Objectives: To study the effects of two different mixtures of the main conjugated linoleic acid (CLA) isomers cis-9, trans-11 CLA and trans-10, cis-12 CLA on human immune function. Design: Double-blind, randomized, parallel, reference-controlled intervention study. Subjects and intervention: Seventy-one healthy males aged 31 -69 y received one of the following treatments: (1) mixture of 50% c9,t11 CLA and 50% t10,c12 CLA isomers (CLA 50:50); (2) mixture of 80% c9,t11 CLA and 20% t10,c12 CLA isomers (CLA 80:20); and (3) sunflower oil fatty acids (reference). The treatments were given as supplements in softgel capsules providing a total of 1.7 g (c9,t11 þ t10,c12) CLA fatty acids (50:50) or 1.6 g (c9,t11 þ t10,c12) CLA glycerides (80:20) per day in treatment groups for 12 weeks. Results: Almost twice as many subjects reached protective antibody levels to hepatitis B when consuming CLA50:50 fatty acids (15=24, 62%) compared with subjects consuming the reference substance (7=21, 33%, P ¼ 0.075). In subjects consuming CLA 80:20 glycerides this was 8=22 (36%). Other aspects of immune function, ie DTH responses, NK cell activity, lymphocyte proliferation and production of TNF-a, IL1-b, IL6, IFN-g, IL2, IL4, and PGE 2 , were not affected.

in several animal models, including hamsters, but the mechanism of action of the main food-derived CLA isomer is unknown in this species. This study thus focused on cis-9,trans-11-CLA (rumenic acid), and its effect was compared with that of fish oil, which is known to influence several aspects of atherogenesis. Syrian hamsters were fed (for 12 wk) diets containing 20% (wt/wt) butter fat (B diet) or the same diet augmented with either 1% (wt/wt) of a cis-9,trans-11-CLArich oil (BR diet) or 1% (wt/wt) fish oil (BF diet). The BR diet induced the lowest aortic lipid deposition (from Ϫ30% to Ϫ45%) among the butter oil-fed hamsters. In this group, plasma also displayed a reduced non-HDL-to-HDL-cholesterol ratio (21% less than in the butter oil group) and inflammatory serum amyloid A levels (70 -80%) and an improvement of anti-oxidized LDL paraoxonase activity (all P Ͻ 0.05). Compared with the B group, the beneficial effects of the BR diet could be further explained in part by preventing the high VCAM-1 expression rate, increasing (30%) ATP-binding cassette subfamily A1 expression in the aorta, and downregulating expression of inflammatory-related genes (TNF-␣, IL-1␤, and cyclooxygenase 2, 2-to 2.8-fold, P Ͻ 0.05). This effect was partly associated with an activation of peroxisome proliferator-activating receptor (PPAR)/liver X receptor (LXR)-␣ signaling cascade. Interestingly, activation of PPAR/LXR-␣ signaling was not observed in hamsters fed the BF diet, in which the early signs of atherogenesis were increased. In conclusion, this study demonstrated that milk fat-rich cis-9,trans-11-CLA reduces the atherogenic process in hyperlipidemic hamsters.

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The present paper describes the oxygen incorporation into naphthalene and anthracene by H2O2-driven microperoxidase-8, forming A-naphthol and anthraquinone, respectively. Microperoxidase-8 is a minienzyme containing a histidinyl-coordinated Fe 3ϩ -protoporphyrin IX cofactor covalently attached to an eight-amino-acid peptide.Additional experiments were performed to investigate whether the reaction mechanism involved is like that of peroxidase and/or cytochrome P-450. A reaction pathway like that of cytochrome P-450 implies oxygen transfer to the substrate from the as yet uncharacterized iron-oxo species formed in the reaction of the heme cofactor with H 2 O 2 . In contrast, a peroxidase-type reaction chemistry involves reaction pathways proceeding by initial one-electron oxidation of, or H-abstraction from, the substrate, followed by incorporation of oxygen from sources other than the iron-oxo species, i.e. from other than H 2 O 2 .The results of the present study exclude Fenton-type chemistry and prove that the minicatalyst is able to catalyze the oxygen incorporation by both peroxidase and cytochrome P-450 types of reaction pathways, while exchange occurs between the high-valency iron-oxo species and H 2 O. The mechanistic implications of this exchange for cytochrome P-450 are discussed.

The biologically active form of interferon gamma is a dimer composed of two noncovalently bound identical polypeptide chains of 17 kDa each. In this study, it was found that dissociation of the dimer into monomers significantly reduced the fluorescence quantum yield and the efficiency of the intermolecular Tyr to Trp radiationless energy transfer. The same process caused significant changes in the fluorescence decay and in the fluorescence anisotropy decay. The kinetic and thermodynamic parameters of the dimer-monomer equilibrium were determined by fluorescence measurements at different temperatures and by a theoretical mathematical model. Dissociation of the dimers into monomers was an endothermic process and was favored by concentrations of the protein lower than 1 microM and by increasing the temperature. It was accompanied by formation of aggregates, a slow and partially reversible process leading to inactivation of the interferon. It is suggested that certain monomeric conformers are competent for aggregation.