Carcinogenic activation

The purpose of this eornpuLer project is Lo examine several polynuclear aromatic hydrocarbons and to relate their electron density patterns to their carcinogenic activity. If nucleophilic binding to DN.A is a significant step in blocking the normal transcription process of DN.A, electron density in the hydrocarbon should be positively correlated to its carcinogenic potency. To begin with, we shall rely on clinical evidence that benzene, naphthalene, and phenanthrene... 

H Me, Ac. NHj. H, NMej, NHCHO 2-(5-nitrofuryl) H Carcinogenic activity in mice 950-952... 

Study on the carcinogenicity of THPC and THPS which concluded that there is no evidence of carcinogenic activity for either compound in rats or mice (162). 

Succinic anhydride is extremely irritating to the eyes. It causes skin, mucous membranes, and respiratory tract irritation. It may be a sensiti2er. There is no evidence of carcinogenic activity in male or female tats given 50 or 100 mg/kg succinic anhydride (186) the Ames test is negative (187). LD q in rat 1510 mg/kg. There ate no estabflshed exposure limits for ACGIH TLV or TWA. 

Health and Safety Factors. MSA is a strong toxic acid and is corrosive to skin. The acute oral toxicity of the sodium salt in mice LD q is 6.2 g/kg. The 1976 edition of the NIOSH Registry of Toxic Effects of Chemical Substances Hsts certain reaction products of MSA as having suspected mutagenic, teratogenic, and carcinogenic activity (410). 

The carcinogenic properties of tricycloquinazoline (60) were studied in detail because of its possible formation from anthranilic acid derivatives in nature. It possessed stronger carcinogenic activity toward mice (72%) than rats (27%). Its action resembled that of embedded plastic materials, because it was recovered unmetabolized. ... 

Leo A, Panthananickal A, Hansch C, Theiss J, Shimkin M, Andrews AW. A comparison of mutagenic and carcinogenic activities of aniline mustards. J Med Chem 1981 24 859-64. 

Recently nitrosamines have attracted attention because of their marked carcinogenic activity in a wide variety of animal species Q, ). Nitrosamines are likely to be carcinogens in man as well human exposure to these compounds is by ingestion, inhalation, dermal contact and vivo formation from nitrite and amines Nitrite and amines react most rapidly at an acidic pH A variety of factors, however, make nitrosation a potentially important reaction above pH 7 these include the presence of microorganisms, and the possibilities of catalysis by thiocyanate, metals and phenols, and of transnitrosation by other nitroso compounds. 

We had found earlier that similar pickling of beans, as eaten in high-risk Latin America, or of borscht, as consumed in Eastern Europe, led to mutagenic activity, and thus presumably carcinogenic activity (57)... 

Chronic animal studies of organophosphates are few in number, but those that do exist provide a useful base from which to draw toxicological insight. In rats and mice exposed orally to tricresyl phosphate for 2 years, endocrine effects were found in a dose-response pattern and hepatic effects were found. Ovarian interstitial hyperplasia was also observed but was not dose related. No chronic-duration MRLs could be derived because of the limited number of studies. Tricresyl phosphate, a component of certain hydraulic fluids, produced no evidence of carcinogenic activity in assays with rats and mice (NTP 1994). However, another component, tributyl phosphate, was associated with an increased incidence of bladder tumors in rats and mice (FMC 1994a, 1994b). 

The carcinogenic activity of chemical substances is important as well. They are present in pesticides of different classes OCPs (DDT, aldrine, heptachlor, methoxychlor), thiocarbamates (thiram, zineb, ziram), carbamides (monuron) [3], etc. Even if the official description of a given pesticide does not denote its carcinogenic (mutagenic, teratogenic, embryotoxic, etc.) activity, this merely means that this particular pesticide was not studied sufficiently. 

Results from VEGA underline the presence of 13 compounds with carcinogenic activity and only two non-carcinogenic compounds (perfhiorobutanesulfonic acid and perfluorotetradecanoic acid). It is crucial to underline that for each selected PFCs, VEGA provides a remarks about the performance of the prediction in fact, the model indicates that all the analyzed compounds are out of the VEGA applicability domain. 

PFOS Positive Compound is out of model Applicability No alerts for carcinogenic activity Positive SAs for the micronucleus... 

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