TY  - JOUR
A1  - Huber, K. W.
A1  - Lutz, Werner K.
T1  - Methylation of DNA in stomach and small intestine of rats after oral administration of methylamine and nitrite
N2  - Young adult male Sprague-Dawley rats were given 30 \(\mu\)mol/kg body weight [\(^{14}\)C]methylamine hydrochloride and 700 \(\mu\)mol/ kg body weight sodium nilrite by oral gavage. DNA isolated from the stomach and from the first 15 cm of the smaß intestine was methylated, containing 7-methylguanine (7mG) at a level of one 7mG molecule per 5x10\8^6\) and lx10\(^7\) nucleotides, respectively. No 7mG was found fn the liver at a limit of detection of one 7mG molecule per 2xl0\(^8\) nucleotides. ln a second experiment, the excised stomachs were incubated with deoxyribonuclease before the isolation of the DNA in order to degrade DNA in the Iumen and in the uppermost lining cells. This treatment resulted in a 30% decrease in the yield of DNA and a 90% reduction in the level of 7mG formation. The results show that nitrosation of a primary alkylamine yields a precursor of an alkylating agent which has a long enough lifetime to diffuse towards and react with intracellular DNA. A correlation of DNA methylation in the stomach with the corresponding tumor formation by the methylating carcinogen N-methyi-N'-nitro-N-nitroso-guanidine was used to estimate the roJe of DNA damage resulting from endogenous nitrosation of dietary methylamine in man. It was concluded that the risk resulting from this single amine must be negligible bot that a similar evaluation of other primary amines is required before the over-aU role of primary amine nitrosation in the etiology of human gastric cancer can be assessed.
KW  - Toxikologie
Y1  - 1984
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60984
ER  - 
TY  - JOUR
A1  - Huber, K. W.
A1  - Lutz, Werner K.
T1  - Methylation of DNA by incubation with methylamine and nitrite
N2  - DNA was incubated in septum-closed reaction vials with [\(^{14}\)C]methylamine and nitrite. The DNA was purified, hydrolysed with hydrochloric acid, and the purines were analysed by h.p.l.c. 7-Methylguanine was detectable as a result of DN A methylation in experiments perfonned in 100 mM acetate at pH 4. Using different concentrations of amine and nitrite a first order reaction for total amine and a second order for total nilrite could be shown. A study on the pH dependence using 100 mM malonate buffer, pH 2.0-6.0, revealed a maximum rate at pH 3.5, with steep slopes above and below this pH value, in agreement with a mathematical analysis of the reaction equations. The data show that the alkylating agent fonned spontaneously by nitrosation and deamination of a primary amine has a long enough lifetime to react with DNA in vitro. Using the reactioil orders established here, an extrapolation to lower concentrations found in the stomach can now be perfonned. Future in vivo experiments on the methylation of gastro-intestinal DNA then would show to what extent DNA in a cell is protected from alkylation.
KW  - Toxikologie
Y1  - 1984
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61011
ER  - 
TY  - JOUR
A1  - Edgecock, T. R.
A1  - Caretta, O.
A1  - Davenne, T.
A1  - Densam, C.
A1  - Fitton, M.
A1  - Kelliher, D.
A1  - Loveridge, P.
A1  - Machida, S.
A1  - Prior, C.
A1  - Rogers, C.
A1  - Rooney, M.
A1  - Thomason, J.
A1  - Wilcox, D.
A1  - Wildner, E.
A1  - Efthymiopoulos, I.
A1  - Garoby, R.
A1  - Gilardoni, S.
A1  - Hansen, C.
A1  - Benedetto, E.
A1  - Jensen, E.
A1  - Kosmicki, A.
A1  - Martini, M.
A1  - Osborne, J.
A1  - Prior, G.
A1  - Stora, T.
A1  - Melo Mendonca, T.
A1  - Vlachoudis, V.
A1  - Waaijer, C.
A1  - Cupial, P.
A1  - Chancé, A.
A1  - Longhin, A.
A1  - Payet, J.
A1  - Zito, M.
A1  - Baussan, E.
A1  - Bobeth, C.
A1  - Bouquerel, E.
A1  - Dracos, M.
A1  - Gaudiot, G.
A1  - Lepers, B.
A1  - Osswald, F.
A1  - Poussot, P.
A1  - Vassilopoulos, N.
A1  - Wurtz, J.
A1  - Zeter, V.
A1  - Bielski, J.
A1  - Kozien, M.
A1  - Lacny, L.
A1  - Skoczen, B.
A1  - Szybinski, B.
A1  - Ustrycka, A.
A1  - Wroblewski, A.
A1  - Marie-Jeanne, M.
A1  - Balint, P.
A1  - Fourel, C.
A1  - Giraud, J.
A1  - Jacob, J.
A1  - Lamy, T.
A1  - Latrasse, L.
A1  - Sortais, P.
A1  - Thuillier, T.
A1  - Mitrofanov, S.
A1  - Loiselet, M.
A1  - Keutgen, Th.
A1  - Delbar, Th.
A1  - Debray, F.
A1  - Trophine, C.
A1  - Veys, S.
A1  - Daversin, C.
A1  - Zorin, V.
A1  - Izotov, I.
A1  - Skalyga, V.
A1  - Burt, G.
A1  - Dexter, A. C.
A1  - Kravchuk, V. L.
A1  - Marchi, T.
A1  - Cinausero, M.
A1  - Gramegna, F.
A1  - De Angelis, G.
A1  - Prete, G.
A1  - Collazuol, G.
A1  - Laveder, M.
A1  - Mazzocco, M.
A1  - Mezzetto, M.
A1  - Signorini, C.
A1  - Vardaci, E.
A1  - Di Nitto, A.
A1  - Brondi, A.
A1  - La Rana, G.
A1  - Migliozzi, P.
A1  - Moro, R.
A1  - Palladino, V.
A1  - Gelli, N.
A1  - Berkovits, D.
A1  - Hass, M.
A1  - Hirsh, T. Y.
A1  - Schuhmann, M.
A1  - Stahl, A.
A1  - Wehner, J.
A1  - Bross, A.
A1  - Kopp, J.
A1  - Neuffer, D.
A1  - Wands, R.
A1  - Bayes, R.
A1  - Laing, A.
A1  - Soler, P.
A1  - Agarwalla, S. K.
A1  - Cervera Villanueva, A.
A1  - Donini, A.
A1  - Ghosh, T.
A1  - Gómez Cadenas, J. J.
A1  - Hernández, P.
A1  - Martín-Albo, J.
A1  - Mena, O.
A1  - Burguet-Castell, J.
A1  - Agostino, L.
A1  - Buizza-Avanzini, M.
A1  - Marafini, M.
A1  - Patzak, T.
A1  - Tonazzo, A.
A1  - Duchesneau, D.
A1  - Mosca, L.
A1  - Bogomilov, M.
A1  - Karadzhov, Y.
A1  - Matev, R.
A1  - Tsenov, R.
A1  - Akhmedov, E.
A1  - Blennow, M.
A1  - Lindner, M.
A1  - Schwetz, T.
A1  - Fernández Martinez, E.
A1  - Maltoni, M.
A1  - Menéndez, J.
A1  - Giunti, C.
A1  - González García, M. C.
A1  - Salvado, J.
A1  - Coloma, P.
A1  - Huber, P.
A1  - Li, T.
A1  - López Pavón, J.
A1  - Orme, C.
A1  - Pascoli, S.
A1  - Meloni, D.
A1  - Tang, J.
A1  - Winter, W.
A1  - Ohlsson, T.
A1  - Zhang, H.
A1  - Scotto-Lavina, L.
A1  - Terranova, F.
A1  - Bonesini, M.
A1  - Tortora, L.
A1  - Alekou, A.
A1  - Aslaninejad, M.
A1  - Bontoiu, C.
A1  - Kurup, A.
A1  - Jenner, L. J.
A1  - Long, K.
A1  - Pasternak, J.
A1  - Pozimski, J.
A1  - Back, J. J.
A1  - Harrison, P.
A1  - Beard, K.
A1  - Bogacz, A.
A1  - Berg, J. S.
A1  - Stratakis, D.
A1  - Witte, H.
A1  - Snopok, P.
A1  - Bliss, N.
A1  - Cordwell, M.
A1  - Moss, A.
A1  - Pattalwar, S.
A1  - Apollonio, M.
T1  - High intensity neutrino oscillation facilities in Europe
JF  - Physical Review Special Topics-Accelerators and Beams
N2  - The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Frejus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of mu(+) and mu(-) beams in a storage ring. The far detector in this case is a 100 kt magnetized iron neutrino detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular He-6 and Ne-18, also stored in a ring. The far detector is also the MEMPHYS detector in the Frejus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the physics reach of each facility, in particular for the measurement of CP violation in the lepton sector, and estimated the cost of construction. These have demonstrated that the best facility to build is the Neutrino Factory. However, if a powerful proton driver is constructed for another purpose or if the MEMPHYS detector is built for astroparticle physics, the Super Beam also becomes very attractive.
KW  - EMMA
KW  - beta-beam
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126611
VL  - 16
IS  - 2
ER  - 
TY  - JOUR
A1  - Sommerlandt, F. M. J.
A1  - Huber, W.
A1  - Spaethe, J.
T1  - Social Information in the Stingless Bee, Trigona corvina Cockerell (Hymenoptera: Apidae): The Use of Visual and Olfactory Cues at the Food Site
JF  - Sociobiology
N2  - For social insects, colony performance is largely dependent on the quantity and quality of food intake and thus on the efficiency of its foragers. In addition to innate preferences and previous experience, foragers can use social information to decide when and where to forage. In some stingless bee (Meliponini) species, individual foraging decisions are shown to be influenced by the presence of social information at resource sites. In dual choice tests, we studied whether visual and/or olfactory cues affect individual decision-making in rigona corvina Cockerell and if this information is species-specific. We found that T. corvina foragers possess local enhancement: they are attracted by olfactory and visual cues released by conspecifics but avoid feeders associated with heterospecific individuals of the species Tetragona ziegleri (Friese). Overall, olfactory cues seem to be more important than visual cues, but information by visual cues alone is sufficient for discrimination.
KW  - visual cues
KW  - recruitment
KW  - local enhancement
KW  - odor marks
KW  - communication
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-118120
VL  - 61
IS  - 4
ER  -