Dimethylnitrosamine
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. Expressão e distribuição da conexina 32 em fígados com fibrose experimentalmente induzida / Expression and distribution of connexin 32 in liver with experimentally induced fibrosis
The connexin 32 (Cx32) is a proteic structure that constitute the channels that promote the cell communication by means of the gap junction (GJIC), allowing the diffusion of short cytoplasmic molecules from a cell to another. This work aimed to study these structures due to their importance in the hepatic metabolic processes. The hepatic fibrosis was trigger
Publicado em: 2004
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2. Pré-concentração de nitrosaminas a partir de amostras aquosas por extração em fase sólida e cromatografia capilar eletrocinética micelar
This paper describes the development of a methodology for solid phase extraction (SPE) and pre-concentration of nitrosamines from aqueous samples using granular activated charcoal as stationary phase. micelar electrokinetic capillary Chromatography (MEKC) was used for the separation and identification of the nitrosamines in the extracts. Using a sample with
Química Nova. Publicado em: 2003-03
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3. Alterações celulares em figado e pulmão de camundongos tratados com dimetilnitrosamina
Ninety one mice (42 males and 49 females) received dimethylnitrosamine (DMN) in the drinking water, ad libitum during six months. The concentration of DMN in the water varied from: a) 17 ppm (parts per million) during the first month to, b) 10,6 ppm during the other five months. DMN produces several changes in hepatocyte nuclei, as seen by Feulgen s reaction
Publicado em: 1980
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4. N-Nitrosamine formation by cultures of several microorganisms.
Of 38 pure cultures of microorganisms tested, only one, Pseudomonas stutzeri, was capable of forming dimethylnitrosamine from dimethylamine and nitrite during growth. Resting cells of P. stutzeri, Cryptococcus terreus, Escherichia coli, and Xanthomonas campestris formed dimethylnitrosamine, although no nitrosamine was found in growing cultures of the latter
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5. Degradation of N-Nitrosamines by Intestinal Bacteria
A major proportion of bacterial types, common in the gastrointestinal tract of many animals and man, were active in degrading diphenylnitrosamine and dimethylnitrosamine, the former being degraded more rapidly than the latter. At low nitrosamine concentrations (<0.05 μmol/ml), approximately 55% of added diphenylnitrosamine, 30% of N-nitrosopyrrolidine, and
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6. Some Toxic Properties of Dimethylnitrosamine
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7. Microbial Formation of Nitrosamines In Vitro
Mortierella parvispora and an unidentified bacterium converted trimethylamine to dimethylamine, and the bacterium (but not the fungus) formed dimethylnitrosamine in the presence of nitrite. Dimethylnitrosamine also appeared in cell suspensions of Escherichia coli and Streptococcus epidermidis and in hyphal mats of Aspergillus oryzae incubated with dimethylam
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8. Effect of treatment in vivo with N,N-dimethylnitrosamine or methyl methanesulphonate on the cytoplasmic DNA polymerase of regenerating rat liver.
A 10-16 fold increase in rat liver cytoplasmic DNA polymerase (DNA polymerase-alpha) was observed by 24 hrs after two thirds partial hepatectomy. Injection of either N,N-dimethylnitrosamine (DMN) or methyl methanesulphonate (MMS) At 6 or 12 hrs after partial hepatectomy completely inhibited this increased production of polymerase, but when given at 20 hours
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9. THE in vitro INDUCTION OF AN INCREASE IN CELL MULTIPLICATION AND CELLULAR LIFE SPAN BY THE WATER-SOLUBLE CARCINOGEN DIMETHYLNITROSAMINE
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10. The in vitro induction of an increase in cell multiplication and cellular life span by the water-soluble carcinogen dimethylnitrosamine.
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11. Induction of Mitotic Crossing over in SACCHAROMYCES CEREVISIAE by Breakdown Products of Dimethylnitrosamine, Diethylnitrosamine, 1-Naphthylamine and 2-Naphthylamine Formed by an IN VITRO Hydroxylation System
Dimethylnitrosamine and diethylnitrosamine, two potent carcinogens, are nonmutagenic when tested directly in microorganisms. Likewise 1-naphthylamine and 2-naphthylamine are also nonmutagenic but the N-hydroxy derivatives are mutagenic in microorganisms. Apparently these compounds require metabolism to breakdown products which are then the proximately active
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12. Prophage Induction in Escherichia coli (Lambda) by N-Nitrosamines
Carcinogenic N-nitrosamines were tested for their ability to induce λ in a lysogenic strain of Escherichia coli K-12 (58-161 F+). Dimethylnitrosamine, di-n-propylnitrosamine, methyl-n-propylnitrosamine, and N-nitrosopiperidine were shown to be inducers of prophage.