Fatty acids and oxidative stress

Oxidative stress is a condition which modifies the normal intracellular balance between oxidant substances produced during aerobic metabolism and antioxidant system processes which perform the function of neutralisation, putting a series of protective mechanisms, of both an enzymatic and non enzymatic nature, in action. Enzymatic systems include dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). In non-enzymatic systems, the most important molecules are glutathione, atocopherol (vitamin E), ascorbic acid (vitamin C), flavonoids, the phenol compounds and the minerals zinc (Zn), copper (Cu) and selenium (Sn)

The use of artificial neural networks to study fatty acids in neuropsychiatric disorders

<p>Abstract</p> <p>Background</p> <p>The range of the fatty acids has been largely investigated in the plasma and erythrocytes of patients suffering from neuropsychiatric disorders. In this paper we investigate, for the first time, whether the study of the platelet fatty acids from such patients may be facilitated by means of artificial neural networks.</p> <p>Methods</p> <p>Venous blood samples were taken from 84 patients with a DSM-IV-TR diagnosis of major depressive disorder and from 60 normal control subjects without a history of clinical depression. Platelet levels of the following 11 fatty acids were analyzed using one-way analysis of variance: C14:0, C16:0, C16:1, C18:0, C18:1 <it>n</it>-9, C18:1 <it>n</it>-7, C18:2 <it>n</it>-6, C18:3 <it>n</it>-3, C20:3 <it>n</it>-3, C20:4 <it>n</it>-6 and C22:6 <it>n</it>-3. The results were then entered into a wide variety of different artificial neural networks.</p> <p>Results</p> <p>All the artificial neural networks tested gave essentially the same result. However, one type of artificial neural network, the self-organizing map, gave superior information by allowing the results to be described in a two-dimensional plane with potentially informative border areas. A series of repeated and independent self-organizing map simulations, with the input parameters being changed each time, led to the finding that the best discriminant map was that obtained by inclusion of just three fatty acids.</p> <p>Conclusion</p> <p>Our results confirm that artificial neural networks may be used to analyze platelet fatty acids in neuropsychiatric disorder. Furthermore, they show that the self-organizing map, an unsupervised competitive-learning network algorithm which forms a nonlinear projection of a high-dimensional data manifold on a regular, low-dimensional grid, is an optimal type of artificial neural network to use for this task.</p

A comparison of oxidative stress in smokers and non-smokers: an in vivo human quantitative study of n-3 lipid peroxidation

<p>Abstract</p> <p>Background</p> <p>Cigarette smoking is believed to cause oxidative stress by several mechanisms, including direct damage by radical species and the inflammatory response induced by smoking, and would therefore be expected to cause increased lipid peroxidation. The aim was to carry out the first study of the relationship of smoking in humans to the level of <it>n</it>-3 lipid peroxidation indexed by the level of ethane in exhaled breath.</p> <p>Methods</p> <p>Samples of alveolar air were obtained from 11 smokers and 18 non-smokers. The air samples were analyzed for ethane using mass spectrometry.</p> <p>Results</p> <p>The two groups of subjects were matched with respect to age and gender. The mean cumulative smoking status of the smokers was 11.8 (standard error 2.5) pack-years. The mean level of ethane in the alveolar breath of the group of smokers (2.53 (0.55) ppb) was not significantly different from that of the group of non-smokers (2.59 (0.29) ppb; <it>p </it>= 0.92). With all 29 subjects included, the Spearman rank correlation coefficient between ethane levels and cumulative smoking status was -0.11 (<it>p </it>= 0.58), while an analysis including only the smokers yielded a corresponding correlation coefficient of 0.11 (<it>p </it>= 0.75).</p> <p>Conclusion</p> <p>Our results show no evidence that cigarette smoking is related to increased <it>n</it>-3 lipid peroxidation as measured by expired ethane.</p