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Biomedical subjects

P Grasso

Publications and source records attributed to P Grasso.

At least 145 records · Page 8Linked to original sources
PubMed1977

Nuclear enlargement and DNA synthesis in mouse epidermis treated with carcinogen and promotor.

An autoradiographic investigation was made into the causes of nuclear size increase observed in the mouse epidermis within a few days of topical benzpyrene treatment. The effects of croton oil pretreatment of posttreatment in combination with benzpyrene were examined to see what effect a growth stimulus had on this response. The degree of nuclear size increase induced in the epidermis suggested that some ploidy level increase resulted from combined croton oil and benzpyrene treatment and evidence was found of a G2 block occurring in association with this. Enhancement of nuclear size increase by croton oil highlighted the importance of a growth stimulus in carcinogen induced nuclear enlargement and the implications of this are discussed. Disappearance of enlarged nuclei was seen when mice were kept for 5 days after combined croton oil and benzpyrene treatment in spite of a reduced cell loss compared with croton oil treatment alone.

Animals↗
PubMed1977

Effects of pyrazole and 3-amino-1,2,4-triazole on the metabolism and toxicity of dimethylnitrosamine in the rat.

Pretreatment of rats with pyrazole or 3-amino-1,2,4-triazole (3-AT) known inhibitors of alcohol metabolism, profoundly inhibited the metabolism of dimethylnitrosamine (DMN), both in terms of [14C]CO2 excretion and of the decline in the blood concentration. Additionally, 4-methylpyrazole, tetraethylthiuram disulfide (disulfiram), methanol, and ethanol inhibited the metabolism of DMN in the whole animal. In parallel experiments with [14C]aminopyrine, no substantial inhibitory effect was found with pyrazole, 3-AT, or disulfiram pretreatment. Investigations into the effects of pyrazole and 3-AT pretreatment on the acute toxicity and hepatotoxicity of DMN showed that pyrazole significantly increased the median lethal dose (LD50) of DMN and provided substantial protection against the hepatotoxicity of DMN, in that centriblobular necrosis was not seen at dose levels of DMN up to 25 mg/kg and early histochemical changes indicative of liver injury were not observed at a dose level of 15 mg DMN/kg. In contrast, 3-AT pretreatment did not affect the LD50 of DMN or provide any protection against the hepatotoxicity of DMN. Further, although both inhibitors delayed the incorporation of radioactivity from [14C]DMN into hepatic subcellular organelles, pyrazole was significantly more effective than was 3-AT.

Amitrole↗
PubMed1976

Cytotoxic carcinogeneic response to monocrotaline pyrrole.

The cytotoxic and carcinogenic effects of MCP, the possible proximate metabolite of the alkaloid monocrotaline, were investigated in rats by the subcutaneous route. Sequential of MCP subcutaneously produced an acute inflammatory reaction with necrosis of the local tissue. A slight delay in connective-tissue repair occurred and markedly enlarged fibroblasts were a distinctive feature of the lesion. Four injection site sarcomas were produced after repeated injection of 60 mug MCP in tricaprylin. Injection of 30 mug MCP in tricaprylin twice weekly gave rise to three local tumours. Controls injected repeatedly with tricaprylin developed two sarcomas at the injection site. The significance of these findings is discussed and it is concluded that MCP is undoubtedly cytotoxic but that its carcinogenic potency is equivocal.

Animals↗