| 31. |
- Basu, Samar, et al.
(författare)
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Oxidative injury and survival during endotoxemia
- 1998
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Ingår i: FEBS Letters. - 0014-5793 .- 1873-3468. ; 438:3, s. 159-160
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates the plasma levels of 8-iso-PGF2alpha, a non-enzymatic, and 15-K-DH-PGF2alpha, a cyclooxygenase catalyzed oxidation product of arachidonic acid in an experimental porcine endotoxemic shock model. A significant (P < 0.001) and rapid appearance and disappearance of PGF2alpha metabolite after endotoxin infusion was very similar in both non-survival and survival groups indicating an acute progression and recession of inflammation. When oxidative injury was assessed by measuring free 8-iso-PGF2alpha the levels in plasma increased significantly up to 2 h and remained at this level until death among the non-survivors. This was apparently different from the survivors where the 8-iso-PGF2alpha levels increased to its height at 1 h, then decreased to the basal levels after 5 h. Thus, free radical and cyclooxygenase catalyzed oxidation of arachidonic acid occurs during endotoxemia. Free radical dependent oxidative injury following endotoxin induced inflammation may be the major cause of organ failure and increased mortality.
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| 32. |
- Basu, Samar, et al.
(författare)
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Ozone exposure effect on systemic prostaglandin F-2 alpha in rat plasma and urine may not reveal pulmonary damage through inflammation
- 2017
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Ingår i: Prostaglandins, Leukotrienes and Essential Fatty Acids. - : Elsevier BV. - 0952-3278 .- 1532-2823. ; 126, s. 79-83
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Tidskriftsartikel (refereegranskat)abstract
- The acute ozone induced lung injury model has been widely used to explore injury and repair processes induced by oxidant overload. The current study evaluated acute ozone exposure effects on prostaglandin F-2 alpha (PGF(2 alpha)) in male Fischer rat plasma and urine with the hypothesis that ozone may induce an inflammatory response in the body that can be measured by the induction of PGF2 alpha. That might then lead to the identification of potential marker for acute lung injury through systemic inflammation. The time and dose-dependent effects of ozone exposure on the plasma and urinary levels of a major PGF(2 alpha) metabolite15-keto-dihydro-PGF(2 alpha) were determined using a radioimmunoassay. No statistically significant differences in the PGF(2 alpha) metabolite were found between the control and the experimental groups at either ozone exposure dose (2 ppm and 5 ppm) or any time point (2 h, 7 h and 16 h) post exposure for plasma and at 7 different post exposure time points (between 2 and 80 h) for urine. It is concluded that acute ozone exposure does not cause changes in plasma and urinary PGF(2 alpha), and therefore their measurement in plasma and urine may not be used to reveal pulmonary inflammation and damage by ozone.
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| 33. |
- Basu, Samar, et al.
(författare)
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Propofol (Diprivan-EDTA) counteracts oxidative injury and deterioration of the arterial oxygen tension during experimental septic shock
- 2001
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Ingår i: Resuscitation. - 0300-9572 .- 1873-1570. ; 50:3, s. 341-348
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Human septic shock can be replicated in the endotoxaemic pig. Endotoxaemia causes a multitude of events, including reduced PaO(2) and increased lipid peroxidation. This study was designed to evaluate the possible effects of a commonly used anaesthetic drug with known antioxidant properties (propofol) during porcine endotoxaemia.METHODS: Ten pigs were anaesthetised and given a 6 h E. coli endotoxin infusion. The animals received, randomly, a supplementary continuous infusion of propofol emulsion (containing 0.005% EDTA) or the corresponding volume of vehicle (controls). Pathophysiologic responses were determined. Non-enzymatic (by measuring plasma 8-iso-PGF(2 alpha) and enzymatic (by measuring plasma 15-keto-dihydro-PGF(2 alpha)) lipid peroxidations were evaluated. Plasma levels of the endogenous antioxidants alpha- and gamma-tocopherols, were also analysed.RESULTS: Endotoxaemia increased plasma levels of 8-iso-PGF(2 alpha) (1st-4th h) and 15-keto-dihydro-PGF(2 alpha) (1st-4th h) significantly more in controls than in the propofol+endotoxin group. PaO(2) was significantly less affected by endotoxin in the propofol treated animals (2nd-4th h). Mean arterial pressure (4th-6th h) and systemic vascular resistance (6th h) were reduced significantly more by endotoxin among the propofol-treated animals. Vitamin E (alpha-tocopherol) increased in all animals, significantly more in the propofol+endotoxin group (1/2-6th h) than in the control group.CONCLUSIONS: Propofol reduced endotoxin-induced free radical mediated and cyclooxygenase catalysed lipid peroxidation significantly. The implication is that propofol counteracts endotoxin-induced deterioration of PaO(2).
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| 34. |
- Basu, Samar, et al.
(författare)
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Propofol mitigates systemic oxidative injury during experimental cardiopulmonary cerebral resuscitation
- 2011
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Ingår i: Prostaglandins, Leukotrienes and Essential Fatty Acids. - : Elsevier BV. - 0952-3278 .- 1532-2823. ; 84:5-6, s. 123-130
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Tidskriftsartikel (refereegranskat)abstract
- Effects of propofol, an intravenous anesthetic agent that exerts potent antioxidant properties, were investigated in an experimental model of cardiac arrest and cardiopulmonary resuscitation. An extended cardiac arrest with 15 randomized piglets was studied to assess the effect of propofol or its solvent intralipid as the control group. Oxidative stress (as measured by a major F(2)-isoprostane) and inflammation (a major metabolite of PGF(2α)) were evaluated in addition to the hemodynamic evaluation, protein S-100β and in situ tissue brain damage by immunochemistry at sacrifice after 3h of reperfusion following cardiac arrest and restoration of spontaneous circulation (ROSC). ROSC increased jugular bulb plasma levels of F(2)-isoprostane and PGF(2α) metabolite significantly more in controls than in the propofol-treated group. In situ tissue damage after ischemia-reperfusion was variable among the pigs at sacrifice, but tended to be greater in the control than the propofol-treated group. Propofol significantly reduced an ROSC-mediated oxidative stress in the brain.
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| 35. |
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| 36. |
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| 37. |
- 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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| 38. |
- Basu, Samar, et al.
(författare)
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Retinol palmitate counteracts oxidative injury during experimental septic shock
- 2001
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Ingår i: Annals of the Academy of Medicine, Singapore. - 0304-4602. ; 30:3, s. 265-269
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Retinols seem to be of clinical importance in ameliorating the clinical consequences of septic shock. These beneficial effects of retinols are suggested to be due to an antioxidant property. The present study was undertaken in order to confirm or rule out such an effect of retinol palmitate (RP) in experimental septic shock by measuring F2-isoprostanes and a major prostaglandin F2 alpha metabolite as indicators of oxidative injury and inflammatory response, respectively. MATERIALS AND METHODS: Fourteen anaesthetised pigs were randomly given an injection of RP (2.300 IU x kg-1) or the corresponding volume of vehicle. All pigs received a continuous infusion of E. coli endotoxin (10 micrograms x kg-1 x h-1). Blood samples were analysed for lipid peroxidation products (8-iso-PGF2 alpha), indicating free radical induced oxidative injury and 15-keto-dihydro-PGF2 alpha indicating cyclooxygenase-mediated inflammatory response). RESULTS: Significantly elevated levels of 8-iso-PGF2 alpha were seen at 3, 5 and 6 hours of endotoxaemia in the vehicle + endotoxin group as compared to RP + endotoxin group. Endotoxin induced cyclooxygenase-mediated inflammatory response was not affected by RP. CONCLUSIONS: This study is the first one to show that RP counteracts oxidative injury rather than inflammatory response in experimental septic shock. These results may be of importance for the understanding of some beneficial effects of RP during endotoxaemia (i.e. improved systemic haemodynamics and reduced serum levels of endotoxin). Our results may explain the therapeutic effects of nutrients rich in caroten/retinols used in some clinical studies.
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| 39. |
- 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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| 40. |
- Basu, Samar, et al.
(författare)
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Time course and attenuation of ischaemia-reperfusion induced oxidative injury by propofol in human renal transplantation
- 2007
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Ingår i: Redox report. - 1351-0002 .- 1743-2928. ; 12:4, s. 195-202
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Tidskriftsartikel (refereegranskat)abstract
- Ischaemia-reperfusion injury resulting from interruption and restoration of blood flow might be related to free radical mediated oxidative stress and inflammation, and subsequently to post-surgery related complications. We studied the impact of renal transplantation on oxidative stress and inflammation by measuring F2-isoprostanes and prostaglandin F2α, respectively, during transplantation and post-surgery. Additionally, due to earlier observations, two dissimilar anaesthetic agents (thiopentone and propofol) were compared to determine their antioxidative capacity rather than their anaesthetic properties. Blood samples were collected before, post-intubation, immediately, 30, 60,120, 240 min, and 12 and 24 h after reperfusion. Oxidative stress and inflammatory response were detected by measuring 8-iso-PGF2α (a major F2-isoprostane and a biomarker of oxidative stress) and 15-keto-dihydro-PGF2α (a major metabolite of PGF2α and a biomarker of COX-mediated inflammatory response), respectively. Reperfusion of the transplanted graft significantly increased plasma levels of 8-iso-PGF2α. PGF2α metabolite levels, although elevated, did not reach statistical significance. In addition, significantly lower levels of 8-iso-PGF2a were observed in the propofol group compared to the thiopentone group. Together, these findings underline an augmented oxidative stress activity following an inflammatory response after human renal transplantation. Furthermore, propofol a well-known anaesthetic, counteracted oxidative stress by lowering the formation of a major F2-isoprostane.
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