Rino Vitali

Induction of Lung Tumors and Lymphomas in BALB/c Mice by Metronidazole

Metronidazole, which is widely used in the treatment of «Trichomonas vaginalis», «Entamoeba histolytica» and «Giardia lamblia» infections, was administered to BALB/c mice by stomach tube in an aqueous solution at a dose rate of 2 mg/day for 100 days (total 200 mg) to test its carcinogenicity. The treatment induced a significant increase in lung tumors in male mice (p < 0.001) and provoked the appearance of lymphomas in females (p < 0.001). Although there is insufficient evidence to pass judgement on the potential carcinogenicity of metronidazole in man, the results of this and other investigations reported in the literature have demonstrated that metronidazole develops carcinogenic activity in rats and mice.

5-Azacytidine carcinogenesis in BALB/c mice

5-Azacytidine, a drug used in the treatment of acute leukaemias and beta-thalassemia, was administered i.p. to BALB/c mice at a dose of 2.0 mg/kg body wt. once a week for 50 weeks to test its carcinogenicity. The treatment induced a significant increase in lung tumours (males P less than 0.001, females P less than 0.05), lymphomas (males P less than 0.01, females P less than 0.01), skin tumours (males P less than 0.05, females P less than 0.01) in both sexes and mammary carcinomas (P less than 0.01) and a variety of other tumours in female mice. These results, with other investigations reported in literature, suggest that 5-azacytidine is carcinogenic in mice.

5-Fluorouracil carcinogenesis in BALB/c mice.

5-Fluorouracil, a drug mainly used in the treatment of gastrointestinal tract neoplasms, was administered i.p. to BALB/c mice at the dose of 30 mg/kg body weight once a week for 50 weeks to test its carcinogenicity. The treatment induced a significant increase in lung tumor in both sexes (males, p < 0.05; females, p < 0.01) and tumors of the lymphoreticular system in female mice (p < 0.001). These results suggest that 5-fluorouracil is carcinogenic in mice.

Computer-assisted immunocytochemical determination of breast cancer steroid receptors on cytological smears of excised surgical specimens compared with frozen sections.

BACKGROUND Due to the widespread use of fine needle aspirate biopsy the practice of determining estrogen (ER) and progesterone (PR) receptors in breast carcinoma from cytological smears (CS) is becoming very common. The aim of this study was to determine concordance between ER and PR assessed by immunocytochemical assay (ICA) on CS and FS both evaluated by image analysis since we have found no data in literature on this. METHODS 104 breast carcinoma cases were selected. For all cases ER and PR determination was performed on CS, obtained by light scraping of the freshly cut surface of the excised surgical tumors at the time of frozen section diagnosis, and FS using the same monoclonal antibodies. Computer-assisted image analysis was performed in all cases using CAS 200. Results were expressed as percent positive area of neoplastic nuclei compared with total nuclear area of the examined neoplastic cells. RESULTS Good correlation was demonstrated between percent positive nuclear neoplastic area by ER-ICA on CS and FS (r = 0.759; P < 0.0001). Concordance of results was 90.19% (P < 0.001). Good correlation was also demonstrated between percent positive nuclear neoplastic area by PR-ICA in CS and FS (r = 0.889; P < 0. 0001). Concordance of results was 97.02% (P < 0.0001). CONCLUSIONS Our data suggest that ICA on CS with automated image analysis is efficient in evaluating ER and PR content in human breast cancer, especially when CS is the only method pathologists have to evaluate receptor status e.g. in advanced breast cancer cases when neoadjuvant therapy is necessary before surgery or when surgery is impossible.

Induction of Mammary Tumors with Metronidazole in Female Sprague-Dawley Rats

Sprague-Dawley rats were administered low doses of metronidazole similar to those used in humans, and then subjected to a long-term follow-up. Metronidazole caused a significant rise in mammary tumors in the female rats (p < 0.001) after a mean latency period of 100.5 weeks.

Carcinogenicity and Cocarcinogenicity Test of Phenobarbital Sodium in Adult BALB/c Mice

The carcinogenic and cocarcinogenic action of phenobarbital sodium was investigated in adult BALB/c mice of both sexes when administered alone at a concentration of 0.05 % in drinking water for life or after the animals had been treated with a single hydrazine sulphate dose of 5.65 mg. The results demonstrated that phenobarbital sodium is not carcinogenic in this strain of mice, but, since a single dose of hydrazine sulphate was carcinogenic, does not clarify whether it is a cocarcinogen in the lung.

Chlorambucil carcinogenesis in BALBc mice

Abstract Chlorambucil, a drug used in the treatment of neoplastic and non-neoplastic disease, was administered by gavage to BALB c mice at a dose of 1.0 mg/kg body wt. 5 times per week for 12 weeks to test its carcinogenicity. The survival was statistically reduced in treated animals of both sexes (P