Determination of fatty acids in plasma: Treatment compliance will be corroborated by determining the fatty acid composition of plasma lipids by gas chromatography. Plasma total lipids will be extracted by the method of Bligh and Dyer with chloroform: methanol (2:1, V: V). Methyl esters of fatty acids will be obtained by transesterification with boron trifluoride in methanol at 80 °C for 60 min. which allows a high recovery of all the lipidic compounds including PUFAs. Aliquot containing the methyl esters of fatty acids will be analyzed with a gas chromatography device (Hewlett-Packard model 5890) on a 30 m. RTX-2330 column (Restek, Bellefonte, PA) with an internal diameter of 0.25 mm equipped with a flame ionization detector. The carrier gas will be helium at a pressure of 105 kPa. To the total separation of the different compounds it has provided with two temperature settings: 140 °C-200 °C to 3 °C/min or in two stages of 140°C-180°C to 4°C/min and 180°C-210°C at 2°C/min. The temperature of the injector and detector is 260 °C. The linear response of the detector will be tested periodically with standard mixtures. Typically, two internal standards with different molecular weight (13:0 and 23:0 or 27:0) will be used. Peaks will be integrated with an integrator D-2500 (Hitachi Ltd., Tokyo) and identified by comparison of retention times with standards. When necessary, the identification may be confirmed by mass spectrometry (Hewlett-Packard detector model 5970B) at an ionization potential of 70 eV.