Chemical-induced neoplasia

The direct effect of inhalation exposure to 1,2-dibromoethane on spermatogenesis in animals has not been studied. Nonetheless, the available data from animal studies indicate that the male reproductive system in rats is affected by exposure to 1,2-dibromoethane at high doses. In all studies discussed below, however, rats had high mortality associated with chemical toxicity and/or chemically-induced neoplasia. It is therefore difficult to attribute effects on the reproductive organs to... 

No consideration has been given to possible synergistic effects with the various anticarcinogenic agents. It is possible that combinations of relatively small nontoxic doses of the anticarcinogenic compounds would protect against chemical-induced neoplasia for a variety of carcinogens. 

The evidence that chemicals induce neoplasia in invertebrates is scarce and has been demonstrated in mollusks (clams, snails, mussels) and planarians exposed to polychlorinated biphenyls and polycyclic aromatic hydrocarbons. Higher mortality of individuals with tumors is common as they could be easily hunted and are more sensitive to various pathogens. 

EPA. 1991a. Alpha2 1-globulin association with chemically induced renal toxicity and neoplasia in the male rat. Washington, DC U.S. Environmental Protection Agency, Risk Assessment Forum. EPA/625/3-91/019F. 

CLA, the acronym for a series of conjugated dienoic isomers of linoleic acid, occurs naturally in many foods, particularly dairy products and other foods derived from ruminant animals (6). Synthetically prepared CLA inhibits chemically-induced mouse epidermal and forestomach neoplasia (7,8) and rat mammary neoplasia (9). Hence, the effect of CLA on carcinogenesis is opposite that of linoleic acid. 

Melnick, R.L., Sills. R.C., Roycroft. J.H., Chou, B.J., Ragan, H.A. Miller, R.A. (1994) Isoprene, an endogenous hydrocarbon and industrial chemical, induces multiple organ neoplasia in rodents after 26 weeks of inhalation exposure. Cancer Res., 54, 5333-5339... 

Soon after the discovery of DNA polymerases in virions of RNA tumor viruses, a great deal of hope was expressed that the discovery might lead to resolve the possibility of the involvement of oncorna viruses in an inapparent form in spontaneous or chemically induced tumors, especially in man. So far, there has been some evidence in support that RNA tumor viruses are related to human neoplasia. 

EPA (1991). Alpha2u-globulin Association with chemically induced renal toxicity and neoplasia in the... 

EPA, alpah2fxrGlobuUn Association with Chemically Induced Renal Toxicity and Neoplasia in the Male Rat, U.S. Environmental Protection Agency, Washington, DC, 1991. 

Inhibition of chemical carcinogen-induced neoplasia by coumarins and alpha-angelicalactone. Cancer Res. 39, 1651-1654. 

Chemically induced tumors are still considered a good model for human neoplasia, and we evaluated the effectiveness of coenzyme Qio in mice with dibenzpyrene-induced tumors. A second test system in this study was a retroviral infection in mice (Friend leukemia vims), a model used in the evaluation of new drags for HIV/AIDS. Qur findings and conclusions could be summarized as follows." ... 

United States Environmental Protection Agency (1991) Alpha 2u-globulln association with chemically Induced renal toxicity neoplasia in the male rat. Submitted to WHO by the International Organization of the Flavor Industry, Bmssels, Belgium (EP/V625/3-91/019F). 

The field of dermatotoxicology includes measurement of absorption of materials as well as assays that evaluate the ability of topically applied chemicals to induce or promote the development of neoplasia, trigger an immune response in the skin (allergic contact dermatitis and immunological contact urticaria), directly destroy the skin (corrosion), irritate the skin, and produce non-inflammatory, painful sensations. The inflammatory responses of skin are the most common chemically induced dermatoses in humans. This chapter briefly introduces the subject the Mar-zulli texts provide more detail (Marzulli and Maibach... 

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