Background: Endothelial dysfunction in cigarette smokers has been ascribed to increased oxidative damage. The aims of the present study were to compare the endothelial function of normotensive smokers with that of non-smokers and to examine its relation to some parameters representative of oxidative damage and of antioxidant capacity.Methods: We investigated 32 chronic smokers (15-30 cigarettes daily) affected by coronary heart disease, ranging from acute myocardial infarction to instable angina pectoris, and 28 matched non-smokers without any definite risk factors. All subjects underwent assessment of nitric oxide (NO)-dependent endothelial function, measured as brachial artery vasodilatation in response to reactive ischemia, using a standardized echographic method. Plasma and urinary levels of NO were also measured in all subjects, as were urinary 15-isoprostane F-2t, plasma serum lipids, homocysteine (Hcy), ascorbic acid, retinol, tocopherol, and alpha- and beta-carotene (by high-performance liquid chromatography).Results: Smokers showed a significantly lower NO-mediated vasodilatation response (3.50% vs. 6.18%, p<0.001) and higher levels of urinary NO metabolites and 15-isoprostane F-2t. They also had higher levels of Hey (p<0.001); these values were significantly and inversely related to NO serum levels (r=-0.512, p<0.001). Moreover, smokers had a significant and corresponding reduction in circulating levels of ascorbic acid, tocopherol, and alpha- and beta-carotene.Conclusions: The present study shows a clear relation between endothelial dysfunction (NO production impairment) and cigarette smoking, especially in the presence of high levels of LDL-cholesterol. It also defines some markers of both oxidative damage and antioxidant protective capacity in this condition. The monitoring of these factors may be advisable in order to assess the amount of endothelial damage. (c) 2007 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Summary: Given the crucial role of iron and porphyrins in oxidative cellular damage in the chronic porphyrias, we undertook an extensive study in families with acute porphyrias to evaluate the possible role of similar oxidative damage in these diseases, whose natural history is often also complicated by neoplastic evolution. Four unrelated patients with acute intermittent porphyria (AIP) were studied together with 37 members of four different families. Aminolevulinic acid and porphobilinogen were measured in urine, and porphyrins in urine, plasma and stools. The activity of the congenitally deficient enzyme, porphobilinogen deaminase, and the concentrations of plasma iron, transferrin, ferritin, and various antioxidants (ascorbic acid, retinol, tocopherol, α- and β-carotene, by a personal HPLC method) and the urinary and plasma metabolites of nitrous oxide were also assayed. The results showed no relationship between the observed increase of porphyrin metabolites and the presence of markers of oxidative damage or the decrease of circulating antioxidants: however, when such a decrease was registered, it depended on spontaneous or iatrogenic iron accumulation. We conclude that family screening, recommended for the identification of AIP carriers, must also include evaluation of iron stores with a view to preventing the oxidative damage and in order to forestall the neoplastic evolution of the disease.

Background: Recent trials in digestive-tract cancer have produced conflicting results regarding the protective role of liposoluble vitamins. Accordingly, we have undertaken an extensive appraisal of the behaviour of retinol and tocopherol in both human upper and lower digestive neoplasms. Materials and Methods: The subjects comprised six healthy controls, 10 patients with symptomatic cholelithiasis, 13 with gastric neoplasms, 12 with colo-rectal neoplasms and 13 with digestive neoplasms and liver metastases. Retinol and tocopherol in the plasma, liver, as well as from secondary malignant nodules of the liver, were determined following a high performance liquid chromatographic technique. Results: The plasma concentration of retinol was significantly reduced only in some neoplastic groups with respect to the non-neoplastic groups. Plasma tocopherol levels remained almost unchanged and, surprisingly, they were higher even in the neoplastic patients and in relation to total serum lipids. There was a sharp decrease in the liver tissue levels of total, mainly esterified, retinol in both cholelithiasis and neoplastic groups; tocopherol, on the other hand, remained more or less unchanged, except in the liver metastatic nodules, where it increased. Conclusion: Levels of plasma vitamin and tissue retinol and tocopherol appear to be unpredictable on the basis of the corresponding circulating levels, and this must be taken into account when prescribing dietary and therapeutic regimes.

Background: It is known that antioxidant liposoluble vitamins and carotenoids are reduced in liver cirrhosis, but little is known about chronic viral hepatitis, where oxidative damage has to be taken into account. Methods: Fifty-five patients with chronic hepatitis, mainly C virus-related, were matched with 16 patients with biliary stones and 20 healthy controls. Plasma and liver analyses were carried out using a well-tried HPLC technique that affords an accurate quantification of retinol, tocopherol, alpha- and beta-carotene, cryptoxanthin, and lycopene. Results: Plasma concentration of retinol, tocopherol, beta-carotene, and lycopene was significantly decreased in both patient groups, particularly in those with chronic hepatitis. In contrast, liver concentration of both esterified and free retinol, tocopherol, and some carotenoids was better preserved in the hepatitis group than in the cholelithiasis group. A strict correspondence between aminotransferases and the amount of liver-stored retinol was documented. Conclusions: Plasma vitamin and carotenoid depletion co-existing with preserved liver storage may indicate a functional defect in liver pool mobilization or even a real depletion of the antioxidant defenses, which play a key role in averting cellular damage. The implications for nutrition and therapy need to be taken into account.