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- Andersson, Agneta, et al.
(författare)
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Whole-grain foods do not affect insulin sensitivity or markers of lipid peroxidation and inflammation in healthy, moderately overweight subjects
- 2007
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Ingår i: Journal of Nutrition. - 0022-3166 .- 1541-6100. ; 137:6, s. 1401-1407
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Tidskriftsartikel (refereegranskat)abstract
- High intakes of whole grain foods are inversely related to the incidence of coronary heart diseases and type 2 diabetes, but the mechanisms remain unclear. Our study aimed to evaluate the effects of a diet rich in whole grains compared with a diet containing the same amount of refined grains on insulin sensitivity and markers of lipid peroxidation and inflammation. In a randomized crossover study, 22 women and 8 men (BMI 28 +/- 2) were given either whole-grain or refined-grain products (3 bread slices, 2 crisp bread slices, 1 portion muesli, and 1 portion pasta) to include in their habitual daily diet for two 6-wk periods. Peripheral insulin sensitivity was determined by euglycemic hyperinsulinemic clamp tests. 8-Iso-prostaglandin F(2alpha) (8-iso PGF(2alpha)), an F(2)-isoprostane, was measured in the urine as a marker of lipid peroxidation, and highly sensitive C-reactive protein and IL-6 were analyzed in plasma as markers of inflammation. Peripheral insulin sensitivity [mg glucose . kg body wt(-1) . min(-1) per unit plasma insulin (mU/L) x 100] did not improve when subjects consumed whole-grain products (6.8 +/- 3.0 at baseline and 6.5 +/- 2.7 after 6 wk) or refined products (6.4 +/- 2.9 and 6.9 +/- 3.2, respectively) and there were no differences between the 2 periods. Whole-grain consumption also did not affect 8-iso-PGF(2alpha) in urine, IL-6 and C-reactive protein in plasma, blood pressure, or serum lipid concentrations. In conclusion, substitution of whole grains (mainly based on milled wheat) for refined-grain products in the habitual daily diet of healthy moderately overweight adults for 6-wk did not affect insulin sensitivity or markers of lipid peroxidation and inflammation.
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| 2. |
- Basu, Samar, et al.
(författare)
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Bioaktiva isoprostaner : nya markörer för oxidativ stress och inflammationsrelaterade sjukdomar
- 2009
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 106:5, s. 274-278
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Tidskriftsartikel (refereegranskat)abstract
- Oxidativ stress (fria radikaler) tros vara orsaken till åldrande och flera sjukdomar, däri bland arterioskleros, men det har saknats en pålitlig metodik för att påvisa aktiviteten av fria radikaler in vivo. Här presenteras isoprostaner som nya och tillförlitliga markörer för mätning av oxidativ stress in vivo genom indirekt mätning av radikalreaktioner. Isoprostaner kan ses i ökad mängd vid flera sjukdomstillstånd som är associerade med oxidativ stress och inflammation, till exempel kardiovaskulära sjukdomar, sjukdomar som är associerade med en ökad kardiovaskulär risk samt lungsjukdomar. Mätning av isoprostaner kan vidare ge ökad kunskap om fria radikalers fysiologiska roll och antioxidanternas roll vid sjukdomar samt vara ett verktyg vid utveckling av nya läkemedel mot oxidativ stress.
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| 3. |
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| 4. |
- Basu, Samar
(författare)
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F2-isoprostane induced prostaglandin formation in the rabbit
- 2006
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Ingår i: Free radical research. - : Informa Healthcare. - 1071-5762 .- 1029-2470. ; 40:3, s. 273-277
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Tidskriftsartikel (refereegranskat)abstract
- F2-isoprostanes, non-enzymatic free radical mediated products of arachidonic acid, have shown to form during various oxidant stress status and have potent biological effects. This study investigates to what extent 8-iso-PGF2α (a major F2-isoprostane), a bioactive product of lipid peroxidation can modify endogenous prostaglandin F2α (PGF2α) formation since prostaglandins are inflammatory as well as potent vasoregulatory substances that modulate diverse important physiological functions, and also form during acute and chronic inflammation. An immediate appearance and disappearance of 8-iso-PGF2α was seen in both plasma and urine within a short interval after i.v. administration of 43 μg/kg of 8-iso-PGF2α to the rabbits. A successive but differential formation of PGF2α resulted in a rapid and pulsatile increase of plasma 15-keto-dihydro-PGF2α, a major metabolite of primary PGF2α. Later, this compound was excreted efficiently as intact compound into the urine during the 3 h of experiment. A 8-fold increase of PGF2α metabolite in plasma at 10 min and 12-fold increase in the urine at 30–60 after the i.v. administration of 8-iso-PGF2α was observed which continued throughout the 3 h of experiment. This observation suggests that pharmacologically administered or endogenously produced 8-iso-PGF2α during oxidant stress induces prostaglandin formation presumbly through the classical cyclooxygenase-catalysed arachidonic acid oxidation which might be inflammatory itself to the cells and exerts further vasoconstrictive effects.
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| 5. |
- Basu, Samar
(författare)
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F2-isoprostanes in human health and diseases : from molecular mechanisms to clinical implications
- 2008
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Ingår i: Antioxidants and Redox Signaling. - : Mary Ann Liebert. - 1523-0864 .- 1557-7716. ; 10:8, s. 1405-1434
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Forskningsöversikt (refereegranskat)abstract
- Oxidative stress is implicated as one of the major underlying mechanisms behind many acute and chronic diseases, and involved in normal aging. However, the measurement of free radicals or their end products is complicated. Thus, proof of association of free radicals in pathologic conditions has been absent. Isoprostanes are prostaglandin-like bioactive compounds that are biosynthesized in vivo independent of cyclooxygenases, principally through free-radical catalyzation of arachidonic acid. Isoprostanes are now considered to be reliable biomarkers of oxidative stress, as evidenced by an autonomous study organized recently by the National Institutes of Health (NIH) in the United States. A number of these compounds have potent biologic activities such as vasoconstrictive and certain inflammatory properties. Isoprostanes are involved in many human diseases. Additionally, elevated levels of F2-isoprostanes have been seen in normal human pregnancy and after intake of some fatty acids, but their physiologic assignments have not yet been distinctive. This evidence indicates that measurement of bioactive F2-isoprostanes in body fluids offers a unique noninvasive analytic utensil to study the role of free radicals in physiology, oxidative stress–related diseases, experimental acute or chronic inflammatory conditions, and also in the assessment of various antioxidants, radical scavengers, and drugs.
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| 6. |
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| 7. |
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| 8. |
- Basu, Samar
(författare)
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Novel cyclooxygenase-catalyzed bioactive prostaglandin F-2 alpha from physiology to new principles in inflammation
- 2007
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Ingår i: Medicinal research reviews (Print). - : Wiley. - 0198-6325 .- 1098-1128. ; 27:4, s. 435-468
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Forskningsöversikt (refereegranskat)abstract
- Prostaglandin F2 (PGF2), a foremost stable vasoactive cyclooxygenase (COX)-catalyzed prostaglandin, regulates a number of key physiological functions such as luteolysis, ovarian function, luteal maintenance of pregnancy, and parturition as a constitutive part of ongoing reproductive processes of the body. It has recently been implicated in the regulation of intricate pathophysiological processes, such as acute and chronic inflammation, cardiovascular and rheumatic diseases. Since the discovery of a second isoform of COXs, it has been shown that PGF2 can be formed in vivo from arachidonic acid through both isoforms of COXs, namely cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Being synthesized in various parts of the body, it metabolizes instantly to a number of rather inactive metabolites mainly in the lungs, liver, kidney, and efficiently excretes into the urine. 15-Keto-dihydro-PGF2, a major stable metabolite of PGF2 that reflects in vivo PGF2 biosynthesis, is found in larger quantities than its parent compound in the circulation and urine in basal physiological conditions, with short-lived pulses during luteolysis, induced termination of pregnancy and parturition, and is increased in tissues and various body fluids during acute, sub-chronic, and severe chronic inflammation. Further, the close relationship of PGF2 with a number of risk factors for atherosclerosis indicates its major role in inflammation pathology. This review addresses multiple aspects of PGF2 in addition to its emerging role in physiology to inflammation.
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| 9. |
- Basu, Samar, et al.
(författare)
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Regulatory factors of basal F(2)-isoprostane formation: population, age, gender and smoking habits in humans.
- 2009
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Ingår i: Free radical research. - : Informa UK Limited. - 1029-2470 .- 1071-5762. ; 43:1, s. 85-91
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative stress is assumed to be the key underlying factor in the pathogenesis of many common diseases. This study describes the basal levels of 8-iso-PGF(2alpha ), a major F(2)-isoprostane and an in vivo oxidative stress biomarker in healthy subjects from three countries, namely Italy, Poland and Sweden, in relation to their smoking habits, age and gender. It studied urinary 8-iso-PGF(2alpha ) in 588 subjects from Sweden (n=220), Italy (n=203) and Poland (n=165). Polish subjects had the highest levels of F(2)-isoprostanes followed by the Swedish and Italians when adjusted for smoking, age, sex and creatinine and the inter-country differences were statistically significant. Smokers had significantly higher levels of 8-iso-PGF(2alpha ) compared to non-smokers in all countries and there was a moderate decrease with age. Women had only slightly lower 8-iso-PGF(2alpha ) than men. There is a difference in F(2)-isoprostane levels in vivo between countries. Smoking, age and gender affect isoprostane formation and should be taken into consideration in clinical studies of oxidative stress.
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| 10. |
- Basu, Samar
(författare)
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The enigma of in vivo oxidative stress assessment: isoprostanes as an emerging target
- 2007
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Ingår i: Scandinavian Journal of Food & Nutrition. - : Informa UK Limited. - 1748-2984 .- 1748-2976. ; 51:2, s. 48-61
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative stress is believed to be one of the major factors behind several acute and chronic diseases, and may also be associated with ageing. Excess formation of free radicals in miscellaneous body environment may originate from endogenous response to cell injury, but also from exposure to a number of exogenous toxins. When the antioxidant defence system is overwhelmed, this leads to cell damage. However, the measurement of free radicals or their endproducts is tricky, since these compounds are reactive and short lived, and have diverse characteristics. Specific evidence for the involvement of free radicals in pathological situations has been difficult to obtain, partly owing to shortcomings in earlier described methods for the measurement of oxidative stress. Isoprostanes, which are prostaglandin-like bioactive compounds synthesized in vivo from oxidation of arachidonic acid, independently of cyclooxygenases, are involved in many human diseases, and their measurement therefore offers a way to assess oxidative stress. Elevated levels of F2-isoprostanes have also been seen in the normal human pregnancy, but their physiological role has not yet been defined. Large amounts of bioactive F2-isoprostanes are excreted in the urine in normal basal situations, with a wide interindividual variation. Their exact role in the regulation of normal physiological functions, however, needs to be explored further. Current understanding suggests that measurement of F2-isoprostanes in body fluids provides a reliable analytical tool to study oxidative stress-related diseases and experimental inflammatory conditions, and also in the evaluation of various dietary antioxidants, as well as drugs with radical-scavenging properties. However, assessment of isoprostanes in plasma or urine does not necessarily reflect any specific tissue damage, nor does it provide information on the oxidation of lipids other than arachidonic acid.
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