Results 121 to 130 of about 2,628 (167)

Effects of N-Nitrosodimethylamine on Tumor Susceptibility

Journal of Leukocyte Biology, 1985
Abstract Dimethylnitrosamine (DMN) exposure altered the activity of the macrophage and natural killer (NK) cell defense mechanisms against the B16F10 melanoma In B6C3F1 adult female mice as assessed by several immunologic assays. Following 14 daily exposures (i.p.) to 1.5, 3.0, or 5.0 mg DMN/kg, mice were injected (i.v.) with B16F10 ...
S S, Duke, L B, Schook, M P, Holsapple
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DETERMINATION OF N-NITROSODIMETHYLAMINE BY HPLC, WITH FLUORESCENCE DETECTION. A SURVEY OF N-NITROSODIMETHYLAMINE IN COMMERCIAL BEERS

Journal of Liquid Chromatography & Related Technologies, 2002
A new method has been developed for determination of N-nitrosodimethylamine (NDMA) in beers. Beer samples, previously degassed, were extracted with diethyl ether containing 25% 2-propanol and the extract was denitrosated by hydrobromic acid-acetic acid to produce secondary amines.
Lourdes Cádenes, Juan H. Ayala, Venerando González, Ana M. Afonso   +3 more
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Denitrosation of N-Nitrosodimethylamine in the Rat in Vivo

1991
The potent hepatocarcinogen N-nitrosodimethylamine (NDMA) has been shown to be metabolized by liver microsomes from acetone-induced rats via two pathways (Figure 1). While the denitrosation pathway has been studied fairly extensively in vitro (Keefer et al., 1987b; Wade et al., 1987; Amelizad et al., 1988), only a few tentative observations about its ...
A J, Streeter, R W, Nims, P R, Sheffels, L K, Keefer   +3 more
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Nitrogen protonation of N-nitrosodimethylamine

Journal of the American Chemical Society, 1988
Preuves de la presence de l'ion Me 2 N(H)NO + dans les solutions aqueuses de (dimethyl nitroso) amine a pH ...
Larry K. Keefer, Joseph A. Hrabie, Bruce D. Hilton, David. Wilbur   +3 more
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Risk characterization of N-nitrosodimethylamine in pharmaceuticals

Food and Chemical Toxicology
Since 2018, N-nitrosodimethylamine (NDMA) has been a reported contaminant in numerous pharmaceutical products. To guide the pharmaceutical industry, FDA identified an acceptable intake (AI) of 96 ng/day NDMA. The approach assumed a linear extrapolation from the Carcinogenic Potency Database (CPDB) harmonic-mean TD50 identified in chronic studies in ...
D.J. Paustenbach, S.E. Brown, J.J. Heywood, M.T. Donnell, D.L. Eaton   +4 more
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Stereoselectivity in the microsomal conversion of N-nitrosodimethylamine to formaldehyde

Chemical Research in Toxicology, 1990
The possibility that N-nitrosodimethylamine (NDMA) might be metabolized preferentially at either the syn (relative to the nitroso oxygen) or the anti methyl group has been examined by comparing the rates of formaldehyde production when unlabeled NDMA, its fully deuteriated analogue (NDMA-d6), and (Z)- or (E)-N-nitrosomethyl(methyl-d3)amine (NDMA-d3 ...
L K, Keefer, M B, Kroeger-Koepke, H, Ishizaki, C J, Michejda, J E, Saavedra, J A, Hrabie, C S, Yang, P P, Roller   +7 more
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Influence of ethyl alcohol on carcinogenesis with N-nitrosodimethylamine

Cancer Letters, 1981
This paper presents the results of an experiment on the combined action of nitrosodimethylamine and ethyl alcohol in C57BL mice. As shown, alcohol can act to change the target organ of that liver carcinogen by favouring development of olfactory neuroepitheliomas, which infiltrate the frontal lobe of the brain.
Griciute, L, Castegnaro, M, Bereziat, J
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Contamination of beer with trace quantities of N-nitrosodimethylamine

Food and Cosmetics Toxicology, 1979
Abstract Chemiluminescence detection was used to analyse 158 samples of commercially available draft, bottled and canned beers of different types for contamination with volatile nitrosamines. Of these samples, 111 (70%) were found to contain N-nitrosodimethylamine, the mean concentration being 2·7 ppb (μg/kg) and the maximum level 68 ppb.
B, Spiegelhalder, G, Eisenbrand, R, Preussmann   +2 more
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N-nitrosodimethylamine in air

Bulletin of Environmental Contamination and Toxicology, 1976
D H, Fine, D P, Rounbehler, E D, Pellizzari, J E, Bunch, R W, Berkley, J, McCrae, J T, Bursey, E, Sawicki, K, Krost, G A, DeMarrais   +9 more
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Metabolism of N-nitrosodimethylamine.

IARC scientific publications, 1981
NDMA and NDEA are metabolized by a microsomal enzyme system that requires NADPH and oxygen. This metabolism leads to an unstable product which decomposes to yield a reactive alkylating species. This species is too reactive chemically to influence significantly organs other than those in which it was generated.
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