The antioxidant effects of alpha- and gamma-tocopherols were evaluated in a model system based on the autooxidation of purified sunflower oil (p-SFO) triacylglycerols at 55 degrees C for 7 d. Both tocopherols were found to cause more than 90% reduction in peroxide value when present at concentrations >20 ppm. Alpha-tocopherol was a better antioxidant than gamma-tocopherol at concentrations < or =40 ppm but a worse antioxidant at concentrations >200 ppm. Neither alpha- nor gamma-tocopherol showed a prooxidant effect at concentrations as high as 2000 ppm. The amount of tocopherols consumed during the course of oxidation was positively correlated to the initial concentration of tocopherols, and the correlation was stronger for alpha- than for gamma-tocopherol. This correlation suggested that, besides reactions with peroxyl radicals, destruction of tocopherols may be attributed to unknown side reactions. Addition of FeSO4, as a prooxidant, caused a 12% increase in the peroxide value of p-SFO in the absence of tocopherols. When tocopherols were added together with FeSO4, some increase in peroxide value was observed for samples containing 200, 600 or 1000 ppm of alpha- but not gamma-tocopherol. The addition of FeSO4, however, caused an increase in the amount of alpha- and gamma-tocopherols destroyed and led to stronger positive correlations between the amount of tocopherols destroyed during oxidation and initial concentration of tocopherols. No synergistic or antagonistic interaction was observed when alpha- and gamma-tocopherols were added together to autooxidizing p-SFO.

Background In staged liver resections, associating liver partition and portal ligation for staged hepatectomy (ALPPS) achieves sufficient hypertrophy of the future liver remnant (FLR) in 7 days. This is based on portal vein ligation and transection, and on occlusion of intrahepatic collaterals. This article presents a new surgical technique for achieving rapid hypertrophy of the FLR, which also involves adding intrahepatic collateral occlusion to portal vein transection. Methods Patients scheduled for two-stage liver resection for primary or secondary liver tumours, in whom the FLR was considered too small, were enrolled prospectively. In the first stage, a tourniquet was placed around the parenchymal transection line, and the right portal vein was ligated and cut (associating liver tourniquet and portal ligation for staged hepatectomy, ALTPS). The tourniquet was placed on the umbilical ligament if a staged right trisectionectomy was planned, and on Cantlie's line for staged right hepatectomy. Results From September 2011, 22 ALTPS procedures were carried out (right trisectionectomy in 15, right hepatectomy in 7). Median FLR at 7 days increased from 410 to 700 ml (median increase 61 (range 33–189) per cent). The median duration of the first stage was 125 min and no patient received a blood transfusion. The median duration of the second stage was 150 min and five patients required a blood transfusion. Fourteen patients had complications, most frequently infected collections, and five patients developed postoperative liver failure. Two patients died. Conclusion The ALTPS technique achieved adequate hypertrophy of the FLR after 7 days. It may provide a less aggressive modification of the ALPPS procedure.

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The effects of variety, rootstock, and geographical location were studied as to their effects on secondary metabolite production in grapefruit and pummelo. The concentration of the flavanones narirutin, naringin, and neohesperidin and of the sesquiterpene nootkatone, which is principally responsible for the grapefruit's aroma, varies during h i t development. The highest flavanone levels are detected during the juvenile stages of fruit development, while nootkatone expression is associated with the processes of maturation and senescence. The possibility of increasing the levels of these metabolites by regulating the associated processes of growth and cell differentiation is discussed.

The biosynthesis of scoparone (6,7-dimethoxycoumarin) was associated with resistance of mature fruits of tangelo Nova, Citrus aurantium, and Citrus paradisi to infection by Phytophthora parasitica. Levels of scoparone increased by treating fruit with Brotomax, which also enhanced the resistance of fruit to the fungus. Lesion development was reduced by as much as 40%. Scoparone is therefore proposed as a possible phytoalexin in fruits of these cultivars. Keywords: Citrus; coumarin; phytoalexin; scoparone