Trans fatty acids in membranes: the free radical path.

The double bond geometry of most of the naturally occurring unsaturated fatty acid residues is cis. Due to the relevance of fatty acids as structural components of cell membranes and as biologically active molecules, the change of the cis geometry means a change of the associated functions and activities. The finding that the cis to trans isomerization is effective in phospholipids by the intervention of radical species led to the discovery that there can indeed occur an endogenous formation of trans fatty acids, whose significance in biological systems started to be addressed with in vitro and in vivo studies.

Reactions of indoles with nitrogen dioxide and nitrous acid in an aprotic solvent.

The reaction of 2-phenyl- and 1-methyl-2-phenylindole with nitrogen dioxide or with nitrous acid (NaNO2-CH3COOH) in benzene leads mainly to the formation of the isonitroso and 3-nitroso indole derivatives, respectively. When reacted with nitrous acid, 1-methyl-2-phenylindole gives also the corresponding azo-bis-indole in good yields. The reaction of indole with nitrogen dioxide leads to 2-(indol-3-yl)-3H-indol-3-one as the main product together with small amounts of 2-(indol-3-yl)-3H-indol-3-oxime; whereas the major product obtained when the same indole is reacted with nitrous acid is represented by 2-(indol-3-yl)-3H-indol-3-oxime.

Microproteinuria in patients with inflammatory bowel disease: is it associated with the disease activity or the treatment with 5-aminosalicylic acid?

Aim: To investigate whether microproteinuria in patients with inflammatory bowel disease (IBD) is associated with the disease activity or the treatment with 5-aminosalicylic acid (5-ASA).

Methods: We prospectively studied microproteinuria in 86 consecutive patients with IBD, 61 with ulcerative colitis (UC) and 25 with Crohn's disease (CD), before as well as 2 and 6 months after their inclusion in the study. Forty-six patients received 5-ASA for a period of 28.

Spin trapping of nitrogen dioxide and of radicals generated from nitrous acid.

Spin trapping of nitrogen dioxide radical by several nitrones has been studied. The reaction results in the formation of persistent acyl nitroxides, after the oxidation of the intermediate spin adducts having an -ONO group on C-2 atom. The intermediate is effectively detected when DEPMPO is used as the spin trap.

Modification of permeability transition pore arginine(s) by phenylglyoxal derivatives in isolated mitochondria and mammalian cells. Structure-function relationship of arginine ligands.

Methylglyoxal and synthetic glyoxal derivatives react covalently with arginine residue(s) on the mitochondrial permeability transition pore (PTP). In this study, we have investigated how the binding of a panel of synthetic phenylglyoxal derivatives influences the opening and closing of the PTP. Using both isolated mitochondria and mammalian cells, we demonstrate that the resulting arginine-phenylglyoxal adduct can lead to either suppression or induction of permeability transition, depending on the net charge and hydrogen bonding capacity of the adduct.