotenoid mixture also enhanced the plasma triglyceride-lowering effect of the fish oil. SPONSORSHIP: : The study was supported by funding from the Greek Studentship Foundation and from Unilever Bestfoods plc. Carotenoids were contributed by Overseal Foods plc.

Adult↗
PubMed2003

Effects of enhanced consumption of fruit and vegetables on plasma antioxidant status and oxidative resistance of LDL in smokers supplemented with fish oil.

OBJECTIVE: To determine whether consumption of five portions of fruit and vegetables per day reduces the enhancement of oxidative stress induced by consumption of fish oil. SUBJECTS: A total of 18 free-living healthy smoking volunteers, aged 18-63 y, were recruited by posters and e-mail in The University of Reading, and by leaflets in local shops. DESIGN: A prospective study. SETTING: Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, The University of Reading, Whiteknights PO Box 226, Reading RG6 6AP, UK. INTERVENTION: All subjects consumed a daily supplement of 4 x 1 g fish oil capsules for 9 weeks. After 3 weeks, they consumed an additional five portions of fruits and vegetables per day, and then they returned to their normal diet for the last 3 weeks of the study. Fasting blood samples were taken at the ends of weeks 0, 3, 6 and 9. RESULTS: The plasma concentrations of ascorbic acid, lutein, beta-cryptoxanthin, alpha-carotene and beta-carotene all significantly increased when fruit and vegetable intake was enhanced (P<0.05). Plasma concentrations of alpha-tocopherol, retinol and uric acid did not change significantly during the period of increased fruit and vegetable consumption. Plasma oxidative stability, assessed by the oxygen radical absorbance capacity (ORAC) assay, also increased from weeks 3-6 (P<0.001) but not in association with increases in measured antioxidants. Lag phase before oxidation of low-density lipoprotein (LDL) significantly decreased in the first 3 weeks of the study, reflecting the incorporation of EPA and DHA into LDL (P<0.0001). Subsequent enhanced fruit and vegetable consumption significantly reduced the susceptibility of LDL to oxidation (P<0.005). CONCLUSION: Fish oil reduced the oxidative stability of plasma and LDL, but the effects were partially offset by the increased consumption of fruit and vegetables.

Adolescent↗
PubMed2001

Antioxidant activity of hydroxytyrosol acetate compared with that of other olive oil polyphenols.

Hydroxytyrosol acetate was synthesized, and the antioxidant activity of this olive oil component was assessed in comparison with that of other olive oil components, namely hydroxytyrosol, oleuropein, 3,4-DHPEA-EA, and alpha-tocopherol in bulk oil and oil-in-water emulsions. The activity of the compounds was also assessed by scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Hydroxytyrosol acetate had a weaker DPPH radical scavenging activity than hydroxytyrosol, oleuropein, or 3,4-DHPEA-EA but it had a radical scavenging activity similar to that of alpha-tocopherol. In oil, the antioxidant activity of hydroxytyrosol acetate was much higher than that of alpha-tocopherol or oleuropein, but in an emulsion 3,4-DHPEA-EA and alpha-tocopherol were more effective as antioxidants than hydroxytyrosol acetate. The antioxidant activity of hydroxytyrosol acetate was rather similar to that of hydroxytyrosol in oil and emulsions despite the difference in DPPH radical scavenging activity.

Acetates↗
PubMed2001

Isolation and characterization of the antioxidant component 3,4-dihydroxyphenylethyl 4-formyl-3-formylmethyl-4-hexenoate from olive (Olea europaea) leaves.

Storage of olive (Olea europaea) leaves for 22 h at 37 degrees C in closed plastic bags caused the content of a nonglycosidic secoiridoid, 3,4-dihydroxyphenylethyl 4-formyl-3-formylmethyl-4-hexenoate (3,4-DHPEA-EDA) to rise from 15% to 50% of the phenolic extract with corresponding falls in the content of oleuropein and two oleuropeindials, which were identified as precursors of 3,4-DHPEA-EDA. Pure product was isolated from one set of stored olive leaves in a 0.16% yield. Storage of olive leaves under various conditions showed that the moisture present in closed plastic bags was important for the formation of 3,4-DHPEA-EDA. The time taken to reach the maximum concentration of the product varied widely for different samples of olive leaves, with a shorter time for the sample with lower initial oleuropein content. The oleuropeindial precursors of the product were readily hydrolyzed to carboxylic acid derivatives, which have been identified by NMR. The antiradical activity of 3,4-DHPEA-EDA, evaluated by scavenging of 2,2-diphenyl-1-picrylhydrazyl radicals, was comparable to that of alpha-tocopherol.

Antioxidants↗
PubMed1998

Antioxidant activity of quercetin and myricetin in liposomes.

The antioxidant activity during storage at 30 degrees C of quercetin, myricetin and alpha-tocopherol in small unilamellar liposomes has been investigated. Myricetin was more effective than alpha-tocopherol as an antioxidant in liposomes under all conditions studied. At pH 5.4 with a concentration of 10(-2) mol/mol phospholipid, myricetin has been shown to be the strongest antioxidant followed by quercetin and alpha-tocopherol. Cupric chloride and ferric chloride strongly reduced the antioxidant activity of myricetin and quercetin with cupric chloride causing a stronger reduction in activity than ferric chloride. At a pH of 7.4, quercetin was less effective than alpha-tocopherol at a concentration of 10(-2) mol/mol phospholipid, but it's activity increased more strongly with concentration and it was very effective at a concentration of 5 x 10(-2) mol/mol phospholipid.

Antioxidants↗
PubMed1995

Intraluminal Palmaz stent implantation for treatment of recurrent carotid artery occlusive disease: a plan for the future.

While carotid endarterectomy (CEA) has been used commonly and with great effectiveness for de novo carotid occlusive lesions, its success in cases of recurrent disease has been attenuated by a higher incidence of complications and lower durability. Although interventional techniques have been introduced cautiously into the cerebrovascular system, balloon dilation for both primary and recurrent carotid atherosclerotic disease has been successful in establishing an adequate lumen without an increase in embolic complications over surgery. Because the likelihood exists that postdilation restenosis may be as common in the carotid arteries as it is in other vascular segments, the use of intraluminal stenting may mitigate this long-term complication, a benefit that has been demonstrated in other high flow vessels such as the aorta and iliac arteries. To begin an investigation of this hypothesis, we treated a 69-year-old symptomatic man who required a third intervention for recurrent carotid disease. A > 90% stenosis of the distal third of his right common carotid artery was successfully dilated, and a Palmaz stent was deployed without incident. The patient experienced no complications to the percutaneous procedure, and at 15 months posttreatment, he is well and asymptomatic. Although greater clinical experience must be accumulated with this new approach, intraluminal stenting following balloon dilation for recurrent carotid disease may surpass redo CEA in long-term patency and may entail fewer procedural complications.

Aged↗
PubMed1980

Calcific stenosis of a glutaraldehyde-treated porcine bioprosthesis in the aortic position.

The porcine xenograft bioprosthesis is used widely at the present time, although its long-term durability is still being evaluated. Calcification resulting in stenosis of the glutaraldehyde-treated bioprosthesis has been reported infrequently. In the patient described herein, severe calcific stenosis of a porcine xenograft in the aortic position occurred 45 months after implantation. This report emphasizes the life-threatening and rapidly progressive nature of this complication in the long-term survivor after valve replacement.

Adult↗
PubMed1976

Liver enlargement demonstrated by scintigraphy in rheumatoid arthritis.

Scintigraphic scanning employing technetium-99m sulfur colloid was used to assess the size of the liver and spleen in 32 consecutive patients with rheumatoid arthritis. The data were correlated with clinical and laboratory assessment. Seven patients had enlarged livers, three enlarged spleens. An expected correlation of liver enlargement with Sjögren's syndrome did not materialize. Splenic enlargement and liver enlargement were discordant. Liver enlargement correlated best with elevations of rheumatoid factor as measured by latex fixation. As liver enlargement is not an appreciated feature of rheumatoid arthritis, these findings suggest that hepatomegaly need not necessarily imply adverse treatment results or the development of lymphoproliferative disorders.

Adult↗