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Occupational cosmic radiation exposure in Portuguese airline pilots: study of a possible correlation with oxidative biological markers., Silva, Rodrigo, Folgosa Filipe, Soares Paulo, Pereira Alice S., Garcia Raquel, Gestal-Otero Juan Jesus, Tavares Pedro, and Gomes da Silva Marco D. R. , Radiation and environmental biophysics, Jun, Volume 52, Number 2, p.211-220, (2013) AbstractWebsite

Several studies have sought to understand the health effects of occupational exposure to cosmic radiation. However, only few biologic markers or associations with disease outcomes have so far been identified. In the present study, 22 long- and 26 medium-haul male Portuguese airline pilots and 36 factory workers who did not fly regularly were investigated. The two groups were comparable in age and diet, were non-smokers, never treated with ionizing radiation and other factors. Cosmic radiation exposure in pilots was quantified based on direct monitoring of 51 flights within Europe, and from Europe to North and South America, and to Africa. Indirect dose estimates in pilots were performed based on the SIEVERT (Système informatisé d'évaluation par vol de l'exposition au rayonnement cosmique dans les transports aériens) software for 6,039 medium- and 1,366 long-haul flights. Medium-haul pilots had a higher cosmic radiation dose rate than long-haul pilots, that is, 3.3 ± 0.2 μSv/h and 2.7 ± 0.3 μSv/h, respectively. Biological tests for oxidative stress on blood and urine, as appropriate, at two time periods separated by 1 year, included measurements of antioxidant capacity, total protein, ferritin, hemoglobin, creatinine and 8-hydroxy-2-deoxyguanosine (8OHdG). Principal components analysis was used to discriminate between the exposed and unexposed groups based on all the biological tests. According to this analysis, creatinine and 8OHdG levels were different for the pilots and the unexposed group, but no distinctions could be made among the medium- and the long-haul pilots. While hemoglobin levels seem to be comparable between the studied groups, they were directly correlated with ferritin values, which were lower for the airline pilots.

Synthesis of catecholamine conjugates with nitrogen-centered bionucleophiles, Siopa, Filipa, Pereira Alice S., Ferreira Luisa M., Matilde Marques M., and Branco Paula S. , BIOORGANIC CHEMISTRY, Oct, Volume {44}, 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA, p.{19-24}, (2012) Abstract

The enzymatic (tyrosinase) and chemical (NaIO4, Ag2O or Fremys's salt) oxidation of biologically relevant catecholamines, such as dopamine (DA), N-acetyldopamine (NADA) and the Ecstasy metabolites (alpha-MeDA and N-Me-alpha-MeDA) generates the corresponding o-quinone which can be trapped with nitrogen bionucleophiles such as N-acetyl-histidine and imidazole in a regioselective reaction that takes place predominantly at the 6-position of the catecholamine. (C) 2012 Elsevier Inc. All rights reserved.

Probing the iron environment in desulforedoxin. EXAFS of oxidized and reduced states, Stalhandske, CMV, Dong J., Tavares P., Liu M. Y., Legall J., Moura J. J. G., Moura I., Park J. B., Adams M. W. W., and Scott R. A. , INORGANICA CHIMICA ACTA, Volume {273}, Number {1-2}, p.{409-411}, (1998) Abstract

Fe XAS data were collected on the oxidized and reduced forms of desulforedoxin from Desulfovibrio gigas, the oxidized form of rubredoxin from Clostridium pasteurianum, and the reduced form of rubredoxin from Pyrococcus furiosus. Analysis of these data is consistent with tetrahedral FeS(4) coordination in both oxidation states, and an expansion of the Fe-S distances from 2.27 to 2.33 Angstrom upon reduction. (C) 1998 Elsevier Science S.A. All rights reserved.